PSY 223 Exam 2

Question 1

Define object recognition. Which visual pathway (ventral or dorsal) and brain regions are important for object recognition?

Answer 1

Object recognition – Definition: Matching representations of organized sensory input to stored representations in memory

The ventral pathway

Inferior temporal cortex

Question 2

Apperceptive Agnosia:

Associative Agnosia:

Prosopagnosia:

Answer 2

Apperceptive Agnosia: failure of object recognition due to problems with visual perception
problems with visual perception - can name touched object, when struggling to name the viewed object: may comment on other features, e.g. color

Associative Agnosia: failure of object recognition but not a problem with perception; normal visual representation.
associative agnosia thought to affect regions later along the ventral visual pathway than apperceptive agnosia,
“cannot derive the associations or assign meaning related to the stimulus input” i.e. not a perception problem - can name touched object,
when struggling to name the viewed object: may guess an object with similar features

Prosopagnosia: failure to identify or recognize individual faces visually

Question 3

What are three reasons why faces might be a special class of visual stimulus? What is the Thatcher effect? What is the composite face effect?

Answer 3

1) Faces need to be recognized as individuals

2) Faces are perceived in a “configuration”: it depends not only what the features are, but where they are in relation to each other

3) Configural perception is disrupted when a face is viewed upside down

Question 4

Know that the fusiform face area (FFA) has been argued to be specially devoted to faces, supporting the previous point that faces might be a special class of visual stimulus. Yet is the link between FFA and faces a perfect one-to-one mapping, such that only the FFA is active for faces, and only faces lead to greater activity in the FFA? Are there brain regions associated with classifying other types of objects?

Localization of function:

Mass action:

Answer 4

Most important for processing faces but also body parts and objects. It is not only active for faces. Are there brain regions associated with classifying other types of objects, the answer is yes there are other regions that have areas for processing.

Is only the FFA is active for faces? No

Do only faces lead to greater activity in the FFA? No

Are there brain regions associated with classifying other types of objects? Yes

Localization of function: each function is localized to a brain region / each brain region has a specific function

Mass action: each function can’t necessarily be localized to a specific brain region / each brain region isn’t specialized for a particular function

Question 5

Semantic memory:

Episodic memory:

Short-term memory (STM):

Working memory (WM):

short-term vs. working:

Answer 5

Semantic memory: Long-standing knowledge, lacks autobiographical component - longer than a few seconds

Episodic memory: Integrating information into an episode or event, Associating information with the time and place it occurred, autobiographical
episodic vs. semantic: both types of long-term memory, but differ in whether it is more about facts or events

Short-term memory (STM): required when the memory retrieval test of the just presented information is (almost) immediately after the memory encoding phase

Working memory (WM): required when the memory retrieval test of the just presented information is (almost) immediately after the encoding phase and performing mental operations on the information may be required

short-term vs. working: differ in whether it requires performing mental operations on the information

Question 5

Encoding:

Processing:

Type of memory:

Answer 5

Encoding: “processing of newly encountered information such that it can be stored and later retrieved”

Memory is like a storing in a filing cabinet and putting the paper in the filing cabinet would be encoding - this is processing and will always happened regardless of the type of memory in order to process/file it

Type of memory is representation so what is being processed specific to certain types of memory
Some regions more unique to verbal memory and some more unique to pictorial memory so this is representation
Some similar across all memory types like MT lobe which is processing regardless of the type of memory

Question 6

What are 3 challenges of studying the cognitive neuroscience of semantic memory?

Answer 6

1. Cognitive neuroscience of semantic encoding is challenging to examine (usually happens on a longer timescale than a single experiment)
2. Disentangling semantic memory from language
3. Some theories of semantic memory make similar predictions in the brain, making it harder to know which is right

Question 7

Which brain regions are important for semantic memory retrieval?

Answer 7

Frontal lobe and temporal cortex (generally more lateral and often more anterior - more toward surface/front)

Question 8

Divisions of of semantic categories - Based on lesion patients and neuroimaging studies, there is evidence that divisions between brain regions reflect:

Domain-specific categories:

Modality-specific categories:

Answer 8

Domain-specific categories: Semantic memory is “organized according to taxonomic categories” → living and nonliving

Modality-specific categories: Semantic memory is “organized according to the functional modalities…from which meaning derives” → not based on categories or subcategories but for living info (objects you receive it more passively but for living people take action or function

Question 9

Repetition suppression:

Dementia:

Semantic variant primary progressive aphasia (more commonly accepted) / semantic dementia:

Answer 9

Repetition suppression: Suppressed, or decreased activity in response to a stimulus that is repeated in short succession
- Different regions show repetition suppression to different types of stimuli => repetition suppression can be used to query a region’s sensitivity to different types of stimuli

Dementia: neurodegeneration leading to “progressive impairment of intellect and behavior that, over time, dramatically alters and restricts normal activities of daily living”

Semantic variant primary progressive aphasia (more commonly accepted) / semantic dementia: “word-finding difficulties, abnormal speech patterns, and prominent spelling errors…other faculties such as memory of daily events, visual and spatial skills…remain relatively intact” - more selective to semantic memories

Question 10

Different ways to study episodic memory or autobiographical memories

Recall task:

Recognition tasks:

Differences between Recall task and Recognition tasks

Relative:

Answer 10

Different ways to study episodic memory or autobiographical memories - could ask someone about their own experiences but has disadvantage bc don’t know if what they are retrieving is correct unless you can verify but also don’t know how recently they thought about that specific memory

Recall task: free recall = recall items in any order - can be more challenging

Recognition tasks: item recognition = recognize individual item as having been studied in the list

Differences between Recall task and Recognition tasks is how you test the memory not changing the words

Relative: recall of a sequence of easily confusable information (e.g. ’a t k p j c’) is worse than for less confusable (e.g. ‘r w k y f c’)

Question 11

Which brain regions are important for episodic memory encoding, and episodic memory retrieval?

Answer 11

medial temporal lobe and prefrontal cortex

Question 12

What is the subsequent memory design trying to determine? Which two types of stimuli are compared in this design, and is brain activity of the stimuli compared from encoding or retrieval?

Answer 12

Subsequent Memory Design: compare brain activity during encoding phase of what was remembered and what was forgotten

Compare neural activity during encoding for items that are subsequently remembered during the memory test vs. subsequently forgotten during the memory test

MT and Prefrontal cortex

Question 13

Define autonoetic and noetic retrieval. What is the difference between autonoetic retrieval and noetic retrieval? How can autonoetic/recollection vs. noetic/familiarity be distinguished in an item recognition test?

Answer 13

1. autonoetic: “necessarily involves the feeling that the present recollection is a reexperience of something that has happened before”

Recollection: Recognize the specific item and its associated category, color, etc. - High confidence

2. noetic (“knowing”)

a) retrieving information with a feeling of familiarity but without retrieving the specific associated episode

b) semantic, i.e. not associated to an episode but more so because it reflects long standing knowledge

Familiarity: Recognize the specific item but not its associated category, etc. - Low confidence

Question 14

Retrograde amnesia:

Anterograde amnesia:

Synaptic plasticity:

Answer 14

Retrograde amnesia: couldn’t retrieve memories of information a few years prior to surgery

Anterograde amnesia: couldn’t form new long-term episodic memories

Synaptic plasticity: “biological process by which specific patterns of synaptic activity result in changes in synaptic strength” - Nature (i.e., how strongly the same signal from the pre-synapse influences the post-synapse)

Question 15

Patient H.M

Answer 15

HM damage to MT and had deficits in long-term memory and explicit memory but no effects on short-term and working memory and nondeclarative memory - leads to “modification of behavior in a manner that does not require conscious access for its expression, and includes…motor learning, and perceptual learning”

Couldn’t form new long term memories and in consolidation - Symptoms assumed to reflect damage to the hippocampus

Surgery removed hippocampus: Retained short-term memory (STM) but unable to transfer info to long-term memory (LTM), Unable to form new LTMs, Short term memory okay but long term memory impaired

Anterograde amnesia (memory loss for information after lesion) - Suggests a deficit in “encoding” memories into LTM. Could have initial experiences but those experiences never made it into memory

H.M.: retrograde amnesia (memory loss for information prior to lesion) - Suggests a deficit in consolidation, or stabilization, of memories

Question 16

Define consolidation. What are 3 ways consolidation might occur?

Answer 16

Consolidation “hypothesized process whereby, over time, memories become more resistant to disruption” and stabilized

Occurs: repeated presentations, sleep, post-encoding rest

Question 17

Define Hebbian learning

What might underlie this change in ‘wiring’?

Strength in connections:

How might changes in synaptic plasticity (and thus Hebbian learning) occur?

Answer 17

Hebbian learning: “Neurons that fire together, wire together.” “When an Axon of cell A is near enough to excite a cell B and repeatedly or consistently takes part in firing it, some…change takes in place in one or both cells such that A’s efficiency, as one of the cells firing B, is increased”

What might underlie this change in ‘wiring’? Synaptic plasticity

Strength in connections:
1) more synapses
2) more channels at the synapse (to receive neurotransmitters on the postsynaptic side)
3) Increase in excitatory postsynaptic potential (EPSP)

How might changes in synaptic plasticity (and thus Hebbian learning) occur? LTP

Long term potentiation (LTP): long-lasting enhancement in signal transmission between two neurons, resulting from stimulating them simultaneously
- “core phenomenon underlying synaptic plasticity in many regions of the brain”, including the hippocampus
- “fundamental to learning and memory”

Question 18

WHICH IS HOW WHY WHAT

Hebbian learning:

Synaptic plasticity:

Long-term potentiation:

Answer 18

WHY - Hebbian learning: “neurons that fire together, wire together” through increased synaptic strength

WHAT - Synaptic plasticity: “specific patterns of synaptic activity result in changes in synaptic strength”

HOW - Long-term potentiation: “core phenomenon underlying synaptic plasticity….learning and memory”

Question 19

What are three proposed primary roles of the hippocampus in memory?

Answer 19

Hippocampus in the MT important for episodic memory and important for both encoding and retrieval

1) Hippocampus “binds”, or associates the elements of a memory together
2) Similarities and differences between memories
3) Spatial information and temporal information

Question 20

Retention interval:

Capacity:

Load:

An individual’s capacity is not absolute, but depends on:

When capacity is maxed out, memory errors may reflect:

Short-term memory (STM): required when the memory retrieval test of the just-presented information is (almost) immediately after the memory encoding phase

Answer 20

Retention interval: Delay period during which information is meant to be held / manipulated in STM /WM

Capacity: maximum amount of information which can be contained in STM/WM for an upcoming STM/WM test

Load: amount of information being held in STM/WM for an upcoming STM/WM test

An individual’s capacity is not absolute, but depends on:
how similar the to-be-remembered items are to each other
how similar the to-be-remembered items are to the information during the retention interval

When capacity is maxed out, memory errors may reflect:
fewer total items remembered
less information about each item is remembered

Short-term memory (STM): required when the memory retrieval test of the just-presented information is (almost) immediately after the memory encoding phase
“Almost immediate”: relative time, not absolute time - after 30sec is long term

Question 21

Which brain region plays an important role in STM and WM (despite some conflicting evidence)? What are 3 hypothesized roles of this region as it relates STM/WM? What are 3 other hypothesized roles for this brain region aside from STM/WM?

Answer 21

Prefrontal cortex (PFC) and short-term/working memory
Damage to PFC leads to deficits in STM/WM
PFC exhibits greater activity during STM/WM tasks. But why?

PFC is hypothesized to primary be involved in for STM/WM to:
process information - active for regardless for type of memory
represent memory load
represent the specific information held in memory

3 other hypothesized roles for PFC:
attention
visual processing
other types of memory

Question 22

What are two theories to describe how load increases with different types of to-be-remembered information? (Suppose we compare a participant’s accuracy on a STM task to remember 4 items with a STM task to remember 5 items. What are 2 theories that explain how the addition of 1 item will influence STM of the other 4 items?)

Answer 22

When more items need to be remembered, is it due to fewer items remembered (but remembered well) or worse memory for each item?

fewer items remembered: some results “can be well explained by a small set of discrete, fixed-resolution representations”, because as load increases, memory does not get worse for any single item

worse memory for each item: some results are “as predicted if working memory resources are shared between items”, because the error for each item gets worse

Question 23

Why is attention important, on a behavioral level and on a neural level?

Answer 23

Why is it important to have attention? The brain has limited resources: Energy metabolism in the brain can support only ~0.1 spikes/sec/neuron on average and Can plan only a limited number of actions at once

Attention makes processing more efficient
Ignore irrelevant information
Devote more resources to more important information
Faster response times
More accurate behavior

Question 24

What is the difference between an alternating attention and a divided attention task?

Answer 24

Alternating attention pay attention to Task 1, pause Task 1 while paying attention to Task 2, then return to Task 1 - requires mentally holding a place to return to in one task while tending to another

Divided attention: -pay attention to Task 1 and Task 2, both at once - requires allocating attentional resources to multiple tasks at the same time

Question 25

What are two ways attention can be measured on a behavioral level?

Answer 25

Reaction times and accuracy

Question 26

Exogenous attention:

Endogenous attention:

Overt attention:

Covert attention:

Answer 26

Exogenous attention: externally-driven attention

Endogenous attention: internally-driven attention

Overt attention: attention deployed toward an object or location by looking directly at it

Covert attention: attention deployed toward an object or location without looking directly at it - talking to friend but also keeping an eye on phone

Question 27

Covert vs. overt attention:

Answer 27

Based on the principle of cortical magnification, more of the object will be attended, and in more detail, closer to the center of the visual field, Changes in overt attention can be easy to measure with eye movements, It is useful (and can be easy) to distinguish between covert and overt attention. Eye movements may not fully track attention, because where someone looks may not actually be what they’re paying attention to. (This is the difference between covert attention and overt attention, actually.)

Question 28

Gain modulation:

The premotor theory of attention:

Re-entry hypothesis:

Answer 28

Gain modulation: the neural signal seems to be multiplied with increased attention

Results from recording in a neuron in parietal cortex - Neural activity is increased (multiplied with increased attention): gain modulation
More activity for movement than attention: consistent with the premotor theory of attention (“spatial attention…derives from a weaker activation of the same frontal-parietal circuits that, in other conditions, determine motor behavior toward specific spatial locations”)

Re-entry hypothesis “attention is an emergent phenomenon that arises from reentry and competitive interactions”

Question 29

What are 3 reasons why attention is best characterized with respect to visual processing?

Answer 29

Covert vs. overt attention:

Based on the principle of cortical magnification, more of the object will be attended, and in more detail, closer to the center of the visual field

Changes in overt attention can be easy to measure with eye movements

It is useful (and can be easy) to distinguish between covert and overt attention

Question 30

Is there a specific brain region which is more active as someone is paying attention, or does it depend on the type of task they are performing?

Answer 30

Answer is no but gain modulation, or a multiplicative change in activity, in the same brain regions which would otherwise be active for the task. As one example, either way right now there is a brown wall in my visual field but in the background, so certain neurons in the visual cortex fire action potentials in response. However, if I specifically pay attention to the wall (without moving my eyes so my visual field remains constant), now those same neurons fire more action potentials.

Question 31

What is cognitive control? What other cognitive processes does it involve?

Answer 31

Cognitive control: ability to guide actions, perceptions thoughts or memories “in accordance with internal goals regardless of the salience of goal-irrelevant stimuli or of goal-irrelevant behavioral choices”
attention
memory
inhibitory control: the ability to inhibit improper actions or responses
task switching and context switching
monitoring of tasks and errors

Cognitive intuition of attention: “Everybody knows what attention is. It is the taking possession by the mind, in clear and vivid form, of one out of what seem several simultaneously possible objects or trains of thought. Focalization, concentration of consciousness are of its essence. It implies withdrawal from some things in order to deal effectively with others” - William James → Spotlight

Question 32

Reactive control:

Proactive control:

Inhibitory control:

Utilization behavior:

Perseveration:

Answer 32

Reactive control: react to stimuli as they come

Proactive control: throughout the task, keep control processes aligned with task demands

Inhibitory control: the ability to inhibit improper actions or responses

Utilization behavior: “exaggerated tendency for one’s behavior to be determined by the external environment” - misusing info in the environment which shows issues with inhibitory control

Perseveration: “repetition of a particular response (such as a word, phrase, or gesture) regardless of the absence of a stimulus”

Question 33

Dorsolateral prefrontal cortex (DLPFC)

Anterior cingulate cortex (ACC) =

Answer 33

Dorsolateral prefrontal cortex (DLPFC) = proactive control
Stroop: keep control processes aligned with task demands (more like endogenous attention) is termed proactive control

Anterior cingulate cortex (ACC) = more challenging, reactive control
Stroop: Reactive control: “reacting to stimuli immediately as they come” is termed reactive control (more like exogenous attention)