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Hiromi Morita

Publications and source records attributed to Hiromi Morita.

4 recordsLinked to original sources
PubMed2006

Attribute-invariant orientation discrimination at an early stage of processing in the human visual system.

This study investigated event-related brain potentials (ERPs) during selective attention to the orientation of a bar comprised of two squares, which were defined by only color or motion (intra-attribute conditions) or both (interattribute condition). An early positive potential in association with orientation selection was elicited for all conditions in similar latency ranges but with different scalp distributions. These results suggest that attribute-invariant orientations can be discriminated at an early stage of processing in the human brain, which fills a gap between monkey electrophysiology and human psychophysics, while attribute-specific orientations are also available in a given context.

Adult↗
PubMed2003

Effects of pictorially-defined surfaces on visual search.

Three experiments of visual search for a cube (for a square pillar in Experiment 3) with an odd conjunction of orientation of faces and color (a cube with a red top face and a green right face among cubes with a green top face and a red right face, for example) showed that the search is made more efficient by arranging cubes (or square pillars) so that their top faces lie in a horizontal surface defined by pictorial cues. This effect shows the same asymmetry as that of the surface defined by the disparity cue did [Perception and Psychophysics, 62 (2000) 540], implying that the effect is independent of the three-dimensional cue and the global surface structure influences the control of attention during the search.

Adult↗
PubMed2003

Integration process of contours defined by different attributes.

We examined how contours defined by different attributes are integrated into a shape using the visual search paradigm and found that the search for the bar orientation is particularly difficult when each bar is composed of motion-defined and luminance- or color-defined contours. This does not support the view that the shape integration process is based on the unified contour representation entirely common to all attributes, but suggests that motion-defined contours are integrated through a different process.

Color Perception↗