Consciousness

• seCtIon tWo: tHe BRAIn
  also show evidence of priming: getting quicker at recognis-
  ing fragmented pictures and completing words if they have
  been seen before. For this reason, amnesic syndrome has
  sometimes been described as a dissociation between perfor-
  mance and consciousness (Farthing, 1992; Young, 1996).
  Are people with amnesia conscious? Surely the answer is yes.
  They are awake, responsive, able to converse, laugh, and show
  emotion. But without the capacity to create new memories, they
  have lost the interaction between current and stored information
  that, according to Oxford psychologist Larry Weiskrantz (1997),
  makes possible the ‘commentary’ that underlies and unifies con-
  scious experience. Some amnesiacs repeatedly exclaim ‘I have
  just woken up!’ or ‘I have just become conscious for the first time!’
  C. W. was a professional musician struck with dense amnesia by
  herpes simplex encephalitis (Wilson and Wearing, 1995). Although
  he could still sight-read and improvise music, and even conduct his
  choir, his episodic memory was almost completely destroyed. He
  kept a diary of what was happening to him and there he recorded,
  hundreds of times, over a period of nine years, that he was now
  fully conscious, as if he had just woken from a long illness. He was conscious all right,
  but trapped in an ephemeral present, unconnected with the past.
  Asking people with amnesia about such matters is difficult. As Sacks puts it,

If a man has lost a leg or an eye, he knows he has lost a leg or an eye; but

if he has lost a self – himself – he cannot know it, because he is no longer

there to know it.

(1985, pp. 35–36)

Amnesics create no memory of a continuous self who lives

their life, or, as some would say, no illusion of a continuous

self who lives their life.

Amnesia will come to many of us, and to our parents and loved

ones, in the form of Alzheimer’s disease or senile dementia. In

this form, it is less specific than the cases described here, and

comes on gradually. For some time, the person may have

enough memory to realise their predicament, which makes

it all the harder. In 2014,  Bruce Francis, Emeritus  Professor

of Electrical Engineering at the  University of Toronto,  gave a

prize lecture on ‘The Robot Rendezvous Problem’, and his first

PowerPoint slide read: ‘I have Parkinson’s disease. To help me

deliver the lecture as smoothly as possible, I’ve written text on the slides and will read

it. You should read it along with me (not aloud). Let’s practice by an example.’ He then

proceeded to give a masterclass in how to present complex ideas from the ground up.

Memory loss can be frightening. Yet, as the Russian psychologist Alexander Luria

pointed out to Sacks, ‘a man does not consist of memory alone. He has feeling,

will, sensibilities, moral being – matters of which neuropsychology cannot speak’

(Sacks, 1985, p. 32). Memory is just one of the kinds of glue we use to give unity

to our consciousness.

‘I have just become

conscious for the first

time’

(C. W., amnesic patient)

Massa
intermedia

Hypothalamus Thalamus

Cerebellum

FIGURE 6.12 • Korsakoff’s syndrome occurs most
often in chronic heavy drinkers.
It is caused by thiamine (vitamin
B1) deficiency, which damages the
thalamus and hypothalamus, as
shown, and is exacerbated by the
neurotoxic effects of alcohol. This
results in anterograde amnesia (the
inability to create new memories).
Other brain areas including the
cerebellum may also be affected.

answer (if RH tries to give her non-verbal clues this

only adds to the fun). Now give RH the bag containing

the various objects, ask him to put in his left hand and

select the correct object. He should do this easily.

2 Recreate MacKay’s experiment.

Ask RH to think of a number between 0 and 9 (or, if

you want better control, prepare numbered cards and

show one to RH out of sight of LH). LH now has to

guess what the number is. For each guess RH points

‘up’ or ‘down’ or nods for the correct answer. You

might like to try inventing a method for playing the

game the other way round.

The twins should be able to play this game

successfully. Does it show that there are two conscious

selves involved? Does this game help us to understand

what it is like to have a split brain?