M7, T3, utilization behaviour disorder

Question 1

Utilization behaviour disorder

Answer 1

occurs when someone executes actions with objects correctly but does so at an inappropriate time, without consideration of context or overall goals
-> e.g. patient might take a spoon and stir it in a cup if a cup and spoon are in front of them, even if the task is to write a letter

These behaviours disrupt performance of multi-step tasks

Question 2

UBD case study, Patient LE, intacts and deficits

Answer 2

• 52 year old male patient with bi-frontal lesion

Tested on an extensive range of neuropsychological measures:
-> Performance on WAIS indicated mild intellectual deterioration
-> Performance on spatial and perceptual tasks intact (e.g., degraded letters)
-> Performance on praxis tasks intact (e.g. imitate simple gestures)
-> Fluent expressive speech in response to questions (e.g., normal prosody)
-> Slightly impaired naming (e.g. graded naming tests)
-> Performance on memory tests severely impaired
-> Performance on all frontal lobe tests was severely impaired (e.g., Tower of London Test; simple recognition memory)

Question 3

Patient LE, how were UB assessments carried out, session 1

Answer 3

• LE performed neuropsych tests in the presence of other objects which, if he interacted with them, could imply utilization behaviour
• Objects were not referenced during the testing session (so no expectation that he should be using them implicitly or explicitly from the examiner)

Question 4

Patient LE, UB observed during assessment, session 1

Answer 4

• Conversation between LE and the examiner + clinical interview + neuropsych tests (irrelevant objects present during)
  -> 23 instances of UB occurring in all sections of the procedure
  -> Toying: e.g. picking up a pencil for no reason (8 times)
  -> Complex Toying: e.g. picking up a pencil and using it to move other objects (2 times)
  -> Coherent Activity: e.g. picking up a pencil and writing (13 times)

Question 5

Patient LE, how were UB assessments carried out, session 2

Answer 5

• Utilization behaviour investigated while LE was being tested in the presence of objects placed on trays
• Some objects were appropriate given context (e.g., pencil) and six were inappropriate given context (e.g., toy gun)
  Three sections:
  -> Experimental section –proximity and location of objects + type of task participant completed (audio verbal, visuo- verbal and visuo-manual) manipulated
  -> Clinical interview section – asked about family and work while objects present
  -> Verbal test section – tests administered that require verbal input and spoken output (e.g. WAIS) while objects present

Question 6

Patient LE, UB observed during assessment, session 2

Answer 6

• 31 UB instances
• Little effect of object congruency on UB
• Less coherent UB activity compared to session 1
• Some types of stimuli elicited UB more often than others – wasn’t related to visual properties of objects or congruency
• No effect of proximity or location

Question 7

Patient LE, comparisons between testing sessions of UB

Answer 7

• The type of task LE completed appeared critical.
• More UB during clinical interview in section 2 compared to formal testing in sections 1 and 3
• In section 1, no UB when visual-verbal or visual-manual tasks performed – but instances when auditory verbal task or when there were intervals between tasks
• Therefore, all UB happened when LE was meant to be doing audio verbal tasks or between tasks.

Question 8

Patient LE, why does UBD occur?

Answer 8

Poor top-down control of actions during a task?

This would mean environmental affordances (objects in the environment) end up being a much stronger trigger for action than our top down goal (i.e. what we want to do)

Question 9

Norman-Shallice functional model of action control and thought

Answer 9

Components
- special-purpose cognitive sub system
- schemata
- triggers
- contention scheduling
- supervisory attentional system (SA)

*look up image

Question 10

Special-purpose cognitive sub system

Answer 10

Things like object processing, spatial processing, etc

recognise where lanes are on the road, where to position car, etc

Question 11

Schemata

Answer 11

Programs that “run” on the cognitive sub systems, hierarchical in nature

procedures describing what to do that rely on the cognitive subsystems
-> e.g. braking at lights involves moving eyes to check mirror, overtaking

Question 12

Triggers

Answer 12

Perceptual inputs or outputs of other schemata that activate new schemata

seeing a red traffic light will activate the braking schemata, the overtaking schemata might trigger the checking mirrors schemata

Question 13

Contention scheduling

Answer 13

Chooses which schemata to control behaviour out of competing ones that are activated

slow car activates the overtaking schemata at the same time a red light activates the braking schemata. Contention Scheduling choose the correct schemata to activate (braking)

Question 14

Supervisory attention system

Answer 14

• Monitoring function active in novel situations when the active schemata do not provide an appropriate response or no schemata is ever activated fully.
• Doesn’t directly cause a response, adds more activation/inhibition to schemata

For LE (our UBD case), perceptual input (e.g. a mug and sugar) would activate the associated schemata and without inhibition from the supervisory system, the behaviour is enacted, even if it is not what the patient is meant to be doing.

Question 15

Why does UBD occur? Frontal lobe damage

Answer 15

• Frontal lobe damage can result in no supervisory attention system
• This allows for activation of various schemata and contention scheduling based purely on perceptual input
• Induced UBD

Question 16

Why does UBD occur? Demand characteristics

Answer 16

• The chance of UB can also depend on demand characteristics (i.e., what schemata are currently active and what is inhibited via contention scheduling)
• If no schemata are active = greater chance that presenting an object to patient would result in utilization behaviour
• Incidental UB