Gradual acquisition of visuospatial associative memory representations via the dorsal precuneus

Abstract

Activation of parietal cortex structures like the precuneus is commonly observed during explicit memory retrieval, but the role of parietal cortices in encoding has only recently been appreciated and is still poorly understood. Considering the importance of the precuneus in human visual attention and imagery, we aimed to assess a potential role for the precuneus in the encoding of visuospatial representations into long-term memory. We therefore investigated the acquisition of constant versus repeatedly shuffled configurations of icons on background images over five subsequent days in 32 young, healthy volunteers. Functional magnetic resonance imaging was conducted on Days 1, 2, and 5, and persistent memory traces were assessed by a delayed memory test after another 5 days. Constant compared to shuffled configurations were associated with significant improvement of position recognition from Day 1 to 5 and better delayed memory performance. Bilateral dorsal precuneus activations separated constant from shuffled configurations from Day 2 onward, and coactivation of the precuneus and hippocampus dissociated recognized and forgotten configurations, irrespective of condition. Furthermore, learning of constant configurations elicited increased functional coupling of the precuneus with dorsal and ventral visual stream structures. Our results identify the precuneus as a key brain structure in the acquisition of detailed visuospatial information by orchestrating a parieto-occipitotemporal network. K E Y W O R D SfMRI, hippocampus, long-term memory, precuneus, visuospatial memory

Shared neural underpinnings of multisensory integration and trial-by-trial perceptual recalibration

“…In humans, the medial superior parietal cortex pinpointed here as mediator of recalibration, in particular the precuneus, has been implied in maintaining spatial and episodic memory (38–40,52,53) used for example during navigation, spatial updating or spatial search (53,54). Our results broaden the functional scope of these parietal regions in multisensory perception, by showing that these regions are also involved in the integration of multiple simultaneous cues to guide subsequent spatial behavior.…”

Cerebellar‐hippocampal processing in passive perception of visuospatial change: An ego‐ and allocentric axis?

“…As already pointed out in Section 1, the medial parietal cortex has recently been found to likely complement the hippocampus in the establishment of memory representations, as it is sensitive to repetitions but suppressed during initial encoding of novel information (Brodt et al, ; Brodt et al, ; Gilmore et al, ; Schott et al, ). We did not find that the activity in the parietal cortex could be explained by the number of repetitions preceding the deviants, suggesting that the activity we see here is not merely a reflection of this reinstatement‐dependent behavior.…”

Abnormal distraction and load‐specific connectivity during working memory in cognitively normal Parkinson's disease

“…Entirely different features of aberrant connectivity in PD were uncovered when retrieving a target encoded in the face of distraction. Here, connectivity disturbances were specific to the bilateral precuneus, which together with other parietal‐occipital regions represent the precision by which items are remembered (Christophel et al, ; Galeano Weber et al, ; Schott et al, ; Wang, Itthipuripat, & Ku, ). Precuneus coupling was strengthened with prefrontal regions (BA 10) that control top‐down attention (Simons, Gilbert, Owen, Fletcher, & Burgess, ) and a memory recollection network (posterior cingulate, PHC) (Jonker, Dimsdale‐Zucker, Ritchey, Clarke, & Ranganath, ; Ranganath & Ritchey, ; Thakral, Wang, & Rugg, ).…”

“…Entirely different features of aberrant connectivity in PD were uncovered when retrieving a target encoded in the face of distraction. Here, connectivity disturbances were specific to the bilateral precuneus, which together with other parietal-occipital regions represent the precision by which items are remembered (Christophel et al, 2015;Galeano Weber et al, 2017;Schott et al, 2019;Wang, Itthipuripat, & Ku, 2019).…”

“…Precuneus coupling was strengthened with prefrontal regions (BA 10) that control top-down attention (Simons, Gilbert, Owen, Fletcher, & Burgess, 2005) and a memory recollection network (posterior cingulate, PHC) (Jonker, Dimsdale-Zucker, Ritchey, Clarke, & Ranganath, 2018;Ranganath & Ritchey, 2012;Thakral, Wang, & Rugg, 2017). Moreover, stronger right precuneus-posterior cingulate connectivity was associated with poorer discriminability of targets, perhaps signifying diminished fidelity of visual representations that were encoded during distraction (Galeano Weber et al, 2017;Schott et al, 2019). In contrast, PD patients with better visual organization skills showed more marked coupling between the left precuneus and middle temporal cortex, which encodes object attributes (Vilberg & Rugg, 2012).…”