S- Gazzaniga (1989) showed that split brain people were better at certain tasks, like being faster at identifying the odd one out in objects- left is watered down by the right (Kingstone 1995)
S- Ethics- Split Bain procedure was done before the experiment, and the task had all the participant's full consent
S- Confounding variable due to the control being neurotypical, and not having epilepsy, meaning the results could be due to the lack of epilepsy not from a full brain.