Outline and evaluate 1 neurobiological theory of functions o
Uploaded by sharmaine on Mar 23, 2007
Outline and evaluate 1 neurobiological theory of functions of dreaming.
In neurobiological models of dreaming, based on the brains psychological activity during REM sleep, the interpretation of human imagery is secondary to explaining the underlying cognitive function of REM sleep.
Crick and Mitchison did research into reverse-learning and came up with the reverse-learning model, a neurobiological model of sleep. They argued, that the brain is offline when dreaming and during this stage, it sifts through the information gathered during the days waking activities and throws out all unwanted information. According to Crick and Mitchison, they throw this material away through reverse learning. The cortex cannot cope with the vast amount of information without developing parasitic thoughts, which effect the efficiency of the organisation of memory within the brain.
Spiny anteaters, which Crick and Mitchison used as evidence, have no REM sleep. This may be used to explain why a spiny anteater does this. It has a huge frontal cortex meaning it can store a lot more memories or parasitic thoughts, whereas others have had to evolve to dispose of the information during sleep.
One problem with their theory is that dreams are often organised into clear narratives or stories. If they consisted only of disposable parasitic thoughts, why should they be organised in a systematic way. However, later on, Crick and Mitchison changed their theory to apply only to dreams with bizarre imagery and not just clear stories.
Hobson and McCarley took a similar approach to that of Crick and Mitchison. Their activation-synthesis hypothesis of dreaming is based on many years of intricate electrophysiological research into the brain mechanisms of REM sleep. Hobson and McCarley’s model is broader than that of Crick and Mitchison and is based on extensive experimental work. It provides a sound account of the brain mechanisms underlying REM sleep and dreaming. Basing psychological interpretation on the neurobiology of REM sleep and dream states does make it more convincing.
Outline and evaluate one psychological theory of the functions of dreaming.
In contrast to neurobiology, psychological theories take the dream imagery itself as the issue to be explained.
Winson suggests a psychological theory into dreaming. He did his research with non-humans, such as cats, dogs and rabbits. He said that theta rhythm of 6 cycles per second from the hippocampus during REM sleep. He claims, that this was responsible for the reactivation of memory in animals for instance territory keeping and hunting. They were...