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‘If psychologists can really identify something that deserves to be called perception without awareness, they must have an operational grasp on not only what it takes to perceive something, but on what it takes to be conscious of it.
Dretske, 2006 p. 148
What does it take to perceive something?
What does it take to be conscious of something?
What, if anything, can we conclude about the function of consciousness?
key source:
Dretske, Fred. Perception without awareness. In T. S. Gendler and J. O. Hawthorne, editors, Perceptual Experience, pages 147–180. OUP, Oxford, 2006. [available via the library]
Dretske, master of distinctions
Perception without Awareness
Type 1 : You perceive it but are unaware of some fact about it
Type 2 : You perceive an object but are unaware of it.
‘Perception without awareness, unconscious perception, is therefore to be understood as perception of some object without awareness (conscious) of that object.’
Operationalising Visual Awareness
‘If psychologists can really identify something that deserves to be called perception without awareness, they must have an operational grasp on not only what it takes to perceive something, but on what it takes to be conscious of it.
Dretske, 2006 p. 148
blindsight:
infer perception from discrimination of visual stimuli
we infer lack of awareness from the subject’s reports
‘If psychologists can really identify something that deserves to be called perception without awareness, they must have an operational grasp on not only what it takes to perceive something, but on what it takes to be conscious of it.
Dretske, 2006 p. 148
blindsight:
infer perception from discrimination of visual stimuli
we infer lack of awareness from the subject’s reports
Can you perceive something without being perceptually aware of it?
Yes : Sidis
Yes : blindsight???
Weiskrantz et al, figure 2
Awareness makes no measurable difference to action.
‘the claim that blindsight involves unconscious perception is largely based on a dissociation between responding in a biased task and performance in an unbiased forced-choice task’
Phillips, 2016 p. 435
Weiskrantz et al, figure 2
‘the claim that blindsight involves unconscious perception is largely based on a dissociation between responding in a biased task and performance in an unbiased forced-choice task’
Phillips, 2016 p. 435
‘He was insistently instructed, and frequently reminded, that he was to signal unaware only when he had absolutely no sensation or feeling or experience of the visual event, and he repeatedly confirmed his conformance with this instruction’
Weiskrantz et al, 1995 p. 6122
Never trust a philosopher!
Can you perceive something without being perceptually aware of it?
Yes : Sidis
Yes : blindsight???
‘If psychologists can really identify something that deserves to be called perception without awareness, they must have an operational grasp on not only what it takes to perceive something, but on what it takes to be conscious of it.
Dretske, 2006 p. 148
blindsight:
infer perception from discrimination of visual stimuli
we infer lack of awareness from the subject’s reports
‘objective criteria’
‘According to ‘objective’ criteria, unaware perception occurs when a subject’s performance in a forced-choice task is at chance’
Pessoa et al, 2005 p. 190
I.e. any discrimination is evidence for perceptual awareness.
'Above-chance performance on a forced-choice task involving the masked stimulus need not necessarily be due to conscious knowledge'
Timmermans & Cleeremans, 2015 p. 27
'The challenge of measuring awareness based on behavioral measures, despite the substantial progress achieved over the years, remains essentially intact'
Timmermans & Cleeremans, 2015 p. 40
awareness : Dretske’s proposal
‘rTa: S is aware of X = S perceives X, and information about X is available to S as a reason (justification) for doing what she wants (chooses, decides) to do’
‘If psychologists can really identify something that deserves to be called perception without awareness, they must have an operational grasp on not only what it takes to perceive something, but on what it takes to be conscious of it.
Dretske, 2006 p. 148
blindsight:
infer perception from discrimination of visual stimuli
we infer lack of awareness from the subject’s reports
we infer lack of awareness from information not being available to the subject as a reason for action
Dretske’s Beautiful Theory
Can there be perception without awareness?
We infer perception from
information about the thing being in the subject
... and available for the control and guidance of action
... and being extracted from stimulation [...] by
‘accredited receptor systems’
We infer lack of awareness from
information not being available to the subject as a reason for action
What are the functions of perceptual awareness?
Perceptual awareness enables you to act for reasons.
(NOT: Perceptual awareness enables you to act.)
a problem
How perceptual awareness is actually operationalised in Weiskranz et al, 1995:
we infer lack of awareness from the subject’s reports
How perceptual awareness should be operationalised according to Dretske, 2006:
we infer lack of awareness from information not being available to the subject as a reason for action
conclusion
What are the functions of perceptual awareness?
Wrong? : Perceptual awareness enables control of action.
Right? : Perceptual awareness enables you to act for reasons.
Can you perceive something without being perceptually aware of it?
Depending on operationalisation ...
blindsight provides evidence that you can.
extra bit
A Process Dissociation Approach to Perception without Awareness
Theoretical point: we shouldn’t expect conscious and nonconscious processes to dissociate cleanly, every effect can be influenced by both.
Debner & Jacoby, 1994
A Task
Stem : tab
Completions : table / taboo
Inclusion task : if you see ‘table’ , use this as the completion for ‘tab’
Exclusion task : if you see ‘table’ , DO NOT use this as the completion for ‘tab’
| task | effect of perceptual awareness on performance | effect of nonconscious perception on performance |
| Inclusion (use the word to complete the stem) | facilitates | facilitates |
| Exclusion | facilitates | impairs |
How perceptual awareness should be operationalised according to Dretske, 2006:
we infer lack of awareness from information not being available to the subject as a reason for action
dividing attention : 23 table 37
Key finding: dividing attention impairs perceptual awareness without affecting nonconscious perception
Conclusion: there is perception without awareness
a problem
How perceptual awareness is actually operationalised in Weiskranz et al, 1995:
we infer lack of awareness from the subject’s reports
How perceptual awareness is actually operationalised in Debner & Jacoby, 1994:
see Dretske!
How perceptual awareness should be operationalised according to Dretske, 2006:
we infer lack of awareness from information not being available to the subject as a reason for action
skip
‘the Mere Motley model of conscious perceptual experience. According to this model the phrase ‘conscious visual experience’ is just a rough and ready label for a typically integrated, but potentially highly dissociable, complex of capacities’
‘Conscious visual experience, if such views are correct, is not usefully understood via the metaphor of a single inner light that is either on or off but consists instead in a motley swathe of surprisingly dissociable elements and effects, relative to which pressing the simple binary question (“is conscious visual experience occurring or not?”) is just a recipe for trouble and confusion’
Clark 2009, p. 1467
todo
‘ using the relationship between confidence and accuracy to assess awareness. Subjects discriminated among stimuli and indicated their confidence in each discrimination response. Subjects were classified as being aware of the stimuli if their confidence judgments predicted accuracy and as being unaware if they did not. ’
\citep{kunimoto:2001_confidence}
Phillips agains blindisght
‘The emphasis on residual visual functioning in the absence of acknowledged awareness (type-1 blindsight) often led people to overlook the fact that certain stimuli can elicit awareness in a subject’s blind field. This residual visual awareness has become known as ‘type-2 blindsight’ (Weiskrantz, Barbur, & Sahraie, 1995), and has been interpreted in many different ways. It is still common to make the error of thinking that there are ‘type-1 (standard) blindsight subjects’, and another subset of people, also with damage to V1, who are ‘type-2 blindsight subjects’. However, the proper distinction is not between different subjects, but rather between different conditions of stimulus presentation. Most subjects with blindsight, whose lesions do not extend to the extrastriate cortex, have ‘type-1 blindsight’ under some stimulus conditions and have ‘type-2 blindsight’ under others’
‘It is not at all clear that blindsight subjects’ residual experiences are visual in nature’
Dretske’s Criteria for Perception and Awareness
perception
‘(1) the information in these states should be available for the control and guidance of action (if the experience is unconscious, of course, the actor need not be aware of this influence); and (2) the information should be extracted from stimulation (as it is with conscious experiences) by accredited receptor systems.’
‘Tp: S perceives x = S has a perceptual experience (in our special inclusive sense) that provides (in a direct way) information about x’
awareness
‘rTa: S is aware of X = S perceives X, and information about X is available to S as a reason (justification) for doing what she wants (chooses, decides) to do’