Neuroscience: learning and memory

Lecture 16

Learning

Process of acquiring new information (studying/practice)

Memory

is the ability to store information & then retrieve that \n information as needed

Memories

stored in the hippocampus before moving to the cortex for long term storage

Memory stages (based on Time)

Sensory buffers (iconic memory) \n Short-term memories \n Long-term memories

sensory buffers

A sensory buffer is a vanishing memory that is not retained

Short Term Memory

\
STM memory lasts for 30 sec without rehearsal \n • Example: Someone tells you a phone number, you remember it long enough to write it down, then memory gone \n When information rehearsed, STM lasts few minutes longer, till we get involved in another task then STM gone

Working Memory

Working memory is a cognitive system that temporarily holds and manipulates information needed to perform complex cognitive tasks, such as learning, reasoning, and decision-making. It is often described as the mental workspace where information is actively processed and manipulated. UNDER SHORT TERM MEMORY

Long term memory

\
Type of memory lasting from days, to months to years \n • LTM has very large capacity \n • LTM divided into different types \n • Forgetting is a normal aspect of LTM, filters out \n unimportant information & frees up space

Declarative memory

things you know & tell others \n (answering questions on a test)

Nondeclarative memory:

things you know that you show \n others (skills, animals can demonstrate)

Subtypes of memory

Two neurochemicals are involved in enhancing memory formation during a high emotional state

epinephrine and norepinephrine

Emotions and memory formation

Emotions cause a release of Epinephrine from adrenal glands. Epinephrine then goes to the amygdala & releases Norepinephrine from the amygdala. Norepinephrine then enhances memory formation.

Memory systems

the three processes involved in memory formation (encoding, consolidation, retrieval)

encoding

Information from sensory systems passed to \n the short term memory

consolidation

Information transferred from short term memory to long term memory.

retrieval

obtaining the stored information from long term memory

factors affecting long term memory

1 .False memories are created because of interference from other information right before or after that LTM forms \n 2. Memory recall or retrieving information from LTM can also cause memories to become temporarily unstable \n 3. Memories can be altered or disrupted before you \n reconsolidate again (send it back to LTM)

engram

physical representation of memory

Retrograde amnesia

Retrograde amnesia: difficulty in retrieving old memories (formed before injury or disorder)

Anterograde amnesia

difficulty in forming new memories (after injury or disorder)

Henry Molaison

Henry Molaison, also known as H.M., was an American man who had brain surgery in 1953 to treat his epilepsy. The surgery involved the removal of parts of his brain, including the hippocampus. As a result, he suffered from severe anterograde amnesia and was unable to form new memories. (lobectomy, hippocampus plus some cortex)

KORSAKOFF’S syndrome

Alcohol Addiction: causes dietary deficiency of Vitamin \n B1(thiamine). This deficiency gives rise to a condition called = Korsakoff’s Syndrome: \n Damage to the mammillary bodies & the dorsomedial thalamus

Symptoms: memory loss, do not remember things that they encounter all the time, deny that anything is wrong with them. Show anterograde amnesia (unable to form new memories) & Confabulations. Confabulation is trying to fill gaps in memory by false \n information that they believe is true