Decoding tactile working memory content reveals performance relevance of parietal fMRI activity patterns

Abstract

Working memory (WM) supports a range of higher order cognitive functions by enabling the short-term maintenance and manipulation of information through dynamic, distributed neural processes. In parallel to findings from the visual modality, tactile WM engages both sensory and higher-order cortical regions, but the temporal dynamics and functional significance of these areas remain incompletely understood. In this fMRI study, we used multivoxel pattern analysis to investigate how spatial features of tactile stimuli are represented and maintained across a short WM delay period. Our results reveal a dynamic engagement of contralateral primary somatosensory cortex (S1) and anterior superior parietal lobe (SPL) during initial encoding, with a shift toward bilateral posterior SPL involvement during later maintenance. Critically, decoding accuracy in the ipsilateral SPL correlated with individual task performance, suggesting that distinctiveness of WM-related representations in this region supports successful memory retention. These findings shed light on the hierarchical organization and temporal evolution of tactile spatial WM, indicating a transformation from concrete sensory to more abstract, distributed representations across parietal regions, modulated by behavioral demands.