Organizers
This event is supported by York University’s Department of Philosophy, Vision: Science to Applications (VISTA) program, and Centre for Vision Research, and by Johns Hopkins University's William H. Miller III Department of Philosophy and Vision Sciences Group.
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The past decade has seen a resurgence in conversation between vision science and philosophy of perception on questions of fundamental interest to both fields, such as: What do we see? What is seeing for? What makes seeing different from remembering, deciding or imagining? But opportunities for conversation between vision scientists and philosophers are still hard to come by. The phiVis workshop is a forum for promoting and expanding this interdisciplinary dialogue. Philosophers of perception can capitalize on the experimental knowledge of working vision scientists, while vision scientists can take advantage of the opportunity to connect their research to long-standing philosophical questions.
Short talks by philosophers of perception that engage with the latest research in vision science will be followed by discussion with a slate of vision scientists, on topics such as probabilistic representation in perception, perceptual constancy, amodal completion, multisensory perception, visual adaptation, and much more.
Schedule
Chairs:
Kevin Lande (York)
Chaz Firestone (Johns Hopkins)
12:30PM
Opening remarks
- Kevin Lande (York University)
- Chaz Firestone (Johns Hopkins)
12:35PM
Ian Phillips (Johns Hopkins) | From Inattentional Blindness to Blindsight: Why Degraded Awareness (Not Unconscious Perception) Should Be Our Default Hypothesis.
The last fifty years of vision science have witnessed the apparent overthrow of many cherished beliefs about perception—challenging both philosophical orthodoxy and commonsense commitments. To take two celebrated examples. First, studies of inattentional blindness (IB; Neisser & Becklen, 1975; Mack & Rock, 1998; Most et al., 2001, 2005) seem to demonstrate that, without attention, awareness is completely abolished. Second, investigations of blindsight appear to show that awareness is quite unnecessary for sophisticated, intentional responding (Pöppel et al., 1973; Weiskrantz et al., 1974; Weiskrantz, 1997; Cowey, 2010). Unsurprisingly, such phenomena have had enormous influence on philosophical thinking, downgrading the scope and significance of perceptual awareness, and motivating a range of different theories of consciousness and cognition. However, although quite different, interpretations of both phenomena rely on a notoriously biased measure of awareness: asking subjects whether they saw or noticed – and taking their word at face value. I begin casting doubt on this measure by summarizing the results of the largest ever set of IB studies conducted (Nartker et al., in prep.). Collectively, these show: (a) that inattentionally blind participants can successfully report the location, color and shape of stimuli they deny noticing; and (b) that participants in IB studies are systematically biased to report not noticing. These results motivate an alternative conception of IB on which inattention does not abolish, but rather degrades awareness (which goes unreported due to conservative response criteria). In light of this evidence of residual sensitivity under inattention, I compare IB and blindsight. I argue that rather than seeing blindsight as a model for interpreting residual sensitivity in IB as unconscious after all, we should—in both cases—adopt a degraded awareness account as our default hypothesis.
- Comments from Jeremy Wolfe (Harvard)
- Q&A
1:10PM
Rosa Cao (Stanford) | Comparing Brains and Models: What Matters for Similarity?
Evaluating the similarity between models and their targets is crucial for determining the goodness of a model (cf. recent discussions of "representational alignment"). But similarity is a tricky notion, one that has been difficult to formalize in terms flexible enough to be useful, but not so open as to become completely subjective. (Goodman 1972, Tversky 1977, Gardenfors 2000, Weisberg 2012). The problem is that evaluating similarity seems to require a perspective – but how do we decide what is the right perspective to privilege? By considering similarity from the perspective of downstream users, we can identify which properties are relevant for comparison (and which may be safely ignored). Inputs that result in the same output after transformation are functionally identical from the perspective of the downstream area. So an intuitive way to assess similarity of two inputs is to look beyond linear predictivity, or statistical summaries such as RSA, and focus more specifically on what is done with those inputs downstream. If what a downstream area (D) does can be fully functionally characterized by the transformation T that it performs on its input to produce its output in turn, then T is also the transform that we should use to assess similarity of inputs to D. Some consequences of this way of thinking: how we measure similarity will differ from context to context – the way we assess a model of rodent hippocampus might require a different mapping of model to target than when we assess a model of primate visual areas. It may turn out that downstream processing is actually similar enough that we can use the same approximate transformations across different brain areas or model layers. But it is an empirical question which differences are ones that make a difference, and which may be ignored for functional purposes.
- Comments from Talia Konkle (Harvard)
- Q&A
1:45PM
Tiina Rosenqvist (Dartmouth) | Seeing with Color: Psychophysics and the Function of Color Vision
What is the function of color vision? Focusing on perceptual phenomena studied in psychophysics, I argue that the best explanation for these phenomena is that the color visual system is a perceptual enhancement system. I first introduce two rival conceptions of the function of color vision: (i) that color vision aims to detect or track the fine-grained colors of distal objects and scenes (Seeing Color) and (ii) that it aims to help organisms discriminate, detect, track and/or recognize ecologically important objects, properties, and relations more directly (Seeing with Color). I then discuss two kinds of systematic perceptual phenomena investigated by psychophysicists: approximate color constancy and color induction. I argue from the premise that Seeing with Color better accommodates and explains these phenomena to the conclusion that it is the conception that both empirically-guided philosophers and vision scientists ought to adopt.