Neural

• Neural explanation

  Genes associated with OCD affect levels of key neurotransmitters and structures of the brain
• role of serotonin

  • regulates mood, sleep and anxiety
  • low levels result in abnormal transmission of mood-relevant information - mental processes including mood are affected
• what have PET scans shown about the role of serotonin?

  people with OCD have relatively low levels of serotonin
• orbital frontal cortex (OFC)

  • responsible for logical thinking, decision making, and impulses
  • when something makes us anxious the OFC sends a signal to the thalamus, causing an urge to act on the impulse
• caudate nucleus

  causes the behaviour to stop as it stops the impulse to perform the activity
• why do people with OCD struggle to ignore impulses?

  the caudate nucleus is dysfunctional, resulting in the failure to suppress minor worry signals
• Comer (1998)

  serotonin plays a key role on the operation of the orbital frontal cortex and the caudate nuclei
• positive evaluation of neural explanation

  • supporting evidence - Hut (2006) compared serotonin activity in 150 OCD sufferers and 250 non sufferers - found lower serotonin levels in OCD patients
• negative evaluation of neural explanation

  • cause & effect - research is based on a negative correlation between variables - we cant determine whether low levels of serotonin are a cause or result of OCD
  • biological reductionism - ignores cognitive and behavioural factors such as faulty processing and conditioning - wrong treatment may be prescribed as the real cause has been ignored