Learning and Memory

Question 1

What is learning?

Answer 1

Learning is the process by which we acquire knowledge about the world
Our ability to learn things is highly dependent on what we know. Prior knowledge provides massive framework in which we can integrate information.

Question 2

What is memory?

Answer 2

Memory is the process by which that knowledge of the world is encoded, stored, and later retrieved

Question 3

What is intelligence?

Answer 3

Intelligence is a very general mental capability that
involves the ability to reason, solve problems, think abstractly, comprehend complex ideas, learn quickly and from experience

Question 4

What are the measures of human intelligence?

Answer 4

IQ (intelligence quotient)

Psychometric tests

Question 5

What is IQ?

Answer 5

General Intelligence” - cognitive and mental ability
Measured as IQ (intelligence quotient),
score derived from one of several
standardised cognitive tests, median
score 100 + 15
IQ results are highly reliable

Question 6

What does psychometric tests measure?

Answer 6

Psychometric tests to measure intelligence cover reasoning, processing speed, executive function,
memory and spatial ability. People who perform well in one domain also tend to perform well in the others.

Question 7

What is the relationship between cortical volume and intelligence?

Answer 7

Cortical volume has been correlated with intelligence - positive correlations especially in the prefrontal and temporal cortices .

Question 8

what is short term memory?

Answer 8

Short term memory
 memories that last seconds to hours
 vulnerable to disruption and readily lost
 information initially stored as short-term memory

Question 9

what is long term memory?

Answer 9

converted from short term memory by consolidation
lasts longer with re-consolidation (e.g. remembering your parents’/siblings’ birthday)
can last for years (e.g. recall of childhood memories)
traumatic event  can boost the consolidation of long-term memory e.g. 9/11 event

Question 10

What is working memory?

Answer 10

Working memory
 temporary form of information storage
 limited in capacity and requires rehearsal
 retention of a telephone number that has just been given to you by repetition

Question 11

What is declarative memory?

Answer 11

Declarative (explicit) Memory
episodic – autobiographical info with temporal/spatial context
semantic - memory for facts and events with no associations for example “Kyoto is a city in Japan”
Declarative memories are accessed for conscious recollection, whereas the tasks we learn, as well as the reflexes and emotional associations we have formed, operate smoothly without conscious recollection
Explicit memory because it results from more conscious effort. Easy to form and are easily forgotten.

Question 12

what is Nondeclarative (implicit) Memory ?

Answer 12

procedural - memory for skills and habits
 classical conditioning – emotional responses
 non-associative – habituation, sensitization
Implicit memory because it results from direct experience.
Forming nondeclarative memories usually require repetition and practice over a longer period of time, but these memories are less likely to be forgotten.

Question 13

what is non-associative learning?

Answer 13

Non-associative- learning describes a change in behavioural response that occurs over time in response to a single type of stimulus.
– Habituation: is learning to ignore a stimulus that lacks meaning
–Sensitization: a form of learning that intensifies your response to all stimuli, even ones that previously evoked little or no reaction.

Question 14

Which part of the brain is associated with declarative memory?

Answer 14

The Temporal Lobes and Declarative Memory
The temporal lobe structures
 hippocampus,
 subiculum,
 parahippocampus,
 rhinal cortical areas,

Question 15

Effects of Temporal Lobectomy (epileptic subject HM) on declarative memory

Answer 15

 removal of temporal lobes had no effect on perception, intelligence, personality
 anterograde amnesia so profound cannot perform basic human activities (and partial retrograde amnesia)
 did not recognize Brenda Milner, who studied him for nearly 50 years
 impaired declarative memory, but spared procedural and working memory

Question 16

anterograde amnesia

Answer 16

Anterograde amnesia refers to a decreased ability to retain new information
Retrograde amnesia (RA) refers to the loss of information that was acquired before the onset of amnesia.

Question 17

Striatum and Procedural Memory

Answer 17

Procedural Memory
 Type of long-term memory of how to perform different actions and involves the development of motor skills.
 Form very early in life as you begin to learn how to walk, talk, eat and play, so ingrained that they are almost automatic.
 Striatum (part of the basal ganglia) is important. Patients with Parkinson’s disease have impaired procedural memory.
 The prefrontal and parietal cortices and cerebellum are also important for motor learning.

Question 18

Hippocampus and Spatial Memory

Answer 18

 Spatial Memory is the part of memory responsible for recording information about one’s environment and its spatial orientation
 Spatial memory is required to navigate around a familiar city
 Hippocampus is important for spatial memory

Question 19

place cell

Answer 19

 Place cells in the hippocampus - neurons that only fire when person is at a particular location

A place cell is a kind of pyramidal neuron within the hippocampus that becomes active when an animal enters a particular place in its environment,

Question 20

Grid cell

Answer 20

 Grid cells in the entorhinal cortex – the neurons activate in a unique spatial pattern in a hexagonal grid

The entorhinal cortex (EC) is an area of the brain located in the medial temporal lobe and functions as a hub in a widespread network for memory, navigation and the perception of time. The EC is the main interface between the hippocampus and neocortex.

Question 21

Prefrontal Cortex and Working Memory

Answer 21

Working Memory
 considered a limited capacity system that allows one to temporarily hold on to and process information over a brief time period.
 a system for temporary storage of information to enable one to work on complex tasks while being able to keep information in mind.
 e.g. the ability to work on a complicated mathematical problem utilizes one’s working memory
Prefrontal cortex
 highly developed in humans
 important in problem solving, complex planning and self-awareness
 interconnected with medial temporal lobe

Question 22

Does Photographic Memory Exist?

Answer 22

 Photographic memory is the ability to remember and recall large volumes of numbers or text in great detail. There is no scientific evidence that this type of memory exists.
 Eidetic memory is the ability to faithfully recall or reproduce a visual or mental image that is captured. This form of memory is subject to distortions.
 Most individuals identified as having eidetic memory are children and prevalence range from 2 – 10 % with no gender difference.

Question 23

What are different stages of memory formation?

Answer 23

Acquisition
Retention/encoding
Consolidation
Retrieval

Question 24

Acquisition

Answer 24

• sensory information is perceived and acquired

* influenced by attention, motivation, ability to learn

Question 25

Retention/encoding

Answer 25

• crucial first step to creating a new memory
• the perceived item of interest to be converted into a construct that can be stored within the brain
 require consolidation to commit to longer term memory

Question 26

Consolidation

Answer 26

 stabilisation of memory trace after acquisition
 two specific processes (1) synaptic consolidation (which occurs within
the first few hours after learning or encoding) and (2) system
consolidation (where hippocampus-dependent memories become
independent of the hippocampus over a period of weeks to years)
 utilizes a phenomenon called long-term potentiation, which allows a
synapse to increase in strength .

Question 27

Retrieval

Answer 27

 subsequent re-accessing of events or information from the past, which
have been previously encoded and stored in the brain.

Question 28

Hebbian Theory - memory results from synaptic modification

Answer 28

Hebbian Theory
 Fire together wire together
 Out of sync lose their link

Question 29

Neural basis of memory

Answer 29

• Learning and memory occur at synapses and result from modifications of synaptic transmission
• Synaptic plasticity (ability of the synapse to change in strength in response to either use or disuse) is an important neurochemical foundation of learning and memory
• Long term potentiation (LTP) of synaptic transmission in the hippocampus - primary experimental model for investigating the synaptic basis of learning and memory in vertebrates

Question 30

LTP in the Hippocampus

Answer 30

Mechanisms of LTP in CA1
 Activation of AMPA/Kainate receptors by glutamate causes post-synaptic membrane depolarisation
 Mg2+ is dissociated from NMDA channels, facilitation of Ca++ entry
 Activation of protein kinases Ca2+ /calmodulin-dependent kinase (CaMKII), Ca2+ /phospholipid dependent kinase (PKC)
 Resulting in postsynaptic protein phosphorylation of AMPA receptors
 Recruitment of AMPA receptors to post-synaptic membrane and upregulation of AMPA receptor
function

Question 31

Mechanisms of LTD in CA1

Answer 31

 Facilitation of postsynaptic Ca++ entry through NMDA receptors
 Key difference between LTP and LTD – level of NMDA receptor activation
 LTD – weak depolarization of postsynaptic neurons, partial blocking of NMDA channels by Mg++, trickle of Ca++ entry
 Activation of protein phosphatases instead of kinases, resulting in protein dephosphorylation

Question 32

Dendritic Spines

Answer 32

 Dendritic spines are sources of synaptic contact that can be altered by experience
 Structural plasticity of dendritic spines underlies
learning, memory and cognition in the cerebral cortex
 Induction of LTP causes enlargement of spine heads,
while LTD causes spine head shrinkage

Question 33

Major risk factor for neurodegenerative diseases

Answer 33

Age is a major risk factor for many neurodegenerative diseases

Question 34

NEURODEGENERATIVE DISEASES

Answer 34

 most neurodegenerative diseases have unknown etiology
 delayed onset; age is a major risk factor
 selective neuronal vulnerability, despite widespread expression of diseaserelated proteins during the whole lifetime;
 abnormal protein processing and aggregation
 many display symptoms of memory loss
 one of the most common form of neurodegenerative disease is Alzheimer’s
disease (AD)