James R. Bloedel

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Intracranial microinjections of the GABAA agonist muscimol were used to assess the involvement of the dentato-interposed cerebellar nuclear complex in the performance of the conditioned (CR) and unconditioned (UR) nictitating membrane responses in the rabbit. Specifically, the experiments test the hypothesis that the cerebellar nuclei are involved in the(More)
This study examined the hypothesis that the kinematics of movements performed by PD (Parkinson's disease) patients are differentially affected depending on whether or not the aiming movement has an accuracy constraint. The aiming movements required elbow extension in the horizontal plane on a digitizer. There were two movement conditions: (1) one having a(More)
 Temporary inactivation of the cerebellar interposed nuclei was used to assess the role of the intermediate cerebellum in the performance of forelimb cutaneo-muscular reflexes in the cat. The following types of reflexive responses were evaluated: the classically conditioned and unconditioned forelimb withdrawal responses and the forelimb tactile placing,(More)
The inferior olive (IO) is a required component of neural circuits controlling the classical conditioning of eyeblink responses. Previous reports indicated that lesioning or inactivating the IO abolishes conditioned eyeblinks (CRs), but there was disagreement regarding the timing of the CR performance deficit. As a result, it was not clear whether IO(More)
The kinematic changes associated with the manipulation and transport components during a prehensile movement were examined using an experimental paradigm that required alterations in only the manipulation component. Instead of starting with the thumb and index finger naturally together (control condition), subjects began the reach-to-grasp movement with(More)
The transport and grip components are two controlled components of a prehensile movement. These components are coordinated so that objects of varying size and shape resting in diverse locations can be grasped easily. It has been suggested that the timing between these two components is a specified parameter, although the origin of such timing is unknown.(More)
Reach-to-grasp movements of patients with pathology restricted to the cerebellum were compared with those of normal controls. Two types of paradigms with different accuracy constraints were used to examine whether cerebellar impairment disrupts the stereotypic relationship between arm transport and grip aperture and whether the variability of this(More)
The purpose of these experiments was to examine the role of the human cerebellum in the acquisition and retention of conditioned reflexes. Normal human subjects and patients with cerebellar lesions were tested for their capacity to acquire, retain and express conditioned eyeblink responses. In acquisition tests, subjects were trained in a delay classical(More)
This review focuses on the role of the cerebellum in regulating cutaneomuscular reflexes and provides a hypothesis regarding the way in which this action contributes to the coordination of goal-directed movements of the extremities. Specific attention is directed towards the cerebellum's role in conditioned and unconditioned eyeblink reflexes and limb(More)
This study examined whether the pattern of coordination between arm-reaching toward an object (hand transport) and the initiation of aperture closure for grasping is different between PD patients and healthy individuals, and whether that pattern is affected by the necessity to quickly adjust the reach-to-grasp movement in response to an unexpected shift of(More)