whats a concussion?
is caused by a blow to the head that results in a disturbance of consciousness
Concussion and retrograde
-associated with permanent retrograde amnesia for the events leading up to the blow
Concussion and Anterograde
associated with permanent anterograde amnesia for the events shortly after regaining consciousness
*occurs even if the person is lucid and speaking
Follwoing a concussion there is gradient of retrograde amnesia
-events jsut before the blow are lost
-older memories survive though
Older memories surviving a concussion suggests that they have been strengthen over time, this is called
Who invented the theory of memory consolidation?
Donald O. Hebb
Memory consolidation theory (2)
-memories of events are stored in short-term memory and are vulnerable
-over time, and without perturbation memories become strenghtened and are less susceptible to loss
Electroconvulsive shock (ECS)
intense but brief seizure-inducing current admisnitered to the brain
*causes retrograde amnesia
*use as a tool for studying consolidation
Electroconvulsive shock supports Hebbs theory
suggest that memory consolidation takes somewehre between 10 min and an hour to take place
Where are memories of events stored?
in short term memory by active synapses
Memories that are hekd while synapses are active are susceptible to...
Over time, with continued activity, synapses become strengthened-strctural changes take place and crcuits holding the memories become less...
susceptibles to loss
Memories are held in the form of...
synapses and connections between particular neurons
Aspects of synapses are not set in stone
-number of receptors on the post synaptic suface can change
- amount of NT release from the pre-synaptic surface can change
Hebbs thoery "cells that fire together wire together"
-if cell A fires an AP and synapses onto cell B and the result is that cell B fires an AP
*this connection will be strengthen
-if cell X also synapses onto cell B and cell X is far less active, cell X will not drive cell B and eventually this connection will weaken
(procedural memory) skill learning
riding a bike is an example
*H.M mirror drawing is an exmaple of skill learning
(procedural memery) Priming
a change in the processing of a stimulus( a word or picture) as a result of prior exposure to the same stimulus
ex) ask to make a word using STA
*more likely to finish it as STAMP if you saw STAMP in the list of words than if you didnt
- an initially neutral stimulus comes to predict an event
characteritics of monkeys with lesioned amygdala
-decreased emotionality, hypersexuality, inability to recognize famiiar objects, and indiscriminate approach behavior
classical conditioning exmalpes
unconditioned simulus: food
unconditioned response: salivation
conditioned stimulus: a bell
contioned response: salivation
is a form of classical conditioning that apears to be heavily dependent on the amygdala
What happens when the central nucleus of amygdala is inactivated?
it impairs enconding and retrival of the memory
learning and memory II