memory and perception

Question 1

is memory a single function

Answer 1

no

Question 2

what are the types of memory?

Answer 2

episodic

semantic

working

procedural

these types of memory can be dissociated from each other and disrupted independently

Question 3

what is episodic memory?

Answer 3

memory of specific events

Question 4

what is sematic memory?

Answer 4

memory for facts

Question 5

what is working memory?

Answer 5

short term

rehearsal

Question 6

what is procedural memory?

Answer 6

motor memory

Question 7

what is damage to memory called?

Answer 7

amnesia

Question 8

what is the neurology of memory?

Answer 8

hippocampus, amygdala and related structures in the medial temporal lobe (MTL)

fornix = major output of hippocampus

mammillary body = further output, pushing towards thalamus (information relay station)

amygdala = emotion processing

Question 9

what is anterograde amnesia?

Answer 9

poor ability to acquire new information

information acquired before damage is relatively spread, especially further back in time

also information in working memory (ongoing rehearsal) is spared

impaired declarative (explicit) memory - episodic, semantic

relatively preservation of non-declarative (implicit) memory - perceptual (familiarity with stimuli) and procedural (motor skills and habits)

Question 10

what are the causes of anterograde amnesia?

Answer 10

disorders - Korsakoff’s syndrome

temporal lobotomy (1950s)

Question 11

what is Korsakoff’s syndrome?

Answer 11

thiamine (vitamin B1 deficiency)

due to alcoholism - poor diet and impaired absorption of thiamine from intestine

produces bilateral degeneration of mammillary bodies

Question 12

what is temporal lobectomy?

Answer 12

1950s

for patients with intractable seizures

bilateral removal of temporal lobes

Question 13

who was HM?

Answer 13

major seizures (epilepsy) since 16 years of age

drugs failed to contain seizures

surgical bilateral removal of anterior hippocampal regions at age 27

circumscribed lesion (surgical)

surgery successful in combating epilepsy

pure deficits - IQ unaffected by surgery, no personality change or other deficits outside of memory

even within memory, deficits are specific to formation of new memories

Question 14

what happened to HM’s working memory?

Answer 14

intact working memory

normal digit span unless interrupted (constant rehearsal)

rate of forgetting within normal range

can hold a conversation but later that day will not remember having held it

Question 15

what happened to HM’s semantic and episodic memory?

Answer 15

semantic memory disputed, absence of new episodic memory

language essentially frozen in 50s

reported date and age as prior to operation

could not remember events or people met post-operation

could not learn location of new home

deficits specific to semantic and episodic memory

Question 16

what happened to HM’s ability to learn new motor tasks?

Answer 16

could learn new motor tasks

improvements in short term

lost when pushed to long term

Question 17

what is the dissociations experimental design?

Answer 17

some tasks impaired while others spared

suggests these tasks use different resources or regions

problem - maybe one task is more difficult so it will always fail first

suggests tasks rely to come extent on different brain structures

Question 18

what are double dissociations?

Answer 18

one patient group task A spared, task B impaired

other patient group task A impaired and task B spared

Question 19

what is the difference between anterograde and retrograde amnesia?

Answer 19

anterograde = since lesion

retrograde = prior to lesion

Question 20

what is the neurology of retrograde amnesia?

Answer 20

hippocampus, amygdala and related structures in the medial temporal lobe

Question 21

did HM have retrograde amnesia?

Answer 21

temporally graded retrograde amnesia

old memories (childhood) still in tact

memories immediately before lesion lost (forgot death of favourite uncle in 1950)

Question 22

what do patients like HM suggest about the hippocampus?

Answer 22

hippocampus doesn’t store memories - old memories are preserved

role of hippocampus not yet completely understood

may enable consolidation of new memories, which are stored elsewhere

consolidation process must take time, possible decades

Question 23

how was retrograde amnesia tested in HM?

Answer 23

photos of celebrities suggest retrograde amnesia spans decades with more distant memories relatively preserved

Question 24

what is the neurology of vision?

Answer 24

occipital lobes and surrounding temporal and parietal, including primary visual cortex, ventral and dorsal stream

damage to these systems can cause agnosia or optic ataxia

Question 25

what is agnosia?

Answer 25

the inability to recognise, a lack of knowing or perception damage to ventral stream

Question 26

what is optic ataxia?

Answer 26

deficits in spatial perception, visuospatial processing and visual guidance of action damage to dorsal stream

Question 27

what are the types of visual agonisa?

Answer 27

apperceptive associative

Question 28

what is apperceptive visual agnosia?

Answer 28

unable to perceive full shape of object despite intact low-level processing inability to extract global structure can see parts, but not whole evidenced by impairments in drawing, copying and visual recognition, even of common objects

Question 29

what is low-level perception?

Answer 29

acuity brightness discrimination colour vision

Question 30

what is associative visual agnosia?

Answer 30

ability to perceive shape, but inability to recognise it (e.g. name it) intact ability to recognise the whole form of shapes no problem copying figures however inability to draw from verbal instruction or to recognise objects using iviosn

Question 31

what is prosopagnosia visual agnosia

Answer 31

tends to involve damage in fusiform gyrus in lower part of occipital and temporal lobe usually right sided

Question 32

what is apperceptive prosopagnosia visual agnosia?

Answer 32

inability to even perceive and cognitively process faces

Question 33

what is associative prosopagnosia visual agnosia?

Answer 33

inability to recognise or apply any meaning to the face despite perceiving it (can still identify individuals through voice, hairstyle, etc)

Question 34

what is the "fusiform face area"?

Answer 34

FFA renamed as a face area due to so many corroborating studies

Question 35

are faces special?

Answer 35

we are experts at processing faces faces are just difficult if faces are special, why are "pure" prosopagnosics so rare?

Question 36

are we experts at processing faces?

Answer 36

faces tend to include all the same features and very similar features are present in different individuals but we still recognise individuals well particular configuration of features is unique to an individual face-processing involves perception of the configuration as well as the features a specialised face-processing system in the brain may process faces "holistically" (as a whole) using configural information

Question 37

are faces just difficult?

Answer 37

most "prosopagnosics" have difficulty recognising differences within other categories (types of car, breed of dog, cows in a herd) FFA is not only concerned with faces also active when observing pictures of birds or cars