Memory and Cognition

Question 1

What is Cognition?

Answer 1

Cognition describes the Integration of all sensory information to make sense of a situation

It is the highest order of brain function and relates to the behaviour that deals with thought processing

Question 2

At a most basic level, what changes happen in the brain in order for cognition to take place?

Answer 2

Cognition involves remembering and learning from events in order for us to make sense of our world

This is made possible by ‘neuronal plasticity’ - the ability central neurones to adapt their neuronal connections in response to new experiences

Question 3

Why are association areas in the brain fundamental to cognition?

Answer 3

Association areas - eg Visual association area

These can integrate information from multiple sources (primary areas can’t)

These do the learning/remembering shit for cognition

Question 4

What 3 areas of the brain are most involved with learning and memory?

Answer 4

Hippocampus - formation of memories

Cortex - Storage of memories

Thalamus - Search and access of memories

Question 5

What is the limbic system’s role in memory?

Answer 5

The Limbic system is key to Emotion

It gives events emotional significance which is essential for memory (makes them stick)

Question 6

Do ya thing

Describe their relevant roles to memory n shit as well

Answer 6

Question 7

Describe the parts that make up the limbic system

Answer 7

Hypothalamus:

• Link between emotion and ANS responses

Hippocampus:

• Learning and formation of memories

Cingulate gyrus:

• Just kinda does emotion stuff

Amygdala:

• Emotion and memory

Question 8

What is the function of the limbic system as a whole?

Answer 8

Responsible for instinctive behaviour, e.g. thirst, sex, hunger etc. and emotive behaviour which is driven by seeking reward or avoiding punishment.

Question 9

What is meant by ‘reward areas’ and ‘punishment areas’?

Answer 9

Certain areas of the limbic system produce feelings of wellbeing, euphoria & sexual arousal when stimulated - Reward areas

Others produce fear, anger & pain - Punishment areas

Our brain basically uses these areas to Motivate us to learn - Reward and punishment form the Affective component of sensory experiences

Reward and punishment drive almost every conscious decision we make

Question 10

How do the Affective components of sensory experiences help dictate what we remember and what we dont?

Answer 10

The frontal cortex and its association with the reward/punishment centres in the limbic system assess the significance of an event

If deemed insignificant (the experience was not rewarding or punishing) then the memory is discarded

Question 11

Describe why the hippocampus is essential for the formation of memories

Answer 11

Almost all sensory information goes through the hippocampus, which in turn relays information to other limbic system structures.

Question 12

What would be the effect of damage to the hippocampus and why?

Answer 12

Hippocampus essential for the Formation of memories

Bilateral Damage = no new long term memories

However, it would not affect existing long term memories or the short term memory function

The effect would be anterograde amnesia

Question 13

Memory can be divided into four types. What are these?

Answer 13

Immediate or sensory memory:

• Experiences held in the mind for a few seconds
• Visual experiences decay fastest, auditory slowest

Short-term memory:

• Seconds - hours
• Used for short-term tasks - dialling a number etc
• Associated with reverberating circuits

Intermediate long-term memory:

• Hours - weeks
• ‘What you did last weekend’ etc
• Associated with chemical adaptation at the presynaptic terminal

Long-term memory:

• Up to lifelong memories
• Associated with Structural changes in synaptic connections

Question 14

What is a reverberating circuit?

Answer 14

Structure used for short-term memory

Basically a small loop of neurones which basically takes a signal and has it travelling about this circuit

This causes maintained excitation of the neurones so the signal is held in place for a bit

Question 15

How do reverberation circuits allow short-term memories to be kept or yeeted

Answer 15

The circuit keeps the memory alive for a brief amount of time

If significant = Reverberation results in the consolidation of the memory into long-term memory storage

If not = Reverberation fades

Question 16

If reverberation is disrupted (eg head injury or infection) - what condition would arise?

Answer 16

Amnesia:

• Anterograde - Cannot form new memories
• Retrograde - Cannot access (more recent) old memories

Question 17

Damage to what areas of the limbic system are associated with each type of amnesia?

Answer 17

Anterograde (No formation) - Hippocampus damage

Retrograde (No access to recent long term memory) - Thalamus damage

Question 18

Intermediate long-term memory is based around Chemical changes at the pre-synaptic terminals

Describe what goes on

Answer 18

Change causes increased Ca²⁺ entry to the pre-synaptic terminals

This causes increased neurotransmitter release

And that causes some stuff to happen

Question 19

What structural changes are involved at synapses for long term memory?

How do these create long term memories?

Answer 19

1. Increase in NT release sites on presynaptic membrane.
2. Increase in number of NT vesicles stored and released.
3. Increase in number of presynaptic terminals

The patterns of neuronal firing (associated with a memory) are repeated - each time strengthening the connection through the above ways^

Question 20

What is this process of strengthening neuronal connections for long-term memories called?

Answer 20

Long term potentiation

“Strengthening of the synapse”

Thus the LTM is a well-established, well-rehearsed pattern of neuronal firing unique to that particular memory

Question 21

Long term memory comes in 2 types. What are these?

Answer 21

Declarative or Explicit LTM:

• Abstract memory for events (episodic memory) and for words, rules and language (semantic memory)
• Strong link to Hippocampus

Procedural/ Reflexive/Implicit LTM:

• Acquired slowly through repetition. Includes motor memory for acquired motor skills such as playing tennis, and rules based learning
• Mainly based in Cerebellum (independent of Hippocampus)

Question 22

What is consolidation?

Why is it such a fragile process?

Answer 22

Process through which we convert Short-term memories to long-term memories

Consolidation involves selective strengthening of synaptic connections through repetition (for minutes to hours)

During the consolidation process, memory simply exists as electrical activity and is vulnerable to being wiped out

Question 23

How are memories organised in the sensory and association cortex of the brain?

Answer 23

New memories are coded then stored alongside existing memories that the brian deems similar

This is why you sometimes see things that do not exist in certain images

Question 24

In this beautifully drawn diagram from the lecture, describe what happens in stages 1, 2 & 3

Answer 24

The sensory input enters the sensory & association areas of the cerebrum and travels to the Frontal cortex

Frontal cortex assesses the significance of the input - by using the reward/punishment areas of the limbic system

Question 25

What happens in stages 4 & 5 in the diagram

Answer 25

(If) the input coming back to the frontal cortex from the LS is significant - it is sent back to the Sensory & association areas of the cerebrum, which begins ‘writing it’ into the long term memory

Question 26

What happens in stages 6 - 9 in the diagram?

Answer 26

The Frontal cortex ‘gates’ the Papez circuit of the limbic system so the Memory basically reverberates around the Papez circuit –> Frontal cortex –> Sensory & association cortex until the consolidation process is complete