Type 2 blindsight and the nature of visual experience.
Consciousness and cognition March 1, 2015 DOI: 10.1016/j.concog.2014.09.017 via PubMed
Summary
AI-generated from the abstractPeople with type 2 blindsight, caused by damage to the primary visual cortex (V1), have some residual visual awareness, but their experience lacks three features often considered essential to ordinary vision: particularity (being directed at specific objects), transparency (the sense of seeing through to the world), and fine-grainedness (detailed sensory content). This case challenges the view that these characteristics are necessary for veridical visual experience and undermines the idea that visual experience is fundamentally a perceptual relation to external objects. The paper also argues that type 2 blindsight reveals how attentional modulation affects perceptual content, and that such modulation does not conflict with the claim that the phenomenology of visual experience arises from its content.
Study at a glance
| Characteristics | Theoretical or philosophical paper Peer reviewed |
|---|---|
| Keywords | Direct realism Particularity of vision Phenomenal consciousness Type 1 blindsight Type 2 blindsight |
| Citations | 37 |
| Key finding | Type 2 blindsight provides a counterexample to the view that particularity, transparency, and fine-grainedness are essential to veridical visual experience, and gives reason to resist the idea that visual experience is essentially a perceptual relation to external objects. |
Abstract
Blindsight is a kind of residual vision found in people with lesions to V1. Subjects with blindsight typically report no visual awareness, but they are nonetheless able to make above-chance guesses about the shape, location, color and movement of visual stimuli presented to them in their blind field. A different kind of blindsight, sometimes called type 2 blindsight, is a kind of residual vision found in patients with V1 lesions in the presence of some residual awareness. Type 2 blindsight differs from ordinary visual experience in lacking the particularity, transparency and fine-grainedness often taken to be essential to visual experience, at least in veridical cases. I argue that the case of type 2 blindsight provides a counterexample to the view that these characteristics are essential to veridical visual experience and that this gives us reason to resist the view that visual experience is essentially a perceptual relation to external objects. In the second part of the paper I argue that the case of type 2 blindsight yields important insights into the effects of attentional modulation on perceptual content and that cases of attentional modulation of appearance are not at odds with the view that the phenomenology of visual experience flows from its content.