lecture 13: cognitive control and the frontal lobes

Question 1

Cognitive Control

Answer 1

mental abilities that involve
planning, controlling, and regulating the flow of information processing

Question 2

Goal-Oriented Behavior

Answer 2

interacting with the
world in a purposeful manner

Question 3

Cognitive Control has Wide Ranging Implications: name 2

Answer 3

“Cognitive control underlies our striking technological achievements over an equally striking range of domains, from agriculture and housing to medicine, transportation, communication and large-scale
economies. ”
David Rand & Jonathan Cohen, Behavioral Scientist, 2017

Question 4

what part of the brain plays a role in cognitive control and goal-oriented behavior

Answer 4

Prefrontal cortex: includes all of the areas in front of the primary and secondary
motor areas. We will focus mainly on lateral PFC.

Question 5

John Fulton

Answer 5

Performed experiment in which he removed
most of the frontal lobes in two
chimpanzees.
Their behavior changed dramatically –
previously wild/uncontrollable; now calm,
‘tamed’.
Presented results at 1935 World Congress of
Neurology in London.

Question 6

Egas Moniz

Answer 6

Attended Fulton’s 1935 talk in
London and wondered whether similar
approach might work in human
psychiatric patients.

Severed white matter connections
between frontal lobe and thalamus
(key relay station) in 20 psychiatric
patients, mainly psychotic and severely
depressed. In 1936 paper, reported that
symptoms improved.

Attended Freeman’s 1935 talk in
London and wondered whether similar
approach might work in human
psychiatric patients.

Severed white matter connections
Between prefrontal cortex and thalamus
(key relay station) in 20 psychiatric
patients, mainly psychotic and severely
depressed. In 1936 paper, reported that
symptoms improved.

Apparently not in all cases – was shot
and paralyzed in 1939 by angry patient
who had received frontal lobe operation.
Moniz received Nobel Prize in 1949 for
this discovery.

Question 7

Walter Freeman

Answer 7

Had attended Fulton’s talk and read
Moniz’s 1936 paper.

Extended and popularized Moniz’s
procedure, called it frontal or transorbital
lobotomy

Came up with a quicker and simpler
method of performing operation:
“ice-pick lobotomy

Question 8

Frontal Lobotomy

Answer 8

A lobotomy is a type of brain surgery that became popular in the 1930s as a treatment for mental health conditions such as schizophrenia. It involves severing the connection between the frontal lobe and thalamus

Question 9

Problems with Frontal Lobotomy

Answer 9

Very limited effectiveness: roughly 1/3 improved, 1/3 unchanged, 1/3 got worse

Consistently produced undesirable side effects in patients: “They are described by the nurses and the doctors, over and over, as dull, apathetic, listless,
without drive or initiative, flat, lethargic, placid and
unconcerned, childlike, docile, needing pushing,
passive, lacking in spontaneity, without aim or purpose, preoccupied and dependent.”
Hoffman (1949, New England J. of Medicine)

Began by lobotomizing severely mentally ill patients who were otherwise untreatable, but became more widespread and applied to adults with less severe forms of depression and children with behavior problems (like howard)

Question 10

working memory

Answer 10

Working memory is a multi-component system which proposes that short-term memory (STM) is a collection of multiple stores which actively process different types of STM includes the central executive, visuospatial sketchpad, phonological loop, and episodic buffer

Dual task test- Baddeley and Hitch (1974) set out to test the hypothesis that the short-term store also functioned as a working memory. They did so by requiring participants to perform reasoning, comprehension or learning tasks at the same time as they were holding in STM between 0 and 8 digits for immediate recall

Question 11

Lateral PFC Role in Working
Memory

Answer 11

Temporary activation of a limited amount of information over a brief time span; rapidly accessible, frequently updated, & used for higher cognitive processes.

Question 12

Human delayed response task:

Answer 12

*Intact & scrambled faces presented.
*Try to hold the intact faces in WM across delay.
*Number of intact faces varied across trials.
*After delay, probe presented and participant
decides whether it was in previously presented set.

Question 13

non lesion monkey delayed response task:

Answer 13

Prefrontal neurons can show sustained activity during delayed- response tasks. Each line represents a single trial. The cue indicated the location of the reward. The monkey was trained to withhold the response until a “Go” signal (arrows) appeared. Each vertical tick represents an action potential. This cell did not
respond during the cue interval. Rather, its activity increased when the cue was turned off.

Question 14

Prefrontal cortex and long-term recency/source
memory: Evidence from neuropsychology and
neuroimaging

Answer 14

Recency memory is thought to depend on the ability
to segregate and organize information (to a greater extent than simple old/new recognition), and therefore might be affected by prefrontal damage.

Tested in patients with parts of prefrontal cortex removed for relief of epilepsy (lobectomy).

Question 15

Recency memory

Answer 15

is thought to depend on the ability
to segregate and organize information (to a greater extent than simple old/new recognition), and therefore might be affected by prefrontal damage.

Tested in patients with parts of prefrontal cortex removed for relief of epilepsy (lobectomy).

Question 16

Recency memory test

Answer 16

Subjects were presented with a series of cards, each one showing a pair of objects. On
test cards, the objects were flanked by question marks, and the subject had to indicate
which object was seen most recently. In the recency test, both objects on the test cards
had been seen previously. In the item recognition test, only one object had appeared
previously

Question 17

Recency deficits observed only in those patients
with lesions to

Answer 17

dorsolateral prefrontal cortex

Question 18

Source Memory (aka Source Monitoring

Answer 18

Recalling the source of information or the context in which the information was learned – e.g., a friend, at a party, the Internet, etc.

Patients with prefrontal damage can learn novel or fictitious facts normally, but have great difficulty remembering which of two experimenters told them the facts or even that the information was acquired earlier during the study phase of the experiment

Question 19

Neuroimaging data have implicated specific PFC regions in cognitive control processes that
are especially important for source memory, such as monitoring and evaluationare especially important for source memory, such as monitoring and evaluation

Answer 19

Question 20

Studies with monkeys and humans indicate that prefrontal cortex is important for

Answer 20

working memory/delayed response task and that prefrontal neurons show sustained activity across delay

Question 21

Neuropsychological and neuroimaging studies implicate mainly lateral prefrontal regions in

Answer 21

recency memory and source memory, which
demand cognitive control during retrieval

Question 22

The Think /No-Think Paradigm

Answer 22

In the classical TNT paradigm participants are instructed to think or not to think of a target item that has previously been associated with a cue. For instance, individuals learn that the words ordeal and roach are associated and are then instructed to recall the target (roach) when exposed to the cue (ordeal). At the same time, for certain cues they are instructed to inhibit memory retrieval of the associated target word by preventing its content from entering consciousness (Anderson and Levy, 2009). Additional targets not presented during the TNT serve as baseline. Results revealed reduced recall for “no-think” targets compared to “think” or “baseline” targets.

Question 23

what were they trying to prove with the think no think paradigm?

Answer 23

avoiding a Memory Makes it
Harder to Recall

Question 24

think no think paradigm FMRI Expt: Procedure

Answer 24

In the classical TNT paradigm participants are instructed to think or not to think of a target item that has previously been associated with a cue. For instance, individuals learn that the words ordeal and roach are associated and are then instructed to recall the target (roach) when exposed to the cue (ordeal). At the same time, for certain cues they are instructed to inhibit memory retrieval of the associated target word by preventing its content from entering consciousness (Anderson and Levy, 2009). Additional targets not presented during the TNT serve as baseline. Results revealed reduced recall for “no-think” targets compared to “think” or “baseline” targets.

Question 25

Memory Impairment is Cue Independent

Answer 25

Question 26

GABA

Answer 26

Using fMRI and magnetic resonance spectroscopy, Schmitz et al. (2017) showed that a higher resting concentration of GABA in the hippocampus is associated with greater ability to suppress “no think” items, and with stronger coupling between the hippocampus and prefrontal cortex during attempted suppressions an inhibitory neurotransmitter.

Question 27

Is the think/no-think effect widely replicable?

Answer 27

Bulevich et al. (2006) reported experiments that failed to replicate the think/no think inhibitory effect But a meta-analysis of 32 studies revealed evidence for a modest but significant think/no think effect (Anderson & Huddleston, 2012). Similar findings from a more recent meta-analysis of 25 studies (Stramaccia et al. 2021, J. Experimal Psychology: General, 150, 828-850).

Question 28

Patients with PTSD are plagued by intrusive memories of traumatic experiences, which could reflect impaired cognitive control. Can they suppress memories in the think/no-think paradigm?

Answer 28

they seem to have difficulties with suppression

Question 29

2015 Paris Terrorist Attacks

Answer 29

130 people killed, deadliest peacetime attacks in French history 130 people killed, deadliest peacetime attacks in French history. Mary et al. (2020, Science) used the think/no-think paradigm and fMRI to study 102 people exposed to the attacks, 55 PTSD+ and 47 PTSD-, and 73 people who were not exposed to the attacks. Types of exposure: directly targeted; witnessed attack; first responders/police; close relative of deceased victim Non-exposed: were not in Paris during the attacks “Inhibitory control models predict that memory suppression will generate more negative coupling between frontally mediated control processes and memory regions PTSD- and non-exposed groups showed decreased coupling between control and memory regions during suppression attempts, whereas the PTSD+ group did not, and these differences were related to impaired memory suppression in the PTSD+ group.

Question 30

Componential Approaches to Prefrontal Cortex

Answer 30

Typically focus on processing differences in specific prefrontal regions, especially the role of task complexity in driving prefrontal activity. Example: Task manipulations related to hierarchical organization

Question 31

Hierarchical task manipulation

Answer 31

1. Simple stimulus-response task rules (e.g., press one key when seeing letter T, another for K) 2. Add task contingencies (e.g., response depends on presentation of target only in one of several colors) 3. More complex contingencies (e.g., change rules from one block of trials to another)

Question 32

Hierarchically ordered executive system

Answer 32

 Posterior-to-Posterior-to- anterior gradient  ‘Branching’ equivalent to maintaining multiple goals over time

Question 33

Cognitive Control of Goal-Directed Behavior

Answer 33

Attaining complex goals involves multiple component processes that depend on prefrontal cortex

Question 34

Wisconsin Card Sorting and Task Switching

Answer 34

Sort according to: Shape Color Numerosity On each trial, subjects place the top card of the deck under one of the target cards. The experimenter indicates whether the response is correct or incorrect, allowing the subject to learn the sorting rule by trial and error. The sorting rule changes whenever the subject makes 10 consecutive correct responses Patients with lateral PFC damage are impaired and are especially prone to repeat the same response (perseverate) even when it is no longer appropriate; have a hard time switching to new rule.

Question 35

A variety of tasks have been developed to try to pinpoint more precisely the problems exhibited by patients with lateral prefrontal damage during goal-directed behavior

Answer 35

Wisconsin Card Sorting and Task Switching Filtering tasks

Question 36

Filtering tasks

Answer 36

Verb generation task (come up with one verb semantically associated to noun) for nouns associated with many actions (high filtering) or few (low filtering). Patients with prefrontal lesions are more impaired in the high filtering than low filtering condition, and prefrontal regions in healthy participants show increased activity in high filtering vs. low filtering condition.

Question 37

Prefrontal Lesions Severely Impair Performance on Everyday Tasks Requiring Complex Goal-Directed Behavior (Shallice & Burgess, 1991)

Answer 37

Question 38

Multiple Errands Task (Shallice & Burgess, 1991) explain what the task is and the difference between a healthy patient and one with prefrontal damage

Answer 38

Requires participants to carry out a variety of errands in a real-world environment. Given list of items to purchase (e.g., loaf of bread), different types of information to collect (e.g, exchange rate for a particular currency), and related types of errands that can be accomplished in everyday (or virtual) setting. Told to spend as little money as possible and take as little time as possible without ‘undue’ rushing Not a memory test – patients have the list, have to figure out where to go and how to accomplish tasks.

Question 39

Patients with lateral prefrontal regions perform poorly on complex goal-directed tasks that require organizing and controlling task components: name and explain 2 experiments

Answer 39

wisconsin card sorting task, filtering task, then put them in everyday life: multiple errands task and six elements task in Shallice & Burgess

Question 40

source memory

Answer 40

Source memory refers to recalling the source of learned information, such as knowledge of when or where something was learned. Often, memories are triggered by contextual information (i.e., time and place).

Question 41

Cognitive control:

Answer 41

mental abilities that involve planning, controlling, and regulating the flow of information processing.

Question 42

Goal-Oriented Behavior:

Answer 42

interacting with the world in a purposeful manner; “goal-directed” is also used

Question 43

what part of the brain plays a crucial role in cognitive control and goal-oriented behavior

Answer 43

pre frontal cortex plays a crucial role in cognitive control and goal-oriented behavior.

Question 44

Frontal Lobotomies

Answer 44

* Performed on psychiatric patients to alleviate symptoms * Patients became much calmer Horrible side effects due to problems with cognitive control and goal directed actions * Lack of drive or initiative, * Lethargic * without aim or purpose * Etc.

Question 45

At least three types of memory rely on cognitive control

Answer 45

* Working memory * Source memory * Recency memory

Question 46

Working memory and the prefrontal cortex Working memory task:

Answer 46

keep in mind which slot the food is in Details: * No cue image on the card & the location of the reward varies randomly from trial to trial. Requires the monkey to keep the location information bonline during the delay Key finding: Lateral prefrontal damage: monkey cannot do the task

Question 47

Working memory and the prefrontal cortex Associative memory task:

Answer 47

Learn the relationship between a picture and food (no information is kept in mind over the delay) Details: Visual cue images on the cards & the location of the food was always associated with one visual cue. Requires the monkey to just remember which cue image was associated with a reward Key Finding: Lateral prefrontal damage: monkey can still do the task

Question 48

Working memory and the prefrontal cortex Monkey experiment

Answer 48

Monkey experiment: lateral prefrontal cortex is necessary for working memory

Question 49

Working memory and the prefrontal cortex Monkey experiment: lateral prefrontal cortex is necessary for working memory * What happens within lateral prefrontal cortex when information is maintained?

Answer 49

Presented with a series of faces, asked to hold in mind for later judgment * Manipulation: vary the number of faces to hold in mind (vary WM load) * Vary the number of faces to hold in mind (vary WM load) to test which brain regions are involved in WM Lateral prefrontal cortex is more engaged when holding more items in mind (=involved in working memory) Same pattern of results in monkeys: * Direct recordings from lateral prefrontal cortex: sustained activity while holding information in mind

Question 50

* Source memory

Answer 50

refers to recalling the source of learned information, such as knowledge of when or where something was learned. * E.g. * Who told me a fact? * Did an event happen in John’s apartment or Jane’s apartment? Evidence: dorsolateral prefrontal cortex damage patients have difficulty with source memory (increased false recognition)

Question 51

Recency Memory

Answer 51

Remembering the order of events * What happened more recently? A party at Jane’s or a dinner at John’s? Why would this rely on cognitive control brain regions? * Thought to rely on the ability to segregate and organize information How do we test whether this is the case? * Lobectomy patients (part of prefrontal cortex is removed for clinical reasons) * Have these patients do a lab version of the example above

Question 52

testing recency memory

Answer 52

* View a series of pictures over time, then judge which one was more recent Frontal damage patients (green) are worse at identifying which items were seen most recently Recency deficits observed only in those patients with lesions to dorsolateral prefrontal cortex (area 46), either in left or right hemisphere

Question 53

* How is information organized within these cognitive control regions?

Answer 53

* Some brain regions are responsible for representing the higher order abstract rules, other regions are responsible for the lower chunks

Question 54

how to cognitively control goal-directed behavior:

Answer 54

1) Identify goals and subgoals 2) Select relevant and filter out irrelevant information 3) Link subgoals into a plan of action 4) Switch from one task to another once you have completed one of the subgoals ** Attaining complex goals depends on multiple component processes that depend on the prefrontal cortex!

Question 54

Hierarchical task manipulations:

Answer 54

1) Simple stimulus-response task rules (press one key when you see ‘T’ & another key when you see ‘K’) 2) Add task contingencies (response depends on the presentation of the target only when its presented in green) 3) More complex contingencies (change the rules from one block of trials to another ** Posterior à anterior gradient as the experimental task becomes more complex** 1) Premotor cortex: stimulus response mappings 2) Caudal LPFC: related to the contextual demands of the task 3) Rostral LPFC: related to the variation in instructions from one scanning run to the next

Question 55

Characterizing deficits after prefrontal damage Elements of cognitive control of goal-directed behavior

Answer 55

1) Identify goals and subgoals 2) Select relevant and filter out irrelevant information 3) Link subgoals into a plan of action 4) Switch from one task to another once you have completed one of the subgoals

Question 56

3 tasks for studying elements of cognitive control of goal-directed behavior

Answer 56

1) Wisconsin card sorting task * Assesses switching from one task to another. Specifically, switching rules/policy halfway through 2) Filtering tasks * Select relevant, and filter out irrelevant, information 3) Task switching * Assesses switching from one task to another

Question 57

1) Wisconsin card sorting task

Answer 57

* Assesses switching from one task to another. Specifically, switching rules/policy halfway through Patients sort cards based on shape, color or number * They must figure out the rule and update how they sort the cards when the rule changes * Results: * Patients with lateral PFC damage are impaired and repeat the same sorting response even when it’s no longer appropriate = perseveration

Question 58

2) Filtering tasks

Answer 58

* Select relevant, and filter out irrelevant, information * Participants sort between competing bits of information * Participants come up with one verb that is associated with the presented noun (verb generation task) * (dog – walking, chewing, petting) * Some nouns are associated with many actions (which requires high filtering) * E.g. rope * Some nouns are associated with few actions (which requires low filtering) * E.g. kite

Question 59

3) Task switching

Answer 59

* Assesses switching from one task to another * Approach: Every 2 trials, task goal is cued by color * Assessment of task switching ability: compare response times between switch and non-switch trials * ‘switch cost’ = how much slower responses on switch trials are compared to non-switch trials Results: Prefrontal patients show greater RT (i.e., greater switching cost!) only in the color condition because it requires more working memory

Question 60

- Cognitive Control

Answer 60

Involves the lateral prefrontal cortex - Is involved in at least 3 types of memory - Working memory, Source memory, Recency memory - Can be characterized by tasks including - Wisconsin Card Sorting Task, Filtering Task, Task-switching

Question 61

* What is the definition of Cognitive Control? Goal-Directed Actions?

Answer 61

* Cognitive control: mental abilities that involve planning, controlling, and regulating the flow of information processing. * Goal-Oriented Behavior: interacting with the world in a purposeful manner; “goal-directed” is also used

Question 62

What were lobotomies, why were they practiced, and why are the observations relevant to the topic we are discussing today?

Answer 62

Frontal Lobotomies * Performed on psychiatric patients to alleviate symptoms * Patients became much calmer * Horrible side effects due to problems with cognitive control and goal directed actions * Lack of drive or initiative, * Lethargic * without aim or purpose * Etc. so frontal lobe lesions = problems with cognitive control

Question 63

What are three types of memory that involve cognitive control? Provide a definition and an example of each.

Answer 63

* Working memory- It's a skill that allows us to work with information without losing track of what we're doing * Source memory- Source memory refers to recalling the source of learned information, such as knowledge of when or where something was learned. Often, memories are triggered by contextual information (i.e., time and place). * Recency memory- Source memory refers to recalling the source of learned information, such as knowledge of when or where something was learned. Often, memories are triggered by contextual information (i.e., time and place).

Question 64

* For each of these three types of memory, which brain regions are involved and what is/are the study/studies that lead to that conclusion?

Answer 64

Working memory and the prefrontal cortex * Presented with a series of faces, asked to hold in mind for later judgment * Manipulation: vary the number of faces to hold in mind (vary WM load) Lateral prefrontal cortex is more engaged when holding more items in mind (=involved in working memory) Source memory and dorsolateral prefrontal cortex Evidence: dorsolateral prefrontal cortex damage patients have difficulty with source memory (increased false recognition) recency memory and prefrontal cortex * Lobectomy patients (part of prefrontal cortex is removed for clinical reasons) * Have these patients do a lab version of the example above * Frontal damage patients are worse at identifying which items were seen most recently.

Question 65

How is information held ‘on-line’ during working memory, and which brain regions are involved in this? * Describe paradigm and evidence from monkeys * Describe paradigm and evidence from humans

Answer 65

Working memory task: keep in mind which slot the food is in Details: * No cue image on the card & the location of the reward varies randomly from trial to trial. Requires the monkey to keep the location information online during the delay Key Finding: Lateral prefrontal damage: monkey cant do the task Associative memory task: Learn the relationship between a picture and food (no information is kept in mind over the delay) Details: Visual cue images on the cards & the location of the food was always associated with one visual cue. Requires the monkey to just remember which cue image was associated with a reward Key Finding: Lateral prefrontal damage: monkey can still do the task human test: Presented with a series of faces, asked to hold in mind for later judgment * Vary the number of faces to hold in mind (vary WM load) to test which brain regions are involved in WM Lateral prefrontal cortex is more engaged when holding more items in mind (=involved in working memory)

Question 66

What are the three types of tasks mentioned in class to study components of cognitive control? * What is each task measuring, what is the experimental paradigm used to study it, and what brain regions are implicated?

Answer 66

Wisconsin Card Sorting task * Patients sort cards based on shape, color or number * They must figure out the rule and update how they sort the cards when the rule changes * Results: * Patients with lateral PFC damage are impaired and repeat the same sorting response even when it’s no longer appropriate = perseveration Filtering Tasks * Participants sort between competing bits of information * Participants come up with one verb that is associated with the presented noun (verb generation task) * (dog – walking, chewing, petting) * Some nouns are associated with many actions (which requires high filtering) * E.g. rope * Some nouns are associated with few actions (which requires low filtering) * E.g. kite Greater activity in left IFC For high filter > low filter conditions Task switching * Approach: Every 2 trials, task goal is cued by color * Assessment of task switching ability: compare response times between switch and non-switch trials * ‘switch cost’ = how much slower responses on switch trials are compared to non-switch trials Results: Prefrontal patients show greater RT (i.e., greater switching cost!) only in the color condition because it requires more working memory