Lecture 37: Episodic/Declarative Memory

What are the time frames for the following?

* immediate memory
* working memory
* long-term memory

* fractions of a second → seconds
* seconds → minutes
* days → years

What does explicit memory require

conscious awareness

What are the two types of explicit memory?

What do they each include?

Semantic memory

* facts and general knowledge (I know what a bicycle is)

Episodic memory

* personally experienced events (I remember falling off my bicycle)

What are the three types of implicit memory?

What do they each include?

Procedural memory

* motor and cognitive skills

Priming

* enhanced identification of words/objects

Learning through Classical Conditioning

How does information enter the following?

* sensory memory
* short term memory
* Long term memory

* sensory input
* attention
* encoding

How is information lost in the following?

* sensory memory
* short term memory
* long term memory

* unattended memory lost
* unrehearsed information lost
* some information may be lost over time

Which two brain regions work closely with short term memory?

* frontal lobe
* medial temporal lobe

What part of the brain is memory stored in?

How do we know?

It is stored all across the brain. We know because of an experiment Lashley did where he made rats go through a maze. Lashley lesioned different parts of the rats brains but they were all still able to do the maze

What did the study of H.M show us?

What kind of amnesia did he mostly suffer from?

That there is a localization of explicit learning in the medial temporal lobes because H.M couldn’t explicitly learn anything new

* suffered from anterograde amnesia

What are the main brain areas associated with declarative memory disorders?

* thalamus
* fornix
* basal forebrain
* prefrontal cortex
* mammillary body
* amygdala
* rhinal cortex
* hippocampus

Did H.M. still maintain their short term memory?

Why or why not?

They did still maintain their short term memory because lesions to the MTL mostly only effect the development of new long term memories

* H.M. could still have conversations and stuff

In what two ways do lesions affect memory?

What does this mean about the MTL?

Global and multimodal

* the MTL is involved in the acquisition of memories that are stored all over the neocortex

What is the main feature of the explicit memory circuit?

The circuit is reciprocal so information can reverberate back and forth

What is the connection between long term potentiation and memory?

components of the neural circuit underlying the memory are more likely to fire in response to activity. Thus, the more likely the underlying neurons are to fire, the more likely the memory will come to mind

How do we know that the hippocampus and spatial memory are connected?

Because of the Morris water maze. When the mouses hippocampus was lesioned, it couldn’t find the platform