Hippocampus activation related to ‘real-time’ processing of visuospatial change

• Published in: Brain research Vol. 1652; pp. 204 - 211
• Main Authors: Beudel, M., Leenders, K.L., de Jong, B.M.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.12.2016
• Subjects: Adult; Brain Mapping; Female; FMRI; Hippocampus; Hippocampus - physiology; Humans; Imagination - physiology; Judgment - physiology; Magnetic Resonance Imaging; Male; Memory; Motion Perception - physiology; Neurology; Neuropsychological Tests; Photic Stimulation; Reaction Time; Space Perception - physiology; Spatial memory; Spatial Memory - physiology; Visuomotor control; Memory; Hippocampus; Visuomotor control; FMRI; Spatial memory
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/j.brainres.2016.10.010

The delay associated with cerebral processing time implies a lack of real-time representation of changes in the observed environment. To bridge this gap for motor actions in a dynamical environment, the brain uses predictions of the most plausible future reality based on previously provided information. To optimise these predictions, adjustments to actual experiences are necessary. This requires a perceptual memory buffer. In our study we gained more insight how the brain treats (real-time) information by comparing cerebral activations related to judging past-, present- and future locations of a moving ball, respectively. Eighteen healthy subjects made these estimations while fMRI data was obtained. All three conditions evoked bilateral dorsal-parietal and premotor activations, while judgment of the location of the ball at the moment of judgment showed increased bilateral posterior hippocampus activation relative to making both future and past judgments at the one-second time-sale. Since the condition of such ‘real-time’ judgments implied undistracted observation of the ball's actual movements, the associated hippocampal activation is consistent with the concept that the hippocampus participates in a top-down exerted sensory gating mechanism. In this way, it may play a role in novelty (saliency) detection. •Actual location assessment of a moving object involves hippocampus activation.•The hippocampus does not serve prediction and recollection of changing locations.•‘on-line’ hippocampal activation may create a perceptual memory buffer.•Such perceptual memory buffer may play a role in novelty (saliency) detection.