Firstpersonapproaches

First Person

Approaches

Plan for today

 Assess new neurophenomenology

movement in consciousness science

 Learning from historical critiques

 Signal Detection Theory

How to measure

consciousness?

 From first class –

 You ask people, right?

 Subjective measures seem obvious

 Behaviours are just behaviours, but

Phenomenological/

Introspective approaches

 Reflect on the contents of their experience

 Training makes you better able to observe

and describe the contents and structure of experience

 Maybe analogous to other scientific training?

 BUT problems arise when subjective reports

are seen as the only proper way to study consciousness

Ramsoy and Overgaard

 History of unconscious perception research

is way more complicated than they suggest….

 Sidis etc 1900 using subjective measures,

problems with subjective measures and introspectionism early 20th Century, Signal

Detection Theory 1950s, resurgence of

subjective measures 1980s, Signal Detection Theory again, and now

Subliminal perception

1. Use some way of ensuring that subjects are not conscious of stimuli

2. Then measure whether stimuli still influence behaviours

 Sometimes use reports for 1, forced choice tasks or priming for 2

 Sometimes use forced choice tasks for 1 and 2

 Sometimes use anaesthesia for 1

Subliminal perception

 Prosopagnosia (inability to recognise faces) – through heightened GSR for familiar faces

Subliminal perception

 All find some degree of processing of a

stimulus in the absence of consciousness of the stimulus

 => Unconscious perception exists!

 But are we really sure that this is

unconscious perception, not just low level conscious perception?

Perceptual Awareness Scale

(PAS)

 Consciousness is graded, but many

response scales are not

 Often dichotomous (conscious or not)

 Response scales also measure the wrong

things

 Difference between performing a task, or

being confident about a response, and

consciously perceiving something more or less clearly

PAS

 Response scale developed using

feedback from subjects

 Supposed to be intuitive and easy to use

 Supposed to better reflect grades of

consciousness than any other scales

 Supposed to uncover cases of low level

PAS

 Subjects shown a stimulus at some

variable stimulus duration

 Subjects first told to report what they

think is presented in terms of shape, colour and position (even if they think nothing is there)

 Then subjects asked to report their

Problems with the PAS (1)

decades to uncover lower grades of perception

 SDT uses graded response scales

 More exhaustive than the PAS

 Used to routinely identify cases of low level conscious perception

 PAS is not new, and objective measures are now

PAS Problems (3)

 Using the PAS requires training

 Introspective training has a bad history in psychology (as we saw earlier)

 Responses are always biased, training

gives you different ones

Dodge 1912

 “No psychological scheme has been too

absurd to be supported by introspection. It shows fashions like hysteria and the

delusions of the insane. Even the

fundamental categories of consciousness change with the years, while new and

previously totally unsuspected facts may be readily introspected as soon as there is

PAS Problems (4)

 The distinction between introspective

measures and ‘behavioural’ measures supports a kind of dualism

 Introspection is seen as the only way to

understand consciousness

 But then how can we ever test its

reliability?

Dodge

 “On these considerations the

methodological dogma that all mental reality is subjectively observable and conversely that the subjectively

Dodge on integration

 “In view of all the evidence I believe that

introspection is only one of the indicators of mental reality. It is a real and important

indicator of peculiar value in special fields but it is only one of many. Equally real I

believe is every pathological or neurological fact, every result of practice, training or

Your questions (1)

Could functional imaging techniques provide some

external validity by correlating neural events with introspective reports?

Aren't many of the criticisms applicable to a variety of

other disciplines? The reliability of a method is always a problem that has to be addressed.

Standardization of scientific instruments requires

quantification and the reference to a common measure. Is it possible to do so with mental reality?

What will happen in case of a switch from pure

Your questions (2)

 _{If I train to be a introspective psychologist, I change the way I} experience things, therefore the results of my introspections will not be applicable to untrained people. This seems not to happen for natural sciences where subject and object of study are two separated things and my knowledge about the object of my study change my theory but not the object itself. Is it a problem that is possible to overcome?

 How can the concepts of 'conscious' and 'unconscious' be defined without any reference to subjective experience? What does the possibility of gnosanopsia (awareness without discrimination) and agnosopisa (discrimination without awareness) tell us about

objective measures of 'conscious' and 'unconscious'?  _{Is a graded categorization of conscious and unconscious}

Integration

 Integrating and comparing subjective

and objective measures seems very sensible

 BUT what do you say when someone

insists that they see ‘all the letters’ but can only identify 4 of them

 OR when someone says they cannot see

Integration

 Is there a principled way of dealing with inconsistencies between reports and

behaviours?

 Which do you trust as the more reliable measure, when and why?

 Can people just be plain wrong in what they report?