In tactile-visual sensory substitution (TVSS), images from a video camera are converted into patterns of vibrotactile stimulation that visually impaired subjects can use to perform tasks ordinarily guided by seeing. A main finding in early experiments conducted by Paul Bach-y-Rita and colleagues is that subjects equipped with a TVSS device engaged in distal attribution – attributed the cause of the stimulations they received to objects in the external, three-dimensional scene – only when they had active control over how the (...) camera moved. Subjects who received visual input passively experienced only a changing pattern of tactile stimulation. Why was this the case? According to proponents of the sensorimotor contingency theory, active control of the camera is necessary for the emergence of distal attribution because it enables the subject to acquire knowledge of the laws of sensorimotor contingency that govern use of the TVSS device. This chapter, by contrast, approaches distal attribution as a solution to a causal inference problem faced by the subject’s perceptual systems. Given all of the available endogenous and exogenous evidence available to those systems, what is the most probable source of stimulation in the substituting modality? From this perspective, active control over the camera’s movements matters for rather different reasons. First, when the subject is unaware of how (or even whether) the camera is moving, all of the evidence at her disposal is consistent with the default haptic interpretation of incoming vibrotactile stimulation: the most probable cause of that stimulation is bodily contact with an object of some kind. It is thus unsurprising that a passively stimulated subject does not learn to discriminate the spatial layout of the external scene by means of TVSS. Second, when the subject has the ability to guide camera movement, she also has a significant amount of voluntary control over whether and how incoming vibrotactile stimulation undergoes change. In consequence, the situation is now one that conflicts with the default haptic interpretation: it is not typically possible to modify sensations on the surface of one’s back by moving a camera mounted on a tripod or on one’s head. Last, active control over the camera’s movements generates proprioceptive and efference-copy based information about the camera’s body-relative position necessary to make use of the spatial cues present in the stimulation that the subject receives for purposes of egocentric object localization. (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 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)
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)
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?
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?
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?
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)
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?
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)
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?
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?
This is an excerpt from a report on the Sensory Substitution and Augmentation Conference at the British Academy in March of 2013. This portion of the report explores the question: How does sensory substitution interact with the brain’s architecture?
This is an excerpt from a report on the Sensory Substitution and Augmentation Conference at the British Academy in March of 2013. This portion of the report explores the question: What can sensory substitution tell us about perceptual learning?
Several recent accounts claim that imagination is a matter of simulating perceptual acts. Although this point of view receives support from both phenomenological and empirical research, I claim that Jean-Paul Sartre's worry formulated in L'imagination (1936) still holds. For a number of reasons, Sartre heavily criticizes theories in which the sensory material of imaginative acts consists in reviving sensory impressions. Based on empirical and philosophical insights, this article explains how simulation theories of imagination can overcome Sartre's critique by (...) paying attention to the motor dimension of imagination. Intending to clarify the status of the sensory in imagination, a motor theory of imagination is presented in which the sensory component of imagination is interpreted in terms of anticipated sensory consequences of preparation for motor action. (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)
This is an excerpt from a report on the Sensory Substitution and Augmentation Conference at the British Academy in March of 2013. This portion of the report explores the question: Does sensory substitution generate perceptual or cognitive states?
This is an excerpt from a report on the Sensory Substitution and Augmentation Conference at the British Academy in March of 2013. This portion of the report explores the question: Can normal non-sensory feelings be generated through sensory substitution?
This is an excerpt from a report on the Sensory Substitution and Augmentation Conference at the British Academy in March of 2013. This portion of the report explores the question: What are the limitations of sensory substitution.
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)
Enacted theories of consciousness conjecture that perception and cognition arise from an active experience of the regular relations that are tying together the sensory stimulation of different modalities and associated motor actions. Previous experiments investigated this concept by employing the technique of sensory substitution. Building on these studies, here we test a set of hypotheses derived from this framework and investigate the utility of sensory augmentation in handicapped people. We provide a late blind subject with a new (...) set of sensorimotor laws: A vibro-tactile belt continually signals the direction of magnetic north. The subject completed a set of behavioral tests before and after an extended training period. The tests were complemented by questionnaires and interviews. This newly supplied information improved performance on different time scales. In a pointing task we demonstrate an instant improvement of performance based on the signal provided by the device. Furthermore, the signal was helpful in relevant daily tasks, often complicated for the blind, such as keeping a direction over longer distances or taking shortcuts in familiar environments. A homing task with an additional attentional load demonstrated a significant improvement after training. The subject found the directional information highly expedient for the adjustment of his inner maps of familiar environments and describes an increase in his feeling of security when exploring unfamiliar environments with the belt. The results give evidence for a firm integration of the newly supplied signals into the behavior of this late blind subject with better navigational performance and more courageous behavior in unfamiliar environments. Most importantly, the complementary information provided by the belt lead to a positive emotional impact with enhanced feeling of security. This experimental approach demonstrates the potential of sensory augmentation devices for the help of handicapped people. (shrink)
Daily our central nervous system receives inputs via several sensory modalities, processes them and integrates information in order to produce a suitable behaviour. The amazing part is that such a multisensory integration brings all information into a unified percept. An approach to start investigating this property is to show that perception is better and faster when multimodal stimuli are used as compared to unimodal stimuli. This forms the first part of the present study conducted in a non-human primate’s model (...) (n=2) engaged in a detection sensory-motor task where visual and auditory stimuli were displayed individually or simultaneously. The measured parameters were the reaction time (RT) between stimulus and onset of arm movement, successes and errors percentages, as well as the evolution as a function of time of these parameters with training. As expected, RTs were shorter when the subjects were exposed to combined stimuli. The gains for both subjects were around 20 and 40 msec, as compared with the auditory and visual stimulus alone, respectively. Moreover the number of correct responses increased in response to bimodal stimuli. We interpreted such multisensory advantage through redundant signal effect which decreases perceptual ambiguity, increases speed of stimulus detection and improves performance accuracy. The second part of the study presents single unit recordings derived from the premotor cortex (PM) of the same subjects during the sensory-motor task. Response patterns to sensory/multisensory stimulation are documented and specific type proportions are reported. Characterization of bimodal neurons indicates a mechanism of audio-visual integration possibly through a decrease of inhibition. Nevertheless the neural processing leading to faster motor response from PM as a polysensory association cortical area remains still unclear. (shrink)
Background: This study investigates the effect of altered auditory feedback (AAF) in musician's dystonia (MD) and discusses whether altered auditory feedback can be considered as a sensory trick in MD. Furthermore, the effect of AAF is compared with altered tactile feedback, which can serve as a sensory trick in several other forms of focal dystonia. Methods: The method is based on scale analysis (Jabusch et al. 2004). Experiment 1 employs synchronization paradigm: 12 MD patients and 25 healthy pianists (...) had to repeatedly play C-major scales in synchrony with a metronome on a MIDI-piano with 3 auditory feedback conditions: 1. normal feedback; 2. no feedback; 3. constant delayed feedback. Experiment 2 employs synchronization-continuation paradigm: 12 MD patients and 12 healthy pianists had to repeatedly play C-major scales in two phases: first in synchrony with a metronome, secondly continue the established tempo without the metronome. There are 4 experimental conditions, among them 3 are the same altered auditory feedback as in Experiment 1 and 1 is related to altered tactile sensory input. The coefficient of variation of inter-onset intervals of the key depressions was calculated to evaluate fine motor control. Results: In both experiments, the healthy controls and the patients behaved very similarly. There is no difference in the regularity of playing between the two groups under any condition, and neither did AAF nor did altered tactile feedback have a beneficial effect on patients’ fine motor control. Conclusions: The results of the two experiments suggest that in the context of our experimental designs, AAF and altered tactile feedback play a minor role in motor coordination in patients with musicians' dystonia. We propose that altered auditory and tactile feedback do not serve as effective sensory tricks and may not temporarily reduce the symptoms of patients suffering from MD in this experimental context. (shrink)
Determining if we, or another agent, were responsible for a sensory event can require an accurate sense of timing. Our sense of appropriate timing relationships must, however, be malleable as there is a variable delay between the physical timing of an event and when sensory signals concerning that event are encoded in the brain. One dramatic demonstration of such malleability involves having people repeatedly press a button thereby causing a beep. If a delay is inserted between button presses (...) and beeps, when it is subsequently taken away beeps can seem to precede the button presses that caused them. For this to occur it is important that people feel they were responsible for instigating the beeps. In terms of their timing, as yet it is not clear what combination of events is important for motor-sensory temporal recalibration. Here, by introducing ballistic reaches, of short or longer extent before a button press, we varied the delay between the intention to act and the sensory consequence of that action. This manipulation failed to modulate recalibration magnitude. By contrast, introducing a similarly lengthened delay between button presses and consequent beeps eliminated recalibration. Thus it would seem that the critical timing relationship for motor-sensory temporal recalibration is between tactile signals relating to the completion of an action and the subsequent auditory percept. (shrink)
Olfactory information is critical to mammalian sexual behavior. Based on parental investment theory the relative importance of olfaction compared with vision, touch, and hearing should be different for human males and females. In particular, because of its link to immunological profile and offspring viability, odor should be a more important determinant of sexual choice and arousal for females than for males. To test this hypothesis a questionnaire was developed and administered to 332 adults (166 males, 166 females). Subjects used a (...) 1–7 scale to indicate how much they agreed with a series of statements concerning the importance of olfactory, visual, auditory, and tactile information for their sexual responsivity. The data reveal that males rated visual and olfactory information as being equally important for selecting a lover, while females considered olfactory information to be the single most important variable in mate choice. Additionally, when considering sexual activity, females singled out body odor from all other sensory experiences as most able to negatively affect desire, while males regarded odors as much more neutral stimuli for sexual arousal. The present results support recent findings in mice and humans concerning the relation of female preferences in body odor and major histocompatibility complex (MHC) compatibility and can be explained by an evolutionary analysis of sex differences in reproductive strategies. This work represents the first direct examination of the role of different forms of sensory information in human sexual behavior. (shrink)
In recent years, produce obtained from organic farming methods (i.e. a system that minimizes pollution and avoids the use of synthetic fertilizers and pesticides) has rapidly increased in developed countries. This may be explained by the fact that organic food meets the standard requirements for quality and healthiness. Among organic products, wine has greatly attracted the interest of the consumers. In the present study, trained assessors and regular wine consumers were respectively required to identify the sensory properties (e.g. odor, (...) taste, flavor and mouthfeel sensations) and to evaluate the hedonic dimension of red wines deriving from organically and conventionally grown grapes. Results showed differences related mainly to taste (sour and bitter) and mouthfeel (astringent) sensations, with odor and flavor playing a minor role. However, these differences did not influence liking, as organic and conventional wines were hedonically comparable. Interestingly, 61% of respondents would be willing to pay more for organically produced wines, which suggests that environmentally sustainable practices related to wine quality have good market prospects. (shrink)
Block (Trends Cogn Sci 7:285–286, 2003) and Prinz (PSYCHE 12:1–19, 2006) have defended the idea that SSD perception remains in the substituting modality (auditory or tactile). Hurley and Noë (Biol Philos 18:131–168, 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 (Conscious Cogn 19:492–500, 2010) describe SSD perception as visual-like but characterize it as a kind of artificially induced synaesthesia. Auvray et al. (Perception 36:416–430, 2007) and Auvray and Myin (Cogn Sci 33:1036–1058, 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, MacPherson (Oxford University Press, New York, 2011a) 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 in Oxford University Press, New York, 2011a, p. 139). (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)