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OBJECTIVE Sensory gating assessed via EEG in a paired-click paradigm has often served as a neurophysiological metric of attentional function in schizophrenia. However, the standard EEG measure of sensory gating using the P50 component at electrode Cz does not foster differential assessment of left and right hemisphere contributions. Magnetoencephalography(More)
The role of motor activity ipsilateral to movement remains a matter of debate, due in part to discrepancies among studies in the localization of this activity, when observed, and uncertainty about its time course. The present study used magnetoencephalography (MEG) to investigate the spatial localization and temporal dynamics of contralateral and(More)
The accurate identification of obscured and concealed objects in complex environments was an important skill required for survival during human evolution, and is required today for many forms of expertise. Here we used transcranial direct current stimulation (tDCS) guided using neuroimaging to increase learning rate in a novel, minimally guided(More)
Human reaction times during sensory-motor tasks vary considerably. To begin to understand how this variability arises, we examined neuronal populational response time variability at early versus late visual processing stages. The conventional view is that precise temporal information is gradually lost as information is passed through a layered network of(More)
Despite numerous studies in which hippocampal abnormalities were found, schizophrenia patients' hippocampal neural activity has not been systematically evaluated on a specific hippocampal-dependent task. The transverse-patterning task (TP) is sensitive to the relational mnemonic capabilities of the hippocampus. Ten schizophrenia patients and 10 controls(More)
Previous work from our laboratory has demonstrated that rats display a preference for directional responding over true place navigation in the Morris water task. The present study evaluated the range of situations in which this preference is observed and attempted to identify methods that favor navigation to the precise location of the escape platform in(More)
The time course of the schizophrenia auditory gating deficit may provide clues to mechanisms of impaired cognition. Magnetoencephalography was recorded during a standard paired-click paradigm. Using source strength of the M50 and M100 components for each click, calculated from dipole locations identified as underlying each component for the first click, a(More)
The hippocampus has long been known to be important for memory, with the right hippocampus particularly implicated in nonverbal/visuo-spatial memory and the left in verbal/narrative or episodic memory. Despite this hypothesized lateralized functional difference, there has not been a single task that has been shown to activate both the right and left(More)
A large and growing literature has demonstrated a deficit in auditory gating in patients with schizophrenia. Although that deficit has been interpreted as a general gating problem, no deficit has been shown in other sensory modalities. Recent research in our laboratory has examined sensory gating effects in the somatosensory system showing no difference in(More)
To evaluate the role of the fusiform gyrus in identifying and processing facial emotional expression in humans, MEG data were collected while six healthy subjects judged whether photographs of faces displayed emotion (happiness or disgust) compared to neutral faces and equiluminant scrambled faces. For all six subjects, a magnetic source localizing to right(More)