Recent research suggests that human memories are stored not between neurons as synaptic weights, but within individual neurons themselves. This opens the possibility to replace the dominant paradigm of brain function – neural networks – with a new one. In this article, I explore how “identified neurons” could explain how memories are stored, and how human traits are implemented in the brain.

Neuronal remodeling is a conserved mechanism that eliminates unwanted neurites and can include the loss of cell bodies. In these processes, a key role for glial cells in events from synaptic pruning to neuron elimination has been clearly identified in the last decades. Signals sent from dying neurons or neurites to be removed are received by appropriate glial cells. After receiving these signals, glial cells infiltrate degenerating sites and then, engulf and clear neuronal debris through phagocytic mechanisms. There (...) are few identified or proposed signals and receptors involved in neuron‐glia crosstalk, which induces the transformation of glial cells to phagocytes during neuronal remodeling in Drosophila. Many of these signaling pathways are conserved in mammals. Here, we particularly emphasize the role of Orion, a recently identified neuronal CX3C chemokine‐like secreted protein, which induces astrocyte infiltration and engulfment during mushroom body neuronal remodeling. Although, chemokine signaling was not described previously in insects we propose that chemokine‐like involvement in neuron/glial cell interaction is an evolutionarily ancient mechanism. (shrink)

Different types of sense organs are present on the larva of Drosophila. Several genes that specify the type of sense organ that will form at a particular position have been recently identified. Here we review the functional and molecular analyses of these genes, and summarize the evidence which supports a role in the choice of which type of organ will be formed. Most or all of these genes are required for the appropriate specification of adult as well as larval (...) sense organs, suggesting that the larval and adult systems share many gene requirements. Interestingly, the specifying genes identified so far in the peripheral nervous system are also expressed in subsets of cells in the central nervous system, where they might have similar roles. (shrink)

Different types of sense organs are present on the larva of Drosophila. Several genes that specify the type of sense organ that will form at a particular position have been recently identified. Here we review the functional and molecular analyses of these genes, and summarize the evidence which supports a role in the choice of which type of organ will be formed. Most or all of these genes are required for the appropriate specification of adult as well as larval (...) sense organs, suggesting that the larval and adult systems share many gene requirements. Interestingly, the specifying genes identified so far in the peripheral nervous system are also expressed in subsets of cells in the central nervous system, where they might have similar roles. (shrink)

The concept of “information” is virtually ubiquitous in contemporary cognitive science. It is claimed to be “processed” (in cognitivist theories of perception and comprehension), “stored” (in cognitivist theories of memory and recognition), and otherwise manipulated and transformed by the human central nervous system. Fred Dretske's extensive philosophical defense of a theory of informational content (“semantic” information) based upon the Shannon-Weaver formal theory of information is subjected to critical scrutiny. A major difficulty is identified in Dretske's equivocations in the use (...) of the concept of a “signal” bearing informational content. Gibson's alternative conception of information (construed as analog by Dretske), while avoiding many of the problems located in the conventional use of “signal”, raises different but equally serious questions. It is proposed that, taken literally, the human CNS does not extract or process information at all; rather, whatever “information” is construed as locatable in the CNS is information only for an observer-theorist and only for certain purposes. (shrink)

I argue that Gold & Stoljar's “trivial neuron doctrine” is not in fact trivial. Many familiar positions in the philosophy of mind run afoul of it, and it is unclear that even those whom Gold & Stoljar identify as adherents of the trivial neuron doctrine can be comfortably described as such.

The inner ear of mammals uses neurosensory cells derived from the embryonic ear for mechanoelectric transduction of vestibular and auditory stimuli (the hair cells) and conducts this information to the brain via sensory neurons. As with most other neurons of mammals, lost hair cells and sensory neurons are not spontaneously replaced and result instead in age‐dependent progressive hearing loss. We review the molecular basis of neurosensory development in the mouse ear to provide a blueprint for possible enhancement of therapeutically useful (...) transformation of stem cells into lost neurosensory cells. We identify several readily available adult sources of stem cells that express, like the ectoderm‐derived ear, genes known to be essential for ear development. Use of these stem cells combined with molecular insights into neurosensory cell specification and proliferation regulation of the ear, might allow for neurosensory regeneration of mammalian ears in the near future. BioEssays 28: 1181–1193, 2006. © 2006 Wiley Periodicals, Inc. (shrink)

There is widespread agreement in neuroscience and psychology that the visual system identifies objects and faces based on a pattern of activation over many neurons, each neuron being involved in representing many different categories. The hypothesis that the visual system includes finely tuned neurons for specific objects or faces for the sake of identification, so‐called “grandmother cells”, is widely rejected. Here it is argued that the rejection of grandmother cells is premature. Grandmother cells constitute a hypothesis of how familiar (...) visual categories are identified, but the primary evidence against this hypothesis comes from studies that have failed to observe neurons that selectively respond to unfamiliar stimuli. These findings are reviewed and it is shown that they are irrelevant. Neuroscientists need to better understand existing models of face and object identification that include grandmother cells and then compare the selectivity of these units with single neurons responding to stimuli that can be identified. (shrink)

Neuron diagrams are heavily employed in academic discussions of causation. Stephen Mumford and Rani Lill Anjum, however, offer an alternative approach employing vector diagrams, which this paper attempts to develop further. I identify three ways in which dispositionalists have taken the activities of powers to be related: stimulation, mutual manifestation, and contribution combination. While Mumford and Anjum do provide resources for representing contribution combination, which might be sufficient for their particular brand of dispositionalism, I argue that those resources are (...) not flexible enough to further accommodate either stimulation or mutual manifestation. Representational tools are provided to address these limitations, improving the general value of the vector model for dispositionalist approaches to causation. (shrink)

The primate brain is able to guide complex decisions that can rapidly be adapted to changing constraints. Unfortunately, the vast numbers of highly interconnected neurons that seem to be needed make it difficult to study the cellular mechanisms that underlie the flexible combination of stored and acute information during a decision. Established simpler networks, particularly with few and identified neurons, would lend themselves more readily to such a dissection. But can simple networks implement complex and flexible decisions similarly? After (...) a brief overview of complex decisions in primates and of decision‐making in simple networks, I argue that simpler systems can combine complexity with accessibility at the cellular level. Indeed, examination of a network in fish may help in dissecting key mechanisms of complex and flexible decision‐making in an established model of synaptic plasticity at the level of identified neurons. (shrink)

A serious crisis is identified in theories of neurocomputation, marked by a persistent disparity between the phenomenological or experiential account of visual perception and the neurophysiological level of description of the visual system. In particular, conventional concepts of neural processing offer no explanation for the holistic global aspects of perception identified by Gestalt theory. The problem is paradigmatic and can be traced to contemporary concepts of the functional role of the neural cell, known as the Neuron Doctrine. (...) In the absence of an alternative neurophysiologically plausible model, I propose a perceptual modeling approach, to model the percept as experienced subjectively, rather than modeling the objective neurophysiological state of the visual system that supposedly subserves that experience. A Gestalt Bubble model is presented to demonstrate how the elusive Gestalt principles of emergence, reification, and invariance can be expressed in a quantitative model of the subjective experience of visual consciousness. That model in turn reveals a unique computational strategy underlying visual processing, which is unlike any algorithm devised by man, and certainly unlike the atomistic feed-forward model of neurocomputation offered by the Neuron Doctrine paradigm. The perceptual modeling approach reveals the primary function of perception as that of generating a fully spatial virtual-reality replica of the external world in an internal representation. The common objections to this picture-in-the-head concept of perceptual representation are shown to be ill founded. Key Words: brain-anchored; Cartesian theatre; consciousness; emergence; extrinsic constraints; filling-in; Gestalt; homunculus; indirect realism; intrinsic constraints; invariance; isomorphism; multistability; objective phenomenology; perceptual modeling; perspective; phenomenology; psychophysical parallelism; psychophysical postulate; qualia; reification; representationalism; structural coherence. (shrink)

Francis Crick has identified a doctrine‐the neuron doctrine‐which he apparently regards as both true and astonishing. I begin by carefully articulating Crick’s doctrine, arguing that whilst plausible it is certainly not astonishing. I then consider a related doctrine, the biological neuroscience thesis (BNT). According to BNT, mental science is biological neuroscience, where biological neuroscience is pretty much exhausted by neuroanatomy, neurophysiology and neurochemistry. Stoljar and Gold argue that BNT is unsupported by current scientific developments. I argue that well‐established (...) results in the cognitive sciences show that it is false. (shrink)

The potential for mirror neuron research to explain various aspects of social cognition has received considerable attention over the past two decades. Initially, mirror neuron research may seem in accordance with a phenomenological understanding of intersubjectivity, but the work of Dan Zahavi will be used to highlight significant incompatibilities between the two. Likewise, the enactivists Thomas Fuchs and Hanne De Jaegher identify significant issues with current interpretations of mirror neuron research and provide an alternative description of intersubjectivity. (...) This article will assess whether the enactivists are able to provide a more phenomenologically consistent alternative to mirror neuron research alone, eventually determining that their enactive account overcomes Zahavi’s incompatibilities. Consequently, Fuchs and De Jaegher should acknowledge their relation to Husserlian descriptions of empathy in their account, and mirror neuron research should be contextualised within a broader, phenomenologically-compatible framework, as that of the enactivists. (shrink)

Twenty five years ago, Sir John Carew Eccles together with Friedrich Beck proposed a quantum mechanical model of neurotransmitter release at synapses in the human cerebral cortex. The model endorsed causal influence of human consciousness upon the functioning of synapses in the brain through quantum tunneling of unidentified quasiparticles that trigger the exocytosis of synaptic vesicles, thereby initiating the transmission of information from the presynaptic towards the postsynaptic neuron. Here, we provide a molecular upgrade of the Beck and Eccles (...) model by identifying the quantum quasiparticles as Davydov solitons that twist the protein α-helices and trigger exocytosis of synaptic vesicles through helical zipping of the SNARE protein complex. We also calculate the observable probabilities for exocytosis based on the mass of this quasiparticle, along with the characteristics of the potential energy barrier through which tunneling is necessary. We further review the current experimental evidence in support of this novel bio-molecular model as presented. (shrink)

This article examines the imagination by way of various studies in cognitive science. It opens by examining the neural correlates of bodily metaphors. It assumes a basic knowledge of metaphor studies, or the primary finding that has emerged from this field: that large swathes of human conceptualization are structured by bodily relations. I examine the neural correlates of metaphor, concentrating on the relation between the sensory motor cortices and linguistic conceptualization. This discussion, however, leaves many questions unanswered. If it is (...) the case that the sensory motor cortices are appropriated in language acquisition, how does this process occur at the neural level? What neural preconditions exist such that this appropriation is possible? It is with these questions in mind that I will turn my attention to studies of neural plasticity, degeneracy and the mirror neuron activation. Whereas some scholarship in philosophy and cognitive neuroscience has aimed to identify the neurological correlates of consciousness, examining plasticity, degeneracy and activation shifts the discussion away from a study of correlates toward an exploration of the neurological dynamics of thought. This shift seems appropriate if we are to examine the processes of the “imagination.”. (shrink)

The topic is characterized by a highly interdisciplinary approach to the issue of action and language integration. Such an approach, combining computational models and cognitive robotics experiments with neuroscience, psychology, philosophy, and linguistic approaches, can be a powerful means that can help researchers disentangle ambiguous issues, provide better and clearer definitions, and formulate clearer predictions on the links between action and language. In the introduction we briefly describe the papers and discuss the challenges they pose to future research. We identify (...) four important phenomena the papers address and discuss in light of empirical and computational evidence: (a) the role played not only by sensorimotor and emotional information but also of natural language in conceptual representation; (b) the contextual dependency and high flexibility of the interaction between action, concepts, and language; (c) the involvement of the mirror neuron system in action and language processing; (d) the way in which the integration between action and language can be addressed by developmental robotics and Human-Robot Interaction. (shrink)

The idea that individual nerve cells might have conscious experiences has been around ever since cells were identified in the seventeenth century, but in the era of modern neuroscience the case for individual human neuronal experience has received little attention. A series of arguments will be presented suggesting that all the human conscious experiences that we talk about are events in individual neurons, not global to the brain or organism. We conclude that cellular consciousness is the only plausible way (...) to explain ‘our’ experiences within current physics and biology, however implausible it might at first seem. This implies that our experiences are multiple in space as well as time, consistent with the neuroscience watchword that there is ‘no single place where everything comes together in the brain’. The central argument is that events of experience must involve rich integration of information and individual neurons are the only places in brains where integration of information occurs. Any more global ‘binding’ is neither required nor physically possible. The detailed nature of events of integration of signals in a neuron’s dendrites remains uncertain but recent developments provide some candidates. (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)

In the present paper we formulate the hypothesis that brain glycogen is a critical determinant in the modulation of carbohydrate supply at the cellular level. Specifically, we propose that mobilization of astrocytic glycogen after an increase in AMP levels during enhanced neuronal activity controls the concentration of glucose phosphates in astrocytes. This would result in modulation of glucose phosphorylation by hexokinase and upstream cell glucose uptake. This mechanism would favor glucose channeling to activated neurons, supplementing the already rich neuron‐astrocyte (...) metabolic and functional partnership with important implications for the energy compounds used to sustain neuronal activity. The hypothesis is based on recent modeling evidence suggesting that rapid glycogen breakdown can profoundly alter the short‐term kinetics of glucose delivery to neurons and astrocytes. It is also based on review of the literature relevant to glycogen metabolism during physiological brain activity, with an emphasis on the metabolic pathways identifying both the origin and the fate of this glucose reserve. (shrink)

Face recognition is one of the core and challenging issues in computer vision field. Compared to computer vision, human visual system can identify a target from complex backgrounds quickly and accurately. This paper proposes a new network model deriving from Where-What Networks (WWNs), which can approximately simulate the information processing pathways (i.e., dorsal pathway and ventral pathway) of human visual cortex and recognize different types of faces with different locations and sizes in complex background. To enhance the recognition performance, synapse (...) maintenance mechanism and neuron regenesis mechanism are both introduced. Synapse maintenance is used to reduce the background interference while neuron regenesis mechanism is introduced to regulate the neuron resource dynamically to improve the network usage efficiency. Experiments have been conducted on human face images of 5 types, 11 sizes, and 225 locations in complex backgrounds. Experiment results demonstrate that the proposed WWN model can basically learn three concepts (type, location and size) simultaneously. The experiment results also show the advantages of the enhanced WWN-7 model for face recognition in comparison with several existing methods. (shrink)

In this paper, we distinguish between a number of different phenomena that have been called imitation, and identify one form—a high fidelity mechanism for social learning—considered to be crucial for the development of language. Subsequently, we consider a common claim in the language evolution literature, which is that prior to the emergence of vocal language our ancestors communicated using a sophisticated gestural protolanguage, the learning of some parts of which required manual imitation. Drawing upon evidence from recent work in neuroscience, (...) primatology, and archeology, we argue that while gestural communication undoubtedly played a crucial role in language evolution, the grounds for thinking that manual imitation did are currently unconvincing. (shrink)

This paper reviews the evidence, from studies of acute denervation plasticity, that NCCs in the sensory cortex are composed of particular patterns of intracolumnar excitation in a certain type of neuron, and not of specific anatomically identified neurons. This leads to an enquiry as to what the microneurological basis of NCCs in general may be. Further evidence is examined as to the possible NCCs of the stroboscopic patterns. The hypotheses are presented that the geometrical bright phase patterns arise (...) as dissipative structures generated by interacting cortical rhythms; whereas the non-geometrical dark phase patterns have as their NCCs dendritic potentials in the GABAergic gap-junction linked network in layers II and III of the visual cortex. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:A Still Life Is Really a Moving LifeThe Role of Mirror Neurons and Empathy in Animating Aesthetic ResponseCarol S. Jeffers (bio)IntroductionIn 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 much too static, offering little more than the lifelessness of inanimate objects.In my experience, even the most unappreciative of students can be persuaded to take a closer look at the inanimate—not by me or any strategies I may have devised but rather by classmates who have chosen still life paintings to serve as their personal metaphors. When shared during the courses I teach, these still lifes and their depicted objects acquire special meanings that are uniquely associated with the individual students who chose them. Reflecting on these class presentations, converted students offered these thoughts: "I related myself with the metaphors and the way my classmates felt"; and "What really stayed with me were the stories and the way my classmates connected with their paintings—how they connected to the art emotionally." Still another wrote: "I really liked the way their presentations went because I got to know [my classmates] a little bit more." Through these connections to still life and other genres, students explored [End Page 31] their concepts of self within a community of others and began to experience the power of empathy.Empathy, typically defined as "the intellectual or emotional identification with another,"1 is a human capacity that, according to the noted neuroscientist Vittorio Gallese, allows us to understand the world of objects as well as the world of others.2 With the recent discovery of the mirror neuron system in the human brain, Gallese and other investigators around the world have identified the neurological basis of empathy.3 Subsequent studies of the remarkable properties of mirror neurons have yielded potent new understandings of the connections between empathy, objects of art and material culture, and intrapersonal relationships among human beings. Interestingly, these twenty-first-century findings tend to confirm a nineteenth-century connection between aesthetics and empathy, or more precisely, Einfuhlung ("in-feeling," or "feeling into"), a term coined by the philosopher Robert Vischer in 1873 to describe the projection of human feeling onto art objects.4 As Vischer himself described this phenomenon, "I transport myself into the inner being of an object and explore its formal character from within, as it were."5These insights, whether gained through the use of state-of-the-art brain imaging technologies or dusty volumes in a German library, have led Gallese to consider some interesting implications, such as, for example, those involving the still life—its bottles, apples, even its brushstrokes—and to claim that "a still life is really a moving life" when understood from the perspective of neuroscience.6 To explore this claim and its relevance to classroom and museum practices, this article examines the relationship between mirror neurons, empathy, and aesthetic response as it developed among preservice teachers who presented metaphorical works of art in two teacher education courses. A brief synopsis of research results highlighting the workings of the mirroring mechanism is presented and then applied to two student presentations: one given by Molly about Cezanne's Still Life with Apples (1893-94) and the other by Deborah about Fantin-Latour's White and Pink Mallows in a Vase (1895). The stories told by Molly, Deborah, and their classmates allow additional insights with implications for art and museum education.Mirror Neurons: Some Research ResultsSome fifteen years ago, what Gallese characterizes as a "strange class" of neurons was discovered, first... (shrink)

In the mammalian central nervous system (CNS), each neuron receives signals from other neurons through numerous synapses located on its cell body and dendrites. Molecules involved in the postsynaptic signaling pathways need to be targeted to the appropriate subcellular domains at the right time during both synaptogenesis and the maintenance of synaptic functions. The presence of messenger RNAs (mRNAs) in dendrites offers a mechanism for synthesizing the appropriate molecules at the right place in response to local extracellular stimuli. Several (...) dendritic mRNAs have been identified, and the mechanisms controlling their localization are beginning to be understood. In many cell types, controls on mRNA stability play an important role in the regulation of gene expression, but it is unclear to what extent this type of control operates in dendrites. The regulation of protein synthesis and the control of mRNA stability in dendrites could have important implications for neuronal function. BioEssays 20:70–78, 1998. © 1998 John Wiley & Sons, Inc. (shrink)

The dauer larva is a specialized third‐larval stage of Caenorhabditis elegans that is long‐lived and resistant to environmental insult. The dauer larva is formed in response to a high external concentration of a constitu‐tively secreted pheromone. Response to the dauer‐inducing pheromone of C. elegans is a promising genetic model for metazoan chemosensory transduction. More than 20 genes have been identified that are required for normal pheromone response. The functions of these genes include production of the pheromone, exposure of sensory (...) neuron endings to the environment, structural and functional integrity of those sensory endings, and the capacity of sensory neurons to make appropriate output. Genetic evidence suggests that two partially redundant sensory pathways act in concert to control dauer formation. At least two classes of chemosensory neurons, ADF and ASI, are implicated in the pheromone response. On the basis of on these findings, a speculative model for the pheromone response is proposed. In this model, the neurons ADF and ASI are pheromone sensors that repress dauer formation in the absence of pheromone and dere‐press dauer formation in response to pheromone. It is currently unclear whether or not the two genetically defined sensory pathways both act in ADF and ASI. (shrink)

In the mammalian central nervous system (CNS), each neuron receives signals from other neurons through numerous synapses located on its cell body and dendrites. Molecules involved in the postsynaptic signaling pathways need to be targeted to the appropriate subcellular domains at the right time during both synaptogenesis and the maintenance of synaptic functions. The presence of messenger RNAs (mRNAs) in dendrites offers a mechanism for synthesizing the appropriate molecules at the right place in response to local extracellular stimuli. Several (...) dendritic mRNAs have been identified, and the mechanisms controlling their localization are beginning to be understood. In many cell types, controls on mRNA stability play an important role in the regulation of gene expression, but it is unclear to what extent this type of control operates in dendrites. The regulation of protein synthesis and the control of mRNA stability in dendrites could have important implications for neuronal function. BioEssays 20:70–78, 1998. © 1998 John Wiley & Sons, Inc. (shrink)

Reading is an amazing skill. As you read this review, meaning flows from the page (or for many readers, the screen) into your brain. This happens automatically—you can’t choose not to understand the written word any more than the spoken one. It’s also highly efficient. Most people can process text two or three times faster than speech. Of course, humans have many amazing skills. We also identify objects, decode speech, and understand complex social situations automatically and efficiently. However, the machinery (...) in the brain that gives us these abilities, and many more, was plausibly constructed by natural selection, and, if so, they are adaptations just like our peculiar pelvis and the thick enamel on our molars. Reading arose a few thousand years ago, and this means that machinery in the brain that allows us to read did not evolve for that purpose. Instead, a series of scribes, priests, and printers working over a few thousand years gradually devised the writing systems that give rise to this amazing skill. In this fascinating book, Stanislaus Dehaene details how cognitive abilities evolved for other purposes were co-opted for reading, how these abilities are instantiated in the brain, and how they constrain the cultural evolution of writing systems. Dehaene does an excellent job explaining how reading works at both the neurobiological and cognitive levels. He takes the reader seriously, laying out diverse kinds of evidence that bear on the problem. For example, when you read, visual information is shunted to a small region in the left hemisphere of your brain, the brain’s ‘‘letter box’’ where the text is decoded. The earliest evidence for this came from the autopsy of a 19th century French stroke victim who lost the ability to read, even though he could still recognize numerals. More recently, PET and fMRI imaging studies have pinned down the location. Amazingly, these results show that it doesn’t matter whether you read Italian or Chinese, the same part of the brain is involved. Electroencephalograms gave us a better temporal resolution, and single neuron recordings of patients undergoing surgery confirm that only some neurons respond to text while others respond to faces, tools.. (shrink)

It seems that I often say things that might mistakenly be thought to identify me as an adherent of the radical neuron doctrine. I take the opportunity to explain my position more clearly and argue that many apparent conflations of the radical and trivial neuron doctrines are merely the result of misunderstanding what is meant when neuroscientists talk about the relations between different levels of description. It follows that there may be considerably fewer followers of the radical doctrine (...) than Gold & Stoljar suggest. (shrink)

A considerable challenge confronts, any developing neuron. Before it can establish a functional and specific connection, it must extend an axon over tens and sometimes hundreds of microns through a complex and mutable environment to reach one out of many possible destinations. The field of axonal guidance concerns the control of this navigation process. To satisfactorily identify the cell interactions and molecular mechanisms that mediate axonal guidance, it is essential to first identify the pertinent cell populations. Embryonic surgeries have (...) provided solid information on which tissues are critical and which are irrelevant to the navigation of motor axons within the chick embryo. The gross anatomical nerve pattern is established as axons respond to both positive (path) and negative (barrier) tissue environments. Analysis of the interactions of motoneurons with these tissues reveals that several cellular interactions – chemotaxis, substratum preference, and perhaps contact paralysis – are important to the common patterns of motor axon advance. Axons simultaneously interact with population‐specific cues that have begun to be identified on the tissue level. (shrink)

Abnormalities in the ability of cells to properly degrade proteins have been identified in many neurodegenerative diseases. Recent work has implicated synaptojanin 1 (SynJ1) in Alzheimer's disease and Parkinson's disease, although the role of this polyphosphoinositide phosphatase in protein degradation has not been thoroughly described. Here, we dissected in vivo the role of SynJ1 in endolysosomal trafficking in zebrafish cone photoreceptors using a SynJ1‐deficient zebrafish mutant, nrca14. We found that loss of SynJ1 leads to specific accumulation of late endosomes (...) and autophagosomes early in photoreceptor development. An analysis of autophagic flux revealed that autophagosomes accumulate because of a defect in maturation. In addition we found an increase in vesicles that are highly enriched for PI(3)P, but negative for an early endosome marker in nrca14 cones. A mutational analysis of SynJ1 enzymatic domains found that activity of the 5'phosphatase, but not the Sac1 domain, is required to rescue both aberrant late endosomes and autophagosomes. Finally, modulating activity of the PI(4,5)P2 regulator, Arf6, rescued the disrupted trafficking pathways in nrca14 cones. Our study describes a specific role for SynJ1 in autophagosomal and endosomal trafficking and provides evidence that PI(4,5)P2 participates in autophagy in a neuronal cell type. -/- . (shrink)

It is widely held that a successful theory of the mind will be neuroscientific. In this paper we ask, first, what this claim means, and, secondly, whether it is true. In answer to the first question, we argue that the claim is ambiguous between two views--one plausible but unsubstantive, and one substantive but highly controversial. In answer to the second question, we argue that neither the evidence from neuroscience itself nor from other scientific and philosophical considerations supports the controversial view.

Gold & Stoljar argue that there are two (often confused) neuron doctrines, one trivial and the other radical, with only the latter having the consequence that non-neuroscientific sciences of the mind will be discarded. They also attempt to show that there is no evidence supporting the radical doctrine. It is argued here that their dichotomy is artificial and misrepresents modern approaches to understanding the neuroscientific correlates of cognition and behavior.

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)

We focus on the thesis that action understanding is a function of the mirror neuron system. According to our opinion, understanding is a process that runs through hermeneutic circles from the “Vorverständnis” (“previous understanding”) to steps of deeper understanding. Our critique relates to the narrow neuroscientific definition of action understanding as the capacity to recognize several movements as belonging to one action. After a reconstruction of the model's developments, we will challenge the claims of the model by Rizzolatti and (...) Sinigaglia (2010). By analyzing the relation between the experimental results and its interpretation, we will conclude that there is no proof that mirror neuron activity leads to action understanding. (shrink)

A central issue of cognitive neuroscience is to understand how a large collection of coupled neurons combines external signals with internal memories into new coherent patterns of meaning. An external stimulus localized at some input spreads over a large assembly of coupled neurons, building up a collective state univocally corresponding to the stimulus. Thus, the synchronization of spike trains of many individual neurons is the basis of a coherent perception. Based on recent investigations of homoclinic chaotic systems and their synchronization, (...) a novel conjecture for the dynamics of single neurons and, consequently, for neuron assemblies is formulated. Homoclinic chaos is proposed as a suitable way to code information in time by trains of equal spikes occurring at apparently erratic times. In order to classify the set of different perceptions, the percept space can be given a metric structure by introducing a distance measure between distinct percepts. The distance in percept space is conjugate to the duration of the perception in the sense that an uncertainty relation in percept space is associated with time-limited perceptions. This coding of different percepts by synchronized spike trains entails fundamental quantum features which are not restricted to microscopic phenomena. It is conjectured that they are related to the details of the perceptual chain rather than depending on Planck's action. (shrink)

A central issue of cognitive neuroscience is to understand how a large collection of coupled neurons combines external signals with internal memories into new coherent patterns of meaning. An external stimulus localized at some input spreads over a large assembly of coupled neurons, building up a collective state univocally corresponding to the stimulus. Thus, the synchronization of spike trains of many individual neurons is the basis of a coherent perception. Based on recent investigations of homoclinic chaotic systems and their synchronization, (...) a novel conjecture for the dynamics of single neurons and, consequently, for neuron assemblies is formulated. Homoclinic chaos is proposed as a suitable way to code information in time by trains of equal spikes occurring at apparently erratic times. In order to classify the set of different perceptions, the percept space can be given a metric structure by introducing a distance measure between distinct percepts. The distance in percept space is conjugate to the duration of the perception in the sense that an uncertainty relation in percept space is associated with time-limited perceptions. This coding of different percepts by synchronized spike trains entails fundamental quantum features which are not restricted to microscopic phenomena. It is conjectured that they are related to the details of the perceptual chain rather than depending on Planck's action. (shrink)

Up until only a few decades ago, not many scholars recognized scientific dignity in the problem of consciousness. In the last few years this scenario has changed. The rapid development of non-invasive research techniques that explore cerebral functions has not only increased our knowledge on the correlations between mental processes and cerebral structures, but it has fed our hopes for the possibility of facing the ancient and elusive question about the mind-brain relationship with a new way of thinking. The meeting (...) between neurosciences and phenomenology represents one of the most promising frontiers of current research. Neurophenomenology , a paradigm of research inaugurated by the Chilean neuroscientist Francisco Varela, tries to indicate a remedy to the various explicatory philosophical and scientific gaps, establishing a methodological and epistemological bridge between the so-called phenomenological reports in “first person” and the scientific evidence in “third person,” incorporating the experience on neurodynamic levels in an explicit and rigorous way and, above all, avoiding every alternative in the direction of any form of ontological reduction. (shrink)

All of our information about the world is derived from the function of our senses, and thus they are the principal source of all our knowledge. This was recognized explicitly by early Greek philosophers, remained an important point of discussion for nineteenth‐century philosophers, and continues to be a key issue for present‐day philosophers, psychologists, and neuroscientists. It is a key issue in cognitive science because, by initiating the processes that store and evaluate information, sensory information transmission can be considered a (...) cognitive initiator. In a very real sense, who we are and how we see the world are the result of the experiences that are mediated by our sensory systems. These are some of the reasons why the study of sensory systems has occupied such a prominent place in modern cognitive neuroscience. (shrink)

Opera is a performing art in which music plays the leading role, and the acting of singers has a synergistic effect with the music. The mirror neuron system represents the neurophysiological mechanism underlying the coupling of perception and action. Mirror neuron activity is modulated by the appropriateness of actions and clarity of intentions, as well as emotional expression and aesthetic values. Therefore, it would be reasonable to assume that an opera performance induces mirror neuron activity in the (...) audience so that the performer effectively shares an embodied performance with the audience. However, it is uncertain which aspect of opera performance induces mirror neuron activity. It is hypothesized that although auditory stimuli could induce mirror neuron activity, audiovisual perception of stage performance is the primary inducer of mirror neuron activity. To test this hypothesis, this study sought to correlate opera performance with brain activity as measured by electroencephalography in singers while watching an opera performance with sounds or while listening to an aria without visual stimulus. We detected mirror neuron activity by observing that the EEG power in the alpha frequency band was selectively decreased in the frontal-central-parietal area when watching an opera performance. In the auditory condition, however, the alpha-band power did not change relative to the resting condition. This study illustrates that the audiovisual perception of an opera performance engages the mirror neuron system in its audience. (shrink)

Explores how to identify future-proof science. Peter Vickers takes a transdisciplinary approach in his analysis of 'scientific fact' in order to defend science against potentially dangerous scepticism.

Anders, Rudi They dance in view, they dance in secret. And yet they dance together...