research

Conscious experiences are rich. Yet they exclude a lot too. Lots of information that's processed unconsciously never makes it into experience. What information gets in for each kind of experience (visual, auditory, emotional, etc.)? Why does that information get in, while much is left out? And what can answers to these questions tell us about the nature and role of experiences? My research aims to shed light on these questions.

 

Unconscious processing shapes experience in many ways. Here are two ways that especially interest me:

 

  1. EncapsulationInformation processed unconsciously in perception is substantially--but not entirely--encapsulated from information processed by other systems (e.g. cognition). For example, in a persistent visual illusion, one’s knowledge of the illusion does not prevent or correct it. However, perceptual processing is influenced in some ways from the outside.  

  2. Precision. For many features represented in experience, there's evidence that the brain unconsciously maintains and updates a range of best guesses, weighted according to their probability. Rather than include all these competing guesses and probabilities for each feature, it usually seems that experiences include much less information. For example, your visual system represents the size of a nearby object. It unconsciously maintains a distribution over a range of sizes. But visual experiences would seem to represent the object as having some size or other--at least when you're attending the object in the center of your visual field. Still, there are ways in which your experiences can seem less precise. For example, experience of objects in the periphery is less precise than experience of objects centrally. Experience of objects in a fog is less precise than experience of objects in clear conditions.    

In a series of papers related to encapsulation, I have addressed the possibility of top-down effects on perceptual processing and experience, especially so-called cognitive penetration. One can model potential top-down effects using hierarchical probabilistic frameworks in which local top-down and bottom-up messages are pervasive in perceptual processing. I’ve argued that top-down processing in perceptual pathways is importantly different from top-down processing in motor pathways (Vance 2017). I’ve argued that, if it occurs, cognitive penetration of perceptual processing is sometimes bad (Vance 2014) and sometimes good (Vance 2015b). I’ve argued that some hierarchical probabilistic accounts of cognitive penetration fail to explain central putative cases of cognitive penetration (Vance & Stokes 2017) and also fail to account for cases of cognitive impenetrability such as known illusions (Vance 2015a). These arguments help shed light on how perceptual experiences are formed as the result of complex processing, some of which is top-down. And they shed light on the role of experiences as rational grounds for belief and as guides for action.

In another project related to precision, I investigate how and why experiences can seem more or less clear or precise. There’s evidence that perceptual systems unconsciously encode probabilistic information and that much of the information does not feature explicitly in experience. In my view, the statistical property of precision in sensory signals helps explain the varying levels of clarity in experiences. Precision can be modeled in terms of the variance of unconscious distributions in perceptual processing (variance is the reciprocal of statistical precision). The view that sensory precision shapes experiences such as blurry vision is supported by successful models in perception science. Precision in a related (but distinct) sense is the opposite of vagueness. In recent work, I argue that there is a kind of vagueness inherent in experiences. Perceptual vagueness shares some features with linguistic vagueness. However, perceptual vagueness also differs from linguistic vagueness in some interesting ways. Thinking about the vagueness and precision of experience encourages us to rethink the nature and role of experiences in several ways. Most modeling in vision science assumes that the upshots of perceptual processing are determinate, distal, feature representations. Vague perception suggests that there may be more to perceptual experience than determinate, distal, feature representation: experiences may also reflect underlying uncertainty in perceptual processing. In addition, reflection on vague perception raises new questions for theories of the representational contents of experience.  

Much of my work has been on visual processing and visual experiences. But I also work on processing and experiences in other sensory modalities, in emotion, and elsewhere. I'm interested in accounting for processing and experiences of all kinds. On this score, I have written about top-down effects in emotion (Vance 2014) and proprioception (Vance 2017). I’ve also written about whether emotional experiences are partly constituted by their subject's rationally evaluable commitments and what light that question might shed on the rational evaluation of perceptual experience (Vance 2018a).

Finally, I have an emerging interest in the psychology, neuroscience, and philosophy of self-representation. I've published one short paper in this area so far (Vance 2018b), and plan to publish more on the self in the coming years. 

 

For links to the papers referenced above, check out my Papers page.