In his ecological approach to perception, james gibson introduced the concept of affordance to refer to the perceived meaning of environmental objects and events. this paper examines the relational and causal character of affordances, as well as the grounds for extending affordances beyond environmental features with transcultural meaning to include those features with culturally-specific meaning. such an extension is seen as warranted once affordances are grounded in an intentional analysis of perception. toward this end, aspects of merleau-ponty's treatment (...) of perception are explored. finally, a resolution of the apparent tension between the relational and perceiver-independent nature of affordances is presented. (shrink)
The two contrasting theoretical approaches to visualperception, the constructivist and the ecological, are briefly presented and illustrated through their analyses of space and size perception. Earlier calls for their reconciliation and unification are reviewed. Neurophysiological, neuropsychological, and psychophysical evidence for the existence of two quite distinct visual systems, the ventral and the dorsal, is presented. These two perceptual systems differ in their functions; the ventral system's central function is that of identification, while the dorsal system (...) is mainly engaged in the visual control of motor behavior. The strong parallels between the ecological approach and the functioning of the dorsal system, and between the constructivist approach and the functioning of the ventral system are noted. It is also shown that the experimental paradigms used by the proponents of these two approaches match the functions of the respective visual systems. A dual-process approach to visualperception emerges from this analysis, with the ecological-dorsal process transpiring mainly without conscious awareness, while the constructivist-ventral process is normally conscious. Some implications of this dual-process approach to visual-perceptual phenomena are presented, with emphasis on space perception. Key Words: constructivist; dual-process approach; ecological; size perception; space perception; two visual systems; visualperception theories. (shrink)
This paper argues that a common form of representationalism has trouble accommodating empirical findings about visual space perception. Vision science tells us that the visual system systematically gives rise to different experiences of the same spatial property. This, combined with a naturalistic account of content, suggests that the same spatial property can have different veridical looks. I use this to argue that a common form of representationalism about spatial experience must be rejected. I conclude by considering alternatives (...) to this view. (shrink)
Fodor & Pylyshyn (1981) criticize J. J. Gibson's ecological account of perception for failing to address what I call the 'correlation problem' in visualperception. That is, they charge that Gibson cannot explain how perceivers learn to correlate detectable properties of the light with perceptible properties of the environment. Furthermore, they identify the correlation problem as a crucial issue for any theory of visualperception, what I call a 'primary problem'—i.e. a problem which plays a (...) definitive role in establishing the concerns of a particular scientific research program. If they are correct, Gibson's failure to resolve this problem would cast considerable doubt upon his ecological approach to perception. In response, I argue that both Fodor & Pylyshyn's problem itself and their proposed inferential solution embody a significant mistake which needs to be eliminated from our thinking about visualperception. As part of my response, I also suggest a Gibsonian alternative to Fodor & Pylyshyn's primary problem formulation. (shrink)
A range of arguments are presented to demonstrate that (1) human visual orientations are conceptually constituted (concept?bound); (2) the concept?boundedness of visual orientations does not require a cognitivist account according to which a mental process of ?inference? or of ?interpretation? must be postulated to accompany a purely ?optical? registration of ?wavelengths of light?, ?photons?, or contentless ?information'; (3) concept?bound visual orientations are not all instances of ?seeing as?, contrary to some currently prominent cognitivist accounts; (4) the dispute (...) between cognitivist and realist accounts about the phenomenon of ?seeing as? is spurious, and is based upon a confusion about the fundamental analytical distinction made by Wittgenstein between ?seeing? and ?seeing as'; (5) ?perceiving?, ?seeing?, and ?seeing as? are but three of a large array of verbs of human visual orientation, and are not ?master categories? under which one can subsume these other modalities; (6) one cannot deduce a continuity of human visual orientation from a continuity of photon?photoreceptor interaction, a point we characterize as the ?staggered character? of human visual orientations; (7) detailed attention to the grammars of the diverse verbs of human visual orientation can open up a domain of study which we here refer to as a ?praxiology of perception'; (8) the nature of such an inquiry can be illustrated with exemplary reference to the analysis of the properties of ?noticing? as embedded in courses of practical action; and (9) such arguments, which claim that existing perceptual theories overly homogenize what is involved in visual orientations to the world, parallel those of Stroll, who proposes that standard accounts of ?what is perceived? overly homogenize the perceptible environment. (shrink)
In this paper I present a transcendental argument based on the findings of cognitive psychology and neurophysiology which invites two conclusions: First and foremost, that a pre-condition of visualperception itself is precisely what the Aristotelian and other commonsense realists maintain, namely, the independent existence of a featured, or pre-packaged world; second, this finding, combined with other reflections, suggests that, contra McDowell and other neo-Kantians, human beings have access to things as they are in the world via non-projective (...)perception. These two conclusions taken together form the basis of Aristotelian metaphysical realism and a refutation of the neo-Kantian two-factor approach to perception. (shrink)
This paper advances a novel argument that speech perception is a complex system best understood nonindividualistically and therefore that individualism fails as a general philosophical program for understanding cognition. The argument proceeds in four steps. First, I describe a "replaceability strategy", commonly deployed by individualists, in which one imagines replacing an object with an appropriate surrogate. This strategy conveys the appearance that relata can be substituted without changing the laws that hold within the domain. Second, I advance a "counterfactual (...) test" as an alternative to the replaceability strategy. Third, I show how the typical objects of cross-modal processes (in this case, auditory-visual speech perception), more clearly irreplaceable than the objects of the unimodal process examined by Burge [(1986) Individualism and psychology, The Philosophical Review, XCV, 3-45], supply a firm basis for a nonindividualist interpretation of such cases. Finally, I demonstrate that the routine violation of the individualist's Replaceability Condition occurs even in unimodal cases - so the violation of the replaceability constraint does not derive simply from the diversity of modal sources but rather from the causal complexity of psychological processes generally. The conclusion is that philosophical progress on this issue must await progress in psychology, or, at least, philosophical progress in accounting for psychological complexity--precisely the vicissitude predicted by a thoroughgoing naturalism. (shrink)
How a visual stimulus is initially categorized as a face in a network of human brain areas remains largely unclear. Hierarchical neuro-computational models of face perception assume that the visual stimulus is first decomposed in local parts in lower order visual areas. These parts would then be combined into a global representation in higher order face-sensitive areas of the occipito-temporal cortex. Here we tested this view in fMRI with visual stimuli that are categorized as faces (...) based on their global configuration rather than their local parts (2-tones Mooney figures and Arcimboldo’s facelike paintings). Compared to the same inverted visual stimuli that are not categorized as faces, these stimuli activated the right middle fusiform gyrus (“Fusiform face area”, FFA) and superior temporal sulcus (pSTS), with no significant activation in the posteriorly located inferior occipital gyrus (i.e., no “occipital face area”, OFA). This observation is strengthened by behavioral and neural evidence for normal face categorization of these stimuli in a brain-damaged prosopagnosic patient (PS) whose intact right middle fusiform gyrus and superior temporal sulcus are devoid of any potential face-sensitive inputs from the lesioned right inferior occipital cortex. Together, these observations indicate that face-preferential activation may emerge in higher order visual areas of the right hemisphere without any face-preferential inputs from lower order visual areas, supporting a non-hierarchical view of face perception in the visual cortex. (shrink)
There is a wide range of acoustic and visual variability across different talkers and different speaking contexts. Listeners with normal hearing accommodate that variability in ways that facilitate efficient perception, but it is not known whether listeners with cochlear implants can do the same. In this study, listeners with normal hearing (NH) and listeners with cochlear implants (CIs) were tested for accommodation to auditory and visual phonetic contexts created by gender-driven speech differences as well as vowel coarticulation (...) and lip rounding in both consonants and vowels. Accommodation was measured as the shifting of perceptual boundaries between /s/ and /ʃ/ sounds in various contexts, as modeled by mixed-effects logistic regression. Owing to the spectral contrasts thought to underlie these context effects, CI listeners were predicted to perform poorly, but showed considerable success. Listeners with cochlear implants not only showed sensitivity to auditory cues to gender, they were also able to use visual cues to gender (i.e. faces) as a supplement or proxy for information in the acoustic domain, in a pattern that was not observed for listeners with normal hearing. Spectrally-degraded stimuli heard by listeners with normal hearing generally did not elicit strong context effects, underscoring the limitations of noise vocoders and/or the importance of experience with electric hearing. Visual cues for consonant lip rounding and vowel lip rounding were perceived in a manner consistent with coarticulation and were generally used more heavily by listeners with CIs. Results suggest that listeners with cochlear implants are able to accommodate various sources of acoustic variability either by attending to appropriate acoustic cues or by inferring them via the visual signal. (shrink)
In recent years, a pair of intriguing phenomena has caused researchers working on vision and visual attention to reevaluate many of their assumptions. These phenomena, which have come to be called change blindness (CB) and inattentional blindness (IB), have led many to the conclusion that ordinary perceivers labor under a ``grand illusion'' concerning perception - an illusion that is..
A traditional view of perception and action makestwo assumptions: that the causal flow betweenperception and action is primarily linear or one-way,and that they are merely instrumentally related toeach other, so that each is a means to the other.Either or both of these assumptions can be rejected.Behaviorism rejects the instrumental but not theone-way aspect of the traditional view, thus leavingitself open to charges of verificationism. Ecologicalviews reject the one-way aspect but not theinstrumental aspect of the traditional view, so thatperception (...) and action are seen as instrumentallyinterdependent. It is argued here that a betteralternative is to reject both assumptions, resultingin a two-level interdependence view in whichperception and action co-depend on dynamicallycircular subpersonal relations and as a result may bemore than merely instrumentally interdependent. Thisis illustrated by reference to motor theories ofperception and control theories of action. (shrink)
The neural substrate of early visual processing in the macaque is used as a framework to discuss recent progress towards a precise anatomical localization and understanding of the functional implications of the syndromes of blindsight, achromatopsia and akinetopsia in humans. This review is mainly concerned with how these syndromes support the principles of organization of the visual system into parallel pathways and the functional hierarchy of visual mechanisms.