Online research in philosophy

Theories of binding have recently come into the focus of the consciousness debate. In this review, we discuss the potential relevance of temporal binding mechanisms for sensory awareness. Specifically, we suggest that neural synchrony with a precision in the millisecond range may be crucial for conscious processing, and may be involved in arousal, perceptual integration, attentional selection and working memory. Recent evidence from both animal and human studies demonstrates that specific changes in neuronal synchrony occur during all of these processes (...) and that they are distinguished by the emergence of fast oscillations with frequencies in the gamma-range. (shrink)

Mirror neurons are widely regarded as an important key to social cognition. Despite such wide agreement, there is very little consensus on how or why they are important. The goal of this paper is to clearly explicate the exact role mirror neurons play in social cognition. I aim to answer two questions about the relationship between mirroring and social cognition: What kind of social understanding is involved with mirroring? How is mirroring related to that understanding? I argue that (...) philosophical and empirical considerations lead us to accord a fairly minimal role for mirror neurons in social cognition. (shrink)

The discovery of mirror neurons has been hailed as one of the most exciting developments in neuroscience in the past few decades. These neurons discharge in response to the observation of others’ actions. But how are we to understand the function of these neurons? In this paper I defend the idea that mirror neurons are best conceived as components of a sensory system that has the function to perceive action. In short, mirror neurons are part (...) of a hitherto unrecognized “sixth sense”. In this spirit, research should move toward developing a psychophysics of mirror neurons. (shrink)

Recently, there has been a resurgence of interest in theories of mindreading. New discoveries in neuroscience have revitalized the languishing debate. The discovery of so-called mirror neurons has revived interest particularly in the Simulation Theory (ST) of mindreading. Both ST proponents and theorists studying mirror neurons have argued that mirror neurons are strong evidence in favor of ST over Theory Theory (TT). In this paper I argue against the prevailing view that mirror neurons are evidence for (...) the ST of mindreading. My view is that on an appropriate construal of their function, mirror neurons do not operate like simulation theorists claim. In fact, mirror neurons are more appropriately understood as one element in an information-rich mindreading process. As such, mirror neurons fit in better with some sort of TT account of mindreading. I offer a positive account, the Model TT, which better explains the role of mirror neurons in social cognition. (shrink)

Despite the recent surge in research on, and interest in, synesthesia, the mechanism underlying this condition is still unknown. Feedforward mechanisms involving overlapping receptive fields of sensory neurons as well as feedback mechanisms involving a lack of signal disinhibition have been proposed. Here I show that a broad range of studies of developmental synesthesia indicate that the mechanism underlying the phenomenon may involve reinstatement of brain activity in different sensory or cognitive streams in a way that is similar to (...) what happens during memory retrieval of semantically associated items. In the paper’s final sections I look at the relevance of synesthesia research, given the memory model, to our understanding of multisensory perception and common mapping patterns. (shrink)

Based on recent insight into the thalamocortical system and its role in perception and conscious experience, a unified pathophysiological framework for hallucinations in neurological and psychiatric conditions is proposed, which integrates previously unrelated neurobiological and psychological findings. Gamma-frequency rhythms of discharge activity from thalamic and cortical neurons are facilitated by cholinergic arousal and resonate in networks of thalamocortical circuits, thereby transiently forming assemblies of coherent gamma oscillations under constraints of afferent sensory input and prefrontal attentional mechanisms. If perception is (...) based on synchronisation of intrinsic gamma activity in the thalamocortical system, then sensory input to specific thalamic nuclei may merely play a constraining role. Hallucinations can be regarded as underconstrained perceptions that arise when the impact of sensory input on activation of thalamocortical circuits and synchronisation of thalamocortical gamma activity is reduced. In conditions that are accompanied by hallucinations, factors such as cortical hyperexcitability, cortical attentional mechanisms, hyperarousal, increased noise in specific thalamic nuclei, and random sensory input to specific thalamic nuclei may, to a varying degree, contribute to underconstrained activation of thalamocortical circuits. The reticular thalamic nucleus plays an important role in suppressing random activity of relay cells in specific thalamic nuclei, and its dysfunction may be implicated in the biological vulnerability to hallucinations in schizophrenia. Combined with general activation during cholinergic arousal, this leads to excessive disinhibition in specific thalamic nuclei, which may allow cortical attentional mechanisms to recruit thalamic relay cells into resonant assemblies of gamma oscillations, regardless of their actual sensory input, thereby producing an underconstrained perceptual experience. Key Words: Charles Bonnet syndrome; gamma oscillations; hallucinations; late paraphrenia; Lewy body dementia; perception; schizophrenia; thalamocortical system. (shrink)

What we perceive is the product of an intrinsic process and not part of external physical reality. This notion is consistent with the philosophical position of transcendental idealism but also agrees with physiological findings on the thalamocortical system. -Frequency rhythms of discharge activity from thalamic and cortical neurons are facilitated by cholinergic arousal and resonate in thalamocortical networks, thereby transiently forming assemblies of coherent oscillations under constraints of sensory input and prefrontal attentional mechanisms. Perception and conscious experience may be (...) based on such assemblies and sensory input to thalamic nuclei plays merely a constraining role in their formation. In schizophrenia, the ability of sensory input to modulate self-organisation of thalamocortical activity may be generally reduced. If during arousal thalamocortical self-organisation is underconstrained by sensory input, then attentional mechanisms alone may determine the content of perception and hallucinations may arise. (shrink)

It is often claimed that the discovery of mirror neurons supports simulation theory (ST). There has been much controversy about this, however, as there are various competing models of the functional contribution of mirror systems, only some of which characterize mirroring as simulation in the sense required by ST. But a brief review of these models reveals that they all include simulation in some sense . In this paper, I propose that the broader conception of simulation articulated by neo-empiricist (...) theories of concepts can subsume the more specific conceptions of simulation presented by ST and by these other models, thereby offering a framework in which each of these models may play a role. According to neo-empiricism, conceptual thought in general involves simulation in the sense that it is grounded in sensory, motor, and other embodied systems (Barsalou, Behavioral and Brain Sciences , 22 , 577–609, 1999 , Philosophical Transactions of the Royal Society of London: Biological Sciences , 364 , 1281–1289, 2009 ; Barsalou et al., Trends in Cognitive Sciences , 7 (2), 84–91, 2003 ; Prinz 2002 , Mind & Language , 25 (5), 612–621, 2010 ; Glenberg and Robertson, Journal of Memory and Language , 43 , 379–401, 2000 ). Crucially, the term “simulation” here refers not to simulations of a target agent’s experience in the sense endorsed by simulation theory but to the activation of sensory, motor, affective, and introspective representations. This difference does not entail that neo-empiricism must be in competition with ST—indeed, I will propose that ST can be embedded as a special case within neo-empiricism. (shrink)

What we perceive is the product of an intrinsic process and not part of external physical reality. This notion is consistent with the philosophical position of transcendental idealism but also agrees with physiological findings on the thalamocortical system. -Frequency rhythms of discharge activity from thalamic and cortical neurons are facilitated by cholinergic arousal and resonate in thalamocortical networks, thereby transiently forming assemblies of coherent oscillations under constraints of sensory input and prefrontal attentional mechanisms. Perception and conscious experience may be (...) based on such assemblies and sensory input to thalamic nuclei plays merely a constraining role in their formation. In schizophrenia, the ability of sensory input to modulate self-organisation of thalamocortical activity may be generally reduced. If during arousal thalamocortical self-organisation is underconstrained by sensory input, then attentional mechanisms alone may determine the content of perception and hallucinations may arise. (shrink)

Recent experiments have shown that the amplitudes of cortical gamma band oscillatory activities that occur during anesthesia are often greater than amplitudes of similar activities that occur without anesthesia. This result is apparently at odds with the hypothesis that synchronized oscillatory activities constitute the neural correlate of consciousness. We argue that while synchronization and oscillatory patterning are necessary conditions for consciousness, they are not sufficient. Based on the results of a binocular rivalry study of Fries et al. (1997), we propose (...) that the degrees of oscillatory strength and synchronization of neuronal activities determine the degree of awareness those activities produce. On the other hand, the overal firing rates of neurons in cortical sensory areas are not correlated with the degree of awareness the activities of those neurons produce. The results of the experiment of Fries et al. (1997) appear to conflict with the results of another binocular rivalry experiment, in which monkeys were trained to pull a lever in order to report which stimulus object was being perceived (Leopold & Logothetis, 1996). In the latter experiment, it was demonstrated that the firing rates of neurons in striate cortex did not change during perceptual alterations, while 90% of neurons in inferior and superior temporal cortices changed their firing rate when the perceived image changed. This result led to the conclusion that activities in temporal cortex are correlated with visual awareness, but those in striate cortex are not. We argue that activities in temporal cortex contribute little, if anything, to perceptual awareness, and that their primary function is computational. Thus the correlation between the firing rates of neurons in these areas and the responses of the monkeys is due to the recognition of a particular stimulus object, which in turn is due to the computations made there. (shrink)

Mirror neurons are neurons which fire in two distinct conditions: (i) when an agent performs a specific action, like a precision grasp of an object using fingers, and (ii) when an agent observes that action performed by another. Some theorists have suggested that the existence of such neurons may lend support to the simulation approach to mindreading (e.g. Gallese and Goldman, 1998, 'Mirror neurons and the simulation theory of mind reading'). In this note I critically examine (...) this suggestion, in both its original and a revised form (due to Iacoboni et al., 2005, 'Grasping the intentions of others with one's own mirror neuron system'), and argue that the existence of mirror neurons can in fact tell us very little about how intentional attribution actually proceeds. (shrink)

The senses can completely dispel rational grounds for a certain kind of doubt, empirical doubt, but they cannot dispel another kind, sceptical doubt. In the first part of this paper, a hitherto unrecognized kind of knowledge-gathering activity, called sensory exploration, is described and discussed. It is argued, further, that sensory exploration eliminates a certain kind of doubt. In the second part, two kinds of doubt are distinguished in an original way. It is argued that only one of these kinds of (...) doubt can be eliminated by sensory exploration. (shrink)

The neurological discovery of mirror neurons is of eminent importance for the phenomenological theory of intersubjectivity. G. Rizzolatti and V. Gallese found in experiments with primates that a set of neurons in the premotor cortex represents the visually registered movements of another animal. The activity of these mirror neurons presents exactly the same pattern of activity as appears in the movement of one's own body. These findings may be extended to other cognitive and emotive functions in humans. (...) I show how these neurological findings might be “translated” phenomenologically into our own experienced sensations, feelings and volitions. (shrink)

Is the brain the biological substrate of consciousness? Most naturalistic philosophers of mind have supposed that the answer must obviously be «yes » to this question. However, a growing number of philosophers working in 4e (embodied, embedded, extended, enactive) cognitive science have begun to challenge this assumption, arguing instead that consciousness supervenes on the whole embodied animal in dynamic interaction with the environment. We call views that share this claim dynamic sensorimotor theories of consciousness (DSM). Clark (2009) a founder and (...) leading proponent of the hypothesis of the extended mind, demurs, arguing that as matter of fact the biology of consciousness doesn’t allow for a brain, body and world boundary crossing architecture. We begin by looking at one of the arguments for DSM, the variable neural correlates argument. We then outline two criticisms that Clark has made of this argument and endorse his criticisms. However we finish up by using the case of sensory substitution to argue that something of this argument for DSM nevertheless survives. We suggest that Clark ought to concede sensory substitution as a case in which the conscious mind extends. (shrink)

The consensus in contemporary philosophy of mind is that how a perceptual experience represents the world to be is built into its sensory phenomenology. I defend an opposing view which I call ‘moderate separatism’, that an experience's sensory phenomenology does not determine how it represents the world to be. I argue for moderate separatism by pointing to two ordinary experiences which instantiate the same sensory phenomenology but differ with regard to their intentional content. Two experiences of an object reflected in (...) a mirror can possess the same spatial phenomenology while representing that object to occupy different spatial locations. So, contrary to the current consensus, the representation of spatial location is not fixed by an experience's sensory phenomenology. (shrink)

According to an influential view, one function of mirror neurons (MNs), first discovered in the brain of monkeys, is to underlie third-person mindreading. This view relies on two assumptions: the activity of MNs in an observer’s brain matches (simulates or resonates with) that of MNs in an agent’s brain and this resonance process retrodictively generates a representation of the agent’s intention from a perception of her movement. In this paper, I criticize both assumptions and I argue instead that the (...) activity of MNs in an observer’s brain is enhanced by a prior representation of the agent’s intention and that their task is to predictively compute the best motor command suitable to satisfy the agent’s intention. (shrink)

This report highlights and explores five questions which arose from The Unity of Consciousness and Sensory Integration conference at Brown University in November of 2011: 1. What is the relationship between the unity of consciousness and sensory integration? 2. Are some of the basic units of consciousness multimodal? 3. How should we model the unity of consciousness? 4. Is the mechanism of sensory integration spatio-temporal? 5. How Should We Study Experience, Given Unity Relations?

Block (2003) and Prinz (2006) have defended the idea that SSD perception remains in the substituting modality (auditory or tactile). Hurley and Noë (2003) instead argued that after substantial training with the device, the perceptual experience that the SSD user enjoys undergoes a change, switching from tactile/auditory to visual. This debate has unfolded in something like a stalemate where, I will argue, it has become difficult to determine whether the perception acquired through the coupling with an SSD remains in the (...) substituting or the substituted modality. Within this puzzling deadlock two new approaches have been recently suggested. Ward and Meijer (2010) describe SSD perception as visual-like but characterize it as a kind of artificially induced synaesthesia. Auvray et al. (2007) and Auvray and Myin (2009) suggest that SSDs let their users experience a new kind of perception. Deroy and Auvray (forthcoming) refine this position, and argue that this new kind of perception depends on pre-existing senses without entirely aligning with any of them. So, they have talked about perceptual experience in SSDs as going “beyond vision”. In a similar vein, Fiona MacPherson (2011b) claims that “if the subjects (SSD users) have experiences with both vision-like and touch-like representational characteristics then perhaps they have a sense that ordinary humans do not” (MacPherson 2011b, p.139). -/- I use this suggestion of MacPherson’s as a motivation for exploring more fully the idea that SSD perception is something new. In this paper, in line with Auvray and Deroy, I therefore argue that SSD perception (at least in long-term, experienced users) doesn’t align with any of the pre-existing senses and that although it relies (quite heavily) on them, it nevertheless counts as something different and partially new. Unlike Auvray and Deroy however, I tentatively explain the new sensory sensitivity that these devices enable in terms of artificially induced synaesthesia. So the main goal of this paper is to synthesize and integrate the empirical work of Ward and Meijer (2010) within the conceptual framework developed by Deroy and Auvray (forthcoming), trying to cash out, in a more specific way, the details of their idea that SSD perception goes “beyond vision”. In suggesting the emergence of a new sensory modality in practised SSD users, I aim to make more explicit the false dilemma on which both Block/Prinz and Hurley/Noë rely; the shared assumption that there are only two options available to explain SSD perception (namely, that it either stays in the substituting modality, or is entirely visual). In endorsing an emergence thesis, which aims at taking us out of the dead-end of the visual vs not-visual (auditory/tactile) dilemma by refusing its two horns, I thus aim at breaking the deadlock in which the philosophical debate about sensory substitution has fallen. (shrink)

This paper raises fundamental questions about the claims of art historian David Freedberg and neuroscientist Vittorio Gallese in their article "Motion, Emotion and Empathy in Esthetic Experience." It does so from several perspectives, all of them rooted in the dynamic realities of movement. It shows on the basis of neuroscientific research how connectivity and pruning are of unmistakable import in the interneuronal dynamic patternings in the human brain from birth onward. In effect, it shows that mirror neurons are contingent (...) on morphology and corporeal-kinetic tactile-kinesthetic experience. Accordingly, it poses and answers the overlooked but seminally important question of how mirror neurons come to be. The original neuromuscular research of Parma neuroscientists and the findings of Marc Jeannerod concerning kinesthesia support the answer that the "underpinnings" of visual art appreciation are themselves underpinned. An abbreviated phenomenological analysis of movement and its implications regarding the fact that the making of all art is quintessentially contingent on movement, hence a dynamic enterprise, further bolster the given answer as does a brief review of an empirical phenomenological analysis of the natural dynamic congruency of emotions and movement. In the end, the paper shows that movement and life are of a piece in the creation and appreciation of art as in everyday life. (shrink)

This is an excerpt of a report that highlights and explores five questions which arose from The Unity of Consciousness and Sensory Integration conference at Brown University in November of 2011. This portion of the report explores the question: What is the relationship between the unity of consciousness and sensory integration?

Both macaque monkeys and humans have been shown to have what are called ‘mirror neurons’, a class of neurons that respond to goal-related motor-actions, both when these actions are performed by the subject and when they are performed by another individual observed by the subject. Gallese and Goldman (1998) contend that mirror neurons may be seen as ‘a part of, or a precursor to, a more general mind- reading ability’, and that of the two competing theories of (...) mind-reading, mirror neurons lend support to simulation theory. I here offer four reasons why I think mirror neurons do not provide support for simulation theory over its contender, theory theory. (shrink)

This is an excerpt of a report that highlights and explores five questions which arose from The Unity of Consciousness and Sensory Integration conference at Brown University in November of 2011. This portion of the report explores the question: Is the mechanism of sensory integration spatio-temporal?

Selected contributions to the symposium on "Mirror neurons and the evolution of brain and language" held on July 5-8, 2000 in Delmenhorst, Germany.

What if a blind person could 'see' with her ears? Thanks to Sensory Substitution Devices (SSDs), blind people now have access to out-of-reach objects, a privilege reserved so far for the sighted. In this paper, we show that the philosophical debates have fundamentally been mislead to think that SSDs should be fitted among the existing senses or that they constitute a new sense. Contrary to the existing assumption that they get integrated at the sensory level, we present a new thesis (...) according to which they are not sensory, and get vertically integrated on the top of existing sensory abilities, from which they should be theoretically distinguished. (shrink)

Despite the impressive body of evidence supporting the existence of a mirror neuron (MN) system for action, the original claim regarding its crucial role in action understanding remains controversial. Emma Borg has recently launched a sharp attack on this claim, with the aim of demonstrating that neither the original version nor the subsequent revisions of the MN hypothesis tell us very much about how intentional attribution actually works. In this article I take up the challenge she issues in the title (...) of her paper (If Mirror Neurons are the Answer, What was the Question?) and argue that what MNs offer is not as Borg claims 'an extremely limited' picture of action understanding but rather an enriched picture that brings to light aspects of social cognition hitherto ignored in the mind-reading literature, showing how intentional motor components of action can shape social cognition prior to and apart from any forms of deliberate mentalizing. (shrink)

This article distinguishes three archetypal ways of articulating spatial cognition: (1) via metric representation of objective geometry, (2) via somatosensory constitution of the peripersonal environment, and (3) via pragmatic comprehension of the finalistic sense of action. The last one is documented by neuroscientific studies concerning mirror neurons. Bio-robotic experiments implementing mirror functions confirm the constitutive role of goal-oriented actions in spatial processes.

This is an excerpt of a report that highlights and explores five questions which arose from The Unity of Consciousness and Sensory Integration conference at Brown University in November of 2011. This portion of the report explores the question: How should we study experience, given unity relations?

Single cell recordings in monkeys provide strong evidence for an important role of the motor system in action understanding. This evidence is backed up by data from studies of the (human) mirror neuron system using neuroimaging or TMS techniques, and behavioral experiments. Although the data acquired from single cell recordings are generally considered to be robust, several debates have shown that the interpretation of these data is far from straightforward. We will show that research based on single-cell recordings allows for (...) unlimited content attribution to mirror neurons. We will argue that a theoretical analysis of the mirroring process, combined with behavioral and brain studies, can provide the necessary limitations. A complexity analysis of the type of processing attributed to the mirror neuron system can help formulate restrictions on what mirroring is and what cognitive functions could, in principle, be explained by a mirror mechanism. We argue that processing at higher levels of abstraction needs assistance of non-mirroring processes to such an extent that subsuming the processes needed to infer goals from actions under the label ?mirroring? is not warranted. (shrink)

This is an excerpt of a report that highlights and explores five questions which arose from The Unity of Consciousness and Sensory Integration conference at Brown University in November of 2011. This portion of the report explores the question: Are some of the basic units of consciousness multimodal?

Primatologists generally agree that monkeys lack higher-order intentional capacities related to theory of mind. Yet the discovery of the so-called “mirror neurons” in monkeys suggests to many neuroscientists that they have the rudiments of intentional understanding. Given a standard philosophical view about intentional understanding, which requires higher-order intentionality, a paradox arises. Different ways of resolving the paradox are assessed, using evidence from neural, cognitive, and behavioral studies of humans and monkeys. A decisive resolution to the paradox requires substantial additional (...) empirical work and perhaps a rejection of the standard philosophical view. (shrink)

This is an excerpt of a report that highlights and explores five questions which arose from The Unity of Consciousness and Sensory Integration conference at Brown University in November of 2011. This portion of the report explores the question: How should we model the unity of consciousness?

Positing the importance of sensorimotor contingencies for perception is by no means denying the presence and importance of representations. Using the evidence of mirror neurons we will show the intrinsic relationship between action control and representation within the logic of forward models.

How could neural processes be associated with phenomenal consciousness? We present a way to answer this question by taking the counterintuitive stance that the sensory feel of an experience is not a thing that happens to us, but a thing we do: a skill we exercise. By additionally noting that sensory systems possess two important, objectively measurable properties, corporality and alerting capacity, we are able to explain why sensory experience possesses a sensory feel, but thinking and other mental processes do (...) not. We are additionally able to explain why different sensory feels differ in the way they do. (shrink)

In ‘Of Sensory Systems and the “Aboutness” of Mental States’, Kathleen Akins (1996) argues against what she calls ‘the traditional view’ about sensory systems, according to which they are detectors of features in the environment outside the organism. As an antidote, she considers the case of thermoreception, a system whose sensors send signals about how things stand with themselves and their immediate dermal surround (a ‘narcissistic’ sensory system); and she closes by suggesting that the signals from many sensory systems may (...) not in any familiar sense be about anything at all. Her presentation of the issues, however, overlooks resources available to ‘the traditional view’—or so I shall argue. Akins’s own thumbnail sketch of what is wrong with the traditional view is that it asks, concerning a given sensory system, ‘what is it detecting?’, when we should instead be asking ‘what is it doing?’ (352). Her point is that on the traditional view the function of a sensory system—what it's ‘for’—is to detect or indicate (values of) features of the outside environment. But at least on one version of the traditional view—namely Ruth Millikan’s—this would never be the sole or main proper function of a sensory system. (Akins does not list Millikan as a traditionalist, but Millikan fits squarely Akins’s description of them, since she believes in a naturalistic theory of aboutness and thinks it should begin with the senses.) For Millikan (1989, 1993), the proper function of a sensory system is in the first instance enabling behavioural systems—in the simplest case, motor routines—to perform their proper function. This they do, roughly, by switching on and steering the behavioural routines. Where features of the outside environment come in is as Normal (= assumed-by-the-design) conditions for the successful performance of the sensory system's proper function. That is, the only strategy for switching on and steering that is simple enough for evolution to have hit upon it, and reliable enough for evolution to have liked it, is a strategy which gears the steering to (values of) features of the outside environment. But as soon as one starts fleshing out the details of this story, one notices that they are probably quite different in the case of thermoreception from how they are with ‘distance’ senses such as vision and olfaction--a point which Akins overlooks.. (shrink)

Sensory substitution devices provide through an unusual sensory modality (the substituting modality, e.g., audition) access to features of the world that are normally accessed through another sensory modality (the substituted modality, e.g., vision). In this article, we address the question of which sensory modality the acquired perception belongs to. We have recourse to the four traditional criteria that have been used to define sensory modalities: sensory organ, stimuli, properties, and qualitative experience (Grice, 1962), to which we have added the criteria (...) of behavioral equivalence (Morgan, 1977), dedication (Keeley, 2002), and sensorimotor equivalence (O’Regan & Noe¨, 2001). We discuss which of them are fulfilled by perception through sensory substitution devices and whether this favors the view that perception belongs to the substituting or to the substituted modality. Though the application of a number of criteria might be taken to point to the conclusion that perception with a sensory substitution device belongs to the substituted modality, we argue that the evidence leads to an alternative view on sensory substitution. According to this view, the experience after sensory substitution is a transformation, extension, or augmentation of our perceptual capacities, rather than being something equivalent or reducible to an already existing sensory modality. We develop this view by comparing sensory substitution devices to other ‘‘mind-enhancing tools’’ such as pen and paper, sketchpads, or calculators. An analysis of sensory substitution in terms of mind-enhancing tools unveils it as a thoroughly transforming perceptual experience and as giving rise to a novel form of perceptual interaction with the environment. (shrink)

The evolutionary continuity between the prespeech functions of premotor cortex and its new linguistic functions, the main thesis of MacNeilage's target article, is confirmed by the recent discovery of “mirror” neurons in monkeys and a corresponding action-observation/action-execution matching system in humans. Physiological data (and other considerations) appear to indicate, however, that brachiomanual gestures played a greater role in language evolution than MacNeilage would like to admit.

Chaotic dynamics can be related to analog computation. A possibility of electronically implementing the chaos-driven contracting system in the target article is explored with an analog electronic circuit with inevitable noise from the viewpoint of analog computation with chaotic neurons.

Commonsense says we are isolated. After all, our bodies are physically separate. But Seneca’s colamus humanitatem, and John Donne’s observation that “no man is an island” suggests we are neither entirely isolated nor separate. A recent discovery in neuroscience—that of mirror neurons—argues that the brain and the mind is neither built nor functions remote from what happens in other individuals. What are mirror neurons? They are brain cells that process both what happens to or is done by an (...) individual, and, as it were, its perceived “refl ection,” when that same thing happens or is done by another individual. Thus, mirror neurons are both activated when an individual does a particular action, and when that individual perceives that same action done by another. The discovery of mirror neurons suggests we need to radically revise our notions of human nature since they offer a means by which we may not be so separated as we think. Humans unlike other apes are adapted to mirror interact nonverbally when together. Notably, our faces have been evolved to display agile and nimble movements. While this is usually explained as enabling nonverbal communication, a better description would be nonverbal commune based upon mirror neurons. I argue we cherish humanity, colamus humanitatem, because mirror neurons and our adapted mirror interpersonal interface blur the physical boundaries that separate us. (shrink)

Mirror neurons are a particular class of visumotorical neurons, originally discovered in area F5 of the monkey premotorical cortex. They discharge both (1) when the animal performs a specific action and (2) when it observes a similar action. Actually, it is often assumed that this unique functioning could explain different abilities ranging from imitation behaviour to faculty of speech. In this article, we discuss the question what is meant by the expression: The neuron x mirrors the action y (...) by perception z . The problem resulted from the fact, that neurons cannot mirror anything—except in the light of a metaphorical description. How can this metaphorical description be dissolved for a distinct and explicit scientific terminology? The basic steps of our argumentation are as follows. (1) The expression to mirror can be defined in mutual relation between different types of actions in respect of at least two participants: the proponent A, who conducts a special action x (e.g. grapping a peanut (A(x)) and the opponent B who observes these actions y (B(y)) and vice versa. (2) In order to detect different tokens as a type of action and to guarantee the changes of the participants there must be constituted a speech act in a dialogue, in which types of actions are defined by the invariance of special equivalence. (3) The change of the participants represents and defines the metaphorical expression to mirror in the light of a non-metaphorical and reproducible schema. (4) Then, the invariance of the type of action can be identified in different speech acts. Three of them (called narratives) were defined paradigmatically: (4.1) the ethological-narrative; (4.2) the neurophysiological-narrative; (4.3) the language-narrative. (5) These narratives are the modelling and explicit formulations of the primarily metaphorical expression: The neuron x mirrors the action y by perception z. (shrink)

Various deficits in the cognitive functioning of people with autism have been documented in recent years but these provide only partial explanations for the condition. We focus instead on an imitative disturbance involving difficulties both in copying actions and in inhibiting more stereotyped mimicking, such as echolalia. A candidate for the neural basis of this disturbance may be found in a recently discovered class of neurons in frontal cortex, 'mirror neurons' (MNs). These neurons show activity in relation (...) both to specific actions performed by self and matching actions performed by others, providing a potential bridge between minds. MN systems exist in primates without imitative and ‘theory of mind’ abilities and we suggest that in order for them to have become utilized to perform social cognitive functions, sophisticated cortical neuronal systems have evolved in which MNs function as key elements. Early developmental failures of MN systems are likely to result in a consequent cascade of developmental impairments characterised by the clinical syndrome of autism. (shrink)

Summary Ideomotor apraxia is a cognitive disorder in which the patient loses the ability to accurately perform learned, skilled actions. This is despite normal limb power and coordination. It has long been known that left supramarginal gyrus lesions cause bilateral upper limb apraxia and it was proposed that this area stored a visualkinaesthetic image of the skilled action, which was translated elsewhere in the brain into the pre-requisite movement formula. We hypothesise that, rather than these two functions occurring separately, both (...) are complementary functions of chains of ‘‘mirror neurons’’ within the left inferior parietal lobe. We go on to propose that this neural mechanism in the supramarginal gyrus and its projection zones, which originally evolved to allow the creation of a direct map between vision and movement, was subsequently exapted to allow other sorts of cross-domain mapping and in particular those sorts of abstract re-conceptualisation, such as metaphor, that make mankind unique. (shrink)

As presently implemented, the neuron doctrine (ND) portrays the brain's neurons and chemical synapses as fundamental components in a computer-like switching circuit, supporting a view of brain = mind = computer. However, close examination reveals individual neurons to be far more complex than simple switches, with enormous capacity for intracellular information processing (e.g., in the internal cytoskeleton). Other poorly appreciated factors (gap junctions, apparent randomness, dendritic-dendritic processing, possible quantum computation, the living state) also suggest that the ND grossly (...) oversimplifies neuronal functions. In the quest to understand consciousness, the presently implemented ND may throw out the baby with the bath water. (shrink)

The neuroanatomical substrates controlling and regulating sleeping and waking, and thus consciousness, are located in the brain stem. Most crucial for bringing the brain into a state conducive for consciousness and information processing is the mesencephalic part of the brain stem. This part controls the state of waking, which is generally associated with a high degree of consciousness. Wakefulness is accompanied by a low-amplitude, high-frequency electroencephalogram, due to the fact that thalamocortical neurons fire in a state of tonic depolarization. (...) Information can easily pass the low-level threshold of these neurons, leading to a high transfer ratio. The complexity of the electroencephalogram during conscious waking is high, as expressed in a high correlation dimension. Accordingly, the level of information processing is high. Spindles, and alpha waves in humans, mark the transition from wakefulness to sleep. These phenomena are related to drowsiness, associated with a reduction in consciousness. Drowsiness occurs when cells undergo moderate hyperpolarizations. Increased inhibitions result in a reduction of afferent information, with a lowered transfer ratio. Information processing subsides, which is also expressed in a diminished correlation dimension. Consciousness is further decreased at the onset of slow wave sleep. This sleep is controlled by the medullar reticular formation and is characterized by a high-voltage, low-frequency electroencephalogram. Slow wave sleep becomes manifest when neurons undergo a further hyperpolarization. Inhibitory activities are so strong that the transfer ratio further drops, as does the correlation dimension. Thus, sensory information is largely blocked and information processing is on a low level. Finally, rapid eye movement sleep is regulated by the pontine reticular formation and is associated with a ''wake-like'' electroencephalographic pattern. Just as during wakefulness, this is the expression of a depolarization of thalamocortical neurons. The transfer ratio of rapid eye movement sleep has not yet been determined, but seems to vary. Evidence exists that this type of sleep, associated with dreaming, with some kind of perception and consciousness, is involved in processing of ''internal'' information. In line with this, rapid eye movement sleep has higher correlation dimensions than slow-wave sleep and sometimes even higher than wakefulness. It is assumed that the ''near-the-threshold'' depolarized state of neurons in the thalamus and cerebral cortex is a necessary condition for perceptual processes and consciousness, such as occurs during waking and in an altered form during rapid eye movement sleep. (shrink)

Moutoussis, K., A. Maier, S. Zeki and N. K. Logothetis: Seeing invisible motion: responses of area V5 neurons in the awake-behaving macaque. Soc. for Neurosci. Abstr. 390.11, 1 (11 2005) Abstract.

1. Properties of mirror neurons in monkeys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (...) . . . . 000 1.1. Action types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 000 1.2. Context effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 000 2. Is there a human ‘mirror neuron system’? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 000 2.1. Monkeys versus humans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 000 2.2. Action understanding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 000 3. The development of mirroring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 000 3.1. Imitation in newborns? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 000 3.2. Effects of experience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 000 3.3. Effects of sensorimotor experience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. (shrink)

Falk's hominin mother-infant model presupposes an emerging infant capacity to perceive and learn from afforded gestures and vocalizations. Unlike back-riding offspring of other primates, who were in no need to decenter their own body-centered perspective, a mirror neurons system may have been adapted in hominin infants to subserve the kind of (m)other-centered mirroring we now see manifested by human infants soon after birth.

During sensory stimulation, visual cortical neurons undergo massive synaptic bombardment. This increases their input conductance, and action potentials mainly result from membrane potential fluctuations. To understand the response properties of neurons operating in this regime, we studied a model neuron with synaptic inputs represented by transient membrane conductance changes. We show that with a simultaneous increase of excitation and inhibition, the firing rate first increases, reaches a maximum, and then decreases at higher input rates. Comodulation of excitation and (...) inhibition, therefore, does not provide a straightforward way of controlling the neuronal firing rate, in contrast to coding mechanisms postulated previously. The synaptically induced conductance increase plays a key role in this effect: it decreases firing rate by shunting membrane potential fluctuations, and increases it by reducing the membrane time constant, allowing for faster membrane potential transients. These findings do not depend on details of the model and, hence, are relevant to cells of other cortical areas as well. (shrink)

A formal neuron has been studied mathematically. The spiking behaviour of a single neuron has been considered and the influence of the other neurons has been replaced by an average activity level. Four different kinds of spiking behaviour are predicted by the model: B (bursts), C (continuous), P (periodic) and S (silent) neurons and several real neurons can be classified within these four categories. Some properties of the spiking neuron are calculated: 1) the time between spikes, 2) (...) the spike train length and 3) the silent time. Because these magnitudes can be measured in the laboratory, an experimental validation of the model is proposed. (shrink)

It has been shown that visual awareness in the blind hemifield of hemianopic cats that have undergone unilateral ablations of visual cortex can be restored by sectioning the commissure of the superior colliculus or by destroying a portion of the substantia nigra contralateral to the cortical lesion (the Sprague effect). We propose that the visual awareness that is recovered is due to synchronized oscillatory activities in the superior colliculus ipsilateral to the cortical lesion. These oscillatory activities are normally partially suppressed (...) by the inhibitory, GABAergic contralateral nigrotectal projection, and the destruction of the substantia nigra, or the sectioning of the collicular commissure, disinhibits the collicular neurons, causing an increase in the extent of oscillatory activity and/or synchronization between activities at different sites. This increase in the oscillatory and synchronized character is sufficient for the activities to give rise to visual awareness. We argue that in rodents and lower vertebrates, normal visual awareness is partly due to synchronized oscillatory activities in the optic tectum and partly due to similar activities in visual cortex. It is only in carnivores and primates that visual awareness is wholly due to cortical activities. Based on von Baerian recapitulation theory, we propose that, even in humans, there is a period in early infancy when visual awareness is partially due to activities in the superior colliculus, but that this awareness gradually disappears as the nigrotectal projection matures. (shrink)

The shapes of neurons and glial cells dictate many important aspects of their functions. In olfactory systems, certain architectural features are characteristics of these two cell types across a wide variety of species. The accumulated evidence suggests that these common features may play fundamental roles in olfactoryinformation processing. For instance, the primary olfactory neuropil in most vertebrate and invertebrate olfactory systems is organized into discrete modules called glomeruli. Inside each glomerulus, sensory axons and CNS neurons branch and synapse (...) in patterns that are repeated across species. In many species, moreover, the glomeruli are enveloped by a thin and ordered layer of glial processes. Theglomerular arrangement reflects the processing of odor information in modules that encode the discrete molecular attributes of odorant stimuli being processed. Recent studies of the mechanisms that guide the development of olfactory neurons and glial cells have revealed complex reciprocal interactions between these two cell types, which may be necessary for the establishment of modular compartments. Collectively, the findings reviewed here suggest that specialized cellular architecture plays key functional roles in the detection, analysis, and discrimination of odors at early steps in olfactory processing. (shrink)

The shapes of neurons and glial cells dictate many important aspects of their functions. In olfactory systems, certain architectural features are characteristics of these two cell types across a wide variety of species. The accumulated evidence suggests that these common features may play fundamental roles in olfactoryinformation processing. For instance, the primary olfactory neuropil in most vertebrate and invertebrate olfactory systems is organized into discrete modules called glomeruli. Inside each glomerulus, sensory axons and CNS neurons branch and synapse (...) in patterns that are repeated across species. In many species, moreover, the glomeruli are enveloped by a thin and ordered layer of glial processes. Theglomerular arrangement reflects the processing of odor information in modules that encode the discrete molecular attributes of odorant stimuli being processed. Recent studies of the mechanisms that guide the development of olfactory neurons and glial cells have revealed complex reciprocal interactions between these two cell types, which may be necessary for the establishment of modular compartments. Collectively, the findings reviewed here suggest that specialized cellular architecture plays key functional roles in the detection, analysis, and discrimination of odors at early steps in olfactory processing. (shrink)

A tendency of auditory cortical neurons to respond at the beginning of major transitions in sounds rather than providing a continuously updated spectral-temporal profile may impede the generation of combination-sensitivity for certain classes of stimuli. Potential consequences of the cortical encoding of voiced stop-consonants on representational principles derived from orderly output constraints are discussed.

In this paper, I critically assess the thesis that the discovery of mirror neuron systems (MNSs) provides empirical support for the simulation theory (ST) of social cognition. This thesis can be analyzed into two claims: (i) that MNSs are involved in understanding others’ intentions or emotions; and (ii) that the way in which they do so supports a simulationist viewpoint. I will be giving qualified support to both claims. Starting with (i), I will present theoretical and empirical points in support (...) of the view that MNSs play a substantial role and are perhaps neces¬sary although not sufficient for understanding at least some intentions or emo¬tions. Turning to (ii), I will argue that the work on MNSs best supports a fairly weak version of ST, according to which social cognition involves simulation simply because conceptual thought in gen¬eral has a simulationist component. In elucidating this idea, I appeal to Law¬rence Barsalou’s embodied theory of concepts (1999, 2005). Crucially, the term “simula¬tion” here refers not to simulations of a target agent’s experience, nor even spe¬cifically to one’s own experience in a similar counterfactual situation, but to simulations of experience in general - activating sensory, motor, proprioceptive, affective, and introspective representations that match representations one would have when perceiving, carrying out actions, experiencing emotions, etc. I then sketch an expanded simulationist framework for understanding the contribution of MNSs to social cognition. The ap¬peal to empirical work on MNSs in support of ST is therefore a two-edged sword; making this appeal persuasive requires us to modify our understanding of simulation to make it line up with the empirical work. (shrink)

Impressions, energy radiated by phenomena in the momentary environmental scene, enter sensory neurons, creating in afferent nerves a data stream. Following Kant, by our inner sense the mind perceives its own thoughts as it ties together sense data into an internalized scene. The mind, residing in the brain, logically a Language Machine, processes and stores items as coded grammatical entities. Kantian synthetic unity in the linguistic brain is able to deliver our experience of the scene as we appear to (...) see it. Uniquely, the brain records its own history, synthesizing a Movie-in-the-Brain, called the Noumenal Cosmos. Attempting thereby to represent the actual Universe, this makes for a sovereign brain that governs itself. The brain is domicile of an Ego, with its selfhood at stake at all times. Yet, it can know itself only by its actions, in which it appears as an actor in its own movie. Phenomena enter garbled, as confused apparitions, and must be put in good form using top–down feedback control by Ego, so that each movie frame makes rational sense within the overall context of the Noumenal Cosmos. A stack of frames is processed typically in 40 Hz rhythm with 300 ms process time each, for about 12 in the stack at any time. Successive neural centers are processing the stack in the brain assembly line, based on data from increasingly global receptive fields. Ego stitches together the movie frames, but only the top frame is in consciousness for 25 ms. The top frame contains the whole scene where the Ego makes an appearance as the actor that imposes Kantian synthetic unity on the scene, merely an assembly of grammatical texts, in a system-internal coded process language, fitting the scene into the Noumenal Cosmos. But Ego observes Ego only to the extent permitted by the objectivity rule, only what it does and thinks, not its true face. From the Noumenal Cosmos, the Ego receives grammatical messages in the internal sense code. They are integrated into a whole in the reaction of the Ego to the momentary scene. The voluntary nature of Ego’s decisions is explained, based on its ability to code in advance its own actions sequentially in time, as it sees fit with a view to an orderly Noumenal Cosmos, records of code being arranged spatially in neural structures. (shrink)

When John von Neumann turned his interest to computers, he was one of the leading mathematicians of his time. In the 1940s, he helped design two of the first stored-program digital electronic computers. He authored reports explaining the functional organization of modern computers for the first time, thereby influencing their construction worldwide (von Neumann, 1945; Burks et al., 1946). In the first of these reports, von Neumann described the computer as analogous to a brain, with an input “organ” (analogous to (...) sensory neurons), a memory, an arithmetical and a logical “organ” (analogous to associative neurons), and an output “organ” (analogous to motor neurons). His experience with computers convinced him that brains and computers, both having to do with the processing of information, should be studied by a new discipline–automata theory. In fact, according to von Neumann, automata theory would cover not only computers and brains, but also any biological or artificial systems that dealt with information and control, including robots and genes. Von Neumann never formulated a full-blown mathematical theory of automata, but he wrote several important exploratory papers (von Neumann, 1951, 1956, 1966). Meanwhile, besides designing hardware, he developed some of the first programs, programming languages, programming techniques, and numerical methods for solving mathematical problems using computers. (Much of his work on computing is reprinted in Aspray and Burks, 1987.) Shortly before his death in 1956, he wrote an informal synthesis of his views about brains. Though von Neumann left his manuscript sketchy and unfinished, Yale University Press published it as The Com- puter and the Brain in 1958. The 2000 reprint of this small but informative book is an opportunity to learn, or be reminded of, von Neumann’s thoughts on the computational organization of the mind-brain. Von Neumann began by explaining computers, which for him were essentially number crunchers: to compute was “to operate on .. (shrink)

Nicolas Malebranche Famously holds that we see all things in the physical world by means of ideas in God. This is the doctrine of Vision in God. In his initial formulation of the doctrine in the first edition of the Search After Truth (1674), Malebranche seems to posit ideas of particular physical objects in God, such as the idea of the sun or the idea of a tree. However, in Elucidations of the Search published four years later he insists that (...) there is only one idea of extension and it is general.1 Malebranche refers to this idea as "intelligible extension," in part because he thinks that we confuse it with its object, material extension, which he takes to be unintelligible in itself. By insisting upon a .. (shrink)

This paper proposes a form of Russellian enhanced physicalism which complements standard physicalism by retaining all of the structure of physics while making room for sensory phenomenology. Features of enhanced physicalism include: attention to the concrete instantiations of physical properties; articulation of a posteriori physicalism; articulation of macro-causation among large and complex shaped configurations of neurons, instantiated by sensations; and strong denials of a priori physicalism, panpsychism, and epiphenomenalism.

Which nonhuman animals experience conscious pain?1 This question is central to the debate about animal welfare, as well as being of basic interest to scientists and philosophers of mind. Nociception—the capacity to sense noxious stimuli—is one of the most primitive sensory capacities. Neurons functionally specialized for nociception have been described in invertebrates such as the leech Hirudo medicinalis and the marine snail Aplysia californica (Walters 1996). Is all nociception accompanied by conscious pain, even in relatively primitive animals such as (...) Aplysia, or is it the case, as some philosophers continue to maintain, that conscious experiences are the exclu- sive province of human beings? What philosophical and scientific resources are presently available for assessing claims lying between these extremes? (shrink)

The same neural structures involved in the unconscious modeling of our acting body in space also contribute to our awareness of the lived body and of the objects that the world contains. Neuroscientific research also shows that there are neural mechanisms mediating between the multi-level personal experience we entertain of our lived body, and the implicit certainties we simultaneously hold about others. Such personal and body-related experiential knowledge enables us to understand the actions performed by others, and to directly decode (...) the emotions and sensations they experience. A common functional mechanism is at the basis of both body awareness and basic forms of social understanding: embodied simulation. It will be shown that the present proposal is consistent with some of the perspectives offered by phenomenology. (shrink)

Introduction: New approaches to knotty old problems -- Avoiding Cartesian materialism -- From causal reductionism to self-directed systems -- From mindless to intelligent action -- How can neural nets mean? -- How does reason get its grip on the brain? -- Who's responsible? -- Neurobiological reductionism and free will.

All complex systems are complex, but some are more complex than others are. Biological systems are generally more complex than physical systems. How do biologists tackle complex systems? In this talk, we will consider two biological systems, the genome and the brain. Scientists know much about them, but much more remains unknown. Ignorance breeds philosophical speculation. Reductionism makes a strong showing here, as it does in other frontier sciences where large gaps remain in our understanding. I will show that reductionism (...) and its claims have no bases in actual scientific research and results. The Human Genome Project will serve as a case in point.. (shrink)

Questions concerning the nature of representation and what representations are about have been a staple of Western philosophy since Aristotle. Recently, these same questions have begun to concern neuroscientists, who have developed new techniques and theories for understanding how the locus of neurobiological representation, the brain, operates. My dissertation draws on philosophy and neuroscience to develop a novel theory of representational content.

Mirror neurons and systems are often appealed to as mechanisms enabling mindreading, i.e., understanding other people’s mental states. Such neural mirroring processes are often treated as instances of mental simulation rather than folk psychological theorizing. I will call into question this assumed connection between mirroring and simulation, arguing that mirroring does not necessarily constitute mental simulation as specified by the simulation theory of mindreading. I begin by more precisely characterizing “mirroring” (Sect. 2) and “simulation” (Sect. 3). Mirroring results in (...) a neural process in an observer that resembles a neural process of the same type in the observed agent. Although simulation is often characterized in terms of resemblance (Goldman, Simulating minds: The philosophy, psychology, and neuroscience of mindreading, 2006), I argue that simulation requires more than mere interpersonal mental resemblance: A simulation must have the purpose or function of resembling its target (Sect. 3.1). Given that mirroring processes are generated automatically, I focus on what is required for a simulation to possess the function of resembling its target. In Sect. 3.2 I argue that this resemblance function, at least in the case of simulation-based mindreading, requires that a simulation serve as a representation or stand-in of what it resembles. With this revised account of simulation in hand, in Sect. 4 I show that the mirroring processes do not necessarily possess the representational function required of simulation. To do so I describe an account of goal attribution involving a motor mirroring process that should not be characterized as interpersonal mental simulation. I end in Sect. 5 by defending the conceptual distinction between mirroring and simulation, and discussing the implications of this argument for the kind of neuroscientific evidence required by simulation theory. (shrink)

What is consciousness? Conventional approaches see it as an emergent property of complex interactions among individual neurons; however these approaches fail to address enigmatic features of consciousness. Accordingly, some philosophers have contended that "qualia," or an experiential medium from which consciousness is derived, exists as a fundamental component of reality. Whitehead, for example, described the universe as being composed of "occasions of experience." To examine this possibility scientifically, the very nature of physical reality must be re-examined. We must come (...) to terms with the physics of spacetime-as described by Einstein's general theory of relativity, and its relation to the fundamental theory of matter-as described by quantum theory. Roger Penrose has proposed a new physics of objective reduction: "OR," which appeals to a form of quantum gravity to provide a useful description of fundamental processes at the quantum/classical borderline.hz Within the OR scheme, we consider that consciousness occurs if an appropriately organized system is able to develop and maintain quantum coherent superposition until a specific "objective" criterion (a threshold related to quantum gravity) is reached; the coherent system then self-reduces (objective reduction: OR). We contend that this type of objective self-collapse introduces non-computability, an essential feature of consciousness which distinguishes our minds from classical computers. Each OR is taken as an instantaneous event-the climax of a self-organizing process in fundamental spacetime-and a candidate for a conscious Whitehead "occasion of experience." How could an OR process occur in the brain, be coupled to neural activities, and account for other features of consciousness? We nominate a quantum computational OR process with the requisite characteristics to be occurring in cytoskeletal microtubules within the brain's neurons. In this model, quantum-superposed states develop in microtubule subunit proteins ("tubulins") within certain brain neurons, remain coherent, and recruit more superposed tubulins until a mass-time-energy threshold (related to quantum gravity) is reached.. (shrink)

Cognitive functions like perception, memory, language, or consciousness are based on highly parallel and distributed information processing by the brain. One of the major unresolved questions is how information can be integrated and how coherent representational states can be established in the distributed neuronal systems subserving these functions. It has been suggested that this so-called ''binding problem'' may be solved in the temporal domain. The hypothesis is that synchronization of neuronal discharges can serve for the integration of distributed neurons (...) into cell assemblies and that this process may underlie the selection of perceptually and behaviorally relevant information. As we intend to show here, this temporal binding hypothesis has implications for the search of the neural correlate of consciousness. We review experimental results, mainly obtained in the visual system, which support the notion of temporal binding. In particular, we discuss recent experiments on the neural mechanisms of binocular rivalry which suggest that appropriate synchronization among cortical neurons may be one of the necessary conditions for the buildup of perceptual states and awareness of sensory stimuli. (shrink)

Recent literature on the role of pictorial representation in the life sciences has focused on the relationship between detailed representations of empirical data and more abstract, formal representations of theory. The standard argument is that in both a historical and epistemic sense, this relationship is a directional one: beginning with raw, unmediated images and moving towards diagrams that are more interpreted and more theoretically rich. Using the neural network diagrams of Warren McCulloch and Walter Pitts as a case study, I (...) argue that while in the empirical sciences, pictorial representation tends to move from data to theory, in areas of the life sciences that are predominantly theoretical, when abstraction occurs at the outset, the relationship between detail and abstraction in pictorial representations can be of a different character. (shrink)

In the Western aesthetic canon, the still life enjoys a certain prestige; its place in the museum and on the pages of the art history text is secure. Art aficionados who appreciate the character of Cezanne's apples help to ensure the lofty standing of the still life, as do students who admire the dewdrops still glistening on flowers picked and painted in the nineteenth century. For some students, however, it is difficult to understand such veneration. Despite the coaxing of dedicated (...) art or museum educators, these students find apples nestled among drapery folds or translucent petals in a spring bouquet to be "boring." No matter how compelling the apples, how exquisitely rendered the blossoms, the still life is .. (shrink)

Challenges most current thinking about consciousness and mind by subjecting neuroscience and cognitive science to philosophical analysis.

A unifying theory of general anesthetic-induced unconsciousness must explain the common mechanism through which various anesthetic agents produce unconsciousness. Functional-brain-imaging data obtained from 11 volunteers during general anesthesia showed specific suppression of regional thalamic and midbrain reticular formation activity across two different commonly used volatile agents. These findings are discussed in relation to findings from sleep neurophysiology and the implications of this work for consciousness research. It is hypothesized that the essential common neurophysiologic mechanism underlying anesthetic-induced unconsciousness is, as with (...) sleep-induced unconsciousness, a hyperpolarization block of thalamocortical neurons. A model of anesthetic-induced unconsciousness is introduced to explain how the plethora of effects anesthetics have on cellular functioning ultimately all converge on a single neuroanatomic/neurophysiologic system, thus providing for a unitary physiologic theory of narcosis related to consciousness. (shrink)

This book is the integrated presentation of a large body of work on understanding the operation of biological brains as systems.

A premise of Corballis's theory is that speech arose when vocalization co-opted existing gestural functions in the left ventral premotor cortex. Yet, visuomotor functions in this region remain largely unchanged between humans and macaques and have no discernible connection to gestural communication. This functional continuity suggests that language production is not the result of modifying existing motor functions in this region.

Neurophysiological studies in monkeys and neuroimaging studies in humans support a model of empathy according to which there exists a shared code between perception and production of emotion. The neural circuitry critical to this mechanism is composed of frontal and parietal areas matching the observation and execution of action, and interacting heavily with the superior temporal cortex. Further, this cortical system is linked to the limbic system by means of an anterior sector of the human insular lobe.

A wide range of systems appear to perform computation: what common features do they share? I consider three examples, a digital computer, a neural network and an analogue route finding system based on soap-bubbles. The common feature of these systems is that they have autonomous dynamics — their states will change over time without additional external influence. We can take advantage of these dynamics if we understand them well enough to map a problem we want to solve onto them. Programming (...) consists of arranging the starting state of a system so that the effects of the system''s dynamics on some of its variables corresponds to the effects of the equations which describe the problem to be solved on their variables. The measured dynamics of a system, and hence the computation it may be performing, depend on the variables of the system we choose to attend to. Although we cannot determine which are the appropriate variables to measure in a system whose computation basis is unknown to us I go on to discuss how grammatical classifications of computational tasks and symbolic machine reconstruction techniques may allow us to rule out some measurements of a system from contributing to computation of particular tasks. Finally I suggest that these arguments and techniques imply that symbolic descriptions of the computation underlying cognition should be stochastic and that symbols in these descriptions may not be atomic but may have contents in alternative descriptions. (shrink)

The communication of emotion in music has with few exceptions, as L. B. Meyer´s Emotion and Meaning in Music (1956) and the contour theory (Kivy 1989, 2002), focused on music structure as representations of emotions. This implies a semiotic approach - the assumption that music is a kind of language that could be read and decoded. Such an approach is largely restricted to the conscious level of knowing, understanding and communication. We suggest an understanding of music and emotion based on (...) action-perception theory - present moment perception, implicit knowledge and imitation. This theory does not demand consciousness or the use of signs. Neuroscientific findings (adaptive oscillators, mirror neurons) are in concordance with our suggestion. Recently these findings have generated articles on empathy – relevant to the understanding of music and emotion. (shrink)

Page's target article presents an argument for the use of localist, connectionist models in future psychological theorising. The “manifesto” marshalls a set of arguments in favour of localist connectionism and against distributed connectionism, but in doing so misses a larger argument concerning the level of psychological explanation that is appropriate to a given domain.

Four distinct models of the functional contribution of mirror neurons to social cognition can be distinguished: direct matching, inverse modeling, response modeling, and predictive coding. Each entails a different way in which an agent's own capacities for action and affective experience contribute to understanding and/or predicting others' actions and affective experience. In this paper, the four models and their theoretical frameworks are elucidated, empirical data and theoretical arguments bearing upon each are reviewed, and falsifiable predictions that could help to (...) distinguish empirically among the models are proposed. (shrink)