Unit 12 - The Executive Brain Flashcards
What are executive functions? What part of the brain are they equated with?
The control processes that enable an individual to optimise performance in situations requiring the operation and coordination of several more basic cognitive processes
The frontal lobes, specifically the prefrontal cortex (PFC)
What classic distinction are executive functions closely linked to?
The distinction between automatic and controlled behaviour
Is behaviour entirely automatic or controlled? Does controlled behaviour require an autonomous controller?
No, this is a matter of degree rather than all or nothing
No, as shown by the homunculus problem
What are the two things out of which decisions may rise out?
Interaction of environmental influences
Influences related to the motivation and goals of the person
What are the three surfaces into which the prefrontal cortex is divided?
The lateral, medial and orbital surfaces
Where does the medial surface lie?
Between the two hemispheres and to the front of the corpus callosum
Where does the lateral surface lie?
Closest to the skull, anterior to the premotor areas and frontal eye fields
Where does the orbital surface lie?
Above the orbits of the eyes and nasal cavity
What important systems does the prefrontal cortex have connections with?
Sensory, Motor, Emotion, and Memory
What does the lateral prefrontal cortex primarily deal with?
Sensory inputs (also multimodal), such as visual, somatosensory and auditory information
What do the medial and orbital frontal cortices primarily deal with?
Long-term memory and processing of emotion
What are two structures that have loops with the prefrontal cortex?
Basal ganglia and the thalamus
What is the function of the loop through the basal ganglia? What does it thus help do?
Making the information stored in working memory less stable so that it can be updated
Learning novel tasks, procedural learning, task efficiency
What was the case of Phineas Gage? Where was the damage to his brain localised?
Large metal rod piece through his skull but maintained most of his cognitive and physical abilities. However, his personality changed drastically, becoming much more unpleasant.
Frontal lobes, particularly orbitofrontal/ventromedial region
Where is the main storage site of information for working memory? How is the prefrontal cortex involved in working memory?
Posterior cortex
Keeps the information active and manipulates active information according to current goals
What are the five main executive functions in practice?
Working memory
Task-setting and problem-solving
Overcoming potent or habitual responses
Task-switching
Multi-tasking
What can a lesion to the lateral prefrontal cortex cause?
Impairment in the ability to hold a stimulus/response in mind over a short delay
What is a self-ordered pointing task?
A task in which participants must point to a new object on each trial and thus maintain a working memory for previously selected items
What is the difference in content of information processed by ventral and dorsal regions in working memory?
Ventral regions support working memory for objects
Dorsal region support spatial working memory
What different processes do the ventrolateral and dorsolateral prefrontal regions engage in regarding working memory?
Ventrolateral activates, retrieves and maintains information in posterior cortex
Dorsolateral manipulates the information held in the posterior cortex
How is problem-solving generally tested?
By giving an endpoint and optionally a starting point, and having participants generate a solution of their own
What is meant by task setting?
Establishing and maintaining the goals and rules for a specific task
What is the FAS test? Damage to what brain region leads to impairments?
A test of verbal fluency in which participants must generate words beginning with a letter in a limited amount of time
Left lateral prefrontal
What is the Stroop test?
Response interference from naming the ink colour of a written colour name (e.g., the word BLUE is printed in red ink and participants are said to say the ink colour, i.e., red)
What is the Go/No-Go test? What two key concepts is this test linked to? Which region of the prefrontal cortex is most involved in this test?
A test of response inhibition in which participants must respond to a frequent stimulus (go trials) but withhold a response to another stimulus (no-go trials)
Impulsivity and inhibition
Medial prefrontal cortex
What is impulsivity? What test is this linked to?
A behavioural tendency to make immediate responses or seek immediate rewards
The Go/No-Go test, since participants must stop their impulsive tendency to go on no-go trials
What is inhibition in terms of neural activity? How about behavioural/cognitive inhibition?
Reduced spiking rate with more negative post-synaptic membrane potential
Reduced likelihood of a particular thought/action and the mechanism behind it
What is the Wisconsin Card Sorting Test? What does it involve? What do patients with damage to the prefrontal cortex fail to do in this task? What important executive function does this include?
A test of executive functions involving rule induction and rule use
Matching a series of cards against reference cards according to one of three dimensions, without knowing the right one. After each trial, participants are told whether they are right or not. If they are incorrect, they must switch the task.
Fail to make the shift, continuing to incorrectly sort according to the previous rule
Task-switching
What is preservation?
A failure to shift away from a previous response
What is task-switching?
Discarding a previous schema and establishing a new one
What is the switch cost? What is the likely reason for this?
A slowing of response time due to discarding a previous schema and setting up a new one
The suppressing of the old task
What is multi-tasking? Damage to what brain region impacts it?
The carrying out of several tasks in succession, requiring both task-switching and maintaining future goals while current goals are dealt with
Prefrontal cortex
What is one of the primary distinctions between different models of executive functions?
The extent to which the models assume that executive functions can be decomposed into several modular-like processes versus executive functions being seen as a unitary idea
What was Egas Moniz’s contribution to neuroscience? What did his creation involve?
The creation of lobotomies
The cutting of connections between the prefrontal cortex and the limbic system
What is the difference between “hot” versus “cold” control processes? Give some examples of both?
Hot control processes refer to control of affective / reward-related stimuli
Cold control processes refer to control of purely cognitive stimuli
Hot - e.g., stimuli including money, food
Cold - e.g., colour, shape
What is reversal learning?
Learning that a previously rewarded stimulus is no longer rewarded
Which part of the prefrontal cortex deals more with hot cognitive processes vs cold cognitive processes?
Hot - orbitofrontal cortex
Cold - lateral PFC
What are the two separate inhibitory control processes?
One reward related, and another sensory-related
What is the Somatic Marker Hypothesis? What areas do these somatic markers link? Where are these somatic markers stored? What is their role? When is their role most important?
A proposal that emotional and bodily states associated with previous behaviour are used to influence decision making
Areas storing previous situations (in the cortex), the feelings of those situations (in areas dedicated to emotion), and representations of the body states
Ventromedial frontal cortex
Controlling behaviour
In situations where feelings are critical
What is the Iowa Gambling task? What does it involve specifically? What was it created to investigate? Damage to which area leads to people not identifying the better strategy?
A task in which participants must learn to avoid risky choices in favour of less risky choices
Players are given four decks of cards (A to D) and a loan of 2000 in fake bank notes, and are instructed to play so that they win the most and lose the least on turning each card. The player receives either a monetary penalty or a gain. Playing mostly from packs A and B leads to a net loss, whilst C and D a net gain.
The somatic marker hypothesis
Ventromedial frontal cortex and orbital PFC
What is sociopathy? What are some symptoms? Damage to which areas are linked with it?
A personality disorder (now called Antisocial Personality Disorder) associated with irresponsible and unreliable behaviour that is not personally advantageous
Inability to form lasting relationships, egocentric thinking, impulsivity, etc.
Orbital and ventromedial prefrontal lobe
What is acquired sociopathy?
Refers to individuals who did not exhibit such symptoms prior to brain injury
What is delay/temporal discounting? Which type of patients most struggle with this?
The tendency for future rewards to have less subjective value than the same reward received now (or in the near future)
Orbitofrontal lesioned patients
What is neuroeconomics? This explores the tension between what two things? What part of the brain is related to which thing?
The use of neuroscientific methods and theories to account for economic decision making
Intuition/emotion (e.g., brand loyalty) vs. Goals/Beliefs (taste preferences)
Dorsolateral PFC linked to brand beliefs
Orbitofrontal cortex linked to actual reward assessment
What are the three elements of cognitive control?
Focusing on the relevant features of the subtask
As a subtask is completed, new elements must be focused upon and old ones discarded
Selected results are passed on from one subtask to another
What is the ultimatum game?
A two player game in which one player proposes a split of money and a responder either accepts the money (and obtains the agreed split) or rejects it (and both players get nothing)
What is the multiple demand network? What regions are included in it?
A set of brain regions in the lateral prefrontal and parietal lobes activated by a large range of tasks relative to the resting baselines
Lateral PFC, anterior cingulate cortex, intraparietal sulcus (IPS)
What is fluid intelligence? What part of the brain is this thought to be related to? Lesions to what part of the brain affect it?
Flexible thinking and problem-solving in novel situations, independent of acquired knowledge
The multi-demand network
Prefrontal cortex
What is crystallised intelligence? What does it involve? Can it be possessed by patients with damage to their prefrontal cortex?
The ability to use prior expertise and knowledge
Mental arithmetic, factual knowledge, speed of processing, etc.
Yes
Where is the rostral prefrontal cortex, and what is it involved in? Are patients with damage to it impaired on individual executive functions? What does this imply?
Anteriormost part of the frontal lobes
Multi-tasking
No they are only impaired on multitasking
A separate neuroanatomical basis for multi-tasking
What is the posterior prefrontal cortex involved in?
Handling single goals and task switching
What are the hemispheric differences of the PFC?
Left lateral PFC specialised for task-setting (maximised when task is open-ended)
Right lateral PFC specialised for task-monitoring
What is monitoring?
The process of relating information currently held in mind back to task requirements
What is sustained attention? What is it ensured by?
What is sustained attention? What is it ensured by?
How are individuals with left vs right lateral PFC damage impaired in task-switching differently?
Left - longer switch costs
Right - more errors (particularly perseveration)
What are the two primary roles of the anterior cingulate in executive functions?
Detecting errors
Evaluates situations where competing responses are triggered by a given stimulus
What is error related negativity? Where does it originate?
An event-related potential component in EEG that can be detected at the scalp when an error is made
The ACC
Is the ACC activated by cognitive or emotional stimuli? For example?
Both, e.g., both pain and money