Consciousness as an alternate interpretation of corollary discharges

M.KarthikeyanY9277Mentor: Prof.Amitabh Mukherjee

AIM•Understanding the nature of

consciousness.•Are corollary discharges (signals in the

brain) what we call as consciousness??•How materialistic is consciousness??

Concepts involved

•Efference signal•Efference copy signal•Forward Internal Model•Corollary Discharge•Reafferent signal

Experimental Procedure• Subjects – 9 Schizophrenic (corollary discharge pathway

affected) patients from Mahendru Hospital,Kanpur.• Methodology:1.Patients were shown a red circle , the stimulus to press a

button.2.Had to say yes when they sensed their intention to press the

button.3.Finally press the button.4.I noted the time instant of ‘YES’ on a millisecond stopwatch.5.Button press time instant was recorded by the software.6.Active trial - subject himself pressed the button7.Passive trial – I pushed the patients finger onto the button• Active trials – 2 sample and 5 subject trials• Passive trials – 2 sample and 5 subject trials

Active-Medium positive

Subject

Time in ms

STD DEV1 A-49.11msP-425.3ms2A-189.3msP-267.7ms

Active-Negative

Subject

Time in ms

3A-114.25P-35.524A-106P-70.15A-237P-961.36A-69.8P-262.57A-120.2P-558.55

Active-Very high positive

Subject

Time in ms

STD DEV8A-74.33P-278.329A-189.34P-267.710A-233.8P-342.01

Data Analysis• The first five results were as expected , resulting

in late realization of action execution. • Time gap difference corresponded to the

subject’s extent of schizophrenia (various levels of the condition)

• Explanations for the very high positive time gaps ??

Scope for improvement•Drawbacks:1.Number of subjects available were low ,

larger number of trials performed per subject.

2.Time instant of ‘YES’ obtained by taking into account the experimenter’s error.

•Highly accurate time estimates might be possible by using EEG(electroencephalography) i.e the exact time instant of conscious realization.

References• 1.Sukhvinder S.Obhi , (Evidence for feedback

dependent conscious awareness of action(Brain Research,2007 1161:88-94).

• 2.Libet, B. (1985) Unconscious cerebral initiative and the role of conscious will in voluntary action. Behavioural and Brain Sciences, 8: 529:566.

• 3. Irwin Feinberg (Efference copy and corollary discharge: implications for thinking and its disorders . Schizophrenia bulletin 1978;4(4):636-40.)

•Thank You!