Tracking the identity of moving words: Stimulus complexity and familiarity affects tracking accuracy

In two experiments, participants tracked the identity and location of moving words. The task bears resemblance to one performed by air traffic controllers who track multiple moving aircraft, where they are identified with relatively complex alphanumeric call signs. In Experiment 1, stimulus familiarity was manipulated by comparing the tracking of familiar words and pseudowords. In Experiment 2, also stimulus complexity was varied by having the participants track short and long words. Stimulus complexity affected tracking: Short words were easier to track than long words. Moreover, familiarity of identity affected tracking of short words (short familiar words were easier to track than short pseudo-words) but not of long words. The results are interpreted within the framework of the model of multiple identity tracking model. Mathematical simulations suggest that observers may not have enough time for full identification of complex identities in a dynamic situation. Practical implications of the results for air traffic control are discussed.     

Quantifying Supervisory Decision Making: Eye‐Tracking Technology Applications for the Promotion of Child Safety

Previous research has investigated various risk factors correlated with childhood injury, but few studies have successfully investigated these variables beyond participant self‐report. The present study utilized infrared eye‐tracking and computer‐based latency measures to evaluate caregiver supervision decisions in injury risk situations for typically developing children and children with autism spectrum disorder. The sample included 99 young women, ages 18–24 years, who are frequent non‐parental caregivers for children. Results indicated that participants altered their speed of response, child monitoring, and intervention decisions on the basis of idiosyncratic assessment of injury risk. Minimal significant differences emerged with regard to supervision behavior and chosen strategies when comparing children with autism spectrum disorder to typically developing children. Overall, results suggest that non‐parental caregivers integrate child characteristics and environmental risk factors when assessing risk and choosing interventions. Implications are discussed with regard to injury prevention programs emphasizing protective aspects of supervision for children across various settings. Copyright © 2015 John Wiley & Sons, Ltd.     

Reach out to one and you reach out to many: Social touch affects third‐party observers

Casual social touch influences emotional perceptions, attitudes, and behaviours of interaction partners. We asked whether these influences extend to third‐party observers. To this end, we developed the Social Touch Picture Set comprising line drawings of dyadic interactions, half of which entailed publicly acceptable casual touch and half of which served as no‐touch controls. In Experiment 1, participants provided basic image norms by rating how frequently they observed a displayed touch gesture in everyday life and how comfortable they were observing it. Results implied that some touch gestures were observed more frequently and with greater comfort than others (e.g., handshake vs. hug). All gestures, however, obtained rating scores suitable for inclusion in Experiments 2 and 3. In Experiment 2, participants rated perceived valence, arousal, and likeability of randomly presented touch and no‐touch images without being explicitly informed about touch. Image characters seemed more positive, aroused, and likeable when they touched as compared to when they did not touch. Image characters seemed more negative and aroused, but were equally likeable, when they received touch as compared to when there was no physical contact. In Experiment 3, participants passively viewed touch and no‐touch images while their eye movements were recorded. Differential gazing at touch as compared to no‐touch images emerged within the first 500 ms following image exposure and was largely restricted to the characters' upper body. Gazing at the touching body parts (e.g., hands) was minimal and largely unaffected by touch, suggesting that touch processing occurred outside the focus of visual attention. Together, these findings establish touch as an important visual cue and provide novel insights into how this cue modulates socio‐emotional processing in third‐party observers.     

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.     

Children's and adults' parafoveal processes in German: Phonological and orthographic effects

Phonological and orthographic information has been shown to play an important role in parafoveal processing in skilled adult reading in English. In the present study, we investigated whether similar parafoveal effects can be found in children using the boundary eye tracking method. Children and adults read sentences in German with embedded target nouns which were presented in original, pseudohomophone (PsH), transposed-letter (TL), lower-case and control conditions to assess phonological and orthographic preview effects. We found evidence of PsH preview benefit effects for children. We also found TL preview benefit effects for adults, while children only showed these effects under specific conditions. Results are consistent with the developmental view that reading initially depends on phonological processes and that orthographic processes become increasingly important.     

The feasibility of an automated eye-tracking-modified Fagan test of memory for human faces in younger Ugandan HIV-exposed children

Objective: The Fagan Test of Infant Intelligence (FTII) uses longer gaze length for unfamiliar versus familiar human faces to gauge visual-spatial encoding, attention, and working memory in infants. Our objective was to establish the feasibility of automated eye tracking with the FTII in HIV-exposed Ugandan infants.

Method: The FTII was administered to 31 perinatally HIV-exposed noninfected (HEU) Ugandan children 6–12 months of age (11 boys; M = 0.69 years, SD = 0.14; 19 girls; M = 0.79, SD = 0.15). A series of 10 different faces were presented (familiar face exposure for 25 s followed by a gaze preference trial of 15 s with both the familiar and unfamiliar faces). Tobii X2-30 infrared camera for pupil detection provided automated eye-tracking measures of gaze location and length during presentation of Ugandan faces selected to correspond to the gender, age (adult, child), face expression, and orientation of the original FTII. Eye-tracking gaze length for unfamiliar faces was correlated with performance on the Mullen Scales of Early Learning (MSEL).

Results: Infants gazed longer at the novel picture compared to familiar across 10 novelty preference trials. Better MSEL cognitive development was correlated with proportionately longer time spent looking at the novel faces (r(30) = 0.52, p = .004); especially for the Fine Motor Cognitive Sub-scale (r(30) = 0.54, p = .002).

Conclusion: Automated eye tracking in a human face recognition test proved feasible and corresponded to the MSEL composite cognitive development in HEU infants in a resource-constrained clinical setting. Eye tracking may be a viable means of enhancing the validity and accuracy of other neurodevelopmental measures in at-risk children in sub-Saharan Africa.     

How do humans group non-rigid objects in multiple object tracking?: Evidence from grouping by self-rotation

Previous studies on perceptual grouping found that people can use spatiotemporal and featural information to group spatially separated rigid objects into a unit while tracking moving objects. However, few studies have tested the role of objects’ self-motion information in perceptual grouping, although it is of great significance to the motion perception in the three-dimensional space. In natural environments, objects always move in translation and rotation at the same time. The self-rotation of the objects seriously destroys objects’ rigidity and topology, creates conflicting movement signals and results in crowding effects. Thus, this study sought to examine the specific role played by self-rotation information on grouping spatially separated non-rigid objects through a modified multiple object tracking (MOT) paradigm with self-rotating objects. Experiment 1 found that people could use self-rotation information to group spatially separated non-rigid objects, even though this information was deleterious for attentive tracking and irrelevant to the task requirements, and people seemed to use it strategically rather than automatically. Experiment 2 provided stronger evidence that this grouping advantage did come from the self-rotation per se rather than surface-level cues arising from self-rotation (e.g. similar 2D motion signals and common shapes). Experiment 3 changed the stimuli to more natural 3D cubes to strengthen the impression of self-rotation and again found that self-rotation improved grouping. Finally, Experiment 4 demonstrated that grouping by self-rotation and grouping by changing shape were statistically comparable but additive, suggesting that they were two different sources of the object information. Thus, grouping by self-rotation mainly benefited from the perceptual differences in motion flow fields rather than in deformation. Overall, this study is the first attempt to identify self-motion as a new feature that people can use to group objects in dynamic scenes and shed light on debates about what entities/units we group and what kinds of information about a target we process while tracking objects.     

Perceptual-cognitive performance of youth soccer players in a 360°-environment – Differences between age groups and performance levels

IntroductionAn important requirement for soccer players is the accurate and rapid processing of dynamic and complex visual scenes. Therefore, in high-level youth soccer the players’ perceptual-cognitive skills are highly relevant from a scientific and practical point of view. The aim of the present study was to investigate differences in perceptual-cognitive performance between youth soccer players of different age groups and soccer performance levels in a dynamic 360°-environment.MethodsIn a sample of 292 elite and sub-elite youth soccer players from the age groups U12–U23, perceptual-cognitive skills were assessed using a 360°-multiple object tracking task. An 8 × 2 (age group x performance level) analysis of variance (ANOVA) was conducted to examine the effects of age group and soccer performance level on performance in the task.ResultsThe analyses revealed a significant main effect of age group. Post hoc analyses showed that youth players belonging to the older age groups (U16, U17, U19, and U23) performed significantly better in the 360°-multiple object tracking task than players of the youngest age group (U12). Yet no significant age-related differences could be found from age group U16 on. Furthermore, there was a significant effect of soccer performance level on the 360°-multiple object tracking performance in favor of the elite players. Significant differences between elite and sub-elite players within the same age group were only present in the highest age groups U19 and U23.ConclusionsThe results suggest that in a dynamic 360°-environment highly talented youth soccer players show better perceptual-cognitive performance with increasing age. Furthermore, elite youth players exhibit distinctive perceptual-cognitive abilities particularly at the highest age groups. These findings provide interesting implications for science and practice regarding the perceptual-cognitive skills of talented soccer players and their role in talent development.     

Resource availability hypothesis: Perceived financial and caloric status affect individuals' height preferences for potential partners

Height is an important concern in human mate choices. Prior research indicates that people who live in areas with abundant resources differ from those who live in areas with scarce resources regarding height preferences. Based on a health‐maximizing principle, we propose a resource availability account for such differences. Compared with women's height preferences, men's height preferences are hypothesized to be more dependent on either financial or caloric resource availability. Specifically, taller females would be more preferred by males who are poor in resources than those who are rich in resources. Results from three studies supported these hypotheses. In Study 1, men from remote areas of China who had lower family income preferred taller women more than those from eastern China who had higher family income. In Study 2, men who were financially dissatisfied preferred taller women more than those who were financially satisfied. In Study 3, men with low caloric status preferred taller women more than men with high caloric status. In addition, women's height preferences in Studies 1, 2 and 3 were less determined by resource availability. These findings suggest that height preferences are changeable, depending on financial or caloric status.     

A low‐cost platform for eye‐tracking research: Using Pupil© in behavior analysis

Tracking eye movements is being increasingly recognized as a valuable source of information about stimulus control. So far, however, eye‐tracking research has suffered from accessibility issues, with expensive hardware and closed‐source software. In this article we review Pupil©, an eye‐tracking platform developed by Pupil Labs and that combines open‐source software with low‐cost hardware components. We offer concrete recommendations about Pupil use in stimulus‐control research and we show how the software can be extended to automatize the analysis of gaze data. Finally, we present the results of a study of visual discrimination and conditioned reinforcement conducted with Pupil, establishing the usefulness of this platform as a research tool in behavior analysis.