Journal of Eye Movement Research

11 pages, 3081 KiB

Open AccessArticle

Influence of Number, Location and Size of Faces on Gaze in Video

by Anis Rahman, Denis Pellerin and Dominique Houzet

J. Eye Mov. Res. 2014, 7(2), 1-11; https://doi.org/10.16910/jemr.7.2.5 (registering DOI) - 5 Apr 2014

Cited by 10 | Viewed by 48

Many studies have reported the preference for faces and influence of faces on gaze, most of them in static images and a few in videos. In this paper, we study the influence of faces in complex free-viewing videos, with respect to the effects of number, location and size of the faces. This knowledge could be used to enrich a face pathway in a visual saliency model. We used eye fixation data from an eye movement experiment, hand-labeled all the faces in the videos watched, and compared the labeled face regions against the eye fixations. We observed that fixations made are in proximity to, or inside the face regions. We found that 50% of the fixations landed directly on face regions that occupy less than 10% of the entire visual scene. Moreover, the fixation duration on videos with face is longer than without face, and longer than fixation duration on static images with faces. Finally, we analyzed the three influencing factors (Eccentricity, Area, Closeness) with linear regression models. For one face, the E + A combined model is slightly better than the E model and better than the A model. For two faces, the three variables (E,A,C) are tightly coupled and the E + A+ C model had the highest score. Full article

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14 pages, 1064 KiB

Open AccessArticle

Visual Search Without Central Vision—No Single Pseudofovea Location Is Best

by Angelika Lingnau, Thorsten Albrecht, Jens Schwarzbach and Dirk Vorberg

J. Eye Mov. Res. 2014, 7(2), 1-14; https://doi.org/10.16910/jemr.7.2.4 (registering DOI) - 4 Apr 2014

Cited by 1 | Viewed by 44

Abstract

We typically fixate targets such that they are projected onto the fovea for best spatial resolution. Macular degeneration patients often develop fixation strategies such that targets are projected to an intact eccentric part of the retina, called pseudofovea. A longstanding debate concerns which pseudofovea location is optimal for non-foveal vision. We examined how pseudofovea position and eccentricity affect performance in visual search when vision is restricted to an offfoveal retinal region by a gaze-contingent display that dynamically blurs the stimulus except within a small viewing window (forced field location). Trained normally sighted participants were more accurate when forced field location was congruent with the required scan path direction; this contradicts the view that a single pseudofovea location is generally best. Rather, performance depends on the congruence between pseudofovea location and scan path direction Full article

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15 pages, 1355 KiB

Open AccessArticle

Detecting Expert’s Eye Using a Multiple-Kernel Relevance Vector Machine

by Giuseppe Boccignone, Mario Ferraro, Sofia Crespi, Carlo Robino and Claudio de’Sperati

J. Eye Mov. Res. 2014, 7(2), 1-15; https://doi.org/10.16910/jemr.7.2.3 (registering DOI) - 2 Apr 2014

Cited by 3 | Viewed by 56

Abstract

Decoding mental states from the pattern of neural activity or overt behavior is an intensely pursued goal. Here we applied machine learning to detect expertise from the oculomotor behavior of novice and expert billiard players during free viewing of a filmed billiard match with no specific task, and in a dynamic trajectory prediction task involving ad-hoc, occluded billiard shots. We have adopted a ground framework for feature space fusion and a Bayesian sparse classifier, namely, a Relevance Vector Machine. By testing different combinations of simple oculomotor features (gaze shifts amplitude and direction, and fixation duration), we could classify on an individual basis which group - novice or expert - the observers belonged to with an accuracy of 82% and 87%, respectively for the match and the shots. These results provide evidence that, at least in the particular domain of billiard sport, a signature of expertise is hidden in very basic aspects of oculomotor behavior, and that expertise can be detected at the individual level both with ad-hoc testing conditions and under naturalistic conditions - and suitable data mining. Our procedure paves the way for the development of a test for the “expert’s eye”, and promotes the use of eye movements as an additional signal source in Brain-Computer-Interface (BCI) systems. Full article

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14 pages, 837 KiB

Open AccessArticle

Visual vs. Spatial Contributions to Microsaccades and Visual-Spatial Working Memory

by Joshua T. Gaunt and Bruce Bridgeman

J. Eye Mov. Res. 2014, 7(2), 1-14; https://doi.org/10.16910/jemr.7.2.2 (registering DOI) - 21 Mar 2014

Cited by 1 | Viewed by 44

Abstract

Microsaccade rates and directions were monitored while observers performed a visual working memory task at varying retinal eccentricities. We show that microsaccades generate no interference in a working memory task, indicating that spatial working memory is at least partially insulated from oculomotor activity. Intervening tasks during the memory interval affected microsaccade patterns; microsaccade frequency was consistently higher during concurrent spatial tapping (no visual component) than during exposure to dynamic visual noise (no task). Average microsaccade rate peaked after appearance of a fixation cross at the start of a trial, and dipped at cue onset and offset, consistent with previous results. Direction of stimuli in choice tasks did not influence microsaccade direction, however. Full article

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13 pages, 696 KiB

Open AccessArticle

Telling People Where to Look in a Soccer-Based Decision Task: A Nomothetic Approach

by Daniel Bishop, Gustav Kuhn and Claire Maton

J. Eye Mov. Res. 2014, 7(2), 1-13; https://doi.org/10.16910/jemr.7.2.1 (registering DOI) - 19 Mar 2014

Cited by 3 | Viewed by 56

Abstract

Research has shown that identifiable visual search patterns characterize skilled performance of anticipation and decision-making tasks in sport. However, to date, the use of experts’ gaze patterns to entrain novices’ performance has been confined to aiming activities. Accordingly, in a first experiment, 40 participants of varying soccer experience viewed static images of oncoming soccer players and attempted to predict the direction in which those players were about to move. Multiple regression analyses showed that the sole predictor of decision-making efficiency was the time taken to initiate a saccade to the ball. In a follow-up experiment, soccer novices undertook the same task as in Experiment 1. Two experimental groups were instructed to either look at the ball, or the player’s head, as quickly as possible; a control group received no instructions. The experimental groups were fastest to make a saccade to the ball or head, respectively, but decision-making efficiency was equivalent across all three groups. The fallibility of a nomothetic approach to training eye movements is discussed. Full article

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J. Eye Mov. Res., Volume 7, Issue 2 (April 2014) – 5 articles

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