Looking for ideas: Eye behavior during goal-directed internally focused cognition

Humans have a highly developed visual system, yet we spend a high proportion of our time awake ignoring the visual world and attending to our own thoughts. The present study examined eye movement characteristics of goal-directed internally focused cognition. Deliberate internally focused cognition was induced by an idea generation task. A letter-by-letter reading task served as external task. Idea generation (vs. reading) was associated with more and longer blinks and fewer microsaccades indicating an attenuation of visual input. Idea generation was further associated with more and shorter fixations, more saccades and saccades with higher amplitudes as well as heightened stimulus-independent variation of eye vergence. The latter results suggest a coupling of eye behavior to internally generated information and associated cognitive processes, i.e. searching for ideas. Our results support eye behavior patterns as indicators of goal-directed internally focused cognition through mechanisms of attenuation of visual input and coupling of eye behavior to internally generated information.     

Improving drivers’ eye fixation using accident scenes of the HazardTouch driver-training tool

This study investigated the effect of a driver-training tool that uses “HazardTouch” software and videos of actual accidents on drivers’ eye fixation through a tablet device (iPad). Drivers’ eye fixation of a video of a car passing thirteen intersections without signals was measured before and after training, using an eye-mark recorder. Three training exposures of four scenes using HazardTouch improved drivers’ eye fixation on the stimulus movie. In particular, the first fixation on the edge of the blind spot at intersections appeared significantly sooner after training. Moreover, fixation frequency for this blind spot increased significantly at post-training. These results suggest that the proposed driver-training tool effectively improves eye-fixation behavior in drivers and may prevent accidents.     

Early perception-action coupling: eye movements and the development of object perception

We investigated the scanning strategies used by 2- to 3.5-month-old infants when viewing partly occluded object displays. Eye movements were recorded with a corneal reflection system as the infants observed stimuli depicting two rod parts above and below an occluding box. Stimulus parameters were chosen on the basis of past research demonstrating the importance of motion, occluder width, and edge alignment to perception of object unity. Results indicated that the infants tailored scanning to display characteristics, engaging in more extensive scanning when unity perception was challenged by a wide occluder or misaligned edges. In addition, older infants tended to scan the lower parts of the displays more frequently than did younger infants. Exploration of individual differences, however, revealed marked contrasts in specific scanning styles across infants. The findings are consistent with views of perceptual development stressing the importance of information processing skills and self-directed action to the acquisition of object knowledge.     

Orienting and maintenance of gaze in contamination fear: Biases for disgust and fear cues

The present study examines the extent to which attentional biases in contamination fear commonly observed in obsessive-compulsive disorder (OCD) are specific to disgust or fear cues, as well as the components of attention involved. Eye tracking was used to provide greater sensitivity and specificity than afforded by traditional reaction time measures of attention. Participants high (HCF; n = 23) and low (LCF; n = 25) in contamination fear were presented with disgusted, fearful, or happy faces paired with neutral faces for 3 s trials. Evidence of both vigilance and maintenance-based biases for threat was found. The high group oriented attention to fearful faces but not disgusted faces compared to the low group. However, the high group maintained attention on both disgusted and fearful expressions compared to the low group, a pattern consistent across the 3 s trials. The implications of these findings for conceptualizing emotional factors that moderate attentional biases in contamination-based OCD are discussed.     

Processing emotion information from both the face and body: An eye-movement study

This study examined the perception of emotional expressions, focusing on the face and the body. Photographs of four actors expressing happiness, sadness, anger, and fear were presented in congruent (e.g., happy face with happy body) and incongruent (e.g., happy face with fearful body) combinations. Participants selected an emotional label using a four-option categorisation task. Reaction times and accuracy for the categorisation judgement, and eye movements were the dependent variables. Two regions of interest were examined: face and body. Results showed better accuracy and faster reaction times for congruent images compared to incongruent images. Eye movements showed an interaction in which there were more fixations and longer dwell times to the face and fewer fixations and shorter dwell times to the body with incongruent images. Thus, conflicting information produced a marked effect on information processing in which participants focused to a greater extent on the face compared to the body.     

Towards testing auditory–vocal interfaces and detecting distraction while driving: A comparison of eye-movement measures in the assessment of cognitive workload

Recently, there has been a growing need among researchers to understand the problem of cognitive workload induced by auditory–verbal–vocal tasks while driving in realistic conditions. This is due to the fact that we need (a) valid methods to evaluate in-vehicle electronic devices using voice control systems and (b) experimental data to build more reliable driver state monitoring systems. In this study, we examined the effects of cognitive workload induced by the delayed digit recall task (n-back) while driving. We used a high-fidelity driving simulator and a highway scenario with moderate traffic to study eye movements in realistic driving conditions. This study included 46 participants, and the results indicate that a change in pupil size is most sensitive for measuring changes in cognitive demand in auditory–verbal–vocal tasks. Less sensitive measures included changes in fixation location and blink rate. Fixation durations and the driving performance metrics did not provide sensitive measures of graded levels of cognitive demand.     

Eye movements during the handwriting of words: Individually and within sentences

Handwriting, a complex motor process involves the coordination of both the upper limb and visual system. The gaze behavior that occurs during the handwriting process is an area that has been little studied. This study investigated the eye-movements of adults during writing and reading tasks. Eye and handwriting movements were recorded for six different words over three different tasks. The results compared reading and handwriting the same words, a between condition comparison and a comparison between the two handwriting tasks. Compared to reading, participants produced more fixations during handwriting tasks and the average fixation durations were longer. When reading fixations were found to be mostly around the center of word, whereas fixations when writing appear to be made for each letter in a written word and were located around the base of letters and flowed in a left to right direction. Between the two writing tasks more fixations were made when words were written individually compared to within sentences, yet fixation durations were no different. Correlation of the number of fixations made to kinematic variables revealed that horizontal size and road length held a strong correlation with the number of fixations made by participants.     

Distractors that signal reward attract the eyes

Salient stimuli and stimuli associated with reward have the ability to attract both attention and the eyes. The current study exploited the effects of reward on the well-known global effect in which two objects appear simultaneously in close spatial proximity. Participants always made saccades to a predefined target, while the colour of a nearby distractor signalled the reward available (high/low) for that trial. Unlike previous reward studies, in the current study these distractors never served as targets. We show that participants made fast saccades towards the target. However, saccades landed significantly closer to the high compared to the low reward signalling distractor. This reward effect was already present in the first block and remained stable throughout the experiment. Instead of landing exactly in between the two stimuli (i.e., the classic global effect), the fastest eye movements landed closer towards the reward signalling distractor. Results of a control experiment, in which no distractor-reward contingencies were present, confirmed that the observed effects were driven by reward and not by physical salience. Furthermore, there were trial-by-trial reward priming effects in which saccades landed significantly closer to the high instead of the low reward signalling distractor when the same distractor was presented on two consecutive trials. Together the results imply that a reward signalling stimulus that was never part of the task set has an automatic effect on the oculomotor system.     

An incremental boundary study on parafoveal preprocessing in children reading aloud: Parafoveal masks overestimate the preview benefit

Parafoveal preprocessing is an important factor for efficient reading and, in eye-movement studies, is typically investigated by means of parafoveal masking: Valid previews are compared to instances in which masks prevent preprocessing. A long-held assumption was that parafoveal preprocessing, as assessed by this technique, only reflects facilitation (i.e., a preview benefit). Recent studies, however, suggested that the benefit estimate is inflated due to interference of the parafoveal masks, i.e., the masks inflict processing costs. With children from Grades 4 and 6, we administered the novel incremental priming technique. The technique manipulates the salience of the previews by systematically varying its perceptibility (i.e., by visually degrading the previews). This technique does not require a baseline condition, but makes it possible to determine whether a preview induces facilitation or interference. Our salience manipulation of valid previews revealed a preview benefit in the children of both Grades. For two commonly used parafoveal masks, we observed interference corroborating the notion that masks are not a proper baseline. With the novel incremental boundary technique, in contrast, one can achieve an accurate estimate of the preview benefit.