Eleni Nasiopoulos

Leftward biases in picture scanning and line bisection: A gaze-contingent window study

A bias for humans to attend to the left side of space has been reported in a variety of experiments. While patients with hemispatial neglect mistakenly bisect horizontal lines to the right of centre, neurologically healthy individuals show a mean leftward error. Here, two experiments demonstrated a robust tendency for participants to saccade to the left when viewing photographs. We were able to manipulate this bias by using an asymmetrical gaze-contingent window, which revealed more of the scene on one side of fixation-causing participants to saccade more often in that direction. A second experiment demonstrated the same change in eye movements occurring rapidly from trial to trial, and investigated whether it would carry over and effect attention during a line bisection task. There was some carry-over from gaze-contingent scene viewing to the eye movements during line bisection. However, despite frequent initial eye movements and many errors to the left, manual responses were not affected by this change in orienting. We conclude that the mechanisms underlying asymmetrical attention in picture scanning and line bisection are flexible and can be separated, with saccades in scene perception driven more by a skewed perceptual span.

Top-down and bottom-up aspects of active search in a real-world environment.

Visual search has been studied intensively in the labouratory, but lab search often differs from search in the real world in many respects. Here, we used a mobile eye tracker to record the gaze of participants engaged in a realistic, active search task. Participants were asked to walk into a mailroom and locate a target mailbox among many similar mailboxes. This procedure allowed control of bottom-up cues (by making the target mailbox more salient; Experiment 1) and top-down instructions (by informing participants about the cue; Experiment 2). The bottom-up salience of the target had no effect on the overall time taken to search for the target, although the salient target was more likely to be fixated and found once it was within the central visual field. Top-down knowledge of target appearance had a larger effect, reducing the need for multiple head and body movements, and meaning that the target was fixated earlier and from further away. Although there remains much to be discovered in complex real-world search, this study demonstrates that principles from visual search in the labouratory influence gaze in natural behaviour, and provides a bridge between these labouratory studies and research examining vision in natural tasks.

Wearable computing: Will it make people prosocial?

We recently reported that people who wear an eye tracker modify their natural looking behaviour in a prosocial manner. This change in looking behaviour represents a potential concern for researchers who wish to use eye trackers to understand the functioning of human attention. On the other hand, it may offer a real boon to manufacturers and consumers of wearable computing (e.g., Google Glass), for if wearable computing causes people to behave in a prosocial manner, then the publics fear that people with wearable computing will invade their privacy is unfounded. Critically, both of these divergent implications are grounded on the assumption that the prosocial behavioural effect of wearing an eye tracker is sustained for a prolonged period of time. Our study reveals that on the very first wearing of an eye tracker, and in less than 10 min, the prosocial effect of an eye tracker is abolished, but by drawing attention back to the eye tracker, the implied presence effect is easily reactivated. This suggests that eye trackers induce a transient social presence effect, which is rendered dormant when attention is shifted away from the source of implied presence. This is good news for researchers who use eye trackers to measure attention and behaviour; and could be bad news for advocates of wearable computing in everyday life.

Eye contact affects attention more than arousal as revealed by prospective time estimation

Eye contact can both increase arousal and engage attention. Because these two changes impact time estimation differently, we were able to use a prospective time estimation task to assess the relative changes in arousal and attention during eye contact. Pairs of participants made a 1-minute prospective time estimate while sitting side-by-side and performing three different gaze trials: looking at the wall away from their partner (baseline/away trials), looking at their partner’s profile (profile trials), or making eye contact with their partner (eye contact trials). We found that participants produced significantly longer estimates when they were engaged in eye contact, more so than when they looked at another person’s profile or baseline. As research has shown that people produce shorter estimates during arousing events and longer estimates when attention is captured, we attribute this difference to the attention-demanding process of interacting with another person, via mutual eye contact, over and above any changes in arousal.

Social Attention, Social Presence, and the Dual Function of Gaze

Research on human attention has traditionally been limited to rather spartan laboratory investigations. In the present chapter, recent work that has introduced an element of complexity to this picture, by examining how social stimuli and social contexts influence attention (i.e., social attention research), is reviewed. Evidence demonstrating that staple social attentional phenomena can change drastically under different social conditions (e.g., looking at images of people vs. real people) is taken to suggest a need to consider more seriously the interaction between social presence and social attention. Research on social presence, both real and implied, is briefly reviewed, and recent work directly investigating the influence of social presence on gaze behavior and the implications of this work for understanding social attention are discussed.

Hide and seek: The theory of mind of visual concealment and search

Researchers have investigated visual search behavior for almost a century. During that time, few studies have examined the cognitive processes involved in hiding items rather than finding them. To investigate this, we developed a paradigm that allowed participants to indicate where they would hide (or find) an item that was to be found (or hidden) by a friend or a foe. We found that (i) for friends more than foes, participants selected the pop-out item in the display, and (ii) when the display was homogeneous, they selected nearby and corner items. These behaviors held for both hiding and finding, although hide and find behaviors were not identical. For pop-out displays, decision times were unusually long when hiding an item from a foe. These data converge on the conclusion that the principles of search and concealment are similar, but not the same. They also suggest that this paradigm will provide researchers a powerful method for investigating theory of mind in adults.

Androgen Deprivation Alters Attention to Sexually Provocative Visual Stimuli in Elderly Men

Introduction Testosterone is known to regulate male sexual interest, but the exact way that androgens influence mens sexual cognition remains unclear. Aim To investigate the influence of androgen deprivation (AD) on visual responses to sexually suggestive stimuli in men treated for prostate cancer with AD therapy. Methods Patients with AD-treated prostate cancer, patients with prostate cancer not on AD therapy, and age-matched healthy control participants were exposed to images of male and female runway models fully or minimally clothed. Eye tracking was used to compare looking behavior among groups. Main Outcome Measures Proportion of fixations on fully clothed vs minimally clothed models and proportion of fixations on target areas of interest (ie, legs, chest, pelvis, and face) of fully clothed and minimally clothed models were analyzed and compared among groups. Results Although men not on AD exhibited a larger proportion of fixations on the minimally clothed compared with the fully clothed images, there was no difference between the 2 image types for men on AD. This was true regardless of whether the images depicted male or female models. Groups did not differ in their fixations to target areas of interest. Conclusion These results suggest that testosterone can influence men’s visual attention to sexual stimuli; specifically, AD can attenuate the time spent fixated on sexualized targets. Palmer-Hague JL, Tsang V, Skead C, et al. Androgen Deprivation Alters Attention to Sexually Provocative Visual Stimuli in Elderly Men. Sex Med 2017;5:e245–e254.

Cognitive Ethology and Social Attention

Abstract We consider a research approach called cognitive ethology, which seeks to link cognitions and behaviors as they operate in everyday life with those studied in controlled lab-based investigations. Our test-bed is human social attention which has been traditionally investigated in the laboratory, using images and videos of people as stimuli. By applying this cognitive ethology approach to the study of human social attention we have drawn attention to a crucial component of everyday human social attention that has heretofore been largely overlooked. This missing factor is that eye gaze serves a dual function in the natural world—it both acquires information from the environment and it signals information to others. Indeed, this duality of gaze is so pronounced that even the implied social presence of others can impact how people behave in the real world.

Evaluation of high dynamic range content viewing experience using eye-tracking data

High Dynamic Range (HDR) technologies have demonstrated that they can play an influential role in the design of camera and consumer display products. Understanding the human visual experience of viewing HDR content is a crucial aspect of such systems. Although the visual experience of Low Dynamic Range (LDR) technologies have been well explored, there are limited comparable studies for HDR content. In this paper, we present a study that evaluates the viewing experience of HDR and LDR content as measured both subjectively, and objectively vis-a-vis eye-tracking data. The eye-tracking data was collected while individuals viewed HDR or LDR videos in a free-viewing task. Our study shows a clear subjective preference for HDR content when individuals are given a choice between HDR and LDR displays, but this preference does not translate into a reliable difference in the subjective or objective eye movement measures when the displays are viewed sequentially, suggesting that objective performance measures are not the foundation upon which subjective preferences are based. Our findings should help in developing new visual attention models for the role of HDR and LDR content on subjective and objective experience and performance.