Reconstructing relational information

Abstract

Hippocampal involvement in learning and remembering relational information has an extensive history, often focusing specifically on spatial information. In humans, spatial reconstruction (SR) paradigms are a powerful tool for evaluating an individuals' spatial-relational memory. In SR tasks, participants study locations of items in space and subsequently reconstruct the studied display after a short delay. Previous work has revealed that patients with hippocampal damage are impaired both in overall placement accuracy as well as on a specific measure of relational memory efficacy, "swaps" (i.e., when the relative location of two items is reversed). However, the necessity of the hippocampus for other types of spatial-relational information involved in reconstruction behaviors (e.g., where in the environment and relative to which other items an item was located) have not yet been investigated systematically. In this work, three patients with hippocampal damage and nine healthy matched comparison participants performed an SR task. An analysis framework was developed to independently assess three first-order types of relations: (1) memory for the binding of specific item identities to locations, (2) memory for arrangement of items in relation to each other or the environment bounds, regardless of memory for the item identity, and (3) higher-order, compound relational errors (i.e., errors involving multiple pieces of relational information). Reconstruction errors were evaluated to determine the degree to which patients and comparisons differed (or not) on each type of spatial-relational information. Data revealed that the primary group difference in performance was for identity-location information. However, when the locations of items were evaluated without regarding the identities, no group difference was found in the number of item placements to studied locations. The present work provides a principled approach to analysis of SR data and clarifies our understanding of the types of spatial relations impaired in hippocampal damaged.

Hippocampal viscoelasticity and episodic memory performance in healthy older adults examined with magnetic resonance elastography

“…Therefore, the data presented in this work is consistent with findings demonstrating a relationship between HC structure and episodic memory with immediate recall only. Indeed, HC amnestic patients show impairment on relational memory tasks even at very short delays (Hannula et al 2006;Horecka et al 2018).…”

Differential development of relational memory and pattern separation

“…The reconstruction portion of each trial was self‐paced and the participant was encouraged to move on to the next trial only once they were satisfied with their object placements. Performance on this task was analyzed according to the metrics outlined by Horecka, Dulas, Schwarb, Lucas, and Cohen (). Specifically, global misplacement was first calculated as the distance (in pixels) between an object's studied location and its reconstructed location.…”

“…T A B L E 2 Summary of performance metrics across MST, spatial reconstruction task, and ODD task F I G U R E 2 Spatial reconstruction task trial design and performance metrics [Color figure can be viewed at wileyonlinelibrary.com] on to the next trial only once they were satisfied with their object placements. Performance on this task was analyzed according to the metrics outlined by Horecka, Dulas, Schwarb, Lucas, and Cohen (2017). Specifically, global misplacement was first calculated as the distance (in pixels) between an object's studied location and its reconstructed location.…”

Impact of 3-Day Combined Anodal Transcranial Direct Current Stimulation-Visuospatial Training on Object-Location Memory in Healthy Older Adults and Patients with Mild Cognitive Impairment

“…Note, though, that our report is based on behavioral data only, therefore, we cannot demonstrate the exact network effects of the stimulation on a functional neuroimaging level. However, a large body of evidence indicates hippocampus and adjacent structures as a central hub for binding processes within the widely distributed fronto-tempo-parietal network [5,85,86], of which we stimulated the temporoparietal part. Although some of the neuropathological changes associated with memory decline in MCI are also common in normal aging [87], additional pathology may be present in MCI due to AD with regard to amyloid and tau pathology [88].…”