Consciousness Flashcards
Isolation Aphasia
Intact speech production mechanism and connections with auditory cortex —> repeat speech, learn new sequences of words. Speech mechanism isolated from other parts of the brain.
Extensive damage from carbon monoxide poisoning. Some disorders related to speech and comprehension appear to disrupt normal consciousness. Produced no evidence of conscious behaviour but could repeat words heard. No indication of awareness of herself or environment.
Describing Consciousness
Stream of consciousness reflects a limited capacity to consciously process information both externally and internally. The study of consciousness is on the frontiers of science. Progress is being made, but much is still unknown. There are a number of brain areas that seem to be important including structures like thalamus, the dorsal-lateral prefrontal cortex, broca’s and wernickes areas. One very important characteristic is that it is limited. We can only think about one idea at a time. William James said that consciousness is like a river where the ideas are limited and flow into each other.
Attention —> select and enhance relevant and new information, ignore irrelevant or uninformative information. Attention is a related but separate phenomenon from consciousness. Attention can be thought of as a bouncer at a bar, they decide who gets in and who doesn’t.
Attended –> conscious, explicit memory
Blindsight
An ability to utilize visual information despite a complete lack of awareness of seeing.
Split - Brain
Independent operation of each hemisphere through severance of the corpus callosum.
Hypnosis
Systematic procedure involving deep relaxation which tends to promote a heightened state of suggestibility. About 10% of population are highly hypnotizable. Weakly related to capacity to suspend reality and become involved in imaginative activities. positive attitude towards hypnosis. Hypnotist suggests that subject is relaxing, describe bodily sensations occurring. People differ in how well they appear to respond to hypnotic induction. Observed effects under hypnosis –> anaesthesia, sensory distortions and hallucinations, disinhibition, posthypnotic suggestions and amnesia.
Effective for pain control, therapy for replacing memories (overcoming phobias) but not memory enhancement. Induced to experience auditory or visual hallucinations. Induced to perform an act that they would normally consider unacceptable. May perform these acts because they feel that they cannot be held responsible. Suggestions may during hypnosis may effect behaviour outside of hypnosis.
Hypnosis
Social Role-Playing
People act out the role of a hypnotic subject and behave accordingly (bias effect, conformity, suspension of self - control). No change in pattern of EEG activity. Non hypnotized subjects can be induced to perform the same behaviours. Recovery of memory very unreliable.
Two main classes of competing theories —> Orne hypnotized subjects back to their 6th birthday and asked them to describe it, despite high confidence the reported events did not agree with recollections of parents and other, other students indicate recovered memories more fanciful than factual.
Altered State of Consciousness
Effects of anesthesia
Dissociation - a splitting off of mental processes into two separate, simultaneous streams of awareness. Divided consciousness common under normal conditions.
Argue that individuals unlikely to endure surgery without anesthetic just to please their physician and live up to their expected role. One stream of consciousness communicates with the hypnotic and the external world. The other stream is a difficult to detect hidden observer. Anesthesia works because pain isn’t registered in the portion of consciousness that communicates with other people.
Sleep
EEG Patterns
Different EEG patterns related to characteristic stages of activity
Awake - Beta, high freq, low amplitude
Relaxed - Alpha, med freq, med amplitude
Light sleep - theta, low freq, med amplitude
Deep sleep - delta, low freq, high amplitude
Awake and Alert - high freq, low amplitude
Deep sleep - low freq, high amplitude
Rapid eye movement –> dreaming
high frequency, low amplitude
Sleep
Sleep acts to reduce stimulation of the brain. Restorative (protein synthesis). Integrate new with the old. Sleep cycle controlled by the BRAC (basic rest activity cycle). Increased stimulation in the brain occurs during REM sleep when most dreaming appears to occur.
Purpose of Dreams
Physiological
Pons sends activation to the cerebrum, interpreter attempts to create meaning from random activation of different areas of the brain. Content of dreams meaningless.
Purpose of Dreams
Psychological
Expression of unconscious activities, inner conflicts, and desires. Analyse dreams as a window to the unconscious.
Purpose of Dreams
Both physiological and psychological
Pons sends activation, but previously activated experiences still remain mostly high activated and interpreter utilizes this information.
Insomnia
Common, avoid medication; develop sleep routine
REM Sleep behaviour disorder
Absence of paralysis while dreaming
Narcolepsy
Direct REM - like onset with paralysis, emotional states
