Clinical Neuropsychology: Executive Functions

• Clinical Neuropsychology, given on the 28th of February 2025, covers Executive Functions
• The presenter is Dr. Priska Zuber, from the Department of Health, Medical and Neuropsychology

Learning Objectives

• Define attention and executive functions.
• Understand the most discussed models/theories of attention and executive functions.
• Identify the characteristics of impaired attention/executive functions.
• Know how attention and executive functions can be assessed.

Outline

• Topics covered are tree of attention, theories, measurement, fractionated vs unitary view of executive functions, models, measurement, neuroanatomy, attention and executive functions over the lifespan, impairment, and if we can improve attention and executive functions
• Models for attention include Mental Shema Theory, Brain Model and Attention Networks Theory

Lucy's Story

• Lucy is a 35-year-old medical assistant who loves to cook
• She had a bicycle accident on the way to work and went to rehabilitation for 3 weeks
• She now realizes difficulties in daily life, problems when cooking, and struggles to take notes in meetings
• She is also suddenly late to work often

Attention Types

• Selectivity refers to Selective, Focused, and Divided Attention
• Intensity refers to Alertness, Phasic Alertness, and Tonic Alertness

Attention Models

• Mental Shema Theory, developed by Norman & Shalice in 1986
• Brain Model, developed by Posner & Petersen in 1990
• Attention Networks Theory, developed by Corbetta & Shulmann in 2002

Mental Schema Theory

• Sensory-perceptual structures, the trigger database, schemas, and the Supervisory Attentional System contribute to psychological processing structures

Attentional Control of Behaviour

• The Central Executive manages the Phonological Loop, Visuospatial Sketchpad, and Episodic Buffer components for attentional control of behaviour

Brain Model

• The Brain Model includes the Posterior Attention System, Visual Word Form Area, Anterior Attention System and Left Frontal Semantic Area

Attention Networks Theory

• The Attention Networks theory has two distinct attentional systems, the ventral and dorsal systems
• Bottom-up attention is passive and activated by external stimuli
• Top-down attention is active and has selective processes

Attention Assessment

• Attention assessment needs to incorporate speed and selection or switching ability
• Attention tasks need two conditions, to perform a task as fast as possible and a timed task where selection is needed

Example Attention Test

• The Stroop Test can be used to highlight a selective attention impairment
• The first condition will show no impairment, but the second condition will be slightly slower with a subject with selective attention impairments

Executive Functions Defined

• Executive functions are abilities that allow a person to adapt to new situations and develop and follow their life goals in a productive and constructive manner

Executive Function History

• Alexander Luria discussed "Higher cortical functions" in 1966
• Muriel Lezak discussed "Executive Functions" in 1982
• Goschke & Bolte discussed the Shielding shifting dilemma
• In 2014 there was a fractionated vs unitary view of executive functions

Shielding/Shifting Dilemma

• Executive functions include goal setting and control of behaviour to achieve the goal
• The dilemma of the control is Protection against distraction (shielding) vs Flexible adaptation of goal (shifting)

Views of Executive Function

• There the perspective that Executive Functioning is a Unitary View
• There is the perspective that Executive Function is a Fractionated View

Executive Function Views

• The Unitary view has a Central Operator which collaborates with other brain regions and is widely present in different models
• The Fractionated view has Multiple processes involved in executive functions like Energisation, Task Setting, Behaviour & Emotions, and Metagcognition & Integration

Executive Function Assessment

• Executive functions are hard to measure, often undetected in neuropsychological evaluation, and possible to measure in 3 ways
• Operational tasks are stimulus driven
• Tactical tasks are memory driven
• Strategic tasks are strategy driven
• Examples of executive function assessments can be found in the Stroop test, Trail Making Test, and Looking for keys task

Trail Making Test

• The ratio of Time for Trail B / Time for Trail A gives an indication of the executive functions involved

Brain Anatomy

• Both the unitary and fractioned views fail to explain how the brain controls itself
• The same areas in the brain are activated by different processes
• The current view is that "networks" is the best model

Fronto-subcortical Networks

• The dorsolateral prefrontal network relates to executive functions planning and problem solving
• The orbitofrontal network relates to social-cognitive and behavioural functions
• Damage to orbitofrontal network affects personality changes and disinhibition
• The anterior cingulate network relates to motivation
• Damage to the anterior cingulate network related to apathy and lack of drive

Functional MRI (fMRI)

• Records Time-varying changes in brain metabolism on the basis of blood flow
• Blood Oxygen Level Dependent (BOLD) fMRI is used to measure Task-related signals

Attention Networks

• The Frontoparietal control network relates to task initiation and adjusting control by error feedback
• The Cingulo-opercular network relates to sustaining control and tonic alertness
• The Default Mode Network relates to when the brain is at rest, monitored by the frontoparietal network, and self related processes

Executive Function Development

• Cognitive flexibility develops around 3-5 years
• Goal directed behaviour and selective attention develops at 7-12 months
• Executive functions peak at 20-29 years
• Cognitive flexibility and executive functions start declining at 50 years, with a steeper decline at 70 years

• Cognitive development can have:
  • "Sticky Fixation"
  • Scaffolding executive functions
  • distractors and working memory
  • university, relationships, travelling, work, family, meta-cognition

Impairments

• Impairments to attention and executive functions include traumatic brain injury, attention deficit hyperactivity disorder, stroke, dementia, multiple sclerosis and alzheimers

Brain Plasticity

• Previously, until 1928 nerve paths were thought to be fixed, ended, and immutable
• Brains change all the time and plasticity is a cornerstone of functioning today after research from Cramer et al., 2011

Cognitive Plasticity

• Cognitive Plasticity is the "... capacity for changes in flexibility, that is, the capacity for changes in the possible range of cognitive performance.", according to Lövdén, Bäckman, Lindenberger, Schaefer, & Schmiedek, 2010

Cognitive Training

• Cognitive Training led to overall improvements on executive functions in preschoolers, according to Scionti et al 2020
• Training of executive functions promotes cognitive and neurobiological enhancement in older age, according to Nguyen, Murphy & Andrews 2019

General Research Questions

• What function is trained?
• Possible relating processes?
• One fits all → What works for whom?