Hiroki Yamamoto

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Functional homology between human and macaque visual cortices has provided an important cue to functional subdivisions of the human visual cortex, but it is unclear beyond V1. We estimated the sizes and the visual field eccentricity functions of the extrastriate visual areas of human brains using MRI and fMRI measurements to analyze the interindividual and(More)
This paper proposes instantaneous environment adaptation techniques for both additive noise and channel distortion based on the fast PMC (FPMC) and the MAP-CMS methods. The instantaneous adaptation techniques enable a recognizer to improve recognition on a single sentence that is used for the adaptation in real-time. The key innovations enabling the system(More)
Humans can readily and effortlessly perceive a rich, stable, and unified visual world from a complex visual scene. Yet our internal representation of a visual object appears to be sparse and fragmented. How and where in the brain are such fragmented representations organized into a whole percept? Recent studies have accumulated evidence that some global(More)
Estrogen replacement in postmenopausal women may help prevent or delay development of Alzheimer's disease. Because loss of basal forebrain cholinergic neurons with reductions in choline acetyltransferase (ChAT) concentration are associated with Alzheimer's disease, we investigated the effect of estradiol (E(2)) and J 861, a non-feminizing estrogen, on(More)
We carried out experiments using a microdialysis method to determine whether activation of 5-HT(3) receptors increases the concentration of GABA in the dorsal horn of the spinal cord. Intrathecal perfusion of a selective 5-HT(3) receptor agonist, 1-phenylbiguanide (0.3, 1.0, and 3.0 mM) dose-dependently, increased GABA concentration, while concentrations of(More)
Occlusion is a primary challenge facing the visual system in perceiving object shapes in intricate natural scenes. Although behavior, neurophysiological, and modeling studies have shown that occluded portions of objects may be completed at the early stage of visual processing, we have little knowledge on how and where in the human brain the completion is(More)
Here we created two different multisubject maps (16 subjects) to characterize interindividual variability in the positions of human visual areas (V1, dorsal and ventral parts of V2/3, V3A, V3B, V7, LOc, MT+, and hV4 [or V4v and V8]), which were localized using fMRI and coregistered using a surface-based method. The first is a probability map representing(More)