8.4 Summary

an engram is

a physical representation of memories in the nervous system

Hebb’s rule

about how neurons change with experience and is often states as

neurons that fire together wire together

long-term potentiation is the

physical representation of Hebb’s rule

work on LTP has taken place in the hippocampus, showing that synapses change and become more efficient when communication between neurons increases

HM had parts of his temporal lobe and hippocampus removed because of epilepsy;

after the surgery, he could not form new memories (anterograde amnesia)

prefrontal lobe is active during

working memory tasks

prefrontal cortex makes connections to other areas of the brain necessary for

working memory, such as the hippocampus

many areas of the brain are also essential for semantic memories 

such as areas of the cortex and hippocampus 

using a process called neural decoding,

Jack Gallant and his colleagues have mapped out brain activities associated with specific memories

hippocampus is

most important in spatial memories

we lose memories gradually over time through passive mechanisms,

but we also have ways to forget memories intentionally with active mechanisms 

head injury, drugs, diseases, and electroconvulsive shock can cause loss of memories of the past (retrograde amnesia)

or inability to create new memories (anterograde amnesia)

exercise can help create new neurons

and protect other neurons and synapses, and so it helps with memory

diets high in cholesterol and saturated fats can harm memory, but diets high in omega-3 fatty acids 

can help memory 

mindfulness meditation can

help with attention and memory