LECTURE 2

LEVELS OF CONSCIOUS AWARENESS

David Pearson

Room T10, William Guild Building

Email: d.g.pearson@abdn.ac.uk

Sigmund Freud (1856 –1939)

• Freud proposed that the human mind consists of three levels of awareness.

1. Conscious All of the thoughts, perceptions, and other

mental events of which we are currently aware.

2. PreconsciousMental events outside current awareness, but

which can be easily recalled under certain conditions.

3. Unconscious

Mental events that cannot be brought into conscious awareness under ordinary circumstances.

Some unconscious events (unacceptable urges and desires, traumatic memories etc.) are kept out of conscious awareness to prevent anxiety or other negative emotions from occurring.

“Many aspects of Freudian theory are indeed out of date, and they should be. Freud died in 1939, and he has been slow to undertake further revisions.”

Drew Western, 1998.• On a broad level, Freud’s general premise

concerning levels of consciousness was correct.

• A great deal of evidence suggests that some mental processes can affect behaviour without conscious awareness.

The Placebo Effect

• It has been known for decades that patients’ symptoms may improve solely because they expect the given drugs to help them.

• Placebo (inactive) substances are commonly used in studies testing the effectiveness of new drugs.

• Kirsch and Sapirstein (1998) carried out a meta-analysis of 2,318 depressed patients who had been randomly assigned either to an antidepressant medication group or to a placebo group.

• Their results suggest that up to 75% of effects of antidepressants are due solely to patients’ expectations of improvement (note: this is a controversial finding!!)

Split-Brain Syndrome

• Some cases of severe epilepsy are treated by severing the corpus callosum that connects the two hemispheres of the brain.

• The corpus callosum allows information to be exchanged between hemispheres.

• With the exception of smell, each hemisphere receives sensory information and controls movement on the opposite side of the body.

• Because of lateralization of mental processes split-brain surgery can lead to disorders in consciousness.

‘Subliminal’ Perception and Priming

• In 1957 market researcher James Vicary reported a study involving 45, 699 patrons at a cinema in New Jersey.

‘Subliminal’ Perception and Priming

• The two messages shown during the film were “Eat Popcorn” and “Drink Coca-Cola”.

• A message was flashed for 3/1000th of a second every five seconds. Claimed this was too fast for conscious awareness.

• Claimed that over a six-month period sales of popcorn rose 57% and sales of Coca-cola rose 18.1%.

• This was the beginning of the concept of subliminal advertising.

• However, these impressive results were never replicated, and in 1962 Vicary admitted the study was a hoax.

• Many claims for subliminal advertising have been made, but concept has been largely discredited.

Cognitive Priming

• ‘Priming’ refers to the influence a non-consciously perceived stimulus can have on subsequent mental processing and behaviour.

• Effects of priming on behaviour during experiments are small but statistically significant.

• Chartrand and Bargh (2000) conducted an experiment in which they subliminally presented college students with nouns.

• The type of nouns presented changed relative to four experimental conditions.

1. Strongly negative (e.g., cancer, cockroach)

2. Mildly negative (e.g., Monday, worm)3. Mildly positive (e.g., parade, clown)4. Strongly positive (e.g., friends, music)• Later students rated their mood on

standard psychological inventories.• Those shown strongly negative words

displayed the saddest mood. Those shown strongly positive words reported the happiest mood.

The ‘Cognitive Unconscious’

• Today cognitive psychologists reject Freud’s notion of an unconscious mind driven by instinctive urges and repressed conflicts.

• Conscious and unconscious mental life are viewed as complementary forms of information processing.

• “[unconscious mental activity is] not an adversary to the conscious mind. Instead, the cognitive unconscious functions as a sophisticated support service, working in harmony with our conscious thoughts.” Daniel Reisberg (1997)

Summary

• Placebo effects, split-brain syndrome, and cognitive priming demonstrate that mental processes can influence behaviour without conscious awareness.

• Therefore, consciousness must reflect only a subset of mental processes occurring in the brain.

• There are many mental processes for which it is not possible for us to become consciously aware.