Lecture 6: Cognition Flashcards
In the discussion on time-course of deficits in SZ, we have covered 5 key points, what were they?
1) Subtle deficits appear ______
2) Deficits visible _______
3) Deficits seen _______
4) ____ change over time
5) However, some people may show ______ late in life
1) early in childhood
2) at first diagnosis
3) before first diagnosis
4) Little
5) increasing cognitive deficits
What were the main finding of the Pre-existing cognitive deficits (Bilder, 2008) study?
Methodology:
- They looked back at cognitive functions before the onset of symptoms.
- Looked at scores on standardized academic tests and estimated global cognitive function
Result showed that onset of disease is accompanied by _________________
additional declines in function
What were the results of the LAM (2018) study?
Methodology:
Singapore (ages 14-29), Ultra-high risk for SZ, Tested at 2-year interval
Compared those whose symptoms improved vs those whose symptoms did not. Remitters = those whose symptoms improved.
Results:
At baseline, all showed ___________ compared to controls
At follow-up. Remitters showed __________
Non-remitters showed ___________
- At baseline all showed deficits compared to controls
- At follow-up remitters showed improved scores, non-remitters showed no improvement
What was the main findings of the McCleery, 2014 study on Changes over the course of the disorder?
Methodology:
They compared SZ to 1st episodes and controls, instead of following up with the same individuals.
- on a large number of cognitive tests
Results:
- Both 1st episodes and controls performed worse _________
- There a few differences between 1st episodes and those who are more chronic in _________
- Cognitive changes are _________ but some areas may _______________
- healthy controls.
- WM and social cognition
- persistent but some areas may get worse over time.
What was the main findings of the Dickenson, 2007 study on Global / specific deficits in SZ?
Methodology: Analysis of data from 2000 people with SZ and controls
Results:
- Global IQ deficit is _____
- Also on _________
- Performance on individual tasks is ______
- large
- many different tasks
- highly correlated
Therefore the key finding of the Dickenson, 2007 study is that the impairments seems to be global or specific?
Global
What is important to remember from the tests that were administered during the Dickenson (2007) study?
Those tests require _________________
- memory,
- executive functions,
- attention
- basic perceptual processing.
Define Executive functions:
- Selecting and inhibiting responses
- Working memory
- Goal-directed behaviors
What are Goal-directed behaviors?
- Staying on task
- Planning and sequencing
- Shifting
- Evaluating outcomes (reward)
Executive functions are associated with which part of the brain?
fronto-parietal network
The fronto-parietal network is also important for ____
Attention
Executive functions are linked which regions of the brain
the temporal lobe memory network
Explain the Wisconsin card sorting task
- Match a series of cards to one of four key cards
- Feedback is only “correct” or “incorrect”
- After a set of correct trials, tester switches the rule, and participant must learn again.
What does the experimenter score on the Wisconsin card sorting task?
# of categories in 128 trials “perseverative” errors rule breaking
What are “perseverative” errors?
when the subject keeps giving the same response even though they were given the feedback that it is incorrect.
What type of skills does the Wisconsin card sorting task measure?
- Strategize,
- feedback learning,
- ignore irrelevant information,
- set shifting,
- inhibition of “prepotent” responses,
- retrieve and monitor working memory
Patients with ______ lesions perform poorly on the Wisconsin card sorting task.
frontal lobe
What were the errors that patients with frontal lobe lesions were making?
- complete fewer categories
- more perseverative errors
- loose track of the rules
SZ patients showed a similar profile than Patients with frontal lobe lesions. This was a consistent finding which suggests what?
impaired frontal lobe function in SZ
Describe the first Brain imaging study which used the WCST (Weinberger, 1986) methodology.
They observed activity in the brain and measured the intake of the gas the patients were inhaling. Regions of the brain that are more active need more blood, so show more Xenon uptake.
20 people with SZ; 25 controls
Xenon 133 inhalation
Xe113 travels in blood to the brain. Emissions detected over scalp
- Compare task performance to control
- Regions that are more active have more Xe 133 uptake
What was the main finding of the study where they administered a shorter version of the Wisconsin Card sorting task (Number match) and the full WCST?
A reduced frontal lobe activity for both task
More precisely:
Reduced activity in frontal lobe during Number Match
Reduced activity during WCST
No increase in frontal lobe for WCST compared to Number Match in SZ
(It shows you that there is a dysfunction in the frontal lobe cortex)
Why is the verbal fluency task related to executive function?
- because you have to retrieve info from memory, hold onto it, keep in mind particular rules and inhibit incorrect answers.
What were the findings when patients with SZ were compared with patients with frontal lobe lesions on the Verbal fluency task ?
Patients with frontal lobe damage do poorly on these tests
- Few words
- Repeat words (perseverative errors)
- Break rules
- SZ show similarly poor performance
SZ show poor performance for which forms of memory
All of them
Discuss the Weschler Memory Scale (WMS) [Family picture task]
It has auditory tasks and visual memory tasks. There is usually an immediate recall and also a delayed recall and a recognition phase.
The Memory and executive function study (Nestor et al., 2008) looked at global function by incorporating which three tasks?
IQ, WMS, WCST
This study was looking at the connectivity between which two lobes?
Frontal lobe and temporal lobe
The ______ connects the frontal lobe to the temporal lobe
Uncinate fasciculus (UF)
The connection between the frontal lobe and the temporal lobe through the Uncinate fasciculus (UF) is responsible for ________________
Connections from object memory stream
The _____ connects the parietal lobe to the temporal lobe
Cingulum bundle (CB)
The connection between the frontal lobe and the parietal lobe through the Cingulum bundle is responsible for ___________
Connections to frontal planning and attention regions
What was the idea behind the Memory and executive function Nestor et al., 2008 study?
The idea was to see if there are changes in these connections related to ______ or the ones that are related to ______ and the Wisconsin task.
- memory
- planning
What were the main findings for the Memory and executive function (Nestor et al., 2008) study?
SZ performed more poorly on the ___________ but dont significantly perform poorly on the ______ task but have more _____________
- global, memory function
- WCST task
- preservative errors (characteristic of SZ).
What was the main finding of this study in relation to the UF?
If they looked at the volume of the fibres in the UF (connected memory areas for objects to the frontal lobe) related to the ______________________
They found that for SZ the more fibres present the ______ the performance.
Therefore, this is an important set of connections important for __________
- WMS family pictures task.
- better the performance.
- visual memory.
What was the main finding of this study in relation to the CB?
It is connected to _______ (task)
The more fibres connected to the _______ the few errors people make on this task.
This finding suggest that SZ is also about ________
- WCST
- executive system
- damage between regions.
