Chapter 10: Attention and executive functions Flashcards
(44 cards)
1
Q
What is attention?
A
- Attention = a process that is responsible for the selection of one or more sources of information, which may be internal (thoughts and memories) or external (sounds and images).
2
Q
Which 2 aspects of attention on a theoretical level do van Zomeren and Brouwer distinguish and what role plays executive control on these 2 aspects?
A
- The 2 theoretical aspects of attention are:
1. Intensity
2. Selectivity - The role of executive control is the higher-order control of these attentional aspects.
3
Q
What are executive functions?
A
- Executive functions = the brain functions that are necessary for:
- Planning,
- Initiating,
- And regulating goal-oriented task behavior in complex, unstructured situations.
- executive functions are self-directed behaviors that arise from an individual’s own intentions and motivations.
4
Q
Why is the concept of attention closely related to the information processing approach to human cognition?
A
- Cognition involves the processes by which sensory input is transformed, reduces, elaborated, stored, retrieved, and used.
- Attention is closely related to human cognition, because attention determines which information is attended, processed and encoded into memory.
- Overall, attention is closely linked to the information processing approach because it is a fundamental aspect of how humans perceive, process, and interact with information in their environment, allowing them to effectively allocate cognitive resources and process information in a meaningful way.
- Also, in the original theories of attention, information processing takes place in successive stages like cognition does.
5
Q
Why is selection of relevant information necessary?
A
- Because the capacity of the human information processing is too limited to precess all available information within certain time margins.
6
Q
What does attention capacity refers to?
A
- Attention capacity = the amount of information or mental processes a person can pay attention to within a given time period.
7
Q
In which 2 ways can attention be directed in?
A
- Passive by bottom-up control: attention is automatically and involuntarily drawn to a stimulus.
- Active by top-down control: attention is directed selectively and voluntarily, and thus the selectivity is determined by the persion.
8
Q
What is directed attention and how can it be tested?
A
- Directed attention = when attention must be completely focused on one source of stimulation, a narrowly defined category of stimuli, or a particular aspect of an object, excluding other stimuli.
- To test directed attention, situations with distracted stimuli are used in which the subject is expected to focus his attention on one aspect of the task.
- E.g., Stroop task
9
Q
What is divided attention and how can it be tested?
A
- Divided attention = when attention is divided over multiple selected sources of stimulation.
- To test divided attention, dual tasks where attention is shifted very rapidly from one task to another. The cost of a dual task is calculated by comparing it with that of performing separate tasks.
10
Q
Which 2 types of information processing do Shiffrin and Schneider (1997) distinguish, and what do they mean?
A
- Controlled information processing = there is no fixed routine and a lot of attention capacity is required. As a result it proceeds slowly, it requires conscious attention and effort, and it’s limited in capacity. Controlled information processing relies heavily on executive functions.
- Automatic information processing = proceed rapidly, are not impeded by capacity constraints, and do not require conscious attention. Automated processes ensure that we can carry out our daily activities efficiently and quickly.
11
Q
On which 2 processes is the intensity of attention depended on?
A
- Alertness
- Sustained attention
12
Q
What is alertness?
A
- Alertness = the central nervous system’s receptivity to stimulation and its fluctuations.
- There are 2 kinds of fluctuations:
1. Phasic fluctuations = short-term changes that are largely determined by the situation or task demands.
2. Tonic fluctuations = occur over longer periods and are more determined by the organism than by the situation. - The fluctuations are not always under one’s control and may interfere with task performance.
13
Q
What is sustained attention and how can it be measured?
A
- Sustained attention = the ability to sustain attention for a long period of time for a task performance.
- Sustained attention can be measured by:
1. Time on task effect = examines the extent to which performance on an attention seeking task deteriorates over time.
2. Task performance variability = f.e., a change in the distribution of reaction times in a reaction time task that lasts several minutes.
3. Vigilance tasks = involves research into alertness during prolonged, very monotonous tasks, with a low frequency of relevant stimuli.
14
Q
Which 3 functional attention networks in which both cortical and subcortical areas participate do Posner and Petersen distinguish?
A
- Vigilance network,
- Posterior attention network,
- And the anterior attentional network.
15
Q
What is the vigilance network (Posner and Petersen) and which brain areas does it involve?
A
- Vigilance network = responsible for responding alertly in situations that call for vigilance and for maintaining this alert state for as long as necessary.
- It includes:
- The brainstem,
- The locus cereleus,
- The intralaminar thalamic nuclei,
- And the right hemisphere (particularly the right lateral frontal lobe).
16
Q
What is the posterior attention network (Posner and Petersen) and which brain areas does it involve?
A
- Posterior attention network = involved in visual-spatial attention.
- it includes:
- The posterior parietal cortex that released attention,
- The colliculus superior that shifts attention,
- And the pulvinar nucleus that attaches attention to a new goal.
17
Q
What is the anterior attentional network (Posner and Petersen) and which brain areas does it involve?
A
- Anterior attentional network = provides executive control of voluntary behavior and thought processes.
- It includes:
- The anterior part of the cingullum and the supplementary motor cortex.
18
Q
When is executive control especially needed and what kind of information processing is according to Shiffrin and Schneider needed to execute these tasks?
A
- Executive control is especially needed in tasks that are new and complex, require planning, error detection, conflict resolution and adaptation, and therefore can be performed less or not at all routinely.
- According to Shiffrin and Schneider, these tasks require controlled information processing.
19
Q
How do Burgess and Simons define executive functions?
A
- Burgess and Simons define executive functions as: the capacities that allow people to function effectively in real, everyday life, by enabling them to adapt to new situations and to conceive and pursue relevant life goals in a constructive and productive manner.
20
Q
Which brain regions are traditionally assigned as a central role in the neurobiological substrate of executive functions?
A
- The preforntal brain regions, but these regions are also part of neural network that also involve other cortical and subcortical regions.
21
Q
What did Luria hypothesize about the frontal lobes and executive functioning?
A
- Luria’s hypothesis emphasized the role of the prefrontal cortex in a central control system for behavior regulation, with executive functions such as problem-solving and decision-making being impaired in patients with prefrontal damage.
- Executive functions are a psychological construct related to higher-level cognitive processes, not synonymous with “frontal functioning.”
22
Q
What is the mental schema theory of Norman and Shallice’s?
A
- The mental schema theory = an information processing model which assumes that all thinking and acting is based on the activation of mental schemas.
- Schemas can be activated by information from the outside world and selection based on relevance is necessary.
- Within the mental schema theory, a distinction is made between routine and non-routine situations of the selection of schemas.
- Three mechanisms regulate the activation threshold and the power relations between schemas:
1. League selection,
2. Lateral modulation,
3. And supervising attention system (SAS).
23
Q
What are schemas?
A
- Schemas = programs or routines that determine the interpretation of incoming information and subsequent actions.
24
Q
What does league selection mean in the mental schema theory?
A
- League selection = the selection of schedules in automatic.
- This is done based on the strength of the scheme, which depends on how often it has been selected before and how recently.
- The strongest scheme wins and becomes active.
25
What does lateral modulation mean in the mental schema theory?
* Lateral modulation = the mutual influence of active schemas on each other, allowing an active schema to suppress a correspondingly incompatible other schema and facilitate a more compatible one.
26
What does Supervising Attention system (SAS) mean in the mental schema theory?
* SAS = routine failure to complete a task. This system becomes active in situations where conscious choices must be made and routine selection of schedules must be suppressed.
* The top-down regulation of schema selection takes place through various control processes.
* The SAS can be compared to the central executive of the working memory.
27
Of which 2 aspects does the conceptual adaptation of Shallice's schema that Brewer and Schmidt came up with consists?
1. The processes that represent essential aspects of executive functions.
2. The implicit automatic aspects of information processing and memory.
28
What 8 executive aspects does Ylvisaker's classification include?
1. Insight into and awareness of own capabilities and needs.
2. Set realistic, concrete goals.
3. Planning the steps that lead to goals.
4. Take initiative to start this planning.
5. Self-assess and evaluate performance according to purpose and plan.
6. Self-inhibition of behavior that does not lead to the stated goal.
7. Flexibility and ability to problem solve when a situation does not go according to plan.
8. Strategic behavior, or the ability to independently apply successful behavior in other situations.
29
In which brain areas are the executive functions located?
* Prefrontal cortex (multiple areas)
* Basal ganglia
* Cerebellum
* Thalamus
* Parietal cortex
30
In which 3 subareas can the prefrontal cortex roughly be divided in?
1. The dorsolateral prefrontal cortex.
2. The ventromedial and orbitofrontal cortex.
3. The gyrus cinguli anterior.
31
How do the subareas of the prefrontal cortex together form circuits that are each important for certain elements of executive functioning according to Tekin and Cummings?
* The dorsolateral prefrontal circuit (DLPFC) = important for executive aspects that are prerequisites for adequate task performance, such as:
- Selective focus of attention,
- Active maintenance and updating of information in working memory,
- Planning,
- goal selection,
- And monitoring and feedback use during complex task performance.
* The orbitofrontal circuit (OFC) = primarily involved in social cognition. The circuit also includes the ventromedial prefrontal cortex (VMPFC). It's involved in aspects that are essential components of executive functioning, such as:
- Processing reward related information,
- Inhibiting automatic responses,
- And adjusting behavior based on negative feedback.
* The anterior gyrus cinguli (AGC) = essential in motivational processes and initiation. It plays a role in error detection and thus has an evaluative function in detecting conflicting information and a guiding role in response selection. In fact, its role is to prevent errors by timely signaling when an adjustment in behavior is needed, resulting in motivation to change behavior and the drive to actually do so.
* Another distinction that can be made is between medial and lateral areas:
- Medial areas = more involved in self-related, endogenous information processing and planning.
- Lateral areas = more specialized in the processing of external, exogenous information in the execution of plans.
32
What is the role of the basal ganglia in executive functioning?
* The basal ganglia have the role of a central selection mechanism specialized in the allocation of availability of (limited) motor and cognitive capacities.
33
What is the role of the Thalamus in executive functioning?
* The thalamus is important as a switching station and is connected to a multitude of brain areas (including the (pre)frontal cortex).
34
What is found in basis of anatomical neuroimaging studies about the role of the cerebellum in executive functioning?
* That executive dysfunction can also occur after brain damage in the cerebellum.
* On basis of anatomical and neuroimaging studies, it is assumed that the cause of these disorders lies in damage to a cortico-ponto-cerebellar network that connects the cerebellum with the anterior brain regions.
35
What is the role of the parietal cortex in executive functioning?
* It appears that the parietal cortex plays a crucial role in executive processes, as part of a frontoparietal control network.
* In this network, the parietal cortex is important for both selecting planning-relevant information from the environment and generating representations of task goals to be achieved through planning.
36
Why can disturbances in attention and/or executive functioning manifest heterogeneously and diversely?
* Because both attention and executive functions are multidimensional constructs, of which the neurological substrate consists of complex neural networks in which not only the prefrontal cortex but also various other brain areas are involved.
37
Why is it not easy to measure attention?
* Attention cannot be measured as a separate phenomenon, but must always be derived from the comparison of performance on a task that requires a lot of attention with a task that requires little attention.
* Attention tasks are always subject to time pressure.
* A common order after brain injury and with brain diseases is delayed information processing (aka mental slowness). This has harmful effects on other cognitive functions and is particularly noticeable in divided attention tasks.
38
How can disorders in attention span be measured?
* Attention span problems are apparent when a task must be performed with strong distractions present and this task performance is disproportionately worse than the task performance without distraction.
39
How do disorders in sustaining attention manifest themselves?
* Disorders in sustaining attention manifest themselves in fluctuations in (prolonged) task performance.
* These indicate the inability to maintain a constant level of task performance over the course of the task.
* The attention fluctuations can be the result of low alertness or of increased distractibility.
40
What involves the SART (sustained attention to response task) that Robertson et al., developed?
* SART = a test that complies with the so-called go/no-go paradigm.
* Go/no-go tasks = reaction time tasks in which 2 types of stimuli are presented, and the test subject is instructed in advance which stimuli to respond to as quickly as possible and which not.
41
When do we speak of a dysexecutive syndrome and what does it mean?
* A dysexecutive syndrome = includes severe impairments in the different executive aspects as in Ylvisaker's definition.
* When executive dysfunctions are prominent after brain damage and can also be observed at behavioral level, we speak of a dysexecutive syndrome.
* A person with a dysexecutive syndrome is severely impaired in independent functioning and is not able to adequeately assess, plan, and execute everyday situations.
42
In which neurological disorders can disorders of executive functions occur?
* Disorders such as:
- Traumatic brain injury,
- A brain tumor,
- Oxygen deficiency,
- And a stroke or encephalitis.
43
In which neurodegenerative disorders can disorders of executive functions occur?
* Neurodegenerative disorders such as:
- Frontotemporal dementia,
- Alzheimer's disease,
- And Parkinson's disease.
44
Why is it difficult to measure executive functioning?
* Executive functions are only operational in situations that are not very structured, new, and complex, in which it's essential to be able to structure things and take initiative.
* However, most neurological tests are highly structured and will not sufficiently address this essence of the executive functions.
* Specific tests have been developed that are supposed to measure executive functions, but the disadvantage of these tasks is that it's difficult to analyse which executive aspects are impaired and which are still intact.
