Chapter 13: Executive Function Pt. I Flashcards
What are three types of executive control functions?
establishing and modifying rules, contextual control, working memory
Why is executive control necessary? (5)
(1) When the situation requires planning or decision-making. (2) When the links between the input and the existing mental representations are novel. (3) When the situation requires a response that competes with habitual responses. (4) When the situation requires error correction or troubleshooting. (5) When the situation is difficult or dangerous.
What brain area is most often linked to executive control? Describe how the development of this brain area is related to changes in executive control across the lifespan.
PFC: Executive functions have been detected as early as 6 months after birth. The frontal lobes continue the processes or arborization, myelinization, and synaptogenesis until the late teens. Improvement of executive functioning in childhood coincides with growth spurts in the maturation of the frontal lobes. Many executive functions decline as we age. This decline is correlated with hippocampal and PFC atrophy. PFC loses 10-17% of its neurons;
You should know the 3 brain networks on page 485
Ventral striatum: get money and give to good cause
Lateral parietal cortex: social cog tasks
Medial prefrontal Cortex: mentalizing and thinking of mental states
What is the difference between Frontal Dysexecutive Syndrome and Frontal Disinhibition Syndrome?
Frontal Dysexecutive Syndrome: Apathy (losing interest in the world, losing social relationships, little spontaneity of thought and action). Attention-span issues; failure to complete tasks. Lack of insight into their condition (confabulation). Disinhibition Syndrome: Caused by damage to the ventral and medial—but not lateral—portions of the PFC. Normal response selection and working memory. Chaotic social lives filled with inappropriate behaviour.
What is abulia?
Damage to lateral but not ventromedial PFC. Patients can perform movements and answer questions, but do both in a slow and distracted manner. Lethargic and withdrawn. Difficulty sustaining actions (e.g., put your finger on your nose for 30 seconds).
What are three elements of goal-directed behaviour?
Identify the goal and sub-goals. Anticipate the consequences of your goal. Examine what is required to achieve the goal
Provide and example of an intradimensional shift and an extradimensional shift. How is dopamine related to attentional set-shifting?
Dopamine firing influences the degree to which relevant and irrelevant information is processed in the PFC. An intra-dimensional shift (IDS) occurs when a subject, trained to respond to a particular stimulus dimension, such as colour or shape, is required to transfer that rule to a novel set of exemplars of that same stimulus dimension. An cxtra- dimensional shift (EDS) occurs when a subject is required to shift response set to an alternative, previously irrelevant dimension
Describe two paradigms that test inhibition.
Oddball task: Participants attend to a continuously changing series of stimuli, most of which require a specific response (clicking button A). On a fraction of the trials, a different stimulus appears; participants must inhibit their usual response and make a different one.
Go/no-go task: In this task, participants respond to most stimuli (“Go”) but inhibit responding to other, infrequently presented, stimuli (“No-Go”) (like a tone)
Schizophrenics tend to show impaired inhibition. What does this tell you about their brains?
frontal lobe defect (can normally do the go tasks, but not the no-go)
What is perseveration? What type of patients show perseveration in the Wisconsin Card-Sorting Task?
is the continuance of a response strategy after the context has changed such that the response is no longer appropriate. Often occurs after lateral PFC damage.
What is the Tower of London test, and which brain area is critical for its performance?
The ability to create mental models of the world around us. Involves manipulating and operating with ideas and thoughts. Left DLPFC damage leads to impaired performance. Frontopolar cortex is particularly involved.
Describe one real-world example of deficits in simulation (e.g., Goel et al., 1997).
had frontal patients create family budgets. Patients understood the goal of the exercise. But, they did not produce reasonable goals (e.g., removing the $10,800 expense of ‘rent’).
Where in the brain are neurons that exhibit rule-selective behaviour?
Neurons within the principal sulcus in the lateral PFC and within the premotor cortex exhibit rule-selective behaviour. Firing occurs independent of the cues. Suggest movement and rule-based behaviours are linked.
What are some symptoms of orbitofrontal damage?
leads to personality and emotional changes, childlike behaviour. makes people indifferent to the consequences of their actions. These people have reduced inhibition and self-concern. Damage to this area leads to poor social interactions.
