Tropism, or asymmetry, of facet joints in the cervical spine has been found to be related degenerative changes and discs. Clinicians often assume that differences segmental mobility are tropism. The aims this study were determine relationship between asymmetry sub-axial (1) (2) spinal levels perceived by therapists have limited mobility. Eighteen participants with idiopathic neck pain had MRIs ...

BACKGROUND AND PURPOSE Identification of lesions in specific locations gains importance in multiple sclerosis imaging diagnostic criteria. In clinical routine, axial scans are usually exclusively obtained to depict the cervical spinal cord or used to confirm suspected lesions on sagittal scans. We sought to evaluate the detection rate for MS lesions on axial T2WI scans with full spinal cord cov...

1. K. S. Lashley, Brain Mechanisms and Intelligence (Dover, New York, 1963). 2. L. Petrinovich and D. Bliss, J. Comp. Physiol. Psychol. 61, 136 (1966); J. W. Stewart and H. W. Ades, ibid. 44, 479 (1951). 3. R. J. Douglas, Psychol. Bull. 67, 416 (1967); G. Goddard, ibid. 62, 89 (1964); J. M. Warren and K. Akert, The Frontal Granular Cortex and Behavior (McGraw-Hill, New York, 1964). 4. Analyses ...

When a person fails to obtain an expected reward from an object in the environment, they face a credit assignment problem: Did the absence of reward reflect an extrinsic property of the environment or an intrinsic error in motor execution? To explore this problem, we modified a popular decision-making task used in studies of reinforcement learning, the two-armed bandit task. We compared a versi...

Movement variability is often considered an unwanted byproduct of a noisy nervous system. However, variability can signal a form of implicit exploration, indicating that the nervous system is intentionally varying the motor commands in search of actions that yield the greatest success. Here, we investigated the role of the human basal ganglia in controlling reward-dependent motor variability as...

We have examined the relationship between the movement and the anticipatory postural adjustments (APAs) that precede that movement during a reaching task in the cat. We recorded ground reaction forces in all 3 planes from all 4 limbs as well as electromyographic (EMG) activity from limb and axial muscles. The reaching movement was always preceded by an APA that was characterized by a loading of...

As a model for learning how reticulospinal networks coordinate movement, we have analyzed the function of the Mauthner (M-) neurons in the escape response of the goldfish. We used water displacements of 3-6 micron to elicit C-start escape responses. These responses consist of 2 fundamental movements that grade into each other: Stage 1 lasts 15-40 msec and rotates the body 30 degrees-100 degrees...