Pupil dilation as an index of preferred mutual gaze duration

Most animals look at each other to signal threat or interest. In humans, this social interaction is usually punctuated with brief periods of mutual eye contact. Deviations from this pattern of gazing behaviour generally make us feel uncomfortable and are a defining characteristic of clinical conditions such as autism or schizophrenia, yet it is unclear what constitutes normal eye contact. Here, we measured, across a wide range of ages, cultures and personality types, the period of direct gaze that feels comfortable and examined whether autonomic factors linked to arousal were indicative of people's preferred amount of eye contact. Surprisingly, we find that preferred period of gaze duration is not dependent on fundamental characteristics such as gender, personality traits or attractiveness. However, we do find that subtle pupillary changes, indicative of physiological arousal, correlate with the amount of eye contact people find comfortable. Specifically, people preferring longer durations of eye contact display faster increases in pupil size when viewing another person than those preferring shorter durations. These results reveal that a person's preferred duration of eye contact is signalled by physiological indices (pupil dilation) beyond volitional control that may play a modulatory role in gaze behaviour.

Conducting research with minimally verbal participants with autism spectrum disorder

A growing number of research groups are now including older minimally verbal individuals with autism spectrum disorder in their studies to encompass the full range of heterogeneity in the population. There are numerous barriers that prevent researchers from collecting high-quality data from these individuals, in part because of the challenging behaviors with which they present alongside their very limited means for communication. In this article, we summarize the practices that we have developed, based on applied behavioral analysis techniques, and have used in our ongoing research on behavioral, eye-tracking, and electrophysiological studies of minimally verbal children and adolescents with autism spectrum disorder. Our goal is to provide the field with useful guidelines that will promote the inclusion of the entire spectrum of individuals with autism spectrum disorder in future research investigations.

Using the Visual World Paradigm to Study Retrieval Interference in Spoken Language Comprehension

The cue-based retrieval theory (Lewis et al., 2006) predicts that interference from similar distractors should create difficulty for argument integration, however this hypothesis has only been examined in the written modality. The current study uses the Visual World Paradigm (VWP) to assess its feasibility to study retrieval interference arising from distractors present in a visual display during spoken language comprehension. The study aims to extend findings from Van Dyke and McElree (2006), which utilized a dual-task paradigm with written sentences in which they manipulated the relationship between extra-sentential distractors and the semantic retrieval cues from a verb, to the spoken modality. Results indicate that retrieval interference effects do occur in the spoken modality, manifesting immediately upon encountering the verbal retrieval cue for inaccurate trials when the distractors are present in the visual field. We also observed indicators of repair processes in trials containing semantic distractors, which were ultimately answered correctly. We conclude that the VWP is a useful tool for investigating retrieval interference effects, including both the online effects of distractors and their after-effects, when repair is initiated. This work paves the way for further studies of retrieval interference in the spoken modality, which is especially significant for examining the phenomenon in pre-reading children, non-reading adults (e.g., people with aphasia), and spoken language bilinguals.

Infants Prefer Female Body Phenotypes; Infant Girls Prefer They Have an Hourglass Shape

Adolescents and adults show preferences for male and female body shapes consistent with evolutionary theories of reproductive fitness and mate selection. However, when these preferences for females with narrow waists (i.e., 0.7 waist-to-hip ratio) and men with broad shoulders (i.e., mesomorphic body shape) emerge during the lifespan is largely unknown. To address this knowledge gap, eye-movements were tracked in 146 infants (3-18 months of age) during computer presentation of three-dimensional human figures varying in body features thought relevant for reproductive success (e.g., secondary sex characteristics, waist-to-hip ratio). When presented with pairs of figures differing in apparent sex, male and female infants looked significantly longer at the female figure compared to the male figure, a new finding that extends previous research showing preferences for female faces in infancy. When presented with same-sex figures differing in characteristics associated with mate value, male and female infants looked longer at a low mate value male (i.e., an endomorphic body type) compared to a high mate value male (i.e., a mesomorphic body type), a finding that replicates the results of previous research. In addition, the novel use of high and low mate value female figures showed a sex difference in visual attention, such that female infants looked longer at the high mate value female figure compared to the low mate female figure whereas male infants showed the opposite pattern of results. In sum, these findings suggest that infants generally do not possess preferences for adult-defined attractive male body shapes. However, infant girls' greater attention to a female figure with an adult-preferred waist-to-hip ratio raises the possibility that evolved preferences for 0.7 waist-to-hip ratio influence girls' later preference for toys representing females with an hourglass shape, perhaps supporting elaboration of adult social behaviors that enhance reproductive success (e.g., cooperative breeding).

A new experimental paradigm to study children's processing of their parent's unscripted language input

This paper introduces a new experimental paradigm for studying children's real-time language processing of their parents' unscripted speech. Focusing on children's processing of referential expressions, or the phrases that parents used to label particular objects, we engaged dyads in a game in which parents labeled one of several objects displayed on a screen, and the child was to quickly identify it as their eye gaze was tracked. There were two conditions; one included a competitor object (e.g., the target was a striped umbrella and the display also included an umbrella with polka dots), while the other one did not (e.g., only one umbrella was present). The results revealed evidence of children's incremental processing of their parents' referential expressions. They also showed faster processing of postnominally-modified as compared to prenominally-modified referential expressions. Parents tended to produce postnominally-modified referential expressions in the more difficult experimental condition in which there was a competitor object, suggesting either that these expressions are also easier for them to produce, or that they accommodate their children by producing more easily processed expressions. We discuss the potential of this paradigm for advancing theories of the relationship between child-directed language input and children's language processing.

Magic and Misdirection: The Influence of Social Cues on the Allocation of Visual Attention While Watching a Cups-and-Balls Routine

In recent years, a body of research that regards the scientific study of magic performances as a promising method of investigating psychological phenomena in an ecologically valid setting has emerged. Seemingly contradictory findings concerning the ability of social cues to strengthen a magic trick’s effectiveness have been published. In this experiment, an effort was made to disentangle the unique influence of different social and physical triggers of attentional misdirection on observers’ overt and covert attention. The ability of 120 participants to detect the mechanism of a cups-and-balls trick was assessed, and their visual fixations were recorded using an eye-tracker while they were watching the routine. All the investigated techniques of misdirection, including sole usage of social cues, were shown to increase the probability of missing the trick mechanism. Depending on the technique of misdirection used, very different gaze patterns were observed. A combination of social and physical techniques of misdirection influenced participants’ overt attention most effectively.

Working Memory Load Affects Processing Time in Spoken Word Recognition: Evidence from Eye-Movements

In daily life, speech perception is usually accompanied by other tasks that tap into working memory capacity. However, the role of working memory on speech processing is not clear. The goal of this study was to examine how working memory load affects the timeline for spoken word recognition in ideal listening conditions. We used the "visual world" eye-tracking paradigm. The task consisted of spoken instructions referring to one of four objects depicted on a computer monitor (e.g., "point at the candle"). Half of the trials presented a phonological competitor to the target word that either overlapped in the initial syllable (onset) or at the last syllable (offset). Eye movements captured listeners' ability to differentiate the target noun from its depicted phonological competitor (e.g., candy or sandal). We manipulated working memory load by using a digit pre-load task, where participants had to retain either one (low-load) or four (high-load) spoken digits for the duration of a spoken word recognition trial. The data show that the high-load condition delayed real-time target discrimination. Specifically, a four-digit load was sufficient to delay the point of discrimination between the spoken target word and its phonological competitor. Our results emphasize the important role working memory plays in speech perception, even when performed by young adults in ideal listening conditions.

Visual processing of emotional dynamic faces in 22q11.2 deletion syndrome

INTRODUCTION

The 22q11.2 deletion syndrome (22q11DS) is a neurogenetic syndrome. Individuals affected by this syndrome present poor social functioning and a high risk for the development of psychiatric disorders. Accurate emotion recognition and visual exploration of faces represent important skills for appropriate development of social cognition in individuals with 22q11DS. For these reasons, there is elevated interest in establishing relevant ways to test the mechanisms associated with emotion recognition in patients with 22q11DS.

METHODS

This study investigated emotional recognition and visual exploration of emotional faces in persons with 22q11DS, with a dynamic emotion task using an eye-tracking device. To our knowledge, no previous studies have used emotional dynamic stimuli with 22q11DS, despite improved ecological validity of dynamic stimuli compared with static images. Furthermore, these stimuli provide the opportunity to collect reaction times, as indicators of the emotional intensity necessary for identifying each emotion.

RESULTS

In our task, we observed comparable accuracy in emotion recognition in the 22q11DS and healthy control groups. However, individuals with 22q11DS were slower to recognise the emotions. They also spent less time looking at the nose during happy and fearful faces.

CONCLUSIONS

These results suggest that individuals with 22q11DS may need either more time or more pronounced emotional cues to correctly label facial expressions.

The Age-related Positivity Effect and Tobacco Warning Labels

OBJECTIVES

This study tested whether age is a factor in viewing time for tobacco warning labels. The approach drew from previous work demonstrating an age-related positivity effect, whereby older adults show preferences toward positive and away from negative stimuli.

METHODS

Participants were 295 daily smokers from Appalachian Ohio (age range: 21-68). All participants took part in an eye-tracking paradigm that captured the attention paid to elements of health warning labels in the context of magazine advertisements. Participants also reported on their past cessation attempts and their beliefs about the dangers of smoking.

RESULTS

Consistent with theory on age-related positivity, older age predicted weaker beliefs about smoking risks, but only among those with no past-year quit attempts. In support of our primary hypothesis, older age was also related to a lower percentage of time spent viewing tobacco warning labels, both overall (text + image) and for the graphic image alone. These associations remained after controlling for cigarettes smoked per day.

CONCLUSIONS

Overall, findings suggest that age is an important consideration for the design of future graphic warning labels and other tobacco risk communications. For older adults, warning labels may need to be tailored to overcome the age-related positivity effect.

Dependency Resolution Difficulty Increases with Distance in Persian Separable Complex Predicates: Evidence for Expectation and Memory-Based Accounts

Delaying the appearance of a verb in a noun-verb dependency tends to increase processing difficulty at the verb; one explanation for this locality effect is decay and/or interference of the noun in working memory. Surprisal, an expectation-based account, predicts that delaying the appearance of a verb either renders it no more predictable or more predictable, leading respectively to a prediction of no effect of distance or a facilitation. Recently, Husain et al. (2014) suggested that when the exact identity of the upcoming verb is predictable (strong predictability), increasing argument-verb distance leads to facilitation effects, which is consistent with surprisal; but when the exact identity of the upcoming verb is not predictable (weak predictability), locality effects are seen. We investigated Husain et al.'s proposal using Persian complex predicates (CPs), which consist of a non-verbal element-a noun in the current study-and a verb. In CPs, once the noun has been read, the exact identity of the verb is highly predictable (strong predictability); this was confirmed using a sentence completion study. In two self-paced reading (SPR) and two eye-tracking (ET) experiments, we delayed the appearance of the verb by interposing a relative clause (Experiments 1 and 3) or a long PP (Experiments 2 and 4). We also included a simple Noun-Verb predicate configuration with the same distance manipulation; here, the exact identity of the verb was not predictable (weak predictability). Thus, the design crossed Predictability Strength and Distance. We found that, consistent with surprisal, the verb in the strong predictability conditions was read faster than in the weak predictability conditions. Furthermore, greater verb-argument distance led to slower reading times; strong predictability did not neutralize or attenuate the locality effects. As regards the effect of distance on dependency resolution difficulty, these four experiments present evidence in favor of working memory accounts of argument-verb dependency resolution, and against the surprisal-based expectation account of Levy (2008). However, another expectation-based measure, entropy, which was computed using the offline sentence completion data, predicts reading times in Experiment 1 but not in the other experiments. Because participants tend to produce more ungrammatical continuations in the long-distance condition in Experiment 1, we suggest that forgetting due to memory overload leads to greater entropy at the verb.

Examining the Link Between Hoarding Symptoms and Cognitive Flexibility Deficits

Executive functioning deficits have been found to underlie primary symptoms of hoarding, such as difficulty discarding belongings and significant clutter. Cognitive flexibility-the ability to inhibit irrelevant material and attend flexibly between different mental sets-may be impaired as well, as individuals experience difficulty staying on task and are often distracted by specific possessions that tend to evoke an exaggerated emotional response. The present study investigated cognitive flexibility deficits via eye-tracking technology as a novel approach. Participants (N=69) with high and low self-reported hoarding symptoms were asked to respond to a series of auditory cues requiring them to categorize a small target number superimposed on one of three distractor image types: hoarding, nature, or a blank control. Across a range of behavioral and eye-tracking outcomes (including reaction time, accuracy rate, initial orientation to distractors, and viewing time for distractors), high hoarding participants consistently demonstrated greater cognitive inflexibility compared to the low hoarding group. However, high hoarding participants did not evidence context-dependent deficits based on preceding distractor types, as performance did not significantly differ as a function of hoarding versus nature distractors. Current findings indicate a pervasive, more global deficit in cognitive flexibility. Those with hoarding may encounter greater difficulty disengaging from previous stimuli and attending to a given task at hand, regardless of whether the context of the distractor is specifically related to hoarding. Implications and future directions for clarifying the nature of cognitive inflexibility are discussed.

Auditory word recognition across the lifespan: Links between linguistic and nonlinguistic inhibitory control in bilinguals and monolinguals

Recent research suggests that bilingual experience reconfigures linguistic and nonlinguistic cognitive processes. We examined the relationship between linguistic competition resolution and nonlinguistic cognitive control in younger and older adults who were either bilingual or monolingual. Participants heard words in English and identified the referent among four pictures while eye-movements were recorded. Target pictures (e.g., cab) appeared with a phonological competitor picture (e.g., cat) and two filler pictures. After each eye-tracking trial, priming probes assessed residual activation and inhibition of target and competitor words. When accounting for processing speed, results revealed that age-related changes in activation and inhibition are smaller in bilinguals than in monolinguals. Moreover, younger and older bilinguals, but not monolinguals, recruited similar inhibition mechanisms during word identification and during a nonlinguistic Stroop task. Results suggest that, during lexical access, bilinguals show more consistent competition resolution and recruitment of cognitive control across the lifespan than monolinguals.

Incrementality in Planning of Speech During Speaking and Reading Aloud: Evidence from Eye-Tracking

Speaking is an incremental process where planning and articulation interleave. While incrementality has been studied in reading and online speech production separately, it has not been directly compared within one investigation. This study set out to compare the extent of planning incrementality in online sentence formulation versus reading aloud and how discourse context may constrain the planning scope of utterance preparation differently in these two modes of speech planning. Two eye-tracking experiments are reported: participants either described pictures of transitive events (Experiment 1) or read aloud the written descriptions of those events (Experiment 2). In both experiments, the information status of an object character was manipulated in the discourse preceding each picture or sentence. In the Literal condition, participants heard a story where object character was literally mentioned (e.g., fly). In the No Mention condition, stories did not literally mention nor prime the object character depicted on the picture or written in the sentence. The target response was expected to have the same structure and content in all conditions (The frog catches the fly). During naming, the results showed shorter speech onset latencies in the Literal condition than in the No Mention condition. However, no significant differences in gaze durations were found. In contrast, during reading, there were no significant differences in speech onset latencies but there were significantly longer gaze durations to the target picture/word in the Literal than in the No Mention condition. Our results shot that planning is more incremental during reading than during naming and that discourse context can be helpful during speaker but may hinder during reading aloud. Taken together our results suggest that on-line planning of response is affected by both linguistic and non-linguistic factors.

Self-Face Recognition in Schizophrenia: An Eye-Tracking Study

Self-face recognition has been shown to be impaired in schizophrenia (SZ), according to studies using behavioral tasks implicating cognitive demands. Here, we employed an eye-tracking methodology, which is a relevant tool to understand impairments in self-face recognition deficits in SZ because it provides a natural, continuous and online record of face processing. Moreover, it allows collecting the most relevant and informative features each individual looks at during the self-face recognition. These advantages are especially relevant considering the fundamental role played by the patterns of visual exploration on face processing. Thus, this paper aims to investigate self-face recognition deficits in SZ using eye-tracking methodology. Visual scan paths were monitored in 20 patients with SZ and 20 healthy controls. Self, famous, and unknown faces were morphed in steps of 20%. Location, number, and duration of fixations on relevant areas were recorded with an eye-tracking system. Participants performed a passive exploration task (no specific instruction was provided), followed by an active decision making task (individuals were explicitly requested to recognize the different faces). Results showed that patients with SZ had fewer and longer fixations compared to controls. Nevertheless, both groups focused their attention on relevant facial features in a similar way. No significant difference was found between groups when participants were requested to recognize the faces (active task). In conclusion, using an eye tracking methodology and two tasks with low levels of cognitive demands, our results suggest that patients with SZ are able to: (1) explore faces and focus on relevant features of the face in a similar way as controls; and (2) recognize their own face.

Greater Pupil Size in Response to Emotional Faces as an Early Marker of Social-Communicative Difficulties in Infants at High Risk for Autism

When scanning faces, individuals with autism spectrum disorder (ASD) have shown reduced visual attention (e.g., less time on eyes) and atypical autonomic responses (e.g., heightened arousal). To understand how these differences might explain sub-clinical variability in social functioning, 9-month-olds, with or without a family history of ASD, viewed emotionally-expressive faces, and gaze and pupil diameter (a measure of autonomic activation) were recorded using eye-tracking. Infants at high-risk for ASD with no subsequent clinical diagnosis (HRA-) and low-risk controls (LRC) showed similar face scanning and attention to eyes and mouth. Attention was overall greater to eyes than mouth, but this varied as a function of the emotion presented. HRA- showed significantly larger pupil size than LRC. Correlations between scanning at 9 months, pupil size at 9 months, and 18-month social-communicative behavior, revealed positive associations between pupil size and attention to both face and eyes at 9 months in LRC, and a negative association between 9-month pupil size and 18-month social-communicative behavior in HRA-. The present findings point to heightened autonomic arousal in HRA-. Further, with greater arousal relating to worse social-communicative functioning at 18 months, this work points to a mechanism by which unaffected siblings might develop atypical social behavior.

Influence of Experience and Training on Dental Students' Examination Performance Regarding Panoramic Images

Physician training has greatly benefitted from insights gained in understanding the manner in which experts search medical images for abnormalities. The aims of this study were to compare the search patterns of 30 fourth-year dental students and 15 certified oral and maxillofacial radiologists (OMRs) over panoramic images and to determine the most robust variables for future studies involving image visualization. Eye tracking was used to capture the eye movement patterns of both subject groups when examining 20 panoramic images classified as normal or abnormal. Abnormal images were further subclassified as having an obvious, intermediate, or subtle abnormality. The images were presented in random order to each participant, and data were collected on duration of the participants' observations and total distance tracked, time to first eye fixation, and total duration and numbers of fixations on and off the area of interest (AOI). The results showed that the OMRs covered greater distances than the dental students (p<0.001) for normal images. For images of pathosis, the OMRs required less total time (p<0.001), made fewer eye fixations (p<0.01) with fewer saccades (p<0.001) than the students, and required less time before making the first fixation on the AOI (p<0.01). Furthermore, the OMRs covered less distance (p<0.001) than the dental students for obvious pathoses. For investigations of images of pathosis, time to first fixation is a robust parameter in predicting ability. For images with different levels of subtlety of pathoses, the number of fixations, total time spent, and numbers of revisits are important parameters to analyze when comparing observer groups with different levels of experience.

Perceptual-Cognitive Changes During Motor Learning: The Influence of Mental and Physical Practice on Mental Representation, Gaze Behavior, and Performance of a Complex Action

Despite the wealth of research on differences between experts and novices with respect to their perceptual-cognitive background (e.g., mental representations, gaze behavior), little is known about the change of these perceptual-cognitive components over the course of motor learning. In the present study, changes in one's mental representation, quiet eye behavior, and outcome performance were examined over the course of skill acquisition as it related to physical and mental practice. Novices (N = 45) were assigned to one of three conditions: physical practice, combined physical plus mental practice, and no practice. Participants in the practice groups trained on a golf putting task over the course of 3 days, either by repeatedly executing the putt, or by both executing and imaging the putt. Findings revealed improvements in putting performance across both practice conditions. Regarding the perceptual-cognitive changes, participants practicing mentally and physically revealed longer quiet eye durations as well as more elaborate representation structures in comparison to the control group, while this was not the case for participants who underwent physical practice only. Thus, in the present study, combined mental and physical practice led to both formation of mental representations in long-term memory and longer quiet eye durations. Interestingly, the length of the quiet eye directly related to the degree of elaborateness of the underlying mental representation, supporting the notion that the quiet eye reflects cognitive processing. This study is the first to show that the quiet eye becomes longer in novices practicing a motor action. Moreover, the findings of the present study suggest that perceptual and cognitive adaptations co-occur over the course of motor learning.

Feasibility of Undertaking Off-Site Infant Eye-Tracking Assessments of Neuro-Cognitive Functioning in Early-Intervention Centres

Recent work suggests that differences in functional brain development are already identifiable in 6- to 9-month-old infants from low socio-economic status (SES) backgrounds. Investigation of early SES-related differences in neuro-cognitive functioning requires the recruitment of large and diverse samples of infants, yet it is often difficult to persuade low-SES parents to come to a university setting. One solution is to recruit infants through early intervention children's centres (CCs). These are often located in areas of high relative deprivation to support young children. Given the increasing portability of eye-tracking equipment, assessment of large clusters of infants could be undertaken in centres by suitably trained early intervention staff. Here, we report on a study involving 174 infants and their parents, carried out in partnership with CCs, exploring the feasibility of this approach. We report the processes of setting up the project and participant recruitment. We report the diversity of sample obtained on the engagement of CC staff in training and the process of assessment itself. We report the quality of the data obtained, and the levels of engagement of parents and infants. We conclude that this approach has great potential for recruiting large and diverse samples worldwide, provides sufficiently reliable data and is engaging to staff, parents and infants.

The slow developmental time course of real-time spoken word recognition

This study investigated the developmental time course of spoken word recognition in older children using eye tracking to assess how the real-time processing dynamics of word recognition change over development. We found that 9-year-olds were slower to activate the target words and showed more early competition from competitor words than 16-year-olds; however, both age groups ultimately fixated targets to the same degree. This contrasts with a prior study of adolescents with language impairment (McMurray, Samelson, Lee, & Tomblin, 2010) that showed a different pattern of real-time processes. These findings suggest that the dynamics of word recognition are still developing even at these late ages, and developmental changes may derive from different sources than individual differences in relative language ability.

Decision Making and Variation in Radiation Exposure Factor Selection by Radiologic Technologists

The goal of radiographic imaging is to produce a diagnostically useful image while minimizing patient radiation dose. This study aimed to review variations in exposure factor selection by radiologic technologists for virtual patients with varying body mass index characteristics. Eleven technologists were asked to assign exposure parameters (kVp, mAs, source-to-image receptor distance, and grid use) to 10 computer-generated patient images for each of four radiographic examinations (anteroposterior [AP] shoulder; AP lumbar spine; lateral lumbar spine; AP portable chest). The virtual patients represented five body mass index categories-underweight, healthy weight, overweight, obese, and superobese. As participants assigned exposures, their visual patterns were recorded by a Tobii TX300 eye-tracker. Significant (P < .05) correlation was found between radiographer age/experience and assignment of mAs for AP shoulder and lumbar examinations. Greater age/experience correlated with higher mAs for the AP shoulder examination, but with lower values for lumbar examinations. Strong correlations also existed between times to first fixations on relevant anatomic areas, and kVp/mAs values existed for the AP portable chest examination. Exposure selection differences related to age/experience highlight inconsistencies in the practice of exposure parameter setting. The reason for these inconsistencies requires further investigation, and how to address deficiencies in practice requires consideration to optimize safe patient care. Because of the small sample size used, further research into the relationship between visual factors and individual examinations is suggested, after the findings regarding the AP portable chest examination.

Accuracy of Outcome Anticipation, But Not Gaze Behavior, Differs Against Left- and Right-Handed Penalties in Team-Handball Goalkeeping

Low perceptual familiarity with relatively rarer left-handed as opposed to more common right-handed individuals may result in athletes' poorer ability to anticipate the former's action intentions. Part of such left-right asymmetry in visual anticipation could be due to an inefficient gaze strategy during confrontation with left-handed individuals. To exemplify, observers may not mirror their gaze when viewing left- vs. right-handed actions but preferentially fixate on an opponent's right body side, irrespective of an opponent's handedness, owing to the predominant exposure to right-handed actions. So far empirical verification of such assumption, however, is lacking. Here we report on an experiment where team-handball goalkeepers' and non-goalkeepers' gaze behavior was recorded while they predicted throw direction of left- and right-handed 7-m penalties shown as videos on a computer monitor. As expected, goalkeepers were considerably more accurate than non-goalkeepers and prediction was better against right- than left-handed penalties. However, there was no indication of differences in gaze measures (i.e., number of fixations, overall and final fixation duration, time-course of horizontal or vertical fixation deviation) as a function of skill group or the penalty-takers' handedness. Findings suggest that inferior anticipation of left-handed compared to right-handed individuals' action intentions may not be associated with misalignment in gaze behavior. Rather, albeit looking similarly, accuracy differences could be due to observers' differential ability of picking up and interpreting the visual information provided by left- vs. right-handed movements.

Role descriptions induce gender mismatch effects in eye movements during reading

The present eye-tracking study investigates the effect of gender typicality on the resolution of anaphoric personal pronouns in English. Participants read descriptions of a person performing a typically male, typically female or gender-neutral occupational activity. The description was followed by an anaphoric reference (he or she) which revealed the referent's gender. The first experiment presented roles which were highly typical for men (e.g., blacksmith) or for women (e.g., beautician), the second experiment presented role descriptions with a moderate degree of gender typicality (e.g., psychologist, lawyer). Results revealed a gender mismatch effect in early and late measures in the first experiment and in early stages in the second experiment. Moreover, eye-movement data for highly typical roles correlated with explicit typicality ratings. The results are discussed from a cross-linguistic perspective, comparing natural gender languages and grammatical gender languages. An interpretation of the cognitive representation of typicality beliefs is proposed.

Wh-filler-gap dependency formation guides reflexive antecedent search

Prior studies on online sentence processing have shown that the parser can resolve non-local dependencies rapidly and accurately. This study investigates the interaction between the processing of two such non-local dependencies: wh-filler-gap dependencies (WhFGD) and reflexive-antecedent dependencies. We show that reflexive-antecedent dependency resolution is sensitive to the presence of a WhFGD, and argue that the filler-gap dependency established by WhFGD resolution is selected online as the antecedent of a reflexive dependency. We investigate the processing of constructions like (1), where two NPs might be possible antecedents for the reflexive, namely which cowgirl and Mary. Even though Mary is linearly closer to the reflexive, the only grammatically licit antecedent for the reflexive is the more distant wh-NP, which cowgirl.

(1). Which cowgirl did Mary expect to have injured herself due to negligence?

Four eye-tracking text-reading experiments were conducted on examples like (1), differing in whether the embedded clause was non-finite (1 and 3) or finite (2 and 4), and in whether the tail of the wh-dependency intervened between the reflexive and its closest overt antecedent (1 and 2) or the wh-dependency was associated with a position earlier in the sentence (3 and 4). The results of Experiments 1 and 2 indicate the parser accesses the result of WhFGD formation during reflexive antecedent search. The resolution of a wh-dependency alters the representation that reflexive antecedent search operates over, allowing the grammatical but linearly distant antecedent to be accessed rapidly. In the absence of a long-distance WhFGD (Experiments 3 and 4), wh-NPs were not found to impact reading times of the reflexive, indicating that the parser's ability to select distant wh-NPs as reflexive antecedents crucially involves syntactic structure.

Comparing methods for assessing receptive language skills in minimally verbal children and adolescents with autism spectrum disorders

This research addresses the challenges of assessing receptive language abilities in minimally verbal children with autism spectrum disorder by comparing several adapted measurement tools: a standardized direct assessment of receptive vocabulary (i.e. Peabody Picture Vocabulary Test-4); caregiver report measures including scores on the Vineland-II Communication domain and a vocabulary questionnaire consisting of a list of words ranging from simple, developmentally early, to more advanced words expected to be understood by at least some older children and adolescents; an eye-tracking test of word comprehension, using a word-image pair matching paradigm similar to that often used in studies of infant language acquisition; and a computerized assessment using a touch screen for directly measuring word comprehension with the same stimuli used in the eye-tracking experiment. Results of this multiple-method approach revealed significant heterogeneity in receptive language abilities across participants and across assessment methods. Our findings underscore the need to find individualized approaches for capturing the potential for language comprehension of minimally verbal children with autism spectrum disorder who remain otherwise untestable, using several types of assessment that may include methods based on eye-tracking or touch-screen responding.

Modelling Ecological Cognitive Rehabilitation Therapies for Building Virtual Environments in Brain Injury

BACKGROUND

Brain Injury (BI) has become one of the most common causes of neurological disability in developed countries. Cognitive disorders result in a loss of independence and patients' quality of life. Cognitive rehabilitation aims to promote patients' skills to achieve their highest degree of personal autonomy. New technologies such as virtual reality or interactive video allow developing rehabilitation therapies based on reproducible Activities of Daily Living (ADLs), increasing the ecological validity of the therapy. However, the lack of frameworks to formalize and represent the definition of this kind of therapies can be a barrier for widespread use of interactive virtual environments in clinical routine.

OBJECTIVES

To provide neuropsychologists with a methodology and an instrument to design and evaluate cognitive rehabilitation therapeutic interventions strategies based on ADLs performed in interactive virtual environments.

METHODS

The proposed methodology is used to model therapeutic interventions during virtual ADLs considering cognitive deficit, expected abnormal interactions and therapeutic hypotheses. It allows identifying abnormal behavioural patterns and designing interventions strategies in order to achieve errorless-based rehabilitation.

RESULTS

An ADL case study ('buying bread') is defined according to the guidelines established by the ADL intervention model. This case study is developed, as a proof of principle, using interactive video technology and is used to assess the feasibility of the proposed methodology in the definition of therapeutic intervention procedures.

CONCLUSIONS

The proposed methodology provides neuropsychologists with an instrument to design and evaluate ADL-based therapeutic intervention strategies, attending to solve actual limitation of virtual scenarios, to be use for ecological rehabilitation of cognitive deficit in daily clinical practice. The developed case study proves the potential of the methodology to design therapeutic interventions strategies; however our current work is devoted to designing more experiments in order to present more evidence about its values.

Eye-tracking in amyotrophic lateral sclerosis: A longitudinal study of saccadic and cognitive tasks

A relative preservation of eye movements is notable in ALS, but saccadic functions have not been studied longitudinally. ALS overlaps with FTD, typically involving executive dysfunction, and eye-tracking offers additional potential for the assessment of extramotor pathology where writing and speaking are both impaired. Eye-tracking measures (including anti-saccade, trail-making and visual search tasks) were assessed at six-monthly intervals for up to two years in a group of ALS (n = 61) and primary lateral sclerosis (n = 7) patients, compared to healthy age-matched controls (n = 39) assessed on a single occasion. Task performance was explored speculatively in relation to resting-state functional MRI (R-FMRI) network connectivity. Results showed that ALS patients were impaired on executive and visual search tasks despite normal basic saccadic function, and impairments in the PLS patients were unexpectedly often more severe. No significant progression was detected longitudinally in either group. No changes in R-FMRI network connectivity were identified in relation to patient performance. In conclusion, eye-tracking offers an objective means to assess extramotor cerebral involvement in ALS. The relative resistance of pure oculomotor function is confirmed, and higher-level executive impairments do not follow the same rate of decline as physical disability. PLS patients may have more cortical dysfunction than has been previously appreciated.

Novel methodology to examine cognitive and experiential factors in language development: combining eye-tracking and LENA technology

Developmental systems theory posits that development cannot be segmented by influences acting in isolation, but should be studied through a scientific lens that highlights the complex interactions between these forces over time (Overton, 2013a). This poses a unique challenge for developmental psychologists studying complex processes like language development. In this paper, we advocate for the combining of highly sophisticated data collection technologies in an effort to move toward a more systemic approach to studying language development. We investigate the efficiency and appropriateness of combining eye-tracking technology and the LENA (Language Environment Analysis) system, an automated language analysis tool, in an effort to explore the relation between language processing in early development, and external dynamic influences like parent and educator language input in the home and school environments. Eye-tracking allows us to study language processing via eye movement analysis; these eye movements have been linked to both conscious and unconscious cognitive processing, and thus provide one means of evaluating cognitive processes underlying language development that does not require the use of subjective parent reports or checklists. The LENA system, on the other hand, provides automated language output that describes a child's language-rich environment. In combination, these technologies provide critical information not only about a child's language processing abilities but also about the complexity of the child's language environment. Thus, when used in conjunction these technologies allow researchers to explore the nature of interacting systems involved in language development.

The Effectiveness of Gaze-Contingent Control in Computer Games

Eye-tracking technology and gaze-contingent control in human-computer interaction have become an objective reality. This article reports on a series of eye-tracking experiments, in which we concentrated on one aspect of gaze-contingent interaction: Its effectiveness compared with mouse-based control in a computer strategy game. We propose a measure for evaluating the effectiveness of interaction based on "the time of recognition" the game unit. In this article, we use this measure to compare gaze- and mouse-contingent systems, and we present the analysis of the differences as a function of the number of game units. Our results indicate that performance of gaze-contingent interaction is typically higher than mouse manipulation in a visual searching task. When tested on 60 subjects, the results showed that the effectiveness of gaze-contingent systems over 1.5 times higher. In addition, we obtained that eye behavior stays quite stabile with or without mouse interaction.

The disengagement of visual attention in Alzheimer's disease: a longitudinal eye-tracking study

INTRODUCTION

Eye tracking provides a convenient and promising biological marker of cognitive impairment in patients with neurodegenerative disease. Here we report a longitudinal study of saccadic eye movements in a sample of patients with Alzheimer's disease and elderly control participants who were assessed at the start of the study and followed up 12-months later.

METHODS

Eye movements were measured in the standard gap and overlap paradigms, to examine the longitudinal trends in the ability to disengage attention from a visual target.

RESULTS

Overall patients with Alzheimer's disease had slower reaction times than the control group. However, after 12-months, both groups showed faster and comparable reductions in reaction times to the gap, compared to the overlap stimulus. Interestingly, there was a general improvement for both groups with more accurately directed saccades and speeding of reaction times after 12-months.

CONCLUSIONS

These findings point to the value of longer-term studies and follow-up assessment to ascertain the effects of dementia on oculomotor control.

Measuring social attention and motivation in autism spectrum disorder using eye-tracking: Stimulus type matters

Autism Spectrum Disorder (ASD) is characterized by social impairments that have been related to deficits in social attention, including diminished gaze to faces. Eye-tracking studies are commonly used to examine social attention and social motivation in ASD, but they vary in sensitivity. In this study, we hypothesized that the ecological nature of the social stimuli would affect participants' social attention, with gaze behavior during more naturalistic scenes being most predictive of ASD vs. typical development. Eighty-one children with and without ASD participated in three eye-tracking tasks that differed in the ecological relevance of the social stimuli. In the "Static Visual Exploration" task, static images of objects and people were presented; in the "Dynamic Visual Exploration" task, video clips of individual faces and objects were presented side-by-side; in the "Interactive Visual Exploration" task, video clips of children playing with objects in a naturalistic context were presented. Our analyses uncovered a three-way interaction between Task, Social vs. Object Stimuli, and Diagnosis. This interaction was driven by group differences on one task only-the Interactive task. Bayesian analyses confirmed that the other two tasks were insensitive to group membership. In addition, receiver operating characteristic analyses demonstrated that, unlike the other two tasks, the Interactive task had significant classification power. The ecological relevance of social stimuli is an important factor to consider for eye-tracking studies aiming to measure social attention and motivation in ASD.

Teasing apart retrieval and encoding interference in the processing of anaphors

Two classes of account have been proposed to explain the memory processes subserving the processing of reflexive-antecedent dependencies. Structure-based accounts assume that the retrieval of the antecedent is guided by syntactic tree-configurational information without considering other kinds of information such as gender marking in the case of English reflexives. By contrast, unconstrained cue-based retrieval assumes that all available information is used for retrieving the antecedent. Similarity-based interference effects from structurally illicit distractors which match a non-structural retrieval cue have been interpreted as evidence favoring the unconstrained cue-based retrieval account since cue-based retrieval interference from structurally illicit distractors is incompatible with the structure-based account. However, it has been argued that the observed effects do not necessarily reflect interference occurring at the moment of retrieval but might equally well be accounted for by interference occurring already at the stage of encoding or maintaining the antecedent in memory, in which case they cannot be taken as evidence against the structure-based account. We present three experiments (self-paced reading and eye-tracking) on German reflexives and Swedish reflexive and pronominal possessives in which we pit the predictions of encoding interference and cue-based retrieval interference against each other. We could not find any indication that encoding interference affects the processing ease of the reflexive-antecedent dependency formation. Thus, there is no evidence that encoding interference might be the explanation for the interference effects observed in previous work. We therefore conclude that invoking encoding interference may not be a plausible way to reconcile interference effects with a structure-based account of reflexive processing.

Eye-spots in Lepidoptera attract attention in humans

Many prey species exhibit defensive traits to decrease their chances of predation. Conspicuous eye-spots, concentric rings of contrasting colours, are one type of defensive trait that some species exhibit to deter predators. We examined the function of eye-spots in Lepidoptera to determine whether they are effective at deterring predators because they resemble eyes ('eye mimicry hypothesis') or are highly salient ('conspicuous signal hypothesis'). We recorded the gaze behaviour of men and women as they viewed natural images of butterflies and moths as well as images in which the eye-spots of these insects were modified. The eye-spots were modified by removing them, scrambling their colours, or replacing them with elliptical or triangular shapes that had either dark or light centres. Participants were generally more likely to look at, spend more time looking at and be faster to first fixate the eye-spots of butterflies and moths that were natural compared with ones that were modified, including the elliptical eye-spots with dark centres that most resembled eyes as well as the scrambled eye-spots that had the same contrast as the natural eye-spots. Participants were most likely to look at eye-spots that were numerous, had a large surface area and were located close to the insects' heads. Participants' pupils were larger when viewing eye-spots compared with the rest of the insects' body, suggesting a greater arousal when viewing eye-spots. Our results provide some support for the conspicuous signal hypothesis (and minimal support for the eye mimicry hypothesis) and suggest that eye-spots may be effective at deterring predators because they are highly conspicuous signals that draw attention.

Inferring Difficulty: Flexibility in the Real-time Processing of Disfluency

Upon hearing a disfluent referring expression, listeners expect the speaker to refer to an object that is previously unmentioned, an object that does not have a straightforward label, or an object that requires a longer description. Two visual-world eye-tracking experiments examined whether listeners directly associate disfluency with these properties of objects, or whether disfluency attribution is more flexible and involves situation-specific inferences. Since in natural situations reference to objects that do not have a straightforward label or that require a longer description is correlated with both production difficulty and with disfluency, we used a mini-artificial lexicon to dissociate difficulty from these properties, building on the fact that recently learned names take longer to produce than existing words in one's mental lexicon. The results demonstrate that disfluency attribution involves situation-specific inferences; we propose that in new situations listeners spontaneously infer what may cause production difficulty. However, the results show that these situation-specific inferences are limited in scope: listeners assessed difficulty relative to their own experience with the artificial names, and did not adapt to the assumed knowledge of the speaker.

First-generation students' underperformance at university: the impact of the function of selection

According to recent research, university not only has the role to educate and train students, it also has the role to select the best students. We argue that this function of selection disadvantages first-generation students, in comparison with continuing-generation students. Thus, the mere activation of the function of selection should be sufficient to produce achievement differences between first-generation and continuing-generation students in a novel academic task. Furthermore, we propose that when the function of selection is salient, first-generation students would be more vigilant to a cue that may confirm their inferiority, which should explain their underperformance. In the present experiment, participants were asked to complete an arithmetic modular task under two conditions, which either made the function of selection salient or reduced its importance. Participants’ vigilance to a threatening cue (i.e., their performance relative to others) was measured through an eye-tracking technique. The results confirmed that first-generation students performed more poorly compared to continuing-generation students only when the function of selection was salient while no differences appeared in the no-selection condition. Regarding vigilance, the results did not confirm our hypothesis; thus, mediation path could not be tested. However, results indicated that at a high level of initial performance, first-generation students looked more often at the threatening cue. In others words, these students seemed more concerned about whether they were performing more poorly than others compared to their continuing-generation counterparts. Some methodological issues are discussed, notably regarding the measure of vigilance.

Does mood influence text processing and comprehension? Evidence from an eye-movement study

BACKGROUND

Previous research has indicated that mood influences cognitive processes. However, there is scarce data regarding the link between everyday emotional states and readers' text processing and comprehension.

AIM

We aim to extend current research on the effects of mood induction on science text processing and comprehension, using eye-tracking methodology. We investigated whether a positive-, negative-, and neutral-induced mood influences online processing, as revealed by indices of visual behaviour during reading, and offline text comprehension, as revealed by post-test questions. We were also interested in the link between text processing and comprehension.

SAMPLE

Seventy-eight undergraduate students randomly assigned to three mood-induction conditions.

METHODS

Students were mood-induced by watching a video clip. They were then asked to read a scientific text while eye movements were registered. Pre- and post-reading knowledge was assessed through open-ended questions.

RESULTS

Experimentally induced moods lead readers to process an expository text differently. Overall, students in a positive mood spent significantly longer on the text processing than students in the negative and neutral moods. Eye-movement patterns indicated more effective processing related to longer proportion of look-back fixation times in positive-induced compared with negative-induced readers. Students in a positive mood also comprehended the text better, learning more factual knowledge, compared with students in the negative group. Only for the positive-induced readers did the more purposeful second-pass reading positively predict text comprehension.

CONCLUSIONS

New insights are given on the effects of normal mood variations and students' text processing and comprehension by the use of eye-tracking methodology. Important implications for the role of emotional states in educational settings are highlighted.

Retrieval interference in reflexive processing: experimental evidence from Mandarin, and computational modeling

We conducted two eye-tracking experiments investigating the processing of the Mandarin reflexive ziji in order to tease apart structurally constrained accounts from standard cue-based accounts of memory retrieval. In both experiments, we tested whether structurally inaccessible distractors that fulfill the animacy requirement of ziji influence processing times at the reflexive. In Experiment 1, we manipulated animacy of the antecedent and a structurally inaccessible distractor intervening between the antecedent and the reflexive. In conditions where the accessible antecedent mismatched the animacy cue, we found inhibitory interference whereas in antecedent-match conditions, no effect of the distractor was observed. In Experiment 2, we tested only antecedent-match configurations and manipulated locality of the reflexive-antecedent binding (Mandarin allows non-local binding). Participants were asked to hold three distractors (animate vs. inanimate nouns) in memory while reading the target sentence. We found slower reading times when animate distractors were held in memory (inhibitory interference). Moreover, we replicated the locality effect reported in previous studies. These results are incompatible with structure-based accounts. However, the cue-based ACT-R model of Lewis and Vasishth (2005) cannot explain the observed pattern either. We therefore extend the original ACT-R model and show how this model not only explains the data presented in this article, but is also able to account for previously unexplained patterns in the literature on reflexive processing.

From the eyes and the heart: a novel eye-gaze metric that predicts video preferences of a large audience

Eye-tracking has been extensively used to quantify audience preferences in the context of marketing and advertising research, primarily in methodologies involving static images or stimuli (i.e., advertising, shelf testing, and website usability). However, these methodologies do not generalize to narrative-based video stimuli where a specific storyline is meant to be communicated to the audience. In this paper, a novel metric based on eye-gaze dispersion (both within and across viewings) that quantifies the impact of narrative-based video stimuli to the preferences of large audiences is presented. The metric is validated in predicting the performance of video advertisements aired during the 2014 Super Bowl final. In particular, the metric is shown to explain 70% of the variance in likeability scores of the 2014 Super Bowl ads as measured by the USA TODAY Ad-Meter. In addition, by comparing the proposed metric with Heart Rate Variability (HRV) indices, we have associated the metric with biological processes relating to attention allocation. The underlying idea behind the proposed metric suggests a shift in perspective when it comes to evaluating narrative-based video stimuli. In particular, it suggests that audience preferences on video are modulated by the level of viewers lack of attention allocation. The proposed metric can be calculated on any narrative-based video stimuli (i.e., movie, narrative content, emotional content, etc.), and thus has the potential to facilitate the use of such stimuli in several contexts: prediction of audience preferences of movies, quantitative assessment of entertainment pieces, prediction of the impact of movie trailers, identification of group, and individual differences in the study of attention-deficit disorders, and the study of desensitization to media violence.

Dutch and English toddlers' use of linguistic cues in predicting upcoming turn transitions

Adults achieve successful coordination during conversation by using prosodic and lexicosyntactic cues to predict upcoming changes in speakership. We examined the relative weight of these linguistic cues in the prediction of upcoming turn structure by toddlers learning Dutch (Experiment 1; N = 21) and British English (Experiment 2; N = 20) and adult control participants (Dutch: N = 16; English: N = 20). We tracked participants' anticipatory eye movements as they watched videos of dyadic puppet conversation. We controlled the prosodic and lexicosyntactic cues to turn completion for a subset of the utterances in each conversation to create four types of target utterances (fully incomplete, incomplete syntax, incomplete prosody, and fully complete). All participants (Dutch and English toddlers and adults) used both prosodic and lexicosyntactic cues to anticipate upcoming speaker changes, but weighed lexicosyntactic cues over prosodic ones when the two were pitted against each other. The results suggest that Dutch and English toddlers are already nearly adult-like in their use of prosodic and lexicosyntactic cues in anticipating upcoming turn transitions.

How hearing impairment affects sentence comprehension: using eye fixations to investigate the duration of speech processing

The main objective of this study was to investigate the extent to which hearing impairment influences the duration of sentence processing. An eye-tracking paradigm is introduced that provides an online measure of how hearing impairment prolongs processing of linguistically complex sentences; this measure uses eye fixations recorded while the participant listens to a sentence. Eye fixations toward a target picture (which matches the aurally presented sentence) were measured in the presence of a competitor picture. Based on the recorded eye fixations, the single target detection amplitude, which reflects the tendency of the participant to fixate the target picture, was used as a metric to estimate the duration of sentence processing. The single target detection amplitude was calculated for sentence structures with different levels of linguistic complexity and for different listening conditions: in quiet and in two different noise conditions. Participants with hearing impairment spent more time processing sentences, even at high levels of speech intelligibility. In addition, the relationship between the proposed online measure and listener-specific factors, such as hearing aid use and cognitive abilities, was investigated. Longer processing durations were measured for participants with hearing impairment who were not accustomed to using a hearing aid. Moreover, significant correlations were found between sentence processing duration and individual cognitive abilities (such as working memory capacity or susceptibility to interference). These findings are discussed with respect to audiological applications.

Hyper-active gap filling

Much work has demonstrated that speakers of verb-final languages are able to construct rich syntactic representations in advance of verb information. This may reflect general architectural properties of the language processor, or it may only reflect a language-specific adaptation to the demands of verb-finality. The present study addresses this issue by examining whether speakers of a verb-medial language (English) wait to consult verb transitivity information before constructing filler-gap dependencies, where internal arguments are fronted and hence precede the verb. This configuration makes it possible to investigate whether the parser actively makes representational commitments on the gap position before verb transitivity information becomes available. A key prediction of the view that rich pre-verbal structure building is a general architectural property is that speakers of verb-medial languages should predictively construct dependencies in advance of verb transitivity information, and therefore that disruption should be observed when the verb has intransitive subcategorization frames that are incompatible with the predicted structure. In three reading experiments (self-paced and eye-tracking) that manipulated verb transitivity, we found evidence for reading disruption when the verb was intransitive, although no such reading difficulty was observed when the critical verb was embedded inside a syntactic island structure, which blocks filler-gap dependency completion. These results are consistent with the hypothesis that in English, as in verb-final languages, information from preverbal noun phrases is sufficient to trigger active dependency completion without having access to verb transitivity information.

The processing of raising and nominal control: an eye-tracking study

According to some views of sentence processing, the memory retrieval processes involved in dependency formation may differ as a function of the type of dependency involved. For example, using closely matched materials in a single experiment, Dillon et al. (2013) found evidence for retrieval interference in subject-verb agreement, but not in reflexive-antecedent agreement. We report four eye-tracking experiments that examine examine reflexive-antecedent dependencies, combined with raising (e.g., "John seemed to Tom to be kind to himself…"), or nominal control (e.g., "John's agreement with Tom to be kind to himself…"). We hypothesized that dependencies involving raising would (a) be processed more quickly, and (b) be less subject to retrieval interference, relative to those involving nominal control. This is due to the fact that the interpretation of raising is structurally constrained, while the interpretation of nominal control depends crucially on lexical properties of the control nominal. The results showed evidence of interference when the reflexive-antecedent dependency was mediated by raising or nominal control, but very little evidence that could be interpreted in terms of interference for direct reflexive-antecedent dependencies that did not involve raising or control. However, there was no evidence either for greater interference, or for quicker dependency formation, for raising than for nominal control.

A physiologically informed virtual reality based social communication system for individuals with autism

Clinical applications of advanced technology may hold promise for addressing impairments associated with autism spectrum disorders (ASD). This project evaluated the application of a novel physiologically responsive virtual reality based technological system for conversation skills in a group of adolescents with ASD. The system altered components of conversation based on (1) performance alone or (2) the composite effect of performance and physiological metrics of predicted engagement (e.g., gaze pattern, pupil dilation, blink rate). Participants showed improved performance and looking pattern within the physiologically sensitive system as compared to the performance based system. This suggests that physiologically informed technologies may have the potential of being an effective tool in the hands of interventionists.

Reducing age of autism diagnosis: developmental social neuroscience meets public health challenge

Autism spectrum disorder (autism) is a highly prevalent and heterogeneous family of neurodevelopmental disorders of genetic origins with potentially devastating implications for child, family, health and educational systems. Despite advances in paper-and-pencil screening and in standardization of diagnostic procedures, diagnosis of autism in the US still hovers around the ages of four or five years, later still in disadvantaged communities, and several years after the age of two to three years when the condition can be reliably diagnosed by expert clinicians. As early detection and treatment are two of the most important factors optimizing outcome, and given that diagnosis is typically a necessary condition for families to have access to early treatment, reducing age of diagnosis has become one of the greatest priorities of the field. Recent advances in developmental social neuroscience promise the advent of cost-effective and community-viable, performance-based procedures, and suggest a complementary method for promoting universal screening and much greater access to the diagnosis process. Small but critical studies have already reported on experiments that differentiate groups of children at risk for autism from controls, and at least one study so far could predict diagnostic classification and level of disability on the basis of a brief experiment. Although the road to translating such procedures into effective devices for screening and diagnosis is still a long one, and premature claims should be avoided, this effort could be critical in addressing this worldwide public health challenge.

Attachment style impacts behavior and early oculomotor response to positive, but not negative, pictures

The present study investigated whether oculomotor behavior is influenced by attachment styles. The Relationship Scales Questionnaire was used to assess attachment styles of forty-eight voluntary university students and to classify them into attachment groups (secure, preoccupied, fearful, and dismissing). Eye-tracking was recorded while participants engaged in a 3-seconds free visual exploration of stimuli presenting either a positive or a negative picture together with a neutral picture, all depicting social interactions. The task consisted in identifying whether the two pictures depicted the same emotion. Results showed that the processing of negative pictures was impermeable to attachment style, while the processing of positive pictures was significantly influenced by individual differences in insecure attachment. The groups highly avoidant regarding to attachment (dismissing and fearful) showed reduced accuracy, suggesting a higher threshold for recognizing positive emotions compared to the secure group. The groups with higher attachment anxiety (preoccupied and fearful) showed differences in automatic capture of attention, in particular an increased delay preceding the first fixation to a picture of positive emotional valence. Despite lenient statistical thresholds induced by the limited sample size of some groups (p < 0.05 uncorrected for multiple comparisons), the current findings suggest that the processing of positive emotions is affected by attachment styles. These results are discussed within a broader evolutionary framework.

Unaddressed participants' gaze in multi-person interaction: optimizing recipiency

One of the most intriguing aspects of human communication is its turn-taking system. It requires the ability to process on-going turns at talk while planning the next, and to launch this next turn without considerable overlap or delay. Recent research has investigated the eye movements of observers of dialogs to gain insight into how we process turns at talk. More specifically, this research has focused on the extent to which we are able to anticipate the end of current and the beginning of next turns. At the same time, there has been a call for shifting experimental paradigms exploring social-cognitive processes away from passive observation toward on-line processing. Here, we present research that responds to this call by situating state-of-the-art technology for tracking interlocutors’ eye movements within spontaneous, face-to-face conversation. Each conversation involved three native speakers of English. The analysis focused on question–response sequences involving just two of those participants, thus rendering the third momentarily unaddressed. Temporal analyses of the unaddressed participants’ gaze shifts from current to next speaker revealed that unaddressed participants are able to anticipate next turns, and moreover, that they often shift their gaze toward the next speaker before the current turn ends. However, an analysis of the complex structure of turns at talk revealed that the planning of these gaze shifts virtually coincides with the points at which the turns first become recognizable as possibly complete. We argue that the timing of these eye movements is governed by an organizational principle whereby unaddressed participants shift their gaze at a point that appears interactionally most optimal: It provides unaddressed participants with access to much of the visual, bodily behavior that accompanies both the current speaker’s and the next speaker’s turn, and it allows them to display recipiency with regard to both speakers’ turns.

Vestibular Function Measurement Devices

Vestibular function laboratories utilize a multitude of diagnostic instruments to evaluate a dizzy patient. Caloric irrigators, oculomotor stimuli, and rotational chairs produce a stimulus whose accuracy is required for the patient response to be accurate. Careful attention to everything from cleanliness of equipment to threshold adjustments determine on a daily basis if patient data are going to be correct and useful. Instrumentation specifications that change with time such as speed and temperature must periodically be checked using calibrated instruments.

An eye-tracking method to reveal the link between gazing patterns and pragmatic abilities in high functioning autism spectrum disorders

The present study illustrates the potential advantages of an eye-tracking method for exploring the association between visual scanning of faces and inferences of mental states. Participants watched short videos involving social interactions and had to explain what they had seen. The number of cognition verbs (e.g., think, believe, know) in their answers were counted. Given the possible use of peripheral vision that could confound eye-tracking measures, we added a condition using a gaze-contingent viewing window: the entire visual display is blurred, expect for an area that moves with the participant’s gaze. Eleven typical adults and eleven high functioning adults with Autism Spectrum Disorders (ASD) were recruited. The condition employing the viewing window yielded strong correlations between the average duration of fixations, the ratio of cognition verbs and standard measures of social disabilities.

A protocol to examine vision and gait in Parkinson's disease: impact of cognition and response to visual cues

Background

Cognitive and visual impairments are common in Parkinson’s disease (PD) and contribute to gait deficit and falls. To date, cognition and vision in gait in PD have been assessed separately. Impact of both functions (which we term ‘visuo-cognition’) on gait however is likely interactive and can be tested using visual sampling (specifically saccadic eye movements) to provide an online behavioural measure of performance. Although experiments using static paradigms show saccadic impairment in PD, few studies have quantified visual sampling during dynamic motor tasks such as gait.

This article describes a protocol developed for testing visuo-cognition during gait in order to examine the: 1) independent roles of cognition and vision in gait in PD, 2) interaction between both functions, and 3) role of visuo-cognition in gait in PD.

Methods

Two groups of older adults (≥50 years old) were recruited; non-demented people with PD (n=60) and age-matched controls (n=40). Participants attended one session and a sub-group (n=25) attended two further sessions in order to establish mobile eye-tracker reliability. Participants walked in a gait laboratory under different attentional (single and dual task), environmental (walk straight, through a door and turning), and cueing (no visual cues and visual cues) conditions. Visual sampling was recorded using synchronised mobile eye-tracker and electrooculography systems, and gait was measured using 3D motion analysis.

Discussion

This exploratory study examined visuo-cognitive processes and their impact on gait in PD. Improved understanding of the influence of cognitive and visual functions on visual sampling during gait and gait in PD will assist in development of interventions to improve gait and reduce falls risk. This study will also help establish robust mobile eye-tracking methods in older adults and people with PD.