Memory and Sleep Flashcards
Brain Areas responsible for Memory
Hippocampus
Basal Ganglia
Cerebellum
Supplementary Motor Area
Amygdala
Prefrontal Cortex
Thalamus
Mammillary Bodies
Hippocampus
Vital for the consolidation of long-term declarative memories, such as transferring memories from short-term to long-term storage.
Basal Ganglia, Cerebellum, and Supplementary Motor Area
Crucial for procedural and implicit memories, involved in learning and performing skills.
Amygdala
Attaches emotions to memories; intact amygdala enhance memory of emotional experiences.
Prefrontal Cortex
Essential for working memory and prospective memory, affecting event-based memory more than time-based memory.
Thalamus and Mammillary Bodies
Damage can lead to anterograde and retrograde amnesia.
Neural Mechanisms
Initial information on the neural mechanisms responsible for learning and memory was provided by research conducted by Kandel and his colleagues (e.g., Kandel, 1976). Their subjects were sea slugs (Aplysia), which were ideal subjects because of the small number and large size of their neurons. The results of their studies indicated that classical conditioning of reflexes had two effects: The short-term storage of information involved an increase in the release of the neurotransmitter serotonin, while long-term storage involved the development of new synapses and changes in the structure of existing neurons.
Short-term Storage
In initial research on sea slugs, Kandel and colleagues found that short-term memory involved increased release of serotonin.
Long-term Storage
Long-term memory formation was associated with the development of new synapses and structural changes in existing neurons.
Long-term Potentiation (LTP)
This phenomenon, observed in various animals and humans, involves increased synaptic strength following rapid or high-frequency stimulation.
Brain Areas
LTP was first observed in glutamate receptors in the hippocampus and later in other regions like the amygdala and entorhinal cortex.
Synaptic Changes
The formation of long-term memories depends on RNA synthesis, necessary for protein synthesis, highlighting the importance of synaptic changes in memory formation. Inhibiting RNA synthesis can prevent the formation of long-term memories.
Synthesis of RNA
Necessary for protein synthesis associated with long-term memory formation.
Serotonin Release
Increases during short-term memory storage, with long-term storage involving structural changes in neurons.
Sleep
Most theories about the function of sleep fall into one of two categories (Eysenck, 2004): Recovery/restoration theories view the purpose of sleep to be repairing damage that occurs during wakefulness, while adaptive/evolutionary theories propose that sleep is related to the need to adapt to environmental threats by, for example, conserving energy.
Stages of Sleep
Sleep is divided into five stages, with each stage having a different electroencephalogram (EEG) pattern
Stage 1
Stage 2:
Stages 3 and 4:
Rapid Eye Movement (REM) Sleep
Stage 1
Is a transitional stage between wakefulness and sleep. During this stage, low frequency, high amplitude alpha waves (which are characteristic of a drowsy state) are replaced by low frequency, low amplitude theta waves.
Theta waves
Continue during Stage 2 but are interrupted by sleep spindles (sudden bursts of moderately fast waves) and K-complexes (large slow waves).
Stage 3
Begins after a person has been asleep for about 20 minutes and is characterized by low frequency, high amplitude delta waves.
Delta waves
Continue during Stage 4 but are of higher amplitude. Stages 3 and 4 are also referred to as slow-wave sleep and deep sleep.
Rapid eye movement (REM)
Sleep begins after a person has been asleep for 80 to 90 minutes, and its EEG pattern is similar to the Stage 1 pattern. REM sleep is also referred to as paradoxical sleep because it’s characterized by an active brain and physiological arousal while the body’s major muscle groups are nearly paralyzed and the person is very difficult to arouse. Most dreams occur during REM sleep and are more vivid, bizarre, and detailed than those that occur during non-REM sleep.
Following about 10 minutes of REM sleep, a person cycles through the non-REM and REM sleep stages again and this continues throughout the sleep period. However, as the night progresses, the duration of REM sleep increases and the duration of Stage 3 and Stage 4 sleep decreases.
Lifespan Changes in Sleep
Infancy: Longer sleep periods, more REM sleep, followed by a shift to more non-REM sleep.
Adulthood: Total sleep time decreases, less deep sleep, more evenly distributed REM sleep, and more wakefulness during the night.
Older Adults: More difficulty falling asleep, less deep sleep, advanced sleep phase with earlier bedtimes and wake times.
