PSYC 322 - Higher Order Cognition I

Define the three core executive functions.

1. Executive Functions - a family of top-down processes needed when you have to concentrate and pay attention. There are three core EFs: inhibitory control, working memory, and cognitive flexibility.

   1. Inhibitory Control - ability to control one’s attention, behaviour, thoughts, and emotions to override a strong internal predisposition or external lure, and instead do what is more appropriate or needed.

   2. Working Memory - holding information in mind and mentally working with it.

   3. Cognitive Flexibility - the ability to change perspectives, either spatially or interpersonally.

      1. Spatially = understanding our environment.

      2. Interpersonally = understanding where someone is coming from (their perspective).

   4. EF in general can be boiled down to reasoning, problem-solving, and planning.

Describe methods to test executive functioning.

1. Intelligence Tests + Neuropsychological Assessments.

   1. Initially used as measures of intelligence (comparing individuals like IQ), but now used more to measure cognitive domains (helpful for diagnosis, screening, and evaluating risk of progression).

   2. Used often for adult / older adult intelligence testing.

      1. Weschler’s Adult Intelligence Scale (WAIS).

         1. Verbal Comprehension Index tested through vocabulary, similarities, and information tasks.

         2. Perceptual Reasoning Index tested through matrix reasoning, visual puzzles, and block design tasks.

         3. Working Memory Span tested through digit span and arithmetic tasks.

         4. Processing Speed Index tested through symbol search and coding tasks (I.e., trail making).

            1. Good to test since it requires attention, visual scanning ability, and numerical sequencing for older adults.

      2. Montreal Cognitive Battery (MoCA).

2. Clock Drawing Test.

   1. Tests planning, attention, and visuospatial skills.

   2. Patients are tasked to draw a clock, and the deficiencies in the clock will be related to their disease.

   3. We want to make sure the shape of the clock, minute and hour hand orientation, and numbers are all correct and that nothing is missing.

3. Wisconsin Sorting Task.

   1. Tests working memory, cognitive flexibility, and inhibition.

   2. Match a given card with a category, but rules change.

      1. Match by colour, shape, or number, but the rules change as to what you should match it to.

Discuss executive function decline with aging and sex.

1. There are consistent within-subjects changes in cognitive domains; we see a steady decline into older adulthood.

2. Younger cohorts are generally better, but this is not consistent between all domains.

3. There is a higher proportion of decline in females.

4. Longitudinally, EF and memory in healthy (cognitively normal) older adults are either stable or decline.

5. There is a relationship between beta amyloid accumulation across the cortex and cognitive decline (EF) in healthy older adults.

   1. Greater beta amyloid accumulation in frontal and parietal regions, associated with EF decline (not memory).

   2. There is a relationship between beta amyloid and executive functioning; specifically, greater beta amyloid accumulation leads to executive functioning decline.

6. There is a relationship between tau accumulation across the cortex and cognitive decline (EF) in healthy, older adults.

   1. Greater tau accumulation in parahippocampal and entorhinal regions is linked with memory decline.