Executive functions

Question 1

What are executive functions?

Answer 1

One conceptualisation (Miyake et al., 2000):
• The ability to over-ride automatic behaviour in
order to deal with novel situations
• The ability to switch flexibly between tasks
• The ability to carry out a task while holding in
mind other goals

Question 2

The prefrontal cortex

Answer 2

• The prefrontal cortex can be ‘divided’ in many
ways.
• One common subdivision of the prefrontal
cortex is into three ‘regions’:
– Dorsolateral prefrontal cortex
– Orbitofrontal cortex
– Mediofrontal cortex

Question 3

The frontal lobes

Answer 3

The frontal lobes are richly connected with
other cortical and subcortical regions of the
brain. Thus, we should not consider the
functions attributed to the frontal circuits or
regions to be solely localised or mediated by a
specific circuit or region.

Question 4

The dorsolateral prefrontal cortex

Answer 4

The DLPFC and its circuitry is involved in
higher order cognitive operations.
• This circuit is often labelled the ‘executive’
circuit, however it’s important to recognise
that executive functioning is also implicated in
the mediation of emotional, motivational, and
social behaviour.

Question 5

Deficits following damage to dorsolateral prefrontal cortex

Answer 5

Deficits following damage to the dorsolateral
prefrontal cortex may include:
– Working memory
– Planning, task-setting, and problem-solving
– Sequencing
– Selective and sustained attention
– Perseveration – “getting stuck”
– Inhibition
– Cognitive flexibility

Question 6

Working memory

Answer 6

• Alan Baddeley’s working memory model
can be thought of as a slightly different
way to characterise short-term memory
• He argued that working memory is a
system that provides temporary storage
for information that is currently being used
in some conscious capacity (Baddeley,
1986)

Question 7

Baddeleys theory working memory visuospatial sketchpad

Answer 7

System for rehearsing visual information

Question 8

Baddeleys theory working memory PHONOLOGICAL loop

Answer 8

System for rehearsing verbal information

Question 9

Baddeleys theory working memory: Central executive

Answer 9

System for controlling how the ‘slave’ systems like
the visuospatial sketchpad and the phonological
loop are used

Question 10

Baddeleys theory: Articulatory loop

Answer 10

“Inner voice” used during rehearsal of verbal
information
• The articulatory loop involves speech.

Question 11

Baddeleys theory: Phonological store

Answer 11

“Inner voice” used during rehearsal of verbal
information
• The articulatory loop involves speech.

Question 12

Working memory: The word length effect

Answer 12

– Short words are easier to (briefly) memorize
than long words
– wit, sum, harm, bay, top  4.5 words
– university, opportunity, aluminum,
constitutional, auditorium  2.6 words
• A crucial factor that
determines the
memory span is
how long it takes to
say a word

Question 13

Working memory: Evidence for the neural architecture

Answer 13

Delayed match-to-sample tasks with monkeys
(Goldman-Rakic, 1992)
• Monkeys with lesions to the frontal cortex
(DLPFC) weren’t able to perform this task

Question 14

Neuropsychological measures sensitive to

dorsolateral frontal damage

Answer 14

Digit span backwards, backwards 7’s, N-Back
(working memory)
• F-A-S test (individuals may repeat items or get stuck)
• Tower of Hanoi / Tower of London (tasksetting/planning,
sequencing, problem-solving)
• Stroop (inhibition)
• Wisconsin card sort (cognitive flexibility

Question 15

The orbitofrontal cortex

Answer 15

In basic terms, the orbitofrontal cortex and its
circuitry is involved in the mediation of
emotional and social responses. It is
responsible for executive processing of
emotional stimuli.

Question 16

The orbitofrontal cortex deficits

Answer 16

Deficits following damage to the orbitofrontal cortex
may include:
– Emotional lability
– Diminished social insight
– Socially inappropriate behavior, esp. conversational skills
– Difficulties with changing reinforcements
– Lack of sensitivity to future outcomes, both positive and
negative
– Lack of empathy

Question 17

Neuropsychological measures sensitive to

orbitofrontal damage

Answer 17

Family/caregiver reports of social behaviour,
empathy, aggression
• F-A-S test (individuals may give socially
inappropriate answers)
• Bechara’s Gambling task

Question 18

The mediofrontal cortex

Answer 18

This prefrontal region is believed to support a
number of overlapping functions, including:
– Response monitoring (control and monitoring of
action)
– Error detection
– Deciding between competing responses
– Motivation or drive behaviour

Question 19

Deficits to the mediofrontal cortex

Answer 19

• Deficits following damage to the mediofrontal
cortex may include:
– Apathy
– Akinesia
– Difficulties with emotion: flat affect
– Difficulties with decision-making
– Diminished verbal output

Question 20

Neurospsychological measures sensitive to mediofrontal damage

Answer 20

Family/caregiver reports (apathy)
• Questionnaires, scales measuring motivation
• Reaction time (individuals with damage to this region
may be slower on speeded tasks)