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Eye-tracking System (eye-tracking + system)
Selected AbstractsThe effects of acute exercise on attentional bias towards smoking-related stimuli during temporary abstinence from smokingADDICTION, Issue 11 2009Kate Janse Van Rensburg ABSTRACT Rationale Attentional bias towards smoking-related cues is increased during abstinence and can predict relapse after quitting. Exercise has been found to reduce cigarette cravings and desire to smoke during temporary abstinence and attenuate increased cravings in response to smoking cues. Objective To assess the acute effects of exercise on attentional bias to smoking-related cues during temporary abstinence from smoking. Method In a randomized cross-over design, on separate days regular smokers (n = 20) undertook 15 minutes of exercise (moderate intensity stationary cycling) or passive seating following 15 hours of nicotine abstinence. Attentional bias was measured at baseline and post-treatment. The percentage of dwell time and direction of initial fixation was assessed during the passive viewing of a series of paired smoking and neutral images using an Eyelink II eye-tracking system. Self-reported desire to smoke was recorded at baseline, mid- and post-treatment and post-eye-tracking task. Results There was a significant condition × time interaction for desire to smoke, F(1,18) = 10.67, P = 0.004, eta2 = 0.36, with significantly lower desire to smoke at mid- and post-treatment following the exercise condition. The percentage of dwell time and direction of initial fixations towards smoking images were also reduced significantly following the exercise condition compared with the passive control. Conclusion Findings support previous research that acute exercise reduces desire to smoke. This is the first study to show that exercise appears to also influence the salience and attentional biases towards cigarettes. [source] Infants' Evolving Representations of Object Motion During Occlusion: A Longitudinal Study of 6- to 12-Month-Old InfantsINFANCY, Issue 2 2004Gustaf Gredebäck Infants' ability to track temporarily occluded objects that moved on circular trajectories was investigated in 20 infants using a longitudinal design. They were first seen at 6 months and then every 2nd month until the end of their 1st year. Infants were presented with occlusion events covering 20% of the target's trajectory (effective occlusion interval ranged from 500,4,000 msec). Gaze was measured using an ASL 504 infrared eye-tracking system. Results effectively demonstrate that infants from 6 months of age can represent the spatiotemporal dynamics of occluded objects. Infants at all ages tested were able to predict, under certain conditions, when and where the object would reappear after occlusion. They moved gaze accurately to the position where the object was going to reappear and scaled their timing to the current occlusion duration. The average rate of predictive gaze crossings increased with occlusion duration. These results are discussed as a 2-factor process. Successful predictions are dependent on strong representations, themselves dependent on the richness of information available during encoding and graded representations. [source] Location of a missing object and detection of its absence by infants: Contribution of an eye-tracking system to the understanding of infants' strategiesINFANT AND CHILD DEVELOPMENT, Issue 4 2004Roger Lécuyer Abstract Previous research has demonstrated infants' capacity to discriminate between situations in which all the objects successively hidden behind a screen are present, or not, after the removal of the screen. Two types of interpretation have been proposed: counting capacity or object memorization capacity. In the usual paradigm, the missing object in the impossible event is usually the last object which is placed behind the screen. Following this, a third interpretation can be offered: infants' exploration is first directed to this object's location, and its presence or absence is noticed. Two experiments using Wynn's (Nature 1992; 358:749) paradigm were performed to test the third hypothesis. The first experiment involved four objects (teddy bears) placed in four squares. Infants looked longer at the impossible event (3 objects, the last one missing) than at the possible event (4 objects) when the impossible event was presented first. No difference in looking duration was observed for the opposite order. In the second experiment, the four objects were disposed in a line and an eye-tracking system was used. No difference in the number of looks was observed between the impossible event (3 objects, the second one missing) and the possible event (4 objects). Therefore, it appears that at least in this complex situation (4 objects used instead of 2 usually), the location of the missing object is a key factor for event discrimination. Eye-tracking also indicated in the second experiment that infants looked less at the second location during an impossible event (object missing) than during the possible event (object present), indicating that the impossibility of the event was not a determining factor for looking durations. Altogether, the data indicate the potential usefulness of eye-tracking analysis in this type of situation. Copyright © 2004 John Wiley & Sons, Ltd. [source] |