Search

Can people react to objects in their visual field that they do not consciously perceive? We investigated how visual perception and motor action respond to moving objects whose visibility is reduced, and we found a dissociation between motion processing for perception and for action. We compared motion perception and eye movements evoked by two orthogonally drifting gratings, each presented separately to a different eye. The strength of each monocular grating was manipulated by inducing adaptation to one grating prior to the presentation of both gratings. Reflexive eye movements tracked the vector average of both gratings (pattern motion) even though perceptual responses followed one motion direction exclusively (component motion). Observers almost never perceived pattern motion. This dissociation implies the existence of visual-motion signals that guide eye movements in the absence of a corresponding conscious percept. [ABSTRACT FROM PUBLISHER]

Abstract: Inspection time (IT) is the most popular simple psychometric measure that is used to account for a large part of the variance in human mental ability, with the estimated corrected correlation between IT and IQ being −0.50. In this study, we investigate the relationship between IT and the performance and oculomotor variables measured during three simple visual tasks. Participants’ ITs were first measured using a slight variation of the standard IT task, which was followed by the three simple visual tasks that were designed to test participants’ visual–attentional control and visual working memory under varying degrees of difficulty; they included a visual search task, a comparative visual search task, and a visual memorization task. Significant correlations were found between IT and performance variables for each of the visual tasks. The implications of the correlation between IT and performance-related variables are discussed. Oculomotor variables on the other hand only correlated significantly with IT during the retrieval phase of the visual memorization task, which is likely a product of differences in participants’ ability to memorize objects during the loading phase of the experiment. This leads us to the conclusion that the oculomotor variables we measured do not correlate with IT in general, but may in the case where a systematic benefit would be realized. [Copyright &y& Elsevier]

Discusses the comparative visual search as an experimental paradigm for investigating the underlying complex processes of perception and cognition. Modes of visual processing which correspond to consecutive stages; Role of perceptual grouping in visual search; Components of visual perception involved in a standard visual search task.

Highlights: [•] Focus of peri-saccadic mislocalization follows salient stimuli, not necessarily the saccade goal. [•] Attracting effect of salient stimuli is not diminished by visible background. [•] Absence of salient stimulus including saccade target results in less compression. [•] A strong visual reference can influence perceived location of peri-saccadic flashes. [ABSTRACT FROM AUTHOR]

Color coding is used to guide attention in computer displays for such critical tasks as baggage screening or air traffic control. It has been shown that a display object attracts more attention if its color is more similar to the color for which one is searching. However, what does similar precisely mean? Can we predict the amount of attention that a display color will receive during a search for a given target color? To tackle this question, two color-search experiments measuring the selectivity of saccadic eye movements and mapping out its underlying color space were conducted. A variety of mathematical models, predicting saccadic selectivity for given target and display colors, were devised and evaluated. The results suggest that applying a Gaussian function to a weighted Euclidean distance in a slightly modified HSI color space is the best predictor of saccadic selectivity in the chosen paradigm. Hue and intensity information by itself provides a basis for useful predictors, spanning a possibly spherical color space of saccadic selectivity. Although the current models cannot predict saccadic selectivity values for a wide variety of visual search tasks, they reveal some characteristics of color search that are of both theoretical and applied interest, such as for the design of human–computer interfaces. [ABSTRACT FROM AUTHOR]