Episodic and Semantic Memory - brain substrates

anterograde amnesia

damage of hippocampus and nearby brain structures

frontal cortex and subcritical areas

determine what get stored and when

semantic memory

cerebral cortex

association cortex

links sensory information between modalities, links semantic and linguistic information

associative visual agnosia

difficulty recognising and naming objects, but can copy them

visual agnosia

damage of inferior temporal lobe

auditory agnosia for speech

damage of superior temporal lobe

tactile agnosia

damage of parietal lobe

agnosia

loss of semantic knowledge linking the perception of an object with its identity

medial temporal lobes

hippocampus, amygdala, entorhinal cortex, parahipocampal cortex

forming new memories

medial temporal lobes

spatial learning

hippocampal regions

remembering words

left hippocampus

hippocampus

bings temporal and spatial context with the object

distinguishing between true and false memories

standard consolidation theory

the neocortex slowly learns long-term memories with a transient support of the hippocampus that quickly learns unstable memories

multiple memory trace model

Memories are encoded by an ensemble of neurons in the hippocampus and cortex for a life time. During repetition and time more connections in the cortex are linked together.

inhibition of hippocampal activity

frontal cortex

front cortex

decides what we store and binds contextual information

korsakoffs disease

• Deficiency in thiamine (a B vitamin) by chronic alcohol abuse.

• Lesions in mediodorsal nucleus of thalamus & mammillary bodies.

• Same anterograde and graded retrograde amnesia as MTL patients, although no MTL damage.

• Confabulations (not lying!)

amnesia in korsakoffs disease

basal forebrain and medio-dorsal thalamus connect frontal cortex and hippocampus

disruption of anterior communicating artery

amnesia similar to hippocampus damage (due to disruption of blood supply in basal forebrain)

formation of new memories

new event → basal forebrain → ACh + GABA (signals novelty) → hippocampus

transient global amnesia

temporary disruption of memory, temporal inability to form new memories

functional amnesia

may be caused by trama → changes in the hippocampal metabolism

infantile amnesia

no develop language

no cognitive self

immature hippocampus and frontal cortex

magic shrinking machine

children can re-anact procedure, but can’t describe it → lack od verbal representation of an event