Study Notes on Chapter 19: Attention and Executive Function

Introduction

• Introduction to Behavioral Neuroscience Chapter 19: Attention and Executive Function

• Source: OpenStax ancillary resource © Rice University under a CC BY-NC-SA 4.0 License

• Chapter by: Kevin D. Wilson, PhD

• Slides prepared by: Elizabeth D. Kirby

Chapter Outline

• 19.1 Psychological processes associated with attention

• 19.2 Implementation of attention in the brain

• 19.3 Fate of unattended information

• 19.4 Relationship between attention and eye movements

• 19.5 Influence of clinical disorders on attention

• 19.6 Use of executive functions in decision-making and achieving goals

19.1 Psychological Processes Associated with Attention

• Attention
    - Definition: A global state of readiness or awareness regarding the processing of information at any moment.
    - Influenced by sleep, drugs, and external/internal signals.

• Arousal
    - Related to the physiological state of being alert or responsive.

• Consciousness
    - Complex and subjective experience; includes awareness of internal and external stimuli.

• Vigilance
    - The ability to maintain focused attention over prolonged periods.

• Selective Attention
    - Defined as the process of selecting certain information for enhanced cognitive processing.
    - Characteristics:
      1. Selected information is processed faster and with greater detail.
      2. Unselected information is processed more slowly with less detail.

• Covert vs. Overt Orienting
    - Overt Orienting: Involves moving the eyes to focus on a specific target.
    - Covert Orienting: Refers to attending to a stimulus without moving the eyes.
    - Example: Attending to a peripheral target while keeping focus on a central fixation point.

• Endogenous vs. Exogenous Attention
    - Endogenous Attention (Top-Down Process):
      - A deliberate shift of attention allocated based on goals and expectations; requires conscious awareness.
    - Exogenous Attention (Bottom-Up Process):
      - Attention captured automatically by novel stimuli in the environment; operates outside of conscious control.

• Test-like Question Scenario:
    - Situation involving Ethan at a cocktail party demonstrating attentional processes. Possible answers analyze whether it’s covert/overt or endogenous/exogenous attention.

19.2 Attention Implementation in the Brain

• Dorsal Attentional Network (DAN)
    - Associated with voluntary or endogenous shifts of attention.

• Ventral Attentional Network (VAN)
    - Related to bottom-up or exogenous shifts of attention.

• Brain Structures:
    - Default Mode Network (DMN):
      - Comprises the medial prefrontal cortex, precuneus, cingulate cortex, and angular gyrus.
      - Activity decreases during external focus and increases during internally directed processes (e.g., mind-wandering).

• Attentional Effects on Sensory Processing:
    - Brain activity varies depending on focal attention; for instance:
      - Increased activity in Fusiform Face Area (FFA) when attending to faces versus Parahippocampal Place Area (PPA) when attending to houses.
      - Visual information remains unchanged, but attention alters brain activity.

• Test-like Question Scenario:
    - Ethan forced to shift attention based on new information, identifying which brain network becomes active (DAN vs. VAN).

19.3 Outcomes of Unattended Information

• Inattentional Blindness
    - Phenomenon where individuals fail to notice unexpected stimuli when focused on a particular task (e.g., participants miss a gorilla in visual tasks).

• Perceptual Load Theory:
    - Attention operates as a limited cognitive resource.
    - Resources must be allocated strategically; remaining resources may unintentionally process task-irrelevant information.

• Experimental Example:
    - Participants search for specific targets while ignoring background patterns, demonstrating variation in brain activity based on task load.
    - Findings showed increased early visual area activity related to background patterns under low-load tasks compared to high-load tasks.

19.4 Attention and Eye Movements Relationship

• Premotor Theory of Attention:
    - Proposes that covert shifts of attention represent planned but unexecuted eye movements.
    - Experimental findings using monkeys support the notion where stimulation of FEF neurons affects detection of luminance changes consistent with covert attention shifts.

19.5 Clinical Disorders and Attention

• Neglect and Extinction:
    - Clinical phenomena revealing deficits in attention due to brain damage. Common methods of detection involve pen and paper tasks.
    - Conditions include:
      - Anosognosia: A lack of awareness of the impairment.
      - Spatial Neglect: Focusing deficits primarily in spatial context.
      - Representational Neglect: Ignoring one side of an object.
      - Object-Based Neglect: Failing to attend to portions of objects, such as letters on one side of words.

• Treatment Approaches:
    1. Prism Adaptation Therapy:
       - Shown to reduce spatial neglect.
    2. rTMS (Repetitive Transcranial Magnetic Stimulation):
       - Targeting unaffected hemispheres to alleviate contralesional neglect.

• Attention Deficit Hyperactivity Disorder (ADHD):
    - Prevalence in about 10% of children, with more boys diagnosed than girls.
    - Symptoms include hyperactivity, impulsivity, and focus challenges.
    - Structural differences observed include lower gray and white matter in prefrontal regions.
    - Treatment includes Methylphenidate (Ritalin) which inhibits norepinephrine and dopamine reuptake.
    - Alternatives include play and exercise proven effective.

19.6 Executive Functions in Decision-Making

• Executive Functions Overview:
    - Involve setting goals, planning actions, task-switching, monitoring progress, and suppressing detrimental impulses.

• Task-Switching Example: Wisconsin Card Sorting Test (WCST)
    - Participants sort cards based on evolving rules; frontal lobe damage leads to difficulties adapting to new conditions.

• Sequencing and Planning Example: Tower of London Game
    - Involves strategic moves to achieve predetermined configurations; assesses planning capabilities.

• Inhibitory Control Example: Stroop Test
    - Task involves stating ink colors of words, revealing cognitive interference in incongruent conditions.

• Neuroanatomy of Executive Functions:
    - Prefrontal Cortex and Anterior Cingulate Cortex (ACC) associated with varied executive functions. Regions exhibit anterior-posterior organization relevant to distinct functional aspects.

• Case Study of Phineas Gage:
    - Post-accident changes showing impaired impulse control and emotional regulation; significant in understanding executive functions.

• Mesocortical Dopamine Pathway:
    - Essential for executive functions;
    - Depletion studies in animal models indicate working memory deficits;
    - Associated with schizophrenia symptoms, including positive and negative types, along with executive function challenges.

• Test-like Question Scenario:
    - Implications for rTMS targeting in treating executive function impairments, notably indicating prefrontal cortex as the best target.