Schizhophrenia

Question 1

What are the three main characteristics of schizophrenia?

Answer 1

• Positive (Type I) symptoms
• Negative (Type II) symptoms
• Cognitive deficits

Question 2

What are some of the most common cognitive deficits seen in schizophrenia?

Answer 2

• Executive functioning/cognitive control
• Attention
• Processing speed
• Memory
• Social cognition

Question 3

Outline dopamine hypothesis

Answer 3

• Important role of mesocortical dopaminergic pathway
• DA agonists such as cocaine and L-dopa can induce positive symptoms
• Disturbances lead to impaired cognitive function

Question 4

What is an issue with antipsychotic drugs?

Answer 4

Only effective in treatment of positive symptoms. Ineffective or even detrimental for negative and cognitive symptoms.

Question 5

What are the 2 phases of Glu modulations

Answer 5

• NMDA-mediated interneuron dysfunction- loss of inhibitory control, INCREASED GLU LEVELS
• Glu-induced Excitotoxicity- loss of Glu connections, DECREASED GLU LEVELS

Question 6

What are some of the neuroanatomical differences seen in schizophrenia brains?

Answer 6

• Weigh less than average
• Enlarged ventricles
• Reduced neurons in PFC
• Thinner parahippocampal gyri
• Abnormal cellular structures and in PFC and hippocampus

Question 7

Outline Dual mechanisms of control model

Answer 7

• goal in WM (proactive control)
• action
• action outcome
• monitoring
• signal need for adjustments
• adaptation (reactive control)

Question 8

What did Barch and Ceaser suggest in 2012?

Answer 8

• Association between proactive control deficits in schizophrenia and impairments in DLPFC activity
• Supported by fMRI studies showing reduced DLPFC activity in schizophrenia patients during tasks requiring proactive control

Question 9

How is WM affected in schizophrenia?

Answer 9

No general WM deficit, but impairments in specific components, namely central executive.

Question 10

How is processing speed affected in schizophrenia?

Answer 10

Processing speed seen to be impaired in schizophrenia patients. May be due to lack of integrity of white matter fibre tracts or due to WM aspects of task

Question 11

How is episodic memory affected in schizophrenic individuals?

Answer 11

• Relational memory more impaired than item memory
• Associated with reduced DLPFC activity
• Recollection also affected during remembering

Question 12

How is decision making affected in schizophrenia patients?

Answer 12

• Motivational impairments in SCZ
• atypical effort-based decision making may contribute to these impairments
• SCZ individuals less willing to exert effort to get monetary rewards in experiments?

Question 13

Which structures are involved in effort based decision making in healthy individuals?

Answer 13

• Anterior cingulate cortex
• Ventral striatum
• Dopamine systems

Question 14

How is BOLD activity affected in schizophrenia?

Answer 14

Reduced BOLD activity in ventral striatum, posterior cingulate and medial frontal cortex during effort based decision making

Question 15

What are some factors that influence effort-decision making?

Answer 15

• Reward responsivity- How much does the person enjoy the reward?
• Anticipatory pleasure- How good will reward be?
• Cognitive control
• Defeatist performance beliefs- SCZ often have negative beliefs about ability to complete task
• Medication- Antipsychotics may modulate activity in brain areas involved in EBDM