title: Ventral prefrontal cortex is not essential for working memory.
abstract: It is widely held that the prefrontal cortex is important for working memory. It has been suggested that the inferior convexity (IC) may play a special role in working memory for form and color (). We have therefore assessed the ability of monkeys with IC lesions to perform visual pattern association tasks and color-matching tasks, both with and without delay. In experiment 1, six monkeys were trained on a visual association task with delays of up to 2 sec. Conservative IC lesions that removed lateral area 47/12 in three animals had no effect on the task. Further experiments showed that these lesions had no effect on the postoperative new learning of a color-matching task with delays of up to 2 sec or versions of the visual association task involving delays of up to 8 sec. In experiment 2, larger lesions of both areas 47/12 and 45A were made in the three control animals. This lesion caused a profound deficit in the ability to relearn simultaneous color matching, but subsequent matching with delays of up to 8 sec was clearly unimpaired. We suggest that the IC may be more important for stimulus selection and attention as opposed to working memory.
authors.affiliation: Department of Experimental Psychology, University of Oxford, Oxford OX1 3UD, United Kingdom.
authors.forename: M F
authors.initials: MF
authors.lastname: Rushworth
authors.forename: P D
authors.initials: PD
authors.lastname: Nixon
authors.forename: M J
authors.initials: MJ
authors.lastname: Eacott
authors.forename: R E
authors.initials: RE
authors.lastname: Passingham
mesh_terms: D000818:Animals; D001245:Association Learning / Q000502:physiology*; D001931:Brain Mapping; D003118:Color Perception; D008253:Macaca mulatta; D008568:Memory / Q000502:physiology*; D010364:Pattern Recognition, Visual; D017397:Prefrontal Cortex / Q000033:anatomy & histology / Q000098:blood supply / Q000502:physiology*; D011930:Reaction Time; D012039:Regional Blood Flow