Autism - explanations.

Biological explanation - Neuronlogical correlates.

The theory proposes that people with autism have one or two abnormalities with the brain. The damages area seems to correlate with the area responsible with development of communication and social functioning and play.

Brian areas & researchers - Cerrebellum size; Courchesne, 1991, Overall brain enlargement; Fombonne et al, 1999, Blood flow abnormalities in the brain; Ohnishi et al, 2000, Abnormal development of the brain stem; Roder, 2000, Amygdala function; Baron - Cohon et al, 2000.

Post mormton studies - Abnormalities in the .... Frontal lobe ( responsible for planning and control), Limbic system( responsible for emotion regulation), Brain stem and cerrebellum ( reponsible for motor coordintation). Evaluation of Post mortom studies - Post mortums must be studied on adult autisitc brains so it is not concluded wether the abnormaltites are from autism or weather autism bring pyschical change in the brain, not possible to determine cause and effect. Abnormalties in the adult brain may be from traumas or injuries from their life.

Neuroimaging - allows for examination of the living brain. The main techniques used for research of autistic brains are .... 1. Positron Emission Temography (PET) 2. Magnetic Resoance Imaging (MRI) 3. Single Photon Emission Computed Temography (SPECT).

MRI - The person is placed inside a large circular tunnel that generates a powerful magnetic feild which produces a seris of pictures of the brain. MRI is used to identify the sturcture of the brain. FMRI ( functional MRI) - slightly different and is used to look at the brain function. pictures taken of the brain so quickly to provide a picture of the working brain rather than its structure. Evaluation - most advance neuroimaging technique to detect abnormalities and tumors. Non-invasive so no harm to patients. Used for children because there is no radation used. Very expensive and needs a specialist to read the results. Patients can experiance chlustaphobia. FMRI allows to see brain function not just brain structure. Not many activities can be performed in a MRI scanner.

PET - Patients are injected with a radioactive trecer via the blood stream. Measures the levels of radioactive in differtent parts of the brain so they can look at where most blood is flowing and see what parts of the brain are most active. Scan the brain when the patient is inactive and then make them active and scan the brain, the difference between the scans show which parts of the brain are active and when. Evaluation - Can identify different activity of certain parts of the brain as the beghaviour happens. Expensive and results are hard to interpret. Slightly invasive because of radiation. Restricts activity so limits functioins. Useful for showing differences for people with and without mental disorders.

SPECT - able to provide 3D information, 2D images are taken from multiple angles and then are put together to produce a 3D image. Uses of injection of radioisotope is injected into the blood. By measuring the different levels of radiation in the brain…