Topic 9: Cognitive Control Flashcards
How does the PFC contribute to cognitive control?
the fact that damage to the PFC did not completely prevent the simple retention of such information, yet did (at times) lead to deficits in appropriately using such information, was interpreted as implicating the role the PFC may play in the control of information being held i STM (without necessarily being the exact location where such representations were stored)
this is a good set of results to revisit in the context of our current discussion of cognitive control, as these results likely reflected deficits in cognitive control (rather than deficits in the ability to temporarily hold onto information)
What is frontal lobe syndrome?
characterized by a pattern of behavioral deficits in various aspects of control
associated with relatively normal ranges of cognitive abilities (e.g., IQ, etc.)
cognitive control often involves inhibition
What is the distinction between the lateral and medial/orbital PFC?
lateral PFC: seems to be associated with control
medial/orbital PFC: seems to be associated with emotion and decision making
What is utilization behavior/syndrome?
an exaggerated tendency to have behavior shaped by the external environment, in which unintentional and/or unconscious actions are triggered by the immediate environment
What is imitation behavior?
spontaneous copying of movements, gestures, etc.
could mirror neurons be involved?
What is the Knight and D’Esposito (2003) study on PFC function in relation to other regions?
discuss the possibility that the parietal lobes may encourage engaging with things in the environment that we are drawn to (i.e., approach behaviors for food), while the frontal lobes may encourage the opposite when appropriate (i.e. avoid behaviors)
in the general population, this may result in the frontal lobes helping to maintain a delicate balance of approach/avoid behaviors by inhibiting the activation that is constantly occurring in the parietal lobes in response to environmental stimuli
in patients with frontal lobe damage, that inhibitory activity that would otherwise keep behavior “in check” may be lost, resulting in greater difficulties with “appropriate” behavior
How is the Wisconsin Card-Sorting Task used to measure behavioral deficits?
this involves a deck of cards with various properties (shape, color, etc.) that need to be attended to in order to successfully perform particular rule-based tasks (e.g. sorting by color)
the rule-based task changes from time to time, which requires an “updating” of behavior based on the latest change: e.g. if you previously sorted by color, then have to sort by shape, you now must ignore color (which you just got used to attending to/acting upon)
What are perseveration errors?
for trials in which the rules have changed are common in patients with frontal lobe damage
involve difficulty changing a behavioral set that has already been learned/reinforced yet is no longer relevant
may reflect a failure of inhibition
some patients could actually (accurately) identify whether or not they were making the correct move, yet were unable to stop themselves during an in-progress error
What is the “A-not-B error”?
- toy hidden in either box A or box B
- several trials i which the toy can be found in box A
- the A-not-B error is said to occur when, if they toy is moved (in front of the infant) to box B, they still look for it in the previous location (box A)
What was Piaget explanation for the “A-not-B error”?
Piaget attributed the A-not-B error to a lack of object permanence (an understanding that objects continue to exist, in a similar location/state, after we stop attending to them)
this characterizes the error as being a failure related to developmental factors
How can the “A-not-B error” be conceived as a failure of working memory?
it has been proposed that the A-not-B error might be conceived of as a failure of working memory
however, this view seems inconsistent with manipulations designed to reduce the working memory load (by keeping all the relevant information constantly visible), which nevertheless still produced this error
results such as these suggest the A-not-B error may be best characterized as a perseveration error
How can we explain the behavior deficits we see associated with frontal lobe damage?
difficulty filtering out irrelevant information (e.g. ignoring the color once it’s no longer relevant)
difficulty selecting relevant information (e.g. not attending to the shape once it’s become relevant)
What is the electrophysiological evidence for difficulty filtering?
irrelevant sounds produces a larger neurological response in patients (larger amplitude of auditory evoked response component, or AEP)
extent of deviation (from controls) correlates with magnitude of behavioral deficit
What is the electrophysiological evidence for difficulty selecting?
relevant sounds produce less of a response in patients (smaller amplitude of N1 component)
What are error signals?
an ERP component related to making an error (o speeded RT tasks) was (somewhat independently) discovered by two groups of researchers at around the same time, and consequently each name it something different
- Ne (error negativity)
- ERN (error-related negativity)
components become apparent just before making an error, and peaks ~100 ms later
one way to think about this is that it may reflect a signal that indicates cognitive control is required (e.g., if performance starts suffering)
What region of the brain is the error signal located in?
the Ne/ERN is thought to be generated in the dorsomedial frontal cortex (dmFC), which includes the posterior anterior cingulate cortex (ACC)
the fact that this region has traditionally been thought of as part of the motor system fits nicely with the idea that “lower-level” modules (like parts of V1 that are involved in direct visual perception) might contribute to “higher-level” cognitive processes (like holding something in WM)
abnormal errors signals have been associated with various anxiety disorders
What are some the situations in which we would expect error signals related to performance monitoring?
pre-response conflict: occurs when a stimuli activates multiple response tendencies (e.g., the stroop effect)
decision uncertainty: lack of confidence in a decision
response error: an error made with some level of awareness
negative feedback: being told you have made a mistake
What are the two subtypes of ERN?
response ERN: occurs without feedback
feedback ERN: peaks ~250-300 ms after feedback indicating a mistake
