台大心理系

Past studies have suggested the activation of rPPC is intimately associated with visual short term memory in terms of encoding, maintenance, and retrieval. Here we show that artificially elevating parietal activity via positively-charged electric current through the skull can rapidly and effortlessly change rPPC activation and improve subsequent performance on a visual short-term memory (VSTM) task. From current results showed that the artificial modulation of rPPC activity and subsequence behavioral performance, however, is dependent on people’s natural VSTM capability such that only the low performers benefitted from the stimulation, whereas high performers did not. Corresponding behavioral and ERP/EEG dichotomy was also found around the parieto-occipital regions via VSTM-related electrophysiological components such as N2pc or CDA, and prestimulus alpha power. Together, these results suggest that the modulation of rPPC closely involved in subsequent VSTM performance/capacity. In addition, low VSTM performers perhaps do not suffer only from poor VSTM capacity, but also broad attentional mechanisms, and N2pc and prestimulus alpha may be an useful tool to understanding the nature of individual differences in VSTM.