<P>We previously delineated the visual short-term memory neural substrate involved in orientation discrimination, using a successive discrimination, i.e. the temporal same-different task (TSD) [1]. This network involves occipito-temporal and cerebellar regions. However, a previous study [2] using the same task paradigm suggests stimulus presentation rate strongly modulates the activity pattern within this network: whereas mainly occipito-temporal regions are differentially activated at a fast rate, a fronto-parietal network is activated at a slow rate. Using a parametric variation of rate, the current study further investigates the contribution of the cerebral and cerebellar regions to sensory discrimination. 