Sperry Core Study

AIM: study functions of separate & independent hemispheres

Left hemisphere: logic, reasoning, language, understanding

Right hemisphere: drawing, spatial awareness, creativity

Contra-lateral control: left hemisphere controls right side of body, right hemisphere controls left side of body.

Corpus callosum connecting two hemispheres is severed in a commissurotomy: an operation done on patients with severe epilepsy.  The experiment is a quasi experiment as the patients had had the commissurotomy before having done the experiment with Sperry, so this variable is naturally-occuring: the independent variable is therefore whether the patient had had the corpus callosum severed or not; the dependent variable is how well they performed on the tasks.

A repeated measures design was used as the same patients were used in each condition (each task).

SAMPLE: 11 patients whom had undergone commissurotomy; whom before this procedure, had had severe epilepsy.  Acquired through an opportunity sample.

[WEAKNESSES: small sample; ungeneralisable & therefore unrepresentative of general population; patients underwent operation at different times in their lives, so some would be more used to the effects than others - this could reduce validity of experiment as some would be better at tasks than others.]

Standardisation of procedure: same images in Visual Task; same equipment (Tachistoscope); one eye covered; same room/environment; same surgery undergone.

PROCEDURE: Visual Task: Tachistoscope, one eye covered; image presented to left visual field or right visual field (or both).  First image shown to right visual field (& therefore left hemisphere…