Alyson K Butler

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The ability of younger and older adults to perceive the 3-D shape, depth, and curvature of smooth surfaces defined by differential motion and binocular disparity was evaluated in six experiments. The number of points defining the surfaces and their spatial and temporal correspondences were manipulated. For stereoscopic sinusoidal surfaces, the spatial(More)
Trauma outcome variables before and after the institution of the Advanced Trauma Life Support (ATLS) program were compared for the largest hospital in Trinidad and Tobago from July 1981 through December 1985 (pre-ATLS) and from January 1986 to June 1990 (post-ATLS). A total of 199 physicians were ATLS trained by June 1990. Outcome data were analyzed for all(More)
During normal cortical development, individual pyramidal neurons form intracortical axonal arbors that are specific for particular cortical layers. Pyramidal neurons within layer 6 are able to develop layer-specific projections in cultured slices of ferret visual cortex, indicating that extrinsic influences, including patterned visual activity, are not(More)
BACKGROUND One purported role of the medial olivocochlear (MOC) efferent system is to reduce the effects of masking noise. MOC system functioning can be evaluated noninvasively in humans through contralateral suppression of otoacoustic emissions. It has been suggested that the strength of the MOC efferent activity should be positively associated with(More)
Symptomatic disease from Strongyloides stercoralis has been recognized for the first time in Trinidad. Five cases are reported, all showing clinical features suggestive of a sprue-like syndrome. Subtotal jejunal villous atrophy was seen in one case and partial villous atrophy in two. Three patients had laparotomies because of suspected partial intestinal(More)
Cortical circuits are characterized by layer-specific axonal arbors. Molecular laminar cues are believed to direct the development of this specificity. We have tested the hypothesis that ephrin-A5 is responsible for preventing layer 2/3 pyramidal cell axons from branching within layer 4 (Castellani et al., 1998) by assessing the laminar specificity of(More)
Inflammatory bowel disease is generally assumed to be rare among negroes and Indians. Over 10 years 34 cases of ulcerative colitis and 14 cases of Crohn's disease were seen in one medical and one surgical unit in Port-of-Spain, Trinidad. Twenty-six patients were Negroes, 18 were Indians, three were of mixed race, and one was Caucasian. In many of these(More)
PURPOSE This study examined reception thresholds for sentences (RTSs) as a function of test session (N = 5) and noise (continuous and interrupted) in normal-hearing adults. It was hypothesized that RTSs would be superior in interrupted noise and would be stable across repeated testing. METHOD Twenty-five normal-hearing adults participated. RTSs were(More)