neuroanatomical explanation of OCD Flashcards
the orbitofrontal cortex
the orbitofrontal cortex is a region of the brain that is responsible for decision making. converting any sensory information into thoughts, notices when something is wrong and alerts the brain to any potential worries in the environment. PET scans have found this area of the brain to be overactive in ocd patients increasing the conversion of sensory information into actions leading to increased worry/panic leading to obsessions
the caudate nuclei
the ofc sends the message of panic/worry to the caudate nucleus. it is responsible for repetitive behaviours, reward experiences and focusing attention .it decides whether messages are important or not and so acts as a filter between the ofc and the thalamus. the problem is that the the caudate nuclei is also overreactive. its impaired function means means faulty messages of panic and worry are not filtered out. T/F the messages are not recognised as faulty and so are passed onto the thalamus. this causes the individual to think about their obsession more and take action.
the thalamus
the caudate nucleus passes on the faulty message of worry/panic to the thalamus. the thalamus’ role is to respond to sensory and motor signals, carrying out the necessary required action in a patient with icd whose thalamus is found to be overactive leading to behaviours that emerge as compulsions. the thalamus then directs messages back to parts of the brain that can interpret them, such as the cingulate gyrius.
the cingulate gyrius
the thalamus passes on the compulsion message to the cingulate gyrius. the cingulate gyrius is responsible for focussing attention on emotionally significant events. and so is the emotional response for the compulsion that has been created. the emotional response will be relief from the compulsion being acted upon. however, the cingulate gyrius will pass this message of relief to the ofc and the dysfunctional neuronal loop will start again
:) Menzies et al
when conducting brain scans of patients with icd found that there is less grey matter in certain areas of the brain, including the orbitofrontal cortex compared to a healthy control groups brain. T/F suggesting a physical difference in orbitofrontal cortex in people with icd and thus supporting the neuroanatomical explanation of ocd
:) max et al
found that when the basal ganglia is disconnected from the frontal cortex, icd like symptoms are reduced.T/F suggesting that the basal ganglia plays a part in icd thus providing support for the neuroanatomical explanation of ocd
:( reductionist
only considers the role of nature in the form of biological structures such as the thalamus. does not consider the role of nurture such as the impact of social influences T/F the theory is reductionist as it is too simple of an explanation.
:( cause and effect
findings that an overreactive thalamus is linked to icd compulsions is only conducted after a diagnosis has been given so it is only correlational T/F reducing the validity of the neuroanatomical explanation of icd.
