Online research in philosophy

I. The framework. 1, Aristotle's project and methods. 2, The perceptual capacity of the soul. 3, The sensory apparatus. 4, The common sense and the related capacities -- II. The terminology. 1, Overlooked occurrences of the phrase 'common sense'. 2, De anima III.1 425a27. 3, De partibus animalium IV.10 686a31. 4, De memoria et reminiscentia 1 450a10. 5, De anima III.7 431b5. 6, Conclusions on the terminology -- III. Functions of the common sense. 1, Simultaneous perception and cross-modal binding. 2, Perceptual discrimination. 3, Waking, sleep, and control of the senses. 4, Perceiving that what we see and hear, and monitoring of the senses. 5, Other roles of the common sense -- Conclusion.

Illusions are thought to make trouble for the intuition that perceptual experience is "open" to the world. Some have suggested, in response to the this trouble, that illusions differ from veridical experience in the degree to which their character is determined by their engagement with the world. An understanding of the psychology of perception reveals that this is not the case: veridical and falsidical perceptions engage the world in the same way and to the same extent. While some contemporary vision scientists propose to draw the distinction between veridical experience and illusion in terms of the satisfaction or non-satisfaction of “hidden assumptions” deployed in the course of normal perceptual inference, I argue for a different approach. I contend that there are, in a sense, no illusions – illusions are as “open” as veridical experiences. Percepts lack the kinds of intentional content that would be needed for perceptual misrepresntation. My view gives a satisfying solution to a philosophical problem for disjunctivism about the good case/bad case distinction: with respect to illusions, every "bad case" of seeing an X can be equally well construed as a "good case" of seeing some Y (different from X).

We can perceive shapes visually and tactilely, and the information we gain about shapes through both sensory modalities is integrated smoothly into and functions in the same way in our behavior independently of whether we gain it by sight or touch. There seems to be no reason in principle we couldn't perceive shapes through other sensory modalities as well, although as a matter of fact we do not. While we can identify shapes through other sensory modalities—e.g., I may know by smell (the scent of mango) that the object causing my sensory experience is round—this is not perceiving an object as shaped, but rather inferring from the character of one's sensory experience and collateral information that an object of a certain shape caused it. That it is possible to perceive shape by other modalities, however, is suggested by the case of bats and aquatic mammals like dolphins which navigate through their environment by a form of sonar. It is plausible that they have some form of auditory representation of space, and so of shape. These facts about shape perception raise important questions about the relation between those features of perceptual experience which are intrinsic to different sensory modalities and the nature of our perceptual representation of shapes, and, more generally, of the space within which we perceive shaped objects to be located. John Campbell's paper, "Molyneux's Problem" (see above), raises a number of interesting and important questions about the nature of our perception of shape properties, particularly the cross-modal nature of shape perception, and ties them to more general questions about the nature both of perceptual..

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Abstract: Vision dominates philosophical thinking about perception, and theorizing about experience in cognitive science traditionally has focused on a visual model. This book presents a systematic treatment of sounds and auditory experience. It demonstrates how thinking about audition and appreciating the relationships among multiple sense modalities enriches our understanding of perception. It articulates the central questions that comprise the philosophy of sound, and proposes a novel theory of sounds and their perception. Against the widely accepted philosophical view that sounds are among the secondary or sensible qualities, and against the scientific view that sounds are waves that propagate through a medium such as air or water, the book argues that sounds are events in which objects or interacting bodies disturb a surrounding medium. This does not imply that sounds propagate through a medium, such as air or water. Rather, sounds are events that take place in one's environment at or near their sources. This account captures the way in which sounds essentially are creatures of time and situates sounds in the world. Sounds are not ethereal, mysterious entities. It also provides a powerful account of echoes, interference, reverberation, Doppler effects, and perceptual constancies that surpasses the explanatory richness of alternative theories. Investigating sounds and audition demonstrates that considering other sense modalities teaches what we could not otherwise learn from thinking exclusively about the visual. This book concludes by arguing that a surprising class of cross-modal perceptual illusions demonstrates that the perceptual modalities cannot be completely understood in isolation, and that a visuocentric model for theorizing about perception — according to which perceptual modalities are discrete modes of experience and autonomous domains of philosophical and scientific inquiry — ought to be abandoned.

Synesthesia is a condition in which stimulation in one modality also gives rise to a perceptual experience in a second modality. In two recent studies we found that the condition is more common than previously reported; up to 5% of the population may experience at least one type of synesthesia. Although the condition has been traditionally viewed as an anomaly (e.g., breakdown in modularity), it seems that at least some of the mechanisms underlying synesthesia do reflect universal cross-modal mechanisms. We review here a number of examples of cross-modal correspondences found in both synesthetes and non-synesthetes including pitch-lightness and vision-touch interaction, as well as cross-domain spatial- numeric interactions. Additionally, we discuss the common role of spatial attention in binding shape and color surface features (whether ordinary or synesthetic color). Consistently with behavioral and neuroimaging data showing that chromatic-graphemic (colored-letter) synesthesia is a genuine perceptual phenomenon implicating extrastriate cortex, we also present electrophysiological data showing modulation of visual evoked potentials by synesthetic color congruency.

This paper provides a categorization of cross-modal experiences. There are myriad forms. Doing so allows us to think clearly about the nature of different cross-modal experiences and allows us to clearly formulate competing hypotheses about the kind of experiences involved in different cross-modal phenomena.

Modality specificity in priming is taken as evidence for independent perceptual systems. However, Easton, Greene, and Srinivas (1997) showed that visual and haptic cross-modal priming is comparable in magnitude to within-modal priming. Where appropriate, perceptual systems might share like information. To test this, we assessed priming and recognition for visual and auditory events, within- and across- modalities. On the visual test, auditory study resulted in no priming. On the auditory priming test, visual study resulted in priming that was only marginally less than within-modal priming. The priming results show that visual study facilitates identification on both visual and auditory tests, but auditory study only facilitates performance on the auditory test. For both recognition tests, within-modal recognition exceeded cross-modal recognition. The results have two novel implications for the understanding of perceptual priming: First, we introduce visual and auditory priming for spatio-temporal events as a new priming paradigm chosen for its ecological validity and potential for information exchange. Second, we propose that the asymmetry of the cross-modal priming observed here may reflect the capacity of these perceptual modalities to provide cross-modal constraints on ambiguity. We argue that visual perception might inform and constrain auditory processing, while auditory perception corresponds to too many potential visual events to usefully inform and constrain visual perception.

I argue that a class of recently-discovered cross-modal illusions gives reason to posit a dimension of content shared across perceptual modalities and to abandon the traditional view according to which perceptual content is exclusively constituted by discrete modality-specific contents.