A current focus in sensorimotor research is the study of human perception and action in increasingly naturalistic tasks and visual environments. This is further enabled by the recent commercial success of virtual reality (VR) technology, which allows for highly realistic but well-controlled three-dimensional (3D) scenes. VR enables a multitude of different ways to interact with virtual objects, but only rarely are such interaction techniques evaluated and compared before being selected for a sensorimotor experiment.
View Article and Find Full Text PDFInteracting with objects in our environment requires determining their locations, often with respect to surrounding objects (i.e., allocentrically).
View Article and Find Full Text PDFReal-world actions require one to simultaneously perceive, think, and act on the surrounding world, requiring the integration of (bottom-up) sensory information and (top-down) cognitive and motor signals. Studying these processes involves the intellectual challenge of cutting across traditional neuroscience silos, and the technical challenge of recording data in uncontrolled natural environments. However, recent advances in techniques, such as neuroimaging, virtual reality, and motion tracking, allow one to address these issues in naturalistic environments for both healthy participants and clinical populations.
View Article and Find Full Text PDFPrevious studies in the macaque monkey have provided clear causal evidence for an involvement of the medial-superior-temporal area (MST) in the perception of self-motion. These studies also revealed an overrepresentation of contraversive heading. Human imaging studies have identified a functional equivalent (hMST) of macaque area MST.
View Article and Find Full Text PDFPrevious neuroimaging studies have shown that inferior parietal and ventral occipital cortex are involved in the transsaccadic processing of visual object orientation. Here, we investigated whether the same areas are also involved in transsaccadic processing of a different feature, namely, spatial frequency. We employed a functional magnetic resonance imaging paradigm where participants briefly viewed a grating stimulus with a specific spatial frequency that later reappeared with the same or different frequency, after a saccade or continuous fixation.
View Article and Find Full Text PDFThe brain may be considered as a synchronized dynamic network with several coherent dynamical units. However, concerns remain whether synchronizability is a stable state in the brain networks. If so, which index can best reveal the synchronizability in brain networks? To answer these questions, we tested the application of the spectral graph theory and the Shannon entropy as alternative approaches in neuroimaging.
View Article and Find Full Text PDFCoordinated reach-to-grasp movements are often accompanied by rapid eye movements (saccades) that displace the desired object image relative to the retina. Parietal cortex compensates for this by updating reach goals relative to current gaze direction, but its role in the integration of oculomotor and visual orientation signals for updating grasp plans is unknown. Based on a recent perceptual experiment, we hypothesized that inferior parietal cortex (specifically supramarginal gyrus [SMG]) integrates saccade and visual signals to update grasp plans in additional intraparietal/superior parietal regions.
View Article and Find Full Text PDFBackground: Noninvasive interventions to aid healthy cognitive aging are considered an important healthcare priority. Traditional approaches typically focus on cognitive training or aerobic exercise training. In the current study, we investigate the effect of exercises that directly combine cognitive and motor functions on visuomotor skills and general cognition in elderly with various degrees of cognitive deficits.
View Article and Find Full Text PDFThe cortical sites for the trans-saccadic storage and integration of visual object features are unknown. Here, we used a variant of fMRI-Adaptation where subjects fixated to the left or right of a briefly presented visual grating, maintained fixation or saccaded to the opposite side, then judged whether a re-presented grating had the same or different orientation. fMRI analysis revealed trans-saccadic interactions (different > same orientation) in a visual field-insensitive cluster within right supramarginal gyrus.
View Article and Find Full Text PDFAnimate objects have been shown to elicit attentional priority in a change detection task. This benefit has been seen for both human and nonhuman animals compared with inanimate objects. One explanation for these results has been based on the importance animate objects have served over the course of our species' history.
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