Theodore R. Bashore

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Twelve subjects responded to target letters "H" or "S" by squeezing dynamometers with the left or right hand. Targets could be surrounded by compatible (e.g., HHHHH) or incompatible noise (SSHSS) letters. Measures of the P300 component of the event-related brain potential and of correct and incorrect electromyographic and squeeze activity were used to study(More)
Results are reported from a new paradigm that uses movement-related brain potentials to detect response preparation based on partial information. The paradigm uses a hybrid choice-reaction go/nogo procedure in which decisions about response hand and whether to respond are based on separate stimulus attributes. A lateral asymmetry in the movement-related(More)
Previous studies have reported electrophysiological brain activity that is modulated when subjects commit errors in speeded reaction time tasks. This activity is thought to index an action monitoring system in anterior cingulate cortex that signals the need for performance adjustments to minimize the risk of future errors. Consistent with this view, we(More)
Past studies show beneficial as well as detrimental effects of subthalamic nucleus deep-brain stimulation on impulsive behaviour. We address this paradox by investigating individuals with Parkinson's disease treated with subthalamic nucleus stimulation (n = 17) and healthy controls without Parkinson's disease (n = 17) on performance in a Simon task. In this(More)
An experiment was conducted to relate individual components of the event-related brain potential to specific stages of information processing in a two-choice reaction time (RT) task in a group of undergraduate students. Specifically, the latency of the P300 component and the lateralized readiness potential (LRP) were studied as a function of variations in(More)
The present study investigated the mechanisms underlying reductions in the susceptibility to interference from irrelevant information that are evident in the developing child. In the first experiment, where the task was to focus on one stimulus dimension and to ignore a second dimension, variations in the degree of spatial integration in multidimensional(More)
Processing irrelevant visual information sometimes activates incorrect response impulses. The engagement of cognitive control mechanisms to suppress these impulses and make proactive adjustments to reduce the future impact of incorrect impulses may rely on the integrity of frontal-basal ganglia circuitry. Using a Simon task, we investigated the effects of(More)
Response selection often occurs in a context of competition among conflicting responses. According to recent models, the basal ganglia may play an integral role in resolving this competition by focusing the selection and inhibition of responses. We hypothesized that basal ganglia dysfunction produced by Parkinson's disease (PD) disrupts selection among(More)