Lecture 4 Neurocognitive Deficits in UHR Flashcards
What are the two lines of argument for cognitive deficits and transition to psychosis
These two areas of brain functioning may be associated with a greater risk of transitioning to psychosis:
- Deficits in memory (hippocampal functioning)
- Deficits in executive functions (fronto-striatal connections and frontal lobe)
What are the 4 neuropsychological memory tests used in UHR research
Rey auditory verbal learning test (RAVLT)
Story Recall
Paired associates
Design learning
What are some of the limitations with the neuropsychological memory tests?
RAVLT: not just testing memory, but the individuals organisational capacity, their lexicon, and this varies depending on education and English being first language (not so much anything to do with psychopathology. Also you can get better as the task goes on in trials, so worth noting how the paper reported the outcome measure
Story Recall: again not pure memory - you can do well on this task by simply having a good understanding of prose
Paired associate : not pure memory, but how well you can associate words
Design learning: it is generally an easy task (perform at ceiling) but despite this, good predictor of transition to psychosis
What is the trail making task
A test of cognitive flexibility, where the individual has to join the numbers in numerical order ASAP. Version A has no distractors, and version B has distractors (letters) - this measures EF as you need to inhibit your response to the distractors, in order carry on with the task ASAP.
What is the continuous performance test
Need to maintain attention in the task (boring and repetitive), and press when you see the same symbol twice in a row.
When people make an error, it is because they were not able to maintain their attention and omitted to seeing something important.
What is the EF test
The Wisconsin Card Sorting test.
You need to sort the cards out by number, colour or form, and then the rules will be changed without the individual knowing, and they have to then order the cards by learning from their mistakes.
What did Ozgurdal et al (2009) find when observing verbal memory in UHR and FEP individuals
The two groups had similar cognitive performance in terms of their verbal memory - we can hence see this as a core cognitive deficit in people with psychosis and those that are at risk.
BUT for the UHR group, their poor performance was on their sustained attention not memory.
Problems with Ozgurdal et als findings?
- The potential impairments on cognitive performance was possibly buffered by the high IQ of the individuals in the sample (both in UHR and FEP group) - biased sample
- ALSO, as we know not everyone in the UHR group transitions (Fusar-Poli et al) so is it worth looking at neurocognitive deficits, given majority of UHR will not transition.
What did Brewer et al (2005) want to find
- Studied UHR individuals with a known outcome (followed up early participants in the PACE study, for which we know if they transitioned or not)
- Seperated into UHR transition and UHR non transition individuals (and used healthy control)
Findings from Brewer et al (2005)
- There was lower premorbid and performance in IQ in the UHR vs HC group
- Impairments in visual and verbal memory were SPECIFIC to the UHR transition group
- The differences between the groups were driven in visual reproduction (design learning) and story recall tasks.
This suggests that the tasks for which people who transition to psychosis do most poorly on, draw on rapid processing and rapid organisation of information - WHICH IS WHY selection of subtests and outcome measures are important.
What did Siedman et al (2010) find
Similar findings to Brewer et al:
- Impaired neuropsychological functioning in UHR and genetic high risk individuals, compared to HC.
- Processing speed and verbal memory were what was discriminating UHR from HC.
- There was greater neuropsychological impairment in UHR transition than nontransition.
What is the argued performance in cognitive tasks related to psychopathology
HC > UHR-NT > UHR-T > FEP.
What is a delusion
A false, unshakeable belief or idea that is not in line with the individuals educational, cultural or social background. It is held with extreme conviction and subjective certainty
- Sims 1995
What are of brain functioning are delusions said to represent?
A frontal-striatal impairment.
What is the formation model of delusions (Freeman et al, 2002)
Delusions result from an intact reasoning mechanism, that helps us make sense of anomalous experiences.
In individuals with psychosis or UHR, they perhaps have impairments in attention and miss out parts of the conversation and information. They then need to make sense of what it is they heard.
This search for meaning, leads them to an atypical conclusion and appraisal, which is influenced by adverse environments, isolation, dysfunctional schemas of the self and world and attributional biases.
