A Level Psychology OCR Practice Exam

Which experimental design was employed in the Sperry et al (1968) study?

1. Repeated measures design

2. Independent groups design

3. Matched pairs design

4. Between-subjects design

The correct answer is: Independent groups design

The Sperry et al. (1968) study used an independent groups design, which involves different participants being assigned to different conditions of the experiment. This design was particularly suitable for the study, as it aimed to investigate the effects of cutting the corpus callosum in patients who had undergone this surgery for epilepsy. Each participant, who had a split-brain condition, provided data that was distinct and did not overlap with other participants’ data. This method effectively minimized potential confounding variables related to individual differences in cognitive functioning and neurological issues since each subject was only tested in one condition. The independent groups design allowed the researchers to directly observe and compare the distinct outcomes in cognitive processing in individuals with split-brain functionality without the possible carryover effects that might occur in repeated measures design. By examining multiple participants in this way, the researchers could draw more generalized conclusions about the brain's lateralization of function based on their observations of the different groups rather than solely relying on a single group undergoing multiple tests.