Time is nature's way of keeping everything from happening at once ........ Howard Hoffman

Timing The Conscious and the Unconscious:
Some Implications for Thinking ... and Thinking About Time

Paul Grobstein
18 March 2003

The Place of the US in the World Community

BACKGROUND
  • From Cheryl Chen
    • conventional vs block model of time
    • issue of free will?
  • From Tony Rothman
    • directionality of time
    • simultaneity/causality
  • From Peter Brodfuehrer
    • all cells have materially-based cyclic rhythms
    • time as change?
    • unconscious time as basis of "prediction", in absence of "awareness" (consciousness, "intentionality"?)

A NEEDED PRELIMINARY:
NOTICING A CONSCIOUS/UNCONSCIOUS DISTINCTION IN BRAIN FUNCTION

(http://serendip.brynmawr.edu/bb/blindspot1.html)


(http://serendip.brynmawr.edu/bb/freewill1.html)

RECOGNIZING A CONSCIOUS/UNCONSCIOUS DISTINCTION
IN THE BRAIN'S HANDLING OF TIME

The issue of time resolution

Two sounds need to be separated by > 40 msec to be correctly reportable in terms of sequence
(cf http://www.nencki.gov.pl/PDF/AN/VOL62/kanab.pdf)

BUT nervous system makes/uses much finer time distinctions

Another way to see the conscious/unconscious time distinction
(cited in B. Libet, Philosophy of Science 48: 182-97 (1981), according to Norretranders, p 225 and note) Simple reaction time is 200-300 msecs, and jumps to much longer times if one tries to slightly increase them. Conscious processes are slower than unconscious ones.

SIMULTANEITY (AND HENCE CAUSALITY) AS A GENERAL PROBLEM
GIVEN THAT THE BRAIN IS A MATERIAL SYSTEM

Different time delays along different pathways
(cf Daniel Dennett, Consciousness Explained, 1991)

BEGINNING TO PUT THINGS (BACK) TOGETHER

Backdating by the unconscious, unknown to consciousness
(cf Tor Norretranders, The User Illusion, 1998, pp 213-251
Benjamin Libet, Neurophysiology of Consciousness, 1993)

Conscious sensation requires ~ 500 msec of cortical or thalamic activity
Stimulation of hand as much as 300 msec AFTER onset of cortical stimulation is reported as preceding sensation due to cortical stimulation
Therefore there must be a "time stamp" added in subcortical circuitry so conscious percept is backdated
Can verify using thalamic stimulation and verbal report ... occurence of sensation dated to beginning of cortical evoked potential rather than 500 msec later

BACKDATING (AND HENCE BIDRECTIONAL CAUSALITY) IS COMMON IN CONSCIOUS TIME ON MULTIPLE TIME SCALES

TIME AS SEQUENCE (and CAUSALITY?) IS CHARACTERISTIC OF CONSCIOUS PROCESSING ("EXPERIENCE", STORY-TELLING),
BUT NOT OF NERVOUS SYSTEM AS A WHOLE
NOR OF ITS PRIMARY INTERACTIONS WITH "REALITY"

RELEVANCE TO FREE WILL?

Some additional useful links on-line

Daniel Dennett and Marcel Kinsbourne (1992) Time and the Observer, Behavioral and Brain Sciences 15: 183-247

Time, from The Internet Encylopedia of Philosophy


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