Overview of Cognition: Attention & Executive Functions

Acquired Neurogenic communication disorders:

• Language & Cognitive communication disorders

• Motor speech disorders

Language & Cognitive communication disorders:

• Aphasia

• Traumatic brain injury (TBI)

• Right hemisphere disorder (RHD)

• Dementia

Motor speech disorders:

• Apraxia

• Dysarthria

Traumatic Brain Injury (TBI):

• _____ occurs when the brain experiences sudden trauma or damage

• _____ is one of the most common etiologies for deficits in cognitive communication functions

• Depending on the site & severity of lesion, _____ can lead to problems with memory, attention, executive functioning, & other related functions (e.g., complex language processing difficulty, personality changes).

Right Hemisphere Disorder (RHD):

• Damage to the side of the brain that is non-dominant for language

• Typically affects specific right hemisphere functions, such as:

  • Music processing

  • Visuospatial functions

  • Prosody

  • Higher-order linguistic abilities (e.g., humor, sarcasm, etc.)

Where does RHD fall?

• Cognition

Dementia:

• a syndrome characterized by acquired, persistent impairment of multiple communicative domains:

  • Memory

  • Attention

  • Executive functions

  • Language

  • Visuospatial abilities

Dementia (AD type):

• Cognition before language

Dementia (Primary Progressive Aphasia type):

• Language before cognition

(Understanding Attention) Attention is always defined in relation to a stimulus, which could be:

• External (originating from the environment), or

• Internal (originating from within the individual)

(Understanding Attention) Attention:

• is closely connected to other processes such as language, memory, & executive function

• Is it possible to create a task that measures only attention & has zero language, working memory, or executive function demands?

(Attention - Capacity Limitation & Selection) What are 2 of the most important features of attention across neuropsychological models?

1. Attention is a limited-capacity resource

2. Attention involves selection of relevant stimuli (& therefore irrelevant stimuli must be somehow filtered out or ignored)

(Divided/Alternating Attention) Alternating:

• the ability to shift focus between tasks or stimuli

(Divided/Alternating Attention) Divided:

• ability to process or react to 2+ demands simultaneously (going back & forth, “multi-tasking”)

• required for daily tasks (doing laundry, cooking, driving)

• Impaired in: acquired cognitive dx (TBI, RHD, Dementia), aphasia

Theories & Models of Attention:

(Neurological Underpinnings of Attention) What is involved in a large range of cognitive abilities such as sustained attention?

• Bilateral Superior Temporal Gyrus (STG)

(Neurological Underpinnings of Attention) Which structure has a specific role in attentional allocation to unexpected signals?

• Right Inferior Frontal Gyrus (IFG)

(Neurological Underpinnings of Attention) What is involved in attentional control & selective attention tasks?

• Superior Frontal Gyrus (SFG) & Medial Frontal Gyrus

(Attention in Specific Populations) TBI:

• Heterogenous, attention is usually impaired, affects ADLS including driving

(Attention in Specific Populations) RHD:

• Impaired attention, may demonstrate neglect, affects ADLs

(Attention in Specific Populations) How is attention impacted in Dementia?

• Usually impaired in later stages except in Lewy Body _____

(Attention in Specific Populations) Aphasia:

• may have poor sustained attention, difficulty allocating attention to different tasks, impact on the use of AAC devices

Executive Function Components:

• Initiation

• Problem-solving

• Planning

• Mental flexibility

• Judgment

• Inhibition

• Reasoning

• Self-regulation

• Meta-cognition

Initiation:

• the action of beginning a goal-directed task

Problem-solving:

• Identifying the problem, generating potential solutions, choosing a solution, & evaluating the outcome

Planning:

• Setting objectives & determining a course of action for achieving those actions

Mental flexibility:

• the ability to change a course of action or thought based on the shifting demands of a situation

Judgment:

• Being able to discern the potentially good & harmful aspects of a situation, & act in a way that makes sense (e.g., problem solving → fire in the house & ask patient what they would do)

Inhibition:

• the ability to select appropriate responses & suppress unwanted actions

Reasoning:

• The process of forming conclusions, judgments, or inferences from facts or premises

  • where many patients may struggle when you ask them to come up with a logical response appropriate for a situation

Self-regulation:

• the regulation of one’s thoughts, emotional responses, actions, & motivations in order to behave in an expected way for a given situation

• similar to inhibition

Meta-cognition:

• Awareness & understanding of one’s own thoughts & skills & how you learn information

• major part of EF that we do in everyday life

What are Executive Functions?

• under the umbrella of cognitive functions but are higher-level more goal-directed than many other cognitive functions

• these functions are commonly referred to as a group, because they are very inter-related & somewhat overlapping

• High-level, interrelated, supervisory skills responsible for generating, selecting, organizing, & monitoring goal-directed and premeditated responses

Cognitive Processing & Regulation:

• All tasks & behaviors activate cognitive processes

• Each cognitive process requires mental effort/resources

(Resource Allocation & Cognitive Control) Automatic processing:

• rapid, unconscious

• the more _____ the task, the fewer resources it requires, thereby leaving more resources for other tasks

• _____ responses can be overwritten/inhibited by conscious cognitive control

(Resource Allocation & Cognitive Control) Controlled processing:

• slow, effortful, conscious

How is resource allocation impacted after brain injury?

• After brain injury → limited resources (or brain areas) for attention

• Amount of resources used for automatic tasks increases

• This leads to even fewer resources for other tasks

• Consequence → previously simple tasks take longer, & become more challenging

(Neurobehavioral Correlates of the Prefrontal Cortex) What is the function of the Dorsolateral PFC?

• monitors & adjusts behavior using working memory & EFs

(Neurobehavioral Correlates of the Prefrontal Cortex) What consequences could arise with a lesion to the Dorsolateral PFC?

• EF deficit

• Disinterest/emotional reactivity

• Decreased attention to relevant stimuli

(Neurobehavioral Correlates of the Prefrontal Cortex) What is the function of the Ventrolateral PFC?

• Response inhibition

• Goal appropriate response selection

• Attentional control viginance

(Neurobehavioral Correlates of the Prefrontal Cortex) What consequences could arise with a lesion to the Ventrolateral PFC?

• Emotional dysregulation

• Poor attention & vigilance

(Neurobehavioral Correlates of the Prefrontal Cortex) What is the function of the Orbitofrontal PFC?

• Emotional input

• Social behavior

• Suppression of distracting signals

(Neurobehavioral Correlates of the Prefrontal Cortex) What consequences could arise with a lesion to the Orbitofrontal PFC?

• Emotional lability; Disinhibition

• Distractability

• Social inappropriateness

(Neurobehavioral Correlates of the Prefrontal Cortex) What is the function of the Dorsomedial PFC?

• Arousal

• Motivation

• Initiation of activity

(Neurobehavioral Correlates of the Prefrontal Cortex) What consequences could arise with a lesion to the Dorsomedial PFC?

• Apathy

• Decreases drive/awareness

• Mutism

(Neurobehavioral Correlates of the Prefrontal Cortex) What is the function of the Ventromedial PFC?

• Emotional control

• empathy

(Neurobehavioral Correlates of the Prefrontal Cortex) What consequences could arise with a lesion to the Ventromedial PFC?

• Impaired judgement

• Inappropriate social behavior