lecture 22: memory

Question 1

Learning

Answer 1

the process by which we acquire
knowledge about the world

Question 2

Memory

Answer 2

the encoded knowledge that is
stored and sometimes later retrieved

Question 3

instincts

Answer 3

an innate, typically fixed pattern of behavior in animals in response to certain stimuli

Can be complex
and remarkably specific, but does not need to be learned. Also known as phylogenetic
memories, as they are based on the experience of a species over eons

Question 4

Declarative or explicit
memories

Answer 4

are memories that
are available to consciousness
and can therefore be expressed
in language (e.g., a phone
number, a picture, an event).
Sometimes divided into
“episodic” (events) and
“semantic” (facts). Semantic is
only kind before ~2yrs of age

Question 5

Procedural or implicit or non- declarative memories

Answer 5

are not easily described with language.
They are basically skills and
learned reactions that are
typically retrieved
unconsciously (how to type,
how to ride a bike, how to play
the Goldberg Variations “by
heart”

Question 6

Memory can be categorized into three general classes
based on the time at which each is acting

Answer 6

immediate
short-term
long-term

Question 7

niko tinbergen herring gull chicks

Answer 7

they crouched and got cover when the silhouette of a birth of prey passed over them because they associate the silhouette with danger but its not based on personal experience

Question 8

immediate/sensory memory

Answer 8

also known as sensory memory, is the term for the shortest element of
memory. It is the ability to retain impressions of sensory information for a couple of seconds after the original stimuli have ended and gives us a sense of the present

Question 9

short-term/working memory

Answer 9

seconds to minutes (e.g.
someone tells you their phone number that you then
“dial”). In certain situations referred to as “working
memory” as when an animal searches a number of
sites sequentially for an object and remembers to skip
places it has recently visited

Question 10

long-term memory

Answer 10

days to decades

Question 11

“consolidation”

Answer 11

how memory passes from the short to long-term category

Question 12

H.M. (Henry Molaison)

Answer 12

• Beginning as a teenager he suffered from almost daily
  bilateral temporal lobe seizures that were untreatable
  with medicines
• At 27 (1953) he sought help from a neurosurgeon Dr.
  William Scoville who elected to remove the foci of
  the seizures bilaterally: the hippocampal formation,
  the amygdala, and parts of temporal cortex
• Seizures were much improved
• Devastating memory deficit: normal immediate
  and short-term memory but no consolidation of short-term declarative memory into long-term
• Long-term memory of events before 1953 was largely intact
• Intelligence unaffected
• Spatial orientation severely affected
• Procedural memory was not affected at all

Question 13

Procedural memory formation
completely spared in HM

Answer 13

• Learned how to mirror draw at normal rate
• Had no idea how he learned it (episodic memory gone)-
  each time he practiced he thought it was the first time
  he had tried- nonetheless he steadily improved

Question 14

“episodic” (event based) memory

Answer 14

involves personal life experiences

Question 15

“semantic” (fact based) memory

Answer 15

Semantic memory is a category of long-term memory that involves the recollection of ideas, concepts and facts commonly regarded as general knowledge. Examples of semantic memory include factual information such as grammar and algebra.

Question 16

HM conclusions

Answer 16

• Medial temporal lobe is important for
  declarative but not procedural memory
  consolidation
• Procedural memory formation can go on
  perfectly well without any conscious
  awareness.
• Spatial learning must be related to medial
  temporal lobe and hippocampus

Question 17

Clive Wearing

Answer 17

viral encephalitis (1985) led to 10 second memory span
(devastating) and profound retrograde and anterograde amnesia: life always
in the moment

Question 18

Retrograde amnesia

Answer 18

for events prior to trauma

Question 19

Anterograde amnesia

Answer 19

for event after a trauma (eg HM
after 1953)

Question 20

how long-term memory works

Answer 20

Peculiarly specific memory impairments suggest a
high degree of spatial locality of some memories

Spatial memory is highly
organized in brain space

Extensive spatial memory experiences cause hypertrophy of part of the
hippocampus and atrophy of another part with functional consequences

All of us have prodigious memories
for some things

Question 21

Hippocampal “place” cells

Answer 21

as animal enters an area (such as the red oval)
some hippocampal cells fire action potentials

Question 22

Entorhinal cortex “grid” cells

Answer 22

individual neurons fire at regular spatial intervals as an animal walks in its enclosure. Cortex innervates hippocampus. Each cell has a different hexagonal receptive field- somehow grid cells give rise to place
cells- not yet clear how

Question 23

Peculiarly specific memory impairments suggest a
high degree of spatial locality of some memories

Answer 23

19 yr old man that couldnt remember colors after encephalitis

Question 24

Spatial memory is highly
organized in brain space

Answer 24

Hippocampal “place” cells
Entorhinal cortex “grid” cells

Question 25

taxi driver memory experiment

Answer 25

Extensive spatial memory experiences cause hypertrophy of part of the hippocampus and atrophy of another part with functional consequences

Question 26

aj memory

Answer 26

Can get enormous amounts memorized without conscious memory tricks * Emotional value of memories important part of the coding (she was “terrible” in history- she couldn’t remember “all those dates”) * Spontaneously arranged calendar in a spatial way- when asked to draw her mental calendar she drew the years in a funny grid then the months in a clock face with January at 11 o’clock- this may be her spatial tag (a “trick”?) * Spent a lot of time thinking about dates (obsessive compulsive tendencies) probably helped

Question 27

Synesthesia

Answer 27

mixed modality perceptions triggered by one sense e.g., the sound of a syllable (“Ba”)- makes some rare individuals think of a color (orange)

Question 28

how are some memories false

Answer 28

misattribution

Question 28

Learning

Answer 28

the process by which our brain adapts and/or we acquire knowledge about the world

Question 29

Memory

Answer 29

the encoded knowledge that is stored and sometimes later retrieved

Question 30

Amnesia

Answer 30

loss of memory due to brain injury, disease or psychological trauma. Loss of memory for events that happened before the onset is retrograde. The inability to create new memories after the event is anterograde

Question 31

tricks to improve memory

Answer 31

affiliate memory with a sequence already in your memory

Question 32

Digit span

Answer 32

an evaluation of short-term memory that tests the number of items (numbers) that a person can repeat back in the correct order immediately after presentation. It is frequently used to quickly evaluate cognitive abilities

Question 33

Hippocampus

Answer 33

area of the mammalian brain, located in the temporal lobe, that is particularly important in memory formation and/or retrieval

Question 33

Entorhinal cortex

Answer 33

part of the medial temporal lobe located near the hippocampus. Important in navigation and memory. The entorhinal cortex is a major input to the hippocampus

Question 34

Place cell

Answer 34

a type of neuron in the hippocampus that fires at a specific spatial location in a specific context. (i.e. in your room, place cell “A” may fire when you're at your bed and place cell “B” may fire when you're at your desk).

Question 35

Grid cell

Answer 35

a type of neuron in the entorhinal cortex with a periodic receptive field that fills the current context with a triangular grid repetition

Question 36

1. List the two main kinds of human memory and briefly describe how they differ.

Question 37

2. List the three temporal categories of memory and define each.

Question 38

3. Define memory consolidation and describe how/why HM’s memory was impaired.