Joe Lau

Readings

Linguistic usage

How do we use the word?

  • Intransitive use
    • Creature consciousness : X is conscious, where X is a person or some creature.
    • State consciousness : X is a conscious mental state, where X is a mental state such as belief / pain, etc.
    • Presumably creature consciousness can be explained in terms of state consciousness.
  • Transitive use
    • X is conscious of Y : Peter is conscious of his headache. Peter is conscious of the blood on his hand.

Different notions of consciousness

@What is meant by consciousness we need not discuss; it is beyond all doubt.^^^Freud (1915). Introductory Lectures on Psychoanalysis.@

Access consciousness

  • Applies only to a state with informational content.
  • A state S is A-conscious = the information in S is poised or directly available for global control. (Global availability)
    • "Direct availability" is meant to rule out beliefs or memory as A-conscious - In the latter cases, some processing is needed to retrieve the information.
    • Information directly available can participate in (inferentially promiscuous) reasoning and control of action, such as verbal report.
    • "Inferentially promiscuous" is Steven Stich's terminology.
  • Example: Baars' global workspace theory

Phenomenal consciousness

  • A mental state S is P-conscious = there is something it is like to have S.
  • What it is like to have a state S = qualia of S (qualitative properties of S)
  • Most puzzling for the mind-body problem : why having a physical state P (e.g. the physical state corresponding to pain) is like the way it is and not some different way?

Monitoring consciousness

  • Monitoring consciousness : having a state that is monitoring some other states of a system.
  • Most creatures have some way of monitoring the state of their body (body map) or the environment. But is this sufficient for consciousness?
  • What about this system? Is ti a matter of complexity?
  • Higher-order thought consciousness : Rosenthal - a state S is conscious iff there is a higher-order state that is about S.
    • Your pain is not conscious until you think about it.
    • A more sophisticated phenomenal conceptual reportoire allows you to make finer phenomenal discrimination.

Self-consciousness

The explanatory gap

  • It seems easier to explain access consciousness, monitoring and self-consciousness in computational terms. But it is not clear how to explain phenomenal consciousness computationally.
  • It is not clear how phenomenal consciousness can emerge from a physical state. Given an identity statement physical state P = conscious state C, one can always ask, why is it that P should feel the way C does and not like some other conscious state D ?

For class discussion - Relationship between A and P consciousness

Is A-consciousness the basis of P-consciousness? If so, maybe they should be empirically correlated. A occurs if and only if P occurs.

A without P?

  • Blindsight - Blindsight patients have blind fields where they claim they cannot see anything. So if there is a glass of water located in the blind field, they will not reach for it even though they might be thirsty. However, if certain stimuli are shown to the blindfield (e.g. lines) and subjects are forced to guess whether the lines are horizontal or vertical, they perform above chance (more than 50% guesses correct), even though they would still say that they have no idea and cannot see a thing.
  • AI / robots?

P without A?

  • Ned Block's example of the drill - Block gives the example of a busy person who suddenly notices that there is a loud drilling noise outside his building. Furthermore, the subject realizes that the noise has been there all morning. But he was preoccupied with other things and was not aware of it. It is suggested that the experience of the noise is P-conscious but not A-conscious.
  • Sperling test http://www.willamette.edu/~mstewart/nwacc/modules/sperling.htm - Three rows of four letters each are flashed briefly to a subject, followed by a tone (high, medium, low). The pitch of the tone identifies the row of letters that the subject has to report. Subjects typically report being able to see all the letters distinctly, but are unable to report on the letters of more than one row. It is suggested that the information regarding the 12 letters are P-conscious but not A-conscious.
  • Aerodontalgia - The term refers to toothache brought on by sudden changes in atmospheric pressure, for example, in high-altitude flying. According to some reports, some dental patients reported experiencing aerodontalgia years after their dental operations. These patients all underwent global but not local anesthesia. The locations of the pain reported correspond to the sites where dental operations were carried out. It is suggested that perhaps these patients actually experienced pain (their pains were P-conscious) during the operation, but they were not A-conscious because of anesthesia.

What about these cases?

  • Anaesthetic awareness

@In 1960 a study had found that more than 1% of patients experienced some kind of awareness whilst under general anaesthetic, ranging from full-blown consciousness to recollection of fragments of surgical events. The Guardian reports a case of a woman called Carol Weihrer who woke up during an operation where her eyeball was removed.@

  • Sleep-walking (somnambulism)

@A sleep disorder where the sufferer engages in activities that are normally associated with wakefulness while asleep or in a sleeplike state. Activities such as eating, dressing or even driving cars have also been recorded as taking place while the subjects are technically asleep. Most cases of sleepwalking, however, usually consist of walking, without the conscious knowledge of the subject. Sleepwalkers engage in their activities with their eyes open so they can navigate their surroundings, not with their eyes closed and their arms outstretched as parodied in cartoons and Hollywood productions. The victims' eyes may have a glazed or empty appearance and if questioned, the subject will be slow to answer or unresponsive. Extracted from wikipedia:Sleepwalking@

Category.Mind