Visual Attention and Cognitive Archaeology: An Eye-Tracking Study of Palaeolithic Stone Tools

The study of lithic technology can provide information on human cultural evolution. This article aims to analyse visual behaviour associated with the exploration of ancient stone artefacts and how this relates to perceptual mechanisms in humans. In Experiment 1, we used eye tracking to record patterns of eye fixations while participants viewed images of stone tools, including examples of worked pebbles and handaxes. The results showed that the focus of gaze was directed more towards the upper regions of worked pebbles and on the basal areas for handaxes. Knapped surfaces also attracted more fixation than natural cortex for both tool types. Fixation distribution was different to that predicted by models that calculate visual salience. Experiment 2 was an online study using a mouse-click attention tracking technique and included images of unworked pebbles and ‘mixed’ images combining the handaxe's outline with the pebble's unworked texture. The pattern of clicks corresponded to that revealed using eye tracking and there were differences between tools and other images. Overall, the findings suggest that visual exploration is directed towards functional aspects of tools. Studies of visual attention and exploration can supply useful information to inform understanding of human cognitive evolution and tool use.

Effects of word predictability on eye movements during Arabic reading

Contextual predictability influences both the probability and duration of eye fixations on words when reading Latinate alphabetic scripts like English and German. However, it is unknown whether word predictability influences eye movements in reading similarly for Semitic languages like Arabic, which are alphabetic languages with very different visual and linguistic characteristics. Such knowledge is nevertheless important for establishing the generality of mechanisms of eye-movement control across different alphabetic writing systems. Accordingly, we investigated word predictability effects in Arabic in two eye-movement experiments. Both produced shorter fixation times for words with high compared to low predictability, consistent with previous findings. Predictability did not influence skipping probabilities for (four- to eight-letter) words of varying length and morphological complexity (Experiment 1). However, it did for short (three- to four-letter) words with simpler structures (Experiment 2). We suggest that word-skipping is reduced, and affected less by contextual predictability, in Arabic compared to Latinate alphabetic reading, because of specific orthographic and morphological characteristics of the Arabic script.

How Do Cardiology Practitioners Interpret an Electrocardiogram: An Eye Tracking Study (Preprint)

BACKGROUND Visual expertise refers to advanced visual skills demonstrated when executing domain‐specific visual tasks. Understanding healthcare practitioners’ visual expertise across different levels in the healthcare sector is crucial in clarifying how to acquire accurate interpretations of electrocardiograms (ECGs). OBJECTIVE The study aims to quantify, through the use of eye-tracking, differences in the visual expertise of medical practitioners, such as medical students, cardiology nurses, technicians, fellows, and consultants, when interpreting ECGs. METHODS Sixty-three participants with different healthcare roles participated in an eye-tracking study that consisted of interpreting 10 ECGs with different heart abnormalities. A counterbalanced within-subjects design was employed with one independent variable consisting of the expertise level of the medical practitioners and two measured eye-tracking dependent variables (fixations count and fixations revisitation). Eye-tracking data was assessed according to the accuracy of interpretation and frequency interpreters visited different leads in ECGs. In addition, the median and standard deviation in the interquartile range for the fixations count and the mean and standard deviation for the ECG lead revisitations were calculated. RESULTS Accuracy of interpretation ranged between 98% among consultants and 52% among medical students. Eye-tracking features also reflected this difference in the accuracy of interpretation. The results of the eye fixations count and eye fixations revisitations indicate that the less experienced medical practitioners need to observe various ECG leads more carefully. However, experienced medical practitioners rely on visual pattern recognition to provide their ECG diagnoses. CONCLUSIONS The results show that visual expertise for ECG interpretation is linked to the practitioner’s role within the healthcare system and the number of years of practical experience interpreting ECGs. Medical practitioners focus on different ECG leads and different waveform abnormalities according to their role in the healthcare sector and their expertise levels.

Wandering Eyes: Using Gaze-Tracking Method to Capture Eye Fixations in Unfamiliar Healthcare Environments

Objective: This study aims to investigate the elements of wayfinding in indoor complex healthcare environments. Background: The study replicates Ghamari and Pati’s 2018 study to identify the environmental attributes that attract eye fixation during wayfinding by objectively tracking eye movements and fixation as healthy subjects navigate through a complex, unfamiliar indoor healthcare setting. The study addressed what do people look at while navigating in unfamiliar healthcare environments? What are the relative time periods of eye fixations on different visual environmental elements of the healthcare-designed environments? And what role do visual environmental attributes in healthcare facilities, such as configuration, color, art, directories, maps, furniture, and so on, play during the wayfinding process. Method: Twenty-four adults in different genders and various age groups participated in this study and navigated five routes with different degrees of difficulty. The sequence of the destinations in this study was randomized. The data were collected by tracking gaze fixations while human subjects navigated an indoor complex healthcare environment. Results: The findings show that identifying signs (29.1%), informative signs (20.8%), and architectural features (11.3%) constituted the most frequent elements attracting gaze, substantially more than the other classes of information. Four types of signage (identifying signs, informative signs, directional, and safety/regulatory signs) were accounted for 62.3% of the total gaze fixation time. Conclusions: The comparison of the ordered list based on frequencies and time of eye fixations on various elements developed in Ghamari and Pati’s study shows a vast degree of similarities.

Effects of pointing movements on visuospatial working memory in a joint-action condition: Evidence from eye movements

Previous studies showed that (a) performing pointing movements towards to-be-remembered locations enhanced their later recognition, and (b) in a joint-action condition, experimenter-performed pointing movements benefited memory to the same extent as self-performed movements. The present study replicated these findings and additionally recorded participants’ fixations towards studied arrays. Each trial involved the presentation of two consecutive spatial arrays, where each item occupied a different spatial location. The item locations of one array were encoded by mere visual observation (the no-move array), whereas the locations of the other array were encoded by observation plus pointing movements (the move array). Critically, in Experiment 1, participants took turns with the experimenter in pointing towards the move arrays (joint-action condition), while in Experiment 2 pointing was performed only by the experimenter (passive condition). The results showed that the locations of move arrays were recognized better than the locations of no-move arrays in Experiment 1, but not in Experiment 2. The pattern of eye-fixations was in line with behavioral findings, indicating that in Experiment 1, fixations to the locations of move arrays were higher in number and longer in duration than fixations to the locations of no-move arrays, irrespective of the agent who performed the movements. In contrast, no differences emerged in Experiment 2. We propose that, in the joint-action condition, self- and other-performed pointing movements are coded at the same representational level and their functional equivalency is reflected in a similar pattern of eye-fixations.

Patterns of Eye Movement Influenced by Multitasking Workload: A Clustering Analysis

Although multitasking has been studied in the past few decades, there has been a lack of investigation on how individuals’ multitasking performance can be predicted using eye movement data. To address this gap, this study proposed an exploratory approach to understand the manifestation of eye movement patterns that could provide diagnostic and predictive information of multitasking performance. Nineteen participants completed Multi-Attribute Task Battery (MATB-II) experiments under both low and high workloads and their eye movement and MATB-II task performance were collected. We applied a hierarchical clustering method that classified the participants into three clusters – clusters with small, medium, and large number of fixations. Then, we compared the MATB-II performance of the three clusters. The results s howed significant differences in average reaction time to stimuli and average error count among the three clusters. Our study showed that hierarchical clustering of eye fixations can effectively predict multitasking performance.

Unsupervised text segmentation predicts eye fixations during reading

Words typically form the basis of psycholinguistic and computational linguistic studies about sentence processing. However, recent evidence shows the basic units during reading, i.e., the items in the mental lexicon, are not always words, but could also be sub-word and supra-word units. To recognize these units, human readers require a cognitive mechanism to learn and detect them. In this paper, we assume eye fixations during reading reveal the locations of the cognitive units, and that the cognitive units are analogous with the text units discovered by unsupervised segmentation models. We predict eye fixations by model-segmented units on both English and Dutch text. The results show the model-segmented units predict eye fixations better than word units. This finding suggests that the predictive performance of model-segmented units indicates their plausibility as cognitive units. The Less-is-Better (LiB) model, which finds the units that minimize both long-term and working memory load, offers advantages both in terms of prediction score and efficiency among alternative models. Our results also suggest that modeling the least-effort principle on the management of long-term and working memory can lead to inferring cognitive units. Overall, the study supports the theory that the mental lexicon stores not only words but also smaller and larger units, suggests that fixation locations during reading depend on these units, and shows that unsupervised segmentation models can discover these units.