Krzysztof Krejtz

• PhD
• Head of Eye Tracking Research Center at SWPS University

Well-being is a dynamic construct that evolves over time and fluctuates within individuals, presenting challenges for accurate quantification. Reduced well-being is often linked to depression or anxiety disorders, which are characterised by biases in visual attention towards specific stimuli, such as human faces. This paper introduces a novel appro...

Cognitive processes underlying inferences regarding inferring mental states (i.e. intentionality ascription) are still to be investigated. To assess how people accumulate social cues in order to attribute intentionality, a measure of gaze transition entropy (GTE) seems indicated to throw some light on these processes. Violent behavior is associated...

This study focused on the prediction of intrinsic and extraneous cognitive load using eye-tracking metrics, heart rate variability, and galvanic skin response. Intrinsic cognitive load is associated with the inherent complexity of the mental task, whereas extraneous cognitive load is related to the distracting and unrelated elements in the task. Th...

Well-being is a dynamic construct that evolves over time and fluctuates within individuals, presenting challenges for accurate quantification. Reduced well-being is often linked to depression or anxiety disorders, which are characterised by biases in visual attention towards specific stimuli, such as human faces. This paper introduces a novel appro...

The advent of Industry 4.0 technologies, encompassing the Internet of Things (IoT), Big data analytics, artificial intelligence (AI), blockchain, location-based services, and virtual and augmented (VR/AR) reality systems, has revolutionized the tourism landscape, automating production and service delivery. As the momentum of Industry 4.0 propels us...

This chapter presents the concept of Gaze-Led Audio Description (GLAD) and its application for the accessibility of city space. Audio Description (AD) is created by domain experts who have deep knowledge of the audio-described matter but might have their own narrative biases. Many studies report that experts’ perception and attentional patterns ove...

This chapter explores accessibility in public transport, focusing on the case study of Warsaw in Poland, and is structured into several key sections. In Sect. 2, the challenges faced by individuals with disabilities in urban spaces are discussed, shedding light on the impediments they encounter in navigating public transportation systems. Section 3...

We present results of a direct replication of Liao et al.’s (2021) study on how subtitle speed and the presence of concurrent video impact subtitle reading among British and Polish viewers. Our goal was to assess the generalisability of the original study’s findings on a cohort of Australian English. The study explored both subtitle-level and word-...

We are excited to provide the third issue of the Proceedings of the ACM on Human-Computer Interaction focusing on contributions from the ACM Eye Tracking Research and Applications (ETRA) community. ETRA is the premier eye-tracking conference bringing together researchers from across disciplines to present advances in eye-tracking systems and method...

This paper presents an eye-tracking study capturing the dynamics of ambient and focal attention of tram drivers as an application of modern technology in improving their training. Twenty-three experts and twenty-four novices were invited to take part in the eye-tracking study. We explored the visual attention dynamics of tram drivers while they wer...

An attempt to identify relationships between the Big Five personality traits and responses to advertising was made by meta-analyzing results of 15 studies (308 correlations). Variables of brand familiarity, types of advertising appeals and types of responses were used as moderators of advertising responses. The overall correlation effect between pe...

The “Friendly City” Project (FCP) supports the blind and visually impaired (BVI) people to perceive the local architectural heritage in Lodz city in Poland. The multidisciplinary project aims on promoting the accessibility of architectural heritage to the BVI community by adding Audio Descriptions (AD) to 85 public places. The ADs in FCP are guided...

The paper contributes to scanpath bundling methods. We propose an analytical approach for statistical comparisons of aggregated scanpath visualizations by means of second-order gaze analysis metrics. The present study explores differences in attention distribution and cognitive processing over architectural objects between architects, art historian...

In 2022, ETRA moved its publication of full papers to a journal-based model, and we are delighted to present the second issue of the Proceedings of the ACM on Human-Computer Interaction to focus on contributions from the Eye Tracking Research and Applications (ETRA) community. ETRA is the premier eye-tracking conference that brings together researc...

This paper examines the attentional mechanism of in-person collaboration by means of System Dynamics-based simulations using an eye tracking experiment. Three experimental conditions were tested: in-person collaboration, remote collaboration, and single user. We hypothesized that collaboration focuses users’ attention on key information facilitatin...

Subtitle production is an increasingly creative accessibility service. New technologies allow for placing subtitles at any location of the screen in a variety of formats, shapes, typography, font size, and colour. The screen now affords accessible creativity, with subtitles able to provide novel experiences beyond those offered by traditional langu...

The Low/High Index of Pupillary Activity (LHIPA), an eye-tracked measure of pupil diameter oscillation, is redesigned and implemented to function in real-time. The novel Real-time IPA (RIPA) is shown to discriminate cognitive load in re-streamed data from earlier experiments. Rationale for the RIPA is tied to the functioning of the human autonomic...

Eye movement analysis in modern 3D rendering systems is reviewed and three new techniques are derived inspired by work developed in early Virtual Reality so-called 2.5D implementations, namely (a) gaze depth (i.e., vergence) estimation, (b) vergence calibration, and (c) real-time 3D event detection that considers eye- and head-coupling. The new 3D...

Aggressive offenders commonly show hostile attribution bias in the perception of facial affect. Individuals’ sensitivity to provocation has been also linked to hostile attribution. However, most studies have been limited to male offenders. The current study investigated whether sensitivity to provocation (SP) predicted bias towards interpretation o...

We are delighted to present a first issue of the Proceedings of the ACM on Human-Computer Interaction to focus on contributions from the Eye Tracking Research and Applications (ETRA) community.

In sports, studies on visual behavior have mostly focused on expert-novice differences dur-ing decision making tasks and during aiming tasks. How visual behavior changes during the early stages of skill acquisition however, has hardly been documented. The current study investigated gaze behavior of young soccer players during the execution of a soc...

Virtual Reality (VR) headsets can open opportunities for users to accomplish complex tasks on large virtual displays, using compact setups. However, interacting with large virtual displays using existing interaction techniques might cause fatigue, especially for precise manipulations, due to the lack of physical surfaces. We designed VXSlate, an in...

A large body of literature documents the sensitivity of pupil response to cognitive load (e.g., Krejtz et al. 2018) and emotional arousal (Bradley et al., 2008). Recent empirical evidence also showed that microsaccade characteristics and dynamics can be modulated by mental fatigue and cognitive load (e.g., Dalmaso et al. 2017). Very little is known...

We discuss several techniques for mapping the gaze point to fiducial markers detected in a video stream, as commonly used in Augmented Reality eye-tracking applications. Specifically, we focus on using the recovered camera rotation and translation determined by the apparent distortion of the marker. We exploit this to map Areas Of Interest (AOIs) i...

Although data privacy is a compelling concern, prior inquiries have found that consumers do not adequately attend to data privacy policies. This research develops a framework delineating the effects of top-down/bottom-up processes and individual consumer differences in the need for cognition (NFC) and perceived control on visual attention to data p...

The enhancement hypothesis suggests that deaf individuals are more vigilant to visual emotional cues than hearing individuals. The present eye-tracking study examined ambient-focal visual attention when encoding affect from dynamically changing emotional facial expressions. Deaf (n = 17) and hearing (n = 17) individuals watched emotional facial exp...

Research has shown that keyframed eye motions are perceived as more realistic when some noise is added to eyeball motions and to pupil size changes. We investigate whether this noise, in contrast to being motion captured, can be synthesized with standard techniques, e.g., procedural or data-driven approaches. In a two-alternative forced choice task...

We evaluate subtle, emotionally-driven models of eye movement animation. Two models are tested, reading and face scanning, each based on recorded gaze transition probabilities. For reading, simulated emotional mood is governed by the probability density function that varies word advancement, i.e., re-fixations, forward, or backward skips. For face...

A significant number of Internet users is unaware of privacy threats and they might not pay much attention to privacy notifications. It is imperative to create effective but, at the same time, non-distracting notifications about privacy policy of different web services. The article presents an eye-tracking study (N = 16) testing the effectiveness o...

Automatic Area Of Interest (AOI) demarcation of facial regions is not yet commonplace in applied eye-tracking research, partially because automatic AOI labeling is prone to error. Most previous eye-tracking studies relied on manual frame-by-frame labeling of facial AOIs. We present a fully automatic approach for facial AOI labeling (i.e., eyes, nos...

Automatic Area Of Interest (AOI) demarcation of facial regions is not yet commonplace in applied eye-tracking research, partially because automatic AOI labeling is prone to error. Most previous eye-tracking studies relied on manual frame-by-frame labeling of facial AOIs. We present a fully automatic approach for facial AOI labeling (i.e., eyes, nos...

A significant number of Internet users is unaware of privacy threats and they might not pay much attention to privacy notifications. It is imperative to create effective but, at the same time, non-distracting notifications about privacy policy of different web services. The article presents an eye-tracking study (N = 16) testing the effectiveness o...

We develop an approach to using microsaccade dynamics for the measurement of task difficulty/cognitive load imposed by a visual search task of a layered surface. Previous studies provide converging evidence that task difficulty/cognitive load can influence microsaccade activity. We corroborate this notion. Specifically, we explore this relationship...

Eye motions constitute an important part of our daily face-to-face interactions. Even subtle details in the eyes’ motions give us clues about a person’s thoughts and emotions. Believable and natural animation of the eyes is therefore crucial when creating appealing virtual characters. In this article, we investigate the perceived naturalness of det...

Pupil diameter and microsaccades are captured by an eye tracker and compared for their suitability as indicators of cognitive load (as beset by task difficulty). Specifically, two metrics are tested in response to task difficulty: (1) the change in pupil diameter with respect to inter- or intra-trial baseline, and (2) the rate and magnitude of micr...

This dataset contains results of NASA-TLX and digit SPAN tests along with the trial-wise averaged main microsaccadic and pupil dilation measures. The dataset was used to prepare the Figs 4, 6 and 7. (CSV)

This dataset contains the main characteristics of microsaccades for microsaccade main sequence analysis. The data were used to prepare the Fig 5. (CSV)

This dataset is for reliability analysis of the NASA task load index (NASA-TLX). The dataset was used for reliability analyses of NASA-TLX scale within the present study. (CSV)

The document contains supporting information on all datasets which were used in the analyses of results presented in the article “Eye tracking cognitive load using pupil diameter and microsaccades with fixed gaze”. The document is structured file by file with description of each dataset and each variable they contain with their value labels (if app...

The aim of the study was to capture the visual processing of dynamical facial expressions during recognition of anger, sadness and happiness. We examined if we could detect differences in speed and accuracy of recognition between faces expressing motions of positive and negative signals. Half of the participants had tested as socially anxious. Resu...

A variety of psychological disorders like antisocial personality disorder have been linked to impairments in facial emotion recognition. Exploring eye movements during categorization of emotional faces is a promising approach with the potential to reveal possible differences in cognitive processes underlying these deficits. Based on this premise we...

This paper demonstrates the utility of ambient-focal attention and pupil dilation dynamics to describe visual processing of emotional facial expressions. Pupil dilation and focal eye movements reflect deeper cognitive processing and thus shed more light on the dynamics of emotional expression recognition. Socially anxious individuals (N = 24) and n...

Gaze as a gaming input modality poses interaction challenges, not the least of which is the well-known Midas Touch problem, when neutral visual scanning leads to unintentional action. This is one of the most difficult problems to overcome. We propose and test a novel method of addressing the Midas Touch problem by using Gaussian-based velocity atte...

In this study, we examined whether interpreters and interpreting trainees are better predisposed to respeaking than people with no interpreting skills. We tested 57 participants (22 interpreters, 23 translators and 12 controls) while respeaking 5-minute videos with two parameters: speech rate (fast/slow) and number of speakers (one/many). Having me...

A novel eye-tracked measure of the frequency of pupil diameter oscillation is proposed for capturing what is thought to be an indicator of cognitive load. The proposed metric, termed the Index of Pupillary Activity, is shown to discriminate task difficulty vis-a-vis cognitive load (if the implied causality can be assumed) in an experiment where par...

The use of gaze promises fast and smart user interaction. Mimicking human gaze interaction, we suggest a framework based on the vision of integrating fixations, pupil size, and microsaccade dynamics. Recent work has shown that fixations can be differentiated between focal and ambient , where the former are important for further decisional processes...

In this article, we report on the results of a usability study on the Open Art mobile application conducted in a museum with blind, deaf and sighted/hearing people. The Open Art application was created following the principles of Universal Design to give all types of users the opportunity to use the app on equal terms. The main goal of the study re...

In this paper we introduce respeaking crisis points (RCPs), understood as potentially problematic moments in the respeaking process, resulting from the difficulty of the source material and/or cognitive overload on the part of the respeakers. We present results of the respeaking study on Polish participants who respoke four videos intralingually (P...

A model of the main sequence is proposed based on the logistic function. The model’s fit to the peak velocity-amplitude relation resembles an S curve, simulta- neously allowing control of the curve’s asymptotes at very small and very large amplitudes, as well as its slope over the mid amplitude range. The proposed inverse-linear logistic model is a...

We demonstrate the use of the ambient/focal coeffcient K for studying the dynamics of visual behavior when performing cartographic tasks. Participants viewed a cartographic map and satellite image of Barcelona while performing a number of map-related tasks. Cartographic maps can be viewed as summary representations of reality, while satellite image...

The last decade was revolutionary in terms of accessibility for the visually and hearing impaired. However, accessibility was regarded from the perspective of granting access to those with impairments. Recently, new ideas seem to emerge – accessibility can be seen as a service that can be provided for all, regardless of their (un)impairment. This i...

Eye movements are an essential part of non-verbal behavior. Non-player characters, as they occur in many games, communicate with the player through dialogue and non-verbal behavior and can have a strong influence on player experience or even on gameplay. In this paper, we evaluate a procedural model designed to synthesize the subtleties of eye moti...

Using coefficient \(\mathcal{K}\), defined on a parametric scale, derived from processing a traditionally eye-tracked time course of eye movements, we propose a straightforward method of visualizing ambient/focal fixations in both scanpath and heatmap visualizations. The \(\mathcal{K}\) coefficient indicates the difference of fixation duration and...

We demonstrate the use of the ambient/focal coecient K for studying the dynamics of visual behavior when performing cartographic tasks. Participants viewed a cartographic map and satellite image of Barcelona while performing a number of map-related tasks. Cartographic maps can be viewed as summary representations of reality, while satellite images...

In this paper we present preliminary results of the study on the cognitive load in intralingual and interlingual respeaking. We tested 57 subjects from three groups: interpreters, translators and controls while respeaking 5-minute videos in two language combinations: Polish to Polish (intralingual) and English to Polish (interlingual). Using two me...

We introduce coefficient K, defined on a novel parametric scale, derived from processing a traditionally eye-tracked time course of eye movements. Positive and negative ordinates of K indicate focal or ambient viewing, respectively, while the abscissa serves to indicate time, so that K acts as a dynamic indicator of fluctuation between ambient/foca...

A convolution-filtering technique is introduced for the synthesis of eye gaze data. Its purpose is to produce, in a controlled manner, a synthetic stream of raw gaze position coordinates, suitable for: (1) testing event detection filters, and (2) rendering synthetic eye movement animations for testing eye tracking gaze estimation algorithms. Synthe...

Eye tracking methodology is used to examine the influence of interactive multimedia on the allocation of visual attention and its dynamics during learning. We hypothesized that an interactive simulation promotes more organized switching of attention between different elements of multimedia learning material, e.g., textual description and pictorial...

Szarkowska, Jankowska, Krejtz and Kowalski present an innovative approach towards creating accessible content following the example of a multimedia app created in the Open Art project, carried out by a consortium of partners including museums, universities, a research institute and a media access foundation. The goal of the project is to create a m...

This article details a two-step method of quantifying eye movement transitions between areas of interest (AOIs). First, individuals' gaze switching patterns, represented by fixated AOI sequences, are modeled as Markov chains. Second, Shannon's entropy coefficient of the fit Markov model is computed to quantify the complexity of individual switching...

Eye movements are an essential part of non-verbal behavior. Non-player characters (NPCs), as they occur in many games, communicate with the player through dialogues and non-verbal behavior and can have a strong influence on the player experience or even on gameplay. In this paper we propose a procedural model to synthesize the subtleties of eye mot...

Respeakers need to master a number of linguistic and technical competences (Arumí Ribas & Romero Fresco 2008, Romero Fresco 2012, Eugeni 2008). Among them is the ability to listen and speak at the same time in the same language or to translate the words spoken in a live programme into another language. Other necessary linguistic skills are the abil...

The challenges of developing an information society in semi-peripheral countries are immersed in a struggle between Westernizing processes and local cultural and social specificity. The expansion of the internet and communication technologies in Poland, a " newcomer " to the European Union, provides an instructive example. This article presents the...

Methods for parallelized eye movement analysis on a cluster are detailed. The distributed approach advocates the single-core job programming strategy, assigning processing of eye movement data across as many cluster cores as are available. A foreman-worker distribution algorithm takes care of job assignment via the Message Passing Interface (MPI) a...

Distinguishing ambient and focal attention, we demonstrate the use of the K coefficient, which can serve as a cue for recommender systems in deciding when to offer information to the user, e.g., when focally attending during search.

A user study is described focusing on the cognitive and us-ability consequences of cueing visual attention in gaze-controlled gaming. Results show that such cueing influences performance and affects the subjective gaming experience. Accordingly , visual cues make the experience less enjoyable and less immersive. Interestingly, gaze-controlled gamin...

We report on an experiment testing gaze-contingent depth-of-field (DOF) for the reduction of visual discomfort when viewing stereoscopic displays. Subjective results are compelling, showing, we believe for the first time, that gaze-contingent depth-of-field significantly reduces visual discomfort. When individual stereoacuity is taken into account,...

We show that the error in 3D gaze depth (vergence) estimated from binocularly-tracked gaze disparity is related to the viewing distance of the screen calibration plane at which 2D gaze is recorded. In a stereoscopic (virtual) environment, this relationship is evident in gaze to target depth error: vergence error behind the screen is greater than in...

The paper introduces a two-step method of quantifying eye movement transitions between Areas of Interests (AOIs). First, individuals' gaze switching patterns, represented by fixated AOI sequences, are modeled as Markov chains. Second, Shannon's entropy coefficient of the fit Markov model is computed to quantify the complexity of individual switchin...

The goal of this paper is to publish the first results of the e-balance project. This project is strictly related to the Smart Grid (SG) development and dedicated to the issue of local energy management with possibly high saturation of Distributed Energy Resources (DER) and different levels of availability of smart appliances at homes. Different as...

In this paper we address the question whether shot changes trigger the re-reading of subtitles. Although it has been accepted in the professional literature on subtitling that subtitles should not be displayed over shot changes as they induce subtitle re-reading, support for this claim in eye movement studies is difficult to find. In this study we...

The present paper aims at describing the concept of how the interaction with computer devices may benefit from joint input of users emotional state and his/her eye movements characteristics. We claim that emotions regulate visual attention, changing its formal characteristics and thus in turn influence the user's behaviour. We hypothesised that dur...

The paper explores the effects of adding audio description to an educational film on children's learning behaviour, manifested by a visual recognition task. We hypothesize that the multimodal educational setting, consisting of both verbal (film dialogue and audio description) and non-verbal (motion pictures) representations of knowledge, fosters kn...

Audio description (AD) has become a cultural revolution for the visually impaired; however, the range of AD beneficiaries can be much broader. We claim that AD is useful for guiding children's attention. The paper presents an eye-tracking study testing the usefulness of AD in selective attention to described elements of a video scene. Forty-four ch...