Lateralization of memory for the visual attributes of objects: evidence from the posterior cerebral artery...

We used the posterior cerebral artery amobarbital test to examine how each temporal lobe mediates memory for objects. Temporal lobectomy candidates were presented with four objects while one hemisphere was anesthetized. We assessed recall and recognition following recovery from the drug. Verbal recall was significantly better following object presentation to the left hemisphere when the left hemisphere was not the seizure focus. Recognition memory, tested with two identical objects, two objects that shared the same name but had different physical characteristics, and two foils, was superior following object presentation to the right hemisphere. Only the right hemisphere could discriminate identical objects from same-name foils. These data confirm that the left temporal lobe has an advantage in encoding the verbal representation of an object and suggest that the right temporal lobe is critical for memory of specific visual attributes of objects.