This study evaluates the influence of stimulation from the auditory modality on visual attention and perception. Behavioral experiments involving patients with neglect are complemented by parallel experiments using functional magnetic resonance imaging (fMRI). This study allows us to determine the parameters of Cross-Modal integration that influence spatial and non-spatial deficits in visual attention, and to determine which brain structures are involved in these processes. This study has recently produced potentially useful information for designing rehabilitation protocols (Van Vleet & Robertson, in press).
This study investigates the use of Cross-Modal training programs for the rehabilitation of neglect. Home-based computer training and other rehabilitation implements are used to systematically train patients with neglect to find and/or identify important information in neglected space. Funtional magnetic resonance imaging (fMRI) will be used to identify neural correlates of training and to examine training effectiveness.
This study investigates the contribution of cortical and subcortical brain areas in neglect and recovery from neglect. Lesion analysis, functional MRI, and event-related potentials assess the functional roles of particular brain areas in attention, the time course with which they are recruited into the attention system, the ways in which these areas interact with each other, and how they interact with other areas that support perception. This work is in collaboration with colleagues at the University of California, Berkeley.
A new type of neuroimaging analysis developed by collaborators at the Martinez VA (Voxel-based Lesion Symptom Mapping, VLSM; Bates et al., 2003) permits us to analyze stroke lesion data similar to ways used in functional neuroimaging so that the relative contributions of different brain regions to a given perceptual or attentional function can be analyzed (see Dronkers, Wilkins, Van Valin, Redfern, & Jaeger, 2004; Baldo et al, in press). This technique is allowing us to visualize networks of brain regions responsible for various attentional / perceptual abilities as characterized in commonly used neuropsychological tests of neglect. This project is lead by Lynn Robertson.s lab at the Martinez VA and the University of California, Berkeley (www.ebire.org/lynnlab/).