What evidence suggests that the ACC may be involved in affective responses?
- Errors are negative events that must be avoided
- Activation in response to defensive/aversive stimuli
- Located near brain areas associated with emotion
What have lesion studies demonstrated about the ACC?
- ACC-lesioned patients have equal Simon effect after previous incongruent controls
- Posterror slowing is absent
- Failure to moderate performance dependent on conflict level
How could error be related to OCD?
Could result from false error signals generated by a hyperactive action monitoring system
What have Stroop tasks shown in OCD patients?
-Increased and longer ERN which is correlated with severity
What are the two possible explanations of the effect seen in Stroop tasks with OCD patients?
- Dysfunction in comparator
- Excessive affective response to error
How does anxiety affect Stroop task performance?
- No effect on Stroop effect but increased ERN in trait anxiety
- No effect on state anxious people (phobias)
How do state axious (spider phobia) people perform in error detection when confronted with fear (turantula condition)?
No effect on ERN
What are the characteristics of someone with depression dealing with errors?
- magnify failure significance
- difficulty recovering from an error
- negative bias of environmental stimuli
What evidence has been shown linking depression to the ACC?
- Depressed individuals have more ACC activity (cortolimbic imbalance)
- Flanker task shows early and exaggerated error-detection responses
- Lesions to this area can reduce depressed symptoms
HOWEVER: depression and anxiety often occur together
How may exteralizing pathologies be linked to error?
- Reflect failure to learn from experience?
- Inability to monitor ongoing behaviour?
How do psycopaths perform in letter and emotional Flanker tasks?
- Letter shows no difference in performance with some ERN
- Emotion shows increased error and no ERN
- However this could be due to psycopaths having difficulty in identifying facial expressions
What have Flanker tasks revealed about error-processing in substance abusors?
- Higher number of errors after commiting an error
- Smaller ERN
How do small ammounts of alcohol affect behaviour monitoring?
alcohol percentages of 0.04% and 1% equally reduce ERN and impair action-monitoring
What effects are seen in schizophrenics conducting a stroop effect?
- Showed less posterror slowing
- absolutely no ERN
- deficit in error detection and correction
(however: only 2 weren’t medicated)
What effect is seen on error signals in ageing?
- Reduced error-related negativity in older patients
- AD patients show stronger impairment
