Robert A. Schmidt

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Behavioral conditioning of cue-reward pairing results in a shift of midbrain dopamine (DA) cell activity from responding to the reward to responding to the predictive cue. However, the precise time course and mechanism underlying this shift remain unclear. Here, we report a combined single-unit recording and temporal difference (TD) modeling approach to(More)
Previous analyses of knowledge of results (KR) and motor learning have generally confounded the transient performance effects as shown when KR is present and the relatively permanent (i.e., learned) effects that we argue should be evaluated on a transfer test without KR. In this review, we classify investigations according to this distinction, and a number(More)
Neuronal oscillations allow for temporal segmentation of neuronal spikes. Interdependent oscillators can integrate multiple layers of information. We examined phase-phase coupling of theta and gamma oscillators in the CA1 region of rat hippocampus during maze exploration and rapid eye movement sleep. Hippocampal theta waves were asymmetric, and estimation(More)
Salient cues can prompt the rapid interruption of planned actions. It has been proposed that fast, reactive behavioral inhibition involves specific basal ganglia pathways, and we tested this by comparing activity in multiple rat basal ganglia structures during performance of a stop-signal task. Subthalamic nucleus (STN) neurons exhibited low-latency(More)
Mariano A. Belluscio,1 Kenji Mizuseki,1 Robert Schmidt,2,3 Richard Kempter,2,3 and György Buzsáki1 1Center for Molecular and Behavioral Neuroscience, Rutgers, The State University of New Jersey, Newark, New Jersey 07102, 2Institute for Theoretical Biology, Department of Biology, Humboldt University of Berlin, 10115 Berlin, Germany, and 3Bernstein Center for(More)
Beta oscillations in cortical-basal ganglia (BG) circuits have been implicated in normal movement suppression and motor impairment in Parkinson's disease. To dissect the functional correlates of these rhythms we compared neural activity during four distinct variants of a cued choice task in rats. Brief beta (∼20 Hz) oscillations occurred simultaneously(More)
A computerized scheme is being developed for the detection of masses in digital mammograms. Based on the deviation from the normal architectural symmetry of the right and left breasts, a bilateral subtraction technique is used to enhance the conspicuity of possible masses. The scheme employs two pairs of conventional screen-film mammograms (the right and(More)
RATIONALE AND OBJECTIVES To develop a method for differentiating malignant from benign masses in which a computer automatically extracts lesion features and merges them into an estimated likelihood of malignancy. MATERIALS AND METHODS Ninety-five mammograms depicting masses in 65 patients were digitized. Various features related to the margin and density(More)
OBJECTIVE The objective of our study was to assess the clinical utility of MR-directed ("second-look") ultrasound examination to search for breast lesions detected initially on MRI. MATERIALS AND METHODS A retrospective review was performed of the records of 158 consecutive patients (202 lesions) with breast abnormalities initially detected on MRI between(More)