SZ

Question 1

Emil Kraepelin (1898):
Described symptoms of patients as what?

Answer 1

“dementia praecox’

dementia = global disruption of perceptual and cognitive processes
praecox = early adulthood onset

Question 2

What did Emil Kraepelin (1898) describe the first symptoms of SZ as?

Answer 2

Main symptoms:
impairments in attention, memory and goal-directed behaviour

Described condition as progressive, no return to premorbid functioning

Question 3

Eugen Bleuler (1911):
Reformulated dementia praecox
What did he coin the term schizophrenia with?

Answer 3

with schizo meaning ‘split’ and ‘phrene’ meaning ‘mind’.
schizo = split
phrene = mind

This term was supposed to characterise fragmented thinking
Distinguished between positive and negative symptoms

Question 4

As defined in Diagnostic and Statistical Manual of Mental Disorders (DSM): SZ is a combination of variable degrees of what 3 types of symptoms?

Answer 4

Positive Symptoms:
- Characteristics or behaviours that are added to normal behaviour or thought processes, something that occurs in addition to what would be considered normal behaviour or thoughts.

Negative symptoms:
- Represent a lack of or reduction of normal behaviour.

Cognitive deficits:
attentional dysfunctions, working memory, executive dysfunctions

Can vary and change across the lifetime of an individual

Question 5

One patient could show predominantly positive symptoms, but not as many negative symptoms, while another patient may show mainly negative symptoms.

Explained in more detail:

Answer 5

Cognitive deficits are common 75 to 80% of schizophrenia patients.

presence of positive and negative symptoms for at least 1 month defines criteria.

not including cognitive symptoms as they are not specific enough,
i.e. a number of other mental health disorders also include cognitive deficits

Cognitive deficits = good predictor of the quality of life and functioning of patient
But clinical practice the focus is mostly toward targeting the negative/ positive symptoms!

Schizophrenia is considered to be a syndrome, i.e. a number of related disorders might be subsumed under the term ‘schizophrenia’ and those disorders have similar symptoms but various causes. Each patient shows slightly different symptoms.

Question 6

Positive symptoms of SZ (type l):

What are false beliefs despite evidence to contrary, distorting reality (e.g. patient beliefs someone is plotting against them), but also:
Thought insertion
Thought withdrawal
Thought broadcasting
Not being in control of own actions

Answer 6

Delusions

Question 7

Positive symptoms of SZ (type l):

What are perceptual experiences that seem real in the absence of physical proof;
most common: auditory, visual, olfactory
(e.g. seeing a person or an animal that is not real)

Answer 7

Hallucinations

Question 8

Name 3 positive symptoms of SZ (type l):

Answer 8

Delusions,

Hallucinations,

Disorganized behaviour

Question 9

Positive symptoms of SZ (type l):
What can affect speech, difficulties with routine tasks, inappropriate emotions?

Answer 9

Disorganized behaviour

Question 10

Summary of the positive (or type I) symptoms:

Give examples of Delusions and Hallucinations:

Answer 10

Delusions:
- Patient beliefs that someone is plotting against them.
- The idea that someone else can insert thoughts into my brain.

Thought withdrawal:
- The idea that someone can delete thoughts from my brain.

Thought broadcasting:
- The belief that my thoughts can be transmitted to another place or another person.
- The feeling of not being in control of my own actions, as if someone else can control what I do.

Hallucinations:
- Perceptual or auditory experiences patient has
- Seeing another person/ animal/ hearing voices, that are not real. Most common are auditory, visual or olfactory hallucinations.

Question 11

Negative (type II) symptoms:

What gives the affects of: blunted affect, mood or emotional state, limited range of emotions

Alogia: poverty of speech, lack of conversation

Answer 11

Diminished Emotional Expression

Question 12

Negative (type II) symptoms:

What is the symptom of poverty of speech, lack of conversation?

Answer 12

Alogia

Question 13

Negative (or type II) symptoms:

Recently, Lim and colleagues have suggested that negative symptoms can be grouped into which 2 subdomains?

Answer 13

1- Diminished Emotional Expressions
blunted affect/ mood and a limited range of emotions that the patient experiences
eg. Alogia/ speech poverty (very reduced speech lack of convo)

2- Avolition
apathy (a lack of motivation)
social withdrawal and anhedonia
eg. an inability to feel pleasure

Question 14

Negative (type II) symptoms:

What is the symptom of apathy (lack of motivation) leading to
social withdrawal

Answer 14

Avolition

Question 15

Negative (type II) symptoms:

What symptom is the inability to feel pleasure

Answer 15

Anhedonia

Question 16

Majority of SZ patients have substantial impairment in overall cognitive performance for most individuals can be variable (either selective or general).

What are the main cognitive deficits of SZ?

Answer 16

Most common deficits in:
Executive functions/cognitive control
(verbal fluency and problem-solving)
Attention (vigilance)
Processing speed
Memory (working memory, episodic memory)
Social cognition

Presence of cognitive deficits associated with poor daily functioning and quality of life

Question 17

Which type of deficit is associated with poor daily functioning, i.e. a lot of everyday tasks can be quite difficult, and lead to a reduced quality of life?

Answer 17

Cognitive deficits of SZ

Question 18

Due to early onset, when are impairments in cognitive functions already detectable?

Answer 18

At stages of childhood/adolescence

Cognitive deficits can be detectable earlier

As SZ is classified as a neural developmental disorder, these cog symptoms are more important!

Question 19

What is a problem with individuals identifying their own cognitive deficits?

Answer 19

Objective assessment of cognitive impairments and subjectively perceived impairments only weakly correlated

the individual doesnt think they are as impaired as they would perform in objective tests

This is known as: anosognosia for cognitive deficits
(in particular, in individuals with more severe deficits)
You do not realise the kind of deficits you might have

Question 20

Stats of SZ:

Answer 20

Combination of genetics and environment (~80% heritable)
Prevalence of SZ: 1%
Children or siblings of affected individuals 10 x more likely to develop SZ
Identical twins of patients have a chance of 40% to develop SZ as well.
Polygenic disorder: at least 108 genes implicated
Genetics only explain small percentage of cognitive variance

Question 21

Pos./Neg. symptoms: during late adolescence
Cognitive deficits detectable in childhood/adolescence
Slow emergence of brain abnormalities (neuro-developmental)

Answer 21

Several genes are identified it is polygenic
all genes are effected, so it is hard to target the main genetic basis of sz- may explain the variabliilty in the symptoms we see

Question 22

Schizophrenia has been categorized as a neurodevelopmental disorder. Explain this:

Answer 22

It typically develops during late adolescence. However, cognitive impairments can often be detected much earlier, i.e. in childhood or early adolescence. Brain abnormalities slowly emerge during adolescence, therefore it is described as neuro developmental condition.

Question 23

It is not clear yet, what causes schizophrenia.
Evidence suggests that it is due to a combination of?

Answer 23

Genetics and environment.

Schizophrenia seems to be about 80% heritable; if a person has a high genetic risk, no adverse environmental factors might be needed for schizophrenia to develop; if the genetic burden is lower, additional environmental factors might lead to schizophrenia.

Question 24

What are some environmental risk factors of developing SZ before or after birth?

Answer 24

Adverse events prenatally or perinatally (e.g. poor maternal nutrition, infection, obstetric complications)
Patients are more likely to have experienced a combination of adverse events before or during birth, for instance, their mothers didn’t take up enough nutrients during pregnancy or they experienced an infection or there were complications during the birth.

Perinatal hippocampal injuries in rats ➟ development of abnormal dopamine organization in prefrontal cortex
- a study in rats who experienced hippocampal injuries perinatally. These rats subsequently developed abnormal dopamine distributions in the prefrontal cortex.

There are also assumptions that infections with certain viruses during early childhood might increase the risk to develop SZ.

Drugs: some individuals develop SZ after taking certain drugs, e.g. cannabis. Again, because this is not the case for everyone, it is likely that this affects only individuals with certain genetic predispositions.

Question 25

What are the Neurotransmitter systems involved in schizophrenia?

Answer 25

Dopamine system X
(linked to positive symptoms and attention, WM, cognitive control)

Acetylcholine (linked to attention and memory AD)

Glutamate (Glu): main excitatory neurotransmitter

GABA: main inhibitory neurotransmitter

Question 26

Which Neurotransmitter systems create an Excitatory/inhibitory (E/I) balance important for SZ?

Answer 26

Glutamate (Glu): main excitatory neurotransmitter

and

GABA: main inhibitory neurotransmitter

Question 27

Dopamine Hypothesis (DA) for SZ:

Answer 27

Important role of mesocortical dopaminergic pathway (from tegmentum)
DA agonists (cocaine, amphetamine, L-DOPA) can induce psychotic symptoms
Disturbances in DA system: impaired cognitive functions

Typical antipsychotic medication reduces DA levels in the brain
Reduce positive symptoms
BUT: Ineffective or even detrimental for negative and cognitive symptoms

Question 28

What is a problem for the Dopamine Hypothesis?

Answer 28

But the disadvantage of these typical antipsychotics being prescribed is that they are not very effective at attenuating the negative symptoms; on the contrary, they sometimes even worsen the negative symptoms.

It’s been assumed that negative symptoms are due to too little DA in other brain areas, i.e. those that have been associated with negative symptoms. So schizophrenia could go along with too much DA in some brain areas and too little DA in others.

Question 29

The role DA in schizophrenia is most likely more complex:

Answer 29

Dopamine hypothesis:
It’s been assumed that pos/neg symptoms are due to too little/ much DA in brain areas,
Dissociation: striatal vs. cortical DA
maybe too much da in the striatal and too little da in the cortical

hypodopaminergic state in cortex
hyperdopaminergic state in striatum

DA levels fluctuate in individuals with SZ over time of illness,
cognitive symptoms much more stable -> close link is unlikely

Overall, modulations in one transmitter system can also affect other neurotransmitter systems.

Question 30

Newer ideas suggest that glutamate plays a central role in schizophrenia, and that the dysregulation of the dopaminergic system is only secondary to impaired glutamatergic functions. Glu is the main excitatory neurotransmitter in the brain, and Glu levels can modulate DA release in the Ventral Tegmental Area, so DA and Glu systems are not working independently, but they interact.

In support of the Glu hypothesis for SZ, a loss of glutamatergic neurons has been shown in the anterior cingulate cortex (or ACC, among other brain areas) in post-mortem brains of schizophrenia patients.

Moghaddam & Javitt (2012) discovered what 2 phases of Glu modulations?

Answer 30

1) NMDA-mediated interneuron dysfunction
➜ loss of inhibitory control, increased Glu levels

2) Glu-induced excitotoxicity
leads to ➜ loss of Glu connections; decreased Glu levels

So this model suggest, that we see a bi-phasic Glu modulation in schizophrenia, and whether you find increased or decreased Glu levels depends on what phase you are looking at.

Question 31

Previously, it was quite a challenge to measure neurotransmitter levels in living people.
However what has recently been used to measure neurometabolites in vivo?

Answer 31

Magnetic resonance spectroscopy (MRS):
measures neurometabolites in vivo
- been done to investigate glu levels in sz patients

Advantages of MRS, compared to PET studies:
NTM levels can be quantified without using radioactive tracers as MRS can be done by using a standard MRI scanner.

The results are more precise with higher scanner field strengths, but still evolving over time.

Question 32

Meta analysis of MRS studies in psychosis patients
Sydnor & Roalf (2020):
investgating glu levels in sz patients has shown:

heavy controls

Answer 32

Main findings:
↓ Glu in patients compared to controls

Question 33

The different neurotransmitter systems are affected to different degrees in different patients. Newer, atypical antipsychotics target a variety of neurotransmitters, e.g. DA in addition to:
Serotonin
Adrenalin
What might this explain?

basically trial and error as some patients react differenlty well not well to others in the trail that have sz

Answer 33

Might explain the variability in symptoms between patients
Why available drugs are not effective to same extent in all patients

Could explain, why the hypothesis would be plausible,
that different subgroups of schizophrenia patients exist.

Question 34

What are the Neuroanatomical differences of a patient with SZ?

Answer 34

Brains of sz patient weigh less than average weight
(brain areas are less connected)

Enlarged ventricles
(if surrounding structures are reduced)
which suggests a loss of / or fewer long range white matter fiber connections.

Reduced neuron numbers in prefrontal cortex
( indicating fewer cells in these structures/ cog symptoms)

Thinner parahippocampal gyri
(cortical structure surrounding hippocampus explaining memory problems)

Furthermore, neurons in prefrontal and hippocampal areas show a different structure in patients compared to controls.

Abnormal cellular structure in prefrontal cortex and hippocampus

Question 35

Schizophrenia patients also show Neuroanatomical brain differences.

Meta-analysis investigated grey matter (GM) loss in individuals with SZ

Findings?

Answer 35

Found:
In chronic SZ, GM reduced in:
Medial frontal cortex, anterior cingulate cortex
Insular cortex bilaterally
Left thalamus and caudate
Amygdala bilaterally

Question 36

Schizophrenia patients also show differences in their brain anatomy.

Post-mortem studies have shown that brains of schizophrenia patients weigh more or less than the average weight of neurologically healthy people.

Answer 36

less

Question 37

Cognitive symptoms: cognitive control
Cognitive impairments determine quality of life and a good predictor of everyday functioning

Positive symptoms can often be treated with antipsychotics;
Negative and cognitive symptoms are difficult to treat and can cause longer-term difficulties

What is a problem with the Cognitive symptoms associated with schizophrenia?

Answer 37

Problem: cognitive impairments comprise large range of different cognitive processes (executive functions, WM, language, episodic memory, processing speed, attention, inhibition, sensory processing)
➜ difficult to understand underlying mechanisms
➜ difficult to develop effective interventions

Question 38

Cognitive symptoms: cognitive control

Barch & Ceaser proposed the hypothesis that:
Common mechanism across cognitive domains ’context processing’, ‘WM’ and ‘episodic memory’

What did they suggest?

What is Proactive control associated with?

Answer 38

They suggest that individuals with SZ show an impairment in representing goal information in WM to guide behaviour.

➜ leading to impairment in representing goal information in WM to guide behaviour

= impairment in proactive control

Proactive control has been associated with a representation of information, and therefore an activation, in the dorsolateral prefrontal cortex (or DLPFC).

Question 39

Cognitive symptoms:
Dual mechanisms of control (Braver et al., 2009)
Explain Proactive control

Answer 39

Proactive control:
- A representation of goal in WM before task starts or decision is made; helps us to trigger appropriate actions/ mental operations.

1- All goal directed behaviour starts with an action
(Proactive control)
2- Then you observe the actions outcome
3- Modify/ adjust motor actions by learning from past mistakes
(reactive control)

Question 40

What does it mean when Proactive control is reduced in patients with SZ?

Answer 40

Due to their negative symptoms (avolition), they lack motivation to have goal-directed behavior and complete action tasks.

They need a lot more reactive control
(things that go wrong so they can react to it)
- reflect long-term goals

Question 41

Which type of control allows us to prepare ourselves for an upcoming task as best as possible?

To return to schizophrenia: Barch & Ceaser have suggested that it’s the proactive control aspect that is impaired in individuals with schizophrenia. These individuals would need to rely more on reactive control when completing tasks.

Answer 41

Proactive control

Question 42

Which type of control is required when things don’t go as planned and adjustments are needed?

Answer 42

Reactive control

Question 43

Cognitive symptoms associated with schizophrenia:

Meta-analysis (Minzenberg et al., 2009) of fMRI studies showed reduced DLPFC activity in schizophrenia patients is seen when they complete tasks that require which type of control?

Answer 43

Proactive control

Question 44

Are there Working memory deficits in patients with SZ?

Answer 44

No general WM deficit, but impairments in specific components:
Central Executive

Question 45

FMRI of WM in SZ patients has shown there is reduced activity compared to a control group in the dorsolateral and dorsal parietal cortex bilaterally when performing a task that required involvement of which component?

Answer 45

The Central executive.

For verbal and non-verbal WM tasks.

Question 46

Meta-analysis (Dickinson et al., 2007)
Findings showed?
Processing speed measured with Digit Symbol Coding-type tasks

Answer 46

Showed impairments in processing speed in patients with sz

Slowed processing speed impairments in patients with SZ
This may be due to lack of integrity of white matter fibre tracts

OR: due to possible WM aspects in the test

Question 47

Types of processing speed assessments:
Besides problems with the CE in the WM, what is one other reason for the slowed processing speed in SZ patients on Digit Symbol Coding-type tasks?

Answer 47

Due to a lack of integrity in patients’ white matter fiber tracts.

These tracts connect different brain areas / crucial for interactions between areas.
If these tracts don’t work, information transfer might be slower
= resulting in a reduced processing speed.

Question 48

Episodic memory in SZ patients:

Relational memory is more impaired than item memory
Associated with reduced DLPFC activity (but hippocampus might play a role as well)
Example task: relational memory

Explain this tasks 2 conditions and its findings:

Answer 48

During an initial encoding phase:
participants get presented with 3 different items on the screen arranged vertically, cat, elephant, butterfly.

2 conditions:
Rehearsal condition (item memory):
Remember the order of items on screen

Reorder condition (relational memory):
Re-arrange items according to weight, from lightest to heaviest

Findings:
SZ patients find it more difficult in Reorder condition
compared to control participants
= deficits in relational memory

Explanation?
Might be due to patients not applying appropriate strategies during the encoding phase
Suggesting a lack of proactive control (weak evidence)

Evidence also suggests that patients have difficulties applying mnemonic strategies
(techniques or strategies consciously used to improve memory by using visual/ auditory clues to help make connections between their own prior knowledge and new information).

Question 49

Episodic memory in schizophrenia patients:
When remembering items what is more impaired recollection or familiarity?

Answer 49

Recollection is more impaired than familiarity during remembering
Recollection: remembering where exactly (in which context) one has seen/heard an item
Familiarity: feeling of knowing (without remembering the context)

Supports hypothesis that encoding items in relation to their context is disrupted in schizophrenia

So basically, coding items in relation to their context is disrupted- we need to encode the context

Question 50

Barch & Ceaser (2012):
summary of their model:
deficits in proactive control central to cognitive symptoms in schizophrenia

Answer 50

They suggest that dysfunctions in the DLPFC and impaired DLPFC connectivity, along with modulations in relevant neurotransmitter systems, lead to deficits in proactive control, which implies that goals are not represented properly.

These deficits in proactive control might in turn lead to impairments in other cognitive domains, like WM, executive control or episodic memory.

Question 51

Cognitive symptoms:
Are SZ patients more or less willing to participate in effort-based decision-making?

Answer 51

less willing to put in effort
- they show reduced effort and this is correlated with their negative symptoms

More negative symptoms shown = less effort to approach the task
Reduced effort allocation is correlated with negative symptom severity

Question 52

Cognitive symptoms:
Culbreth et al argued that SZ patients show which type of
effort-based decision-making?

Effort-based decision-making: estimation of physical/mental effort to reach certain outcome

Answer 52

Atypical effort-based decision-making
which may contribute to motivational impairments

➜ this affects social and occupational functioning

Individuals with schizophrenia less willing to exert effort to get monetary rewards in experiments
Reduced effort allocation is correlated with negative symptom severity

Question 53

Cognitive symptoms: decision-making
Physical and mental effort

When tasks require physical or mental effort, individuals with sz will usually pick which task:

a) completing a hard task = a higher amount of money
b) completing an easy task = a low amount of money

Answer 53

b) More likely to choose the easier task compared to a healthy control group.

➜ correlation with negative symptoms:
Those with more severe negative symptoms are
least willing to exert more effort.

Question 54

Cognitive symptoms of SZ:

What are the 3 structures involved with effort-based decision-making in healthy individuals?

Answer 54

During effort-based decision-making:

Medial frontal cortex/ACC
- Correlates with subjective action values
SZ= reduced BOLD activity

Ventral striatum
- Increasing activity with reward value
(how important the outcome is for the individual),
but decreasing with effort
(the more effort the participant needs to exert to get the reward
the more attenuated is the brain activity in these areas)
SZ= reduced BOLD activity

Dopamine systems
- Involved in decision-making processes.

Question 55

Cognitive symptoms of SZ: Neural correlates

In individuals with schizophrenia, fMRI studies have shown reduced activity in the which brain areas during effort-based decision-making compared to healthy controls?

Answer 55

ventral striatum, the posterior cingulate and medial frontal cortex

Question 56

Cognitive symptoms: effort-based decision-making

Individuals with schizophrenia often show motivational impairments when compared to healthy controls.

How do these motivational deficits cause problems for the individual?

Answer 56

They affect their social and occupational functioning.

Currently, no effective treatments available for motivational impairments due to unclear underlying mechanisms.

Question 57

Cognitive symptoms: effort-based decision-making

Culbreth and colleagues have suggested that atypical effort-based decision-making processes in schizophrenia patients contribute to which type of impairments?

Answer 57

Motivational impairments

Reduced effort allocation is also correlated with the severity of negative symptoms.

Question 58

What term is used to describe cognitive processes that individuals perform to estimate the physical or mental effort that will be required to obtain a desired outcome?

Answer 58

Effort-based decision-making

Question 59

INFO SLIDE
Cognitive symptoms: effort-based decision-making

Situation: example
Person A thinks about making delicious cookies that he had at a friend’s place last week. While deciding whether or not to start baking, he considers the reward (➜ delicious cookie) and the probability to receive the reward (e.g. what if cookies burn accidentally).
Then, he considers the effort (➜ shopping for ingredient, time spent in kitchen) and the precision of his effort estimation (could it be easier or harder than anticipated?).
Finally, his motivational state is important (➜ is he hungry?).

Answer 59

Person A wants to decide whether or not to bake those delicious cookies that he ate at a friend’s place last week. During this process of making this decision, he will consider the type of reward
(i.e. he will get cookies)
and the probability of actually getting this reward
(for example, what if the cookies burn accidentally?).
He also considers the effort
(for instance, he will need to go to the shops first to get all ingredients, he will spend some time in the kitchen, etc.)
and he might also take the precision of his effort estimation into account (i.e. could it be easier or harder for some unexpected reason to make these cookies)?

And finally, his motivational state is important (i.e. Is he hungry right now?)

All of these factors will influence his decision whether or not to make the cookies, i.e. to exert the effort to get the desired reward.

To evaluate how difficult the task will be will lead to an outcome:
Effort testing issue!!!!

Question 60

What are the 4 factors influencing effort-based decision-making?

Answer 60

Reward responsivity (can I be bothered to make cookies?) -nono

Anticipatory pleasure (how good will the cookies taste?) -best one

Cognitive control (are there more urgent things to do first?) -no

Defeatist performance beliefs
(belief that cookies wont taste as good= lack of motivation to put effort into making cookies)

Question 61

Factors influencing effort-based decision-making:

Reward responsivity
- How much does the person enjoy the reward

Patients with SZ show increased or reduced reward responsivity?

Answer 61

Reduced; Less likely to take huge effort to get a reward

The more Adam enjoys cookies, the more likely he is to bake them.

Hypothesis: individuals with SZ show reduced reward responsivity, thus are less likely to exert effort
➜ would fit with negative symptoms (anhedonia)

Disadvantages:
lab studies have shown that self-reported levels of pleasure during task did not differ from that of control participants
(both groups had similar levels of reward responsivity)

Thus reduced reward responsivity= an unlikely mechanism for reduced effort allocation in schizophrenia.

Question 62

Factors influencing effort-based decision-making:

Cognitive control Deficits
- Utilising representations of cost and reward; competing goals

Do patients with SZ show Cognitive control Deficits?

Answer 62

Cognitive control deficit has been demonstrated in individuals with schizophrenia
➜ associated with reduced DLPFC activity
BUT: more robust evidence showing direct link to effort still required

Question 63

Factors influencing effort-based decision-making:

Anticipatory pleasure
- Whether a person can imagine the future reward including the pleasure that it will elicit

Do patients with SZ have strong anticipatory pleasure?

Answer 63

Individuals with SZ show reduced anticipatory pleasure
➜ are less motivated and less likely to exert effort

Evidence:
Studies have shown those who reported more anticipatory pleasure, expended more effort in task completion

This refers to the fact whether a person is able to imagine the future reward including the pleasure that it will elicit.

eg. Adam might think about how good the cookies will taste once they are ready.

Question 64

Factors influencing effort-based decision-making:

Defeatist performance beliefs
- Negative beliefs about their ability to complete a task successfully

Do patients with SZ have Defeatist performance beliefs?

Answer 64

Individuals with schizophrenia often have negative beliefs about their ability to complete a task successfully
(belief that task is alot harder)

➜ if Adam thinks he is not good at baking, he is less likely to attempt to do it
➜ belief influences precision of estimated effort (task might be a lot harder than you thought if you are not good at something)

Question 65

Which term describes individuals with schizophrenia often having negative beliefs about their ability to complete a task successfully?

Answer 65

Defeatist performance beliefs

-These beliefs also influence the precision of the estimated effort, If you belief you are not good at something:

More uncertainty about task duration
(costs uncertainty + uncertain reward) =
you might be less willing to start it in the first place

Question 66

Effort-based decision-making has been associated with which type of medication

Answer 66

Striatal dopamine

Antipsychotics that block dopaminergic (D2) receptor sites modulate brain activity in areas that are involved in effort-based decision-making.

Culbreth et al found correlation between D2 affinity of patient drug taken at the time of the study and the willingness of this patient to exert effort in a task
with the willingness to put effort in a task
However:
Only had small sample size and correlation confounded with most severe negative symptoms

Results may have been confounded with negative symptom severity- may be the type of drug!

Question 67

To summarise this section on effort-based decision-making:

• Effort-based decision-making seems to be modulated in individuals with schizophrenia
• The neural correlates of effort-based decision-making are: the ventral striatum, the cingulate cortex, and the DLPFC in association with impaired cognitive control.
• Factors that seems to influence the decision-making process are: Anticipatory pleasure, impaired cognitive control and defeatist performance beliefs. The factors might all contribute to a reduced willingness to expend effort.
• As the dopaminergic system plays a prominent role in effort-based decision-making, antipsychotic medication might be detrimental for this cognitive function as well.
• However, the evidence so far is not very reliable and larger studies and more replications are needed.

Answer 67

lmao

Question 68

General summary:

The positive symptoms are most dominant at early stages of SZ!

Answer 68

Schizophrenia consists of positive, negative and cognitive symptoms (pos. symptoms dominant in early phases)

Negative and cognitive symptoms difficult to treat

Multiple genes and environmental factors could cause schizophrenia to develop (polygenic) marijuana

Various neurotransmitter systems seem to be involved, most prominently dopamine and glutamate
Brain areas that are modulated in structure and function include the DLPFC, medial prefrontal cortex (incl. ACC), ventral striatum, (most likely) hippocampus

Several cognitive impairments could be linked to modulations in proactive control
Different components of effort-based decision-making seem to be modulated in individuals with schizophrenia