Physiological correlates of anxiety in childhood and adolescence: A systematic review and meta-analysis.

Anxiety is one of the most prevalent problems that affects children and adolescents. The vast majority of diagnostic tools for anxiety depend on written or verbal reports from children and adolescents or their significant others. The validity and reliability of such reports can be compromised by their subjective nature. Thus, there is growing interest in whether anxiety can be indexed with objective physiological measures. The key aim of this systematic review and meta-analysis was to determine which physiological measures are most reliably associated with elevated levels of anxiety amongst children and adolescents. Online databases (e.g., PsycINFO, Embase, Medline) were searched for relevant studies according to pre-determined criteria. Twenty-five studies comprising 2502 participants (N = 1160 with high anxiety) met inclusion, identifying 11 groups of physiological measures. Our meta-analysis revealed that skin conductance level is the most sensitive measure of anxiety (d = 0.83), followed by electromyography (EMG) measures (d = 0.71) and skin conductance response (d = 0.58). However, the included studies varied in terms of subjective measures, study designs, experimental task measures, and physiological measures. Consideration of these differences in methodology offer potential directions for future research.

A scoping review on the use of consumer-grade EEG devices for research.

BACKGROUND: Commercial electroencephalography (EEG) devices have become increasingly available over the last decade. These devices have been used in a wide variety of fields ranging from engineering to cognitive neuroscience. PURPOSE: The aim of this study was to chart peer-review articles that used consumer-grade EEG devices to collect neural data. We provide an overview of the research conducted with these relatively more affordable and user-friendly devices. We also inform future research by exploring the current and potential scope of consumer-grade EEG. METHODS: We followed a five-stage methodological framework for a scoping review that included a systematic search using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines. We searched the following online databases: PsycINFO, MEDLINE, Embase, Web of Science, and IEEE Xplore. We charted study data according to application (BCI, experimental research, validation, signal processing, and clinical) and location of use as indexed by the first author's country. RESULTS: We identified 916 studies that used data recorded with consumer-grade EEG: 531 were reported in journal articles and 385 in conference papers. Emotiv devices were used most, followed by the NeuroSky MindWave, OpenBCI, interaXon Muse, and MyndPlay Mindband. The most common usage was for brain-computer interfaces, followed by experimental research, signal processing, validation, and clinical purposes. CONCLUSIONS: Consumer-grade EEG is a useful tool for neuroscientific research and will likely continue to be used well into the future. Our study provides a comprehensive review of their application, as well as future directions for researchers who plan to use these devices.

Are comorbidities of poor reading related to elevated anxiety in children?

Studies of the association between dyslexia and mental health have typically tried to minimise the influence of dyslexia comorbidities on the outcomes. However, in the "real world", many children with dyslexia have these comorbidities. In this study, we tested (1) if children with dyslexia with three common comorbidities - inattention, hyperactivity, language difficulties - experience more anxiety than children with dyslexia without these comorbidities; and (2) if any type of comorbidity is related to a certain type of anxiety (reading, social, generalised, or separation). The data of 82 children with dyslexia (mean age = 9 years and 4 months; 25 girls) were analysed using Fisher exact tests, which revealed that those with inattention (40.54%) or hyperactivity (42.30%) were statistically significantly more likely to experience elevated anxiety than children with dyslexia without these comorbidities (8.11 and 14.28%, respectively). This was not the case for language difficulties (24.5% versus 30%). Spearman ρ correlations (α = .05) indicated significant moderate relationships between inattention and reading anxiety (.27), social anxiety (.37), and generalised anxiety (.24); and between hyperactivity and social anxiety (.24) and generalised anxiety (.28). There were no significant correlations between language and anxiety. Examination of highly inter-correlated variables suggested a specific relationship between one type of comorbidity (inattention) and one type of anxiety (reading anxiety).

The effect of an integrated reading and anxiety intervention for poor readers with anxiety.

A recent systematic review has reported that poor reading is reliably associated with anxiety. However, we currently lack evidence-based intervention for children who have both poor reading and anxiety (PRAX). In this study, we tested a new PRAX intervention in 8- to 12-year-old children using a double-baseline intervention case series design. Analyses of both group and individual data revealed that 12 weeks of PRAX intervention significantly improved children's reading and spelling accuracy, and significantly reduced both anxiety disorders and symptoms. These results support PRAX intervention as a treatment for comorbid reading and anxiety problems in children and pave the way to a randomised controlled trial.

It's all about time: precision and accuracy of Emotiv event-marking for ERP research.

BACKGROUND: The use of consumer-grade electroencephalography (EEG) systems for research purposes has become more prevalent. In event-related potential (ERP) research, it is critical that these systems have precise and accurate timing. The aim of the current study was to investigate the timing reliability of event-marking solutions used with Emotiv commercial EEG systems. METHOD: We conducted three experiments. In Experiment 1 we established a jitter threshold (i.e. the point at which jitter made an event-marking method unreliable). To do this, we introduced statistical noise to the temporal position of event-marks of a pre-existing ERP dataset (recorded with a research-grade system, Neuroscan SynAmps2 at 1,000 Hz using parallel-port event-marking) and calculated the level at which the waveform peaks differed statistically from the original waveform. In Experiment 2 we established a method to identify 'true' events (i.e. when an event should appear in the EEG data). We did this by inserting 1,000 events into Neuroscan data using a custom-built event-marking system, the 'Airmarker', which marks events by triggering voltage spikes in two EEG channels. We used the lag between Airmarker events and events generated by Neuroscan as a reference for comparisons in Experiment 3. In Experiment 3 we measured the precision and accuracy of three types of Emotiv event-marking by generating 1,000 events, 1 s apart. We measured precision as the variability (standard deviation in ms) of Emotiv events and accuracy as the mean difference between Emotiv events and true events. The three triggering methods we tested were: (1) Parallel-port-generated TTL triggers; (2) Arduino-generated TTL triggers; and (3) Serial-port triggers. In Methods 1 and 2 we used an auxiliary device, Emotiv Extender, to incorporate triggers into the EEG data. We tested these event-marking methods across three configurations of Emotiv EEG systems: (1) Emotiv EPOC+ sampling at 128 Hz; (2) Emotiv EPOC+ sampling at 256 Hz; and (3) Emotiv EPOC Flex sampling at 128 Hz. RESULTS: In Experiment 1 we found that the smaller P1 and N1 peaks were attenuated at lower levels of jitter relative to the larger P2 peak (21 ms, 16 ms, and 45 ms for P1, N1, and P2, respectively). In Experiment 2, we found an average lag of 30.96 ms for Airmarker events relative to Neuroscan events. In Experiment 3, we found some lag in all configurations. However, all configurations exhibited precision of less than a single sample, with serial-port-marking the most precise when paired with EPOC+ sampling at 256 Hz. CONCLUSION: All Emotiv event-marking methods and configurations that we tested were precise enough for ERP research as the precision of each method would provide ERP waveforms statistically equivalent to a research-standard system. Though all systems exhibited some level of inaccuracy, researchers could easily account for these during data processing.

Videoconferencing Interventions for Children with Reading and Spelling Difficulties: A Pilot Study.

Background: Many children in rural and remote areas do not have access to professionals providing literacy interventions. However, delivery of services through videoconferencing would increase access and choice for end users. Introduction: This pilot study investigated the efficacy of videoconferencing literacy interventions. As videoconferencing platforms become easier and cheaper to use, this form of telehealth delivery is increasing in popularity. However, there is currently no strong evidence base to support this practice. Materials and Methods: We studied 18 children, aged 7-12 years, with poor reading and/or spelling, and whose literacy interventions were videoconferenced into their homes and/or schools. Children were tested on three reading measures: (1) reading words, (2) reading nonwords, and (3) letter-sound knowledge, twice before their interventions commenced and once after their intervention concluded. Results: Children's raw and standardized scores on 2 of 3 outcome measures increased significantly more during the intervention than in the no-intervention period before their training commenced. Discussion and Conclusions: This study demonstrates that videoconferencing is a promising delivery mode for literacy interventions, and the results justify running a larger, randomized controlled trial.

Profiling the Word Reading Abilities of School-Age Children with Neurofibromatosis Type 1.

OBJECTIVE: Reading difficulties are one of the most significant challenges for children with neurofibromatosis type 1 (NF1). The aims of this study were to identify and categorize the types of reading impairments experienced by children with NF1 and to establish predictors of poor reading in this population. METHOD: Children aged 7-12 years with NF1 (n = 60) were compared with typically developing children (n = 36). Poor word readers with NF1 were classified according to impairment type (i.e., phonological, surface, mixed), and their reading subskills were compared. A hierarchical multiple regression was conducted to identify predictors of word reading. RESULTS: Compared to controls, children with NF1 demonstrated significantly poorer literacy abilities. Of the 49 children with NF1 classified as poor readers, 20 (41%) were classified with phonological dyslexia, 24 (49%) with mixed dyslexia, and 5 (10%) fell outside classification categories. Children with mixed dyslexia displayed the most severe reading impairments. Stronger working memory, better receptive language, and fewer inattentive behaviors predicted better word reading skills. CONCLUSIONS: The majority of children with NF1 experience deficits in key reading skills which are essential for them to become successful readers. Weaknesses in working memory, receptive language, and attention are associated with reading difficulties in children with NF1.

A validation of Emotiv EPOC Flex saline for EEG and ERP research.

BACKGROUND: Previous work has validated consumer-grade electroencephalography (EEG) systems for use in research. Systems in this class are cost-effective and easy to set up and can facilitate neuroscience outside of the laboratory. The aim of the current study was to determine if a new consumer-grade system, the Emotiv EPOC Saline Flex, was capable of capturing research-quality data. METHOD: The Emotiv system was used simultaneously with a research-grade EEG system, Neuroscan Synamps2, to collect EEG data across 16 channels during five well-established paradigms: (1) a mismatch negativity (MMN) paradigm that involved a passive listening task in which rare deviant (1,500 Hz) tones were interspersed amongst frequent standard tones (1,000 Hz), with instructions to ignore the tones while watching a silent movie; (2) a P300 paradigm that involved an active listening task in which participants were asked to count rare deviant tones presented amongst frequent standard tones; (3) an N170 paradigm in which participants were shown images of faces and watches and asked to indicate whether the images were upright or inverted; (4) a steady-state visual evoked potential (SSVEP) paradigm in which participants passively viewed a flickering screen (15 Hz) for 2 min; and (5) a resting state paradigm in which participants sat quietly with their eyes open and then closed for 3 min each. RESULTS: The MMN components and P300 peaks were equivalent between the two systems (BF10 = 0.25 and BF10 = 0.26, respectively), with high intraclass correlations (ICCs) between the ERP waveforms (>0.81). Although the N170 peak values recorded by the two systems were different (BF10 = 35.88), ICCs demonstrated that the N170 ERP waveforms were strongly correlated over the right hemisphere (P8; 0.87-0.97), and moderately-to-strongly correlated over the left hemisphere (P7; 0.52-0.84). For the SSVEP, the signal-to-noise ratio (SNR) was larger for Neuroscan than Emotiv EPOC Flex (19.94 vs. 8.98, BF10 = 51,764), but SNR z-scores indicated a significant brain response at the stimulus frequency for both Neuroscan (z = 12.47) and Flex (z = 11.22). In the resting state task, both systems measured similar alpha power (BF10 = 0.28) and higher alpha power when the eyes were closed than open (BF10 = 32.27). CONCLUSIONS: The saline version of the Emotiv EPOC Flex captures data similar to that of a research-grade EEG system. It can be used to measure reliable auditory and visual research-quality ERPs. In addition, it can index SSVEP signatures and is sensitive to changes in alpha oscillations.

The effect of non-communicative eye movements on joint attention.

Eye movements provide important signals for joint attention. However, those eye movements that indicate bids for joint attention often occur among non-communicative eye movements. This study investigated the influence of these non-communicative eye movements on subsequent joint attention responsivity. Participants played an interactive game with an avatar which required both players to search for a visual target on a screen. The player who discovered the target used their eyes to initiate joint attention. We compared participants' saccadic reaction times (SRTs) to the avatar's joint attention bids when they were preceded by non-communicative eye movements that predicted the location of the target (Predictive Search), did not predict the location of the target (Random Search), and when there were no non-communicative eye gaze movements prior to joint attention (No Search). We also included a control condition in which participants completed the same task, but responded to a dynamic arrow stimulus instead of the avatar's eye movements. For both eye and arrow conditions, participants had slower SRTs in Random Search trials than No Search and Predictive Search trials. However, these effects were smaller for eyes than for arrows. These data suggest that joint attention responsivity for eyes is relatively stable to the presence and predictability of spatial information conveyed by non-communicative gaze. Contrastingly, random sequences of dynamic arrows had a much more disruptive impact on subsequent responsivity compared with predictive arrow sequences. This may reflect specialised social mechanisms and expertise for selectively responding to communicative eye gaze cues during dynamic interactions, which is likely facilitated by the integration of ostensive eye contact cues.

Self-concept in poor readers: a systematic review and meta-analysis.

BACKGROUND: The aims of this systematic review and meta-analyses were to determine if there is a statistically reliable association between poor reading and poor self-concept, and if such an association is moderated by domain of self-concept, type of reading impairment, or contextual factors including age, gender, reading instruction, and school environment. METHODOLOGY: We searched 10 key databases for published and unpublished studies, as well as reference lists of included studies, and studies that cited included studies. We calculated standardised mean differences (SMDs) and 95% confidence intervals for one primary outcome (average self-concept) and 10 secondary outcomes (10 domains of self-concept). We assessed the data for risk of bias, heterogeneity, sensitivity, reporting bias, and quality of evidence. RESULTS: Thirteen studies with 3,348 participants met our selection criteria. Meta-analyses revealed statistically significant SMDs for average self-concept (-0.57) and five domains of self-concept (reading/writing/spelling: -1.03; academic: -0.67; math: -0.64; behaviour: -0.32; physical appearance: -0.28). The quality of evidence for the primary outcome was moderate, and for secondary outcomes was low, due to lack of data. CONCLUSIONS: These outcomes suggest a probable moderate association between poor reading and average self-concept; a possible strong association between poor reading and reading-writing-spelling self-concept; and possible moderate associations between poor reading and self-concept in the self-concept domains of academia, mathematics, behaviour, and physical appearance.

The mind minds minds: The effect of intentional stance on the neural encoding of joint attention.

Recent neuroimaging studies have observed that the neural processing of social cues from a virtual reality character appears to be affected by "intentional stance" (i.e., attributing mental states, agency, and "humanness"). However, this effect could also be explained by individual differences or perceptual effects resulting from the design of these studies. The current study used a new design that measured centro-parietal P250, P350, and N170 event-related potentials (ERPs) in 20 healthy adults while they initiated gaze-related joint attention with a virtual character ("Alan") in two conditions. In one condition, they were told that Alan was controlled by a human; in the other, they were told that he was controlled by a computer. When participants believed Alan was human, his congruent gaze shifts, which resulted in joint attention, generated significantly larger P250 ERPs than his incongruent gaze shifts. In contrast, his incongruent gaze shifts triggered significantly larger increases in P350 ERPs than his congruent gaze shifts. These findings support previous studies suggesting that intentional stance affects the neural processing of social cues from a virtual character. The outcomes also suggest the use of the P250 and P350 ERPs as objective indices of social engagement during the design of socially approachable robots and virtual agents.

The association between poor reading and internalising problems: A systematic review and meta-analysis.

Numerous studies have demonstrated an association between learning disabilities and internalising problems such as anxiety and depression. However, our understanding of this association for people with specific types of learning disability - such as poor reading - is poorly understood. Here, we present the first systematic review and meta-analysis of studies that have examined associations between poor reading and internalising problems - including anxiety and depression - in children, adolescents, and adults. Our systematic search identified 34 studies comprising 16,275 participants (N = 2491 poor readers). Our meta-analysis revealed statistically significant differences between poor readers and typical readers on general measures of internalising problems (d = 0.41), as well as specific measures of anxiety (d = 0.41) and depression (d = 0.23). These outcomes suggest that poor readers are at moderate risk for experiencing internalising problems compared to typical readers, which appears to stem from a greater risk for anxiety than depression.

Syntactic and non-syntactic sources of interference by music on language processing.

Music and language are complex hierarchical systems in which individual elements are systematically combined to form larger, syntactic structures. Suggestions that music and language share syntactic processing resources have relied on evidence that syntactic violations in music interfere with syntactic processing in language. However, syntactic violations may affect auditory processing in non-syntactic ways, accounting for reported interference effects. To investigate the factors contributing to interference effects, we assessed recall of visually presented sentences and word-lists when accompanied by background auditory stimuli differing in syntactic structure and auditory distraction: melodies without violations, scrambled melodies, melodies that alternate in timbre, and environmental sounds. In Experiment 1, one-timbre melodies interfered with sentence recall, and increasing both syntactic complexity and distraction by scrambling melodies increased this interference. In contrast, three-timbre melodies reduced interference on sentence recall, presumably because alternating instruments interrupted auditory streaming, reducing pressure on long-distance syntactic structure building. Experiment 2 confirmed that participants were better at discriminating syntactically coherent one-timbre melodies than three-timbre melodies. Together, these results illustrate that syntactic processing and auditory streaming interact to influence sentence recall, providing implications for theories of shared syntactic processing and auditory distraction.

Phonics training for English-speaking poor readers.

BACKGROUND: The reading skills of 16% of children fall below the mean range for their age, and 5% of children have significant and severe reading problems. Phonics training is one of the most common reading treatments used with poor readers, particularly children. OBJECTIVES: To measure the effect of phonics training and explore the impact of various factors, such as training duration and training group size, that might moderate the effect of phonics training on literacy-related skills in English-speaking poor readers. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, 12 other databases, and three trials registers up to May 2018. We also searched reference lists of included studies and contacted experts in the field to identify additional studies. SELECTION CRITERIA: We included studies that used randomisation, quasi-randomisation, or minimisation to allocate participants to a phonics intervention group (phonics training only or phonics training plus one other literacy-related skill) or a control group (no training or non-literacy training). Participants were English-speaking poor readers with word reading one standard deviation below the appropriate level for their age (children, adolescents, and adults) or one grade or year below the appropriate level (children only), for no known reason. Participants had no known comorbid developmental disorder, or physical, neurological, or emotional problem. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. MAIN RESULTS: We included 14 studies with 923 participants in this review. Studies took place in Australia, Canada, the UK, and the USA. Six of the 14 included studies were funded by government agencies and one was funded by a university grant. The rest were funded by charitable foundations or trusts. Each study compared phonics training alone, or in conjunction with one other reading-related skill, to either no training (i.e. treatment as usual) or alterative training (e.g. maths). Participants were English-speaking children or adolescents, of low and middle socioeconomic status, whose reading was one year, one grade, or one standard deviation below the level expected for their age or grade for no known reason. Phonics training varied between studies in intensity (up to four hours per week), duration (up to seven months), training group size (individual and small groups), and delivery (human and computer). We measured the effect of phonics training on seven primary outcomes (mixed/regular word reading accuracy, non-word reading accuracy, irregular word reading accuracy, mixed/regular word reading fluency, non-word reading fluency, reading comprehension, and spelling). We judged all studies to be at low risk of bias for most risk criteria, and used the GRADE approach to assess the quality of the evidence.There was low-quality evidence that phonics training may have improved poor readers' accuracy for reading real and novel words that follow the letter-sound rules (standardised mean difference (SMD) 0.51, 95% confidence interval (CI) 0.13 to 0.90; 11 studies, 701 participants), and their accuracy for reading words that did not follow these rules (SMD 0.67, 95% CI 0.26 to 1.07; 10 studies, 682 participants). There was moderate-quality evidence that phonics training probably improved English-speaking poor readers' fluency for reading words that followed the letter-sounds rules (SMD 0.45, 95% CI 0.19 to 0.72; 4 studies, 224 participants), and non-word reading fluency (SMD 0.39, 95% CI 0.10 to 0.68; 3 studies, 188 participants), as well as their accuracy for reading words that did not follow these rules (SMD 0.84, 95% CI 0.30 to 1.39; 4 studies, 294 participants). In addition, there was low-quality evidence that phonics training may have improved poor readers' spelling (SMD 0.47, 95% CI -0.07 to 1.01; 3 studies, 158 participants), but only slightly improve their reading comprehension (SMD 0.28, 95% CI -0.07 to 0.62; 5 studies, 343 participants). AUTHORS' CONCLUSIONS: Phonics training appears to be effective for improving literacy-related skills, particularly reading fluency of words and non-words, and accuracy of reading irregular words. More studies are needed to improve the precision of outcomes, including word and non-word reading accuracy, reading comprehension, spelling, letter-sound knowledge, and phonological output. More data are also needed to determine if phonics training in English-speaking poor readers is moderated by factors such as training type, intensity, duration, group size, or administrator.

Variations within a subtype: Developmental surface dyslexias in English.

Surface dyslexia is characterised by poor reading of irregular words while nonword reading can be completely normal. Previous work has identified several theoretical possibilities for the underlying locus of impairment in surface dyslexia. In this study, we systematically investigated whether children with surface dyslexia showed different patterns of reading performance that could be traced back to different underlying levels of impairment. To do this, we tested 12 English readers, replicating previous work in Hebrew (Gvion & Friedmann, 2013; 2016; Friedmann & Lukov, 2008; Friedmann & Gvion, 2016). In our sample, we found that poor irregular word reading was associated with deficits at the level of the orthographic input lexicon and with impaired access to meaning and spoken word forms after processing written words in the orthographic input lexicon. There were also children whose surface dyslexia seemed to be caused by impairments of the phonological output lexicon. We suggest that further evidence is required to unequivocally support a fourth pattern where the link between orthography and meaning is intact while the link between orthography and spoken word forms is not functioning. All patterns found were consistent with dual route theory while possible patterns of results, which would be inconsistent with dual route theory, were not detected.

Language Skills, but Not Frequency Discrimination, Predict Reading Skills in Children at Risk of Dyslexia.

This study evaluated the claim that auditory processing deficits are a cause of reading and language difficulties. We report a longitudinal study of 245 children at family risk of dyslexia, children with preschool language impairments, and control children. Children with language impairments had poorer frequency-discrimination thresholds than controls at 5.5 years, but children at family risk of dyslexia did not. A model assessing longitudinal relationships among frequency discrimination, reading, language, and executive function skills showed that frequency discrimination was predicted by executive skills but was not a longitudinal predictor of reading or language skills. Our findings contradict the hypothesis that frequency discrimination is causally related to dyslexia or language impairment and suggest that individuals at risk for dyslexia or who have language impairments may perform poorly on auditory processing tasks because of comorbid attentional difficulties.

Syntactic processing in music and language: Effects of interrupting auditory streams with alternating timbres.

Music and language both rely on the processing of spectral (pitch, timbre) and temporal (rhythm) information to create structure and meaning from incoming auditory streams. Behavioral results have shown that interrupting a melodic stream with unexpected changes in timbre leads to reduced syntactic processing. Such findings suggest that syntactic processing is conditional on successful streaming of incoming sequential information. The current study used event-related potentials (ERPs) to investigate whether (1) the effect of alternating timbres on syntactic processing is reflected in a reduced brain response to syntactic violations, and (2) the phenomenon is similar for music and language. Participants listened to melodies and sentences with either one timbre (piano or one voice) or three timbres (piano, guitar, and vibraphone, or three different voices). Half the stimuli contained syntactic violations: an out-of-key note in the melodies, and a phrase-structure violation in the sentences. We found smaller ERPs to syntactic violations in music in the three-timbre compared to the one-timbre condition, reflected in a reduced early right anterior negativity (ERAN). A similar but non-significant pattern was observed for language stimuli in both the early left anterior negativity (ELAN) and the left anterior negativity (LAN) ERPs. The results suggest that disruptions to auditory streaming may interfere with syntactic processing, especially for melodic sequences.

Joint attention difficulties in autistic adults: An interactive eye-tracking study.

Joint attention - the ability to coordinate attention with a social partner - is critical for social communication, learning and the regulation of interpersonal relationships. Infants and young children with autism demonstrate impairments in both initiating and responding to joint attention bids in naturalistic settings. However, little is known about joint attention abilities in adults with autism. Here, we tested 17 autistic adults and 17 age- and nonverbal intelligence quotient-matched controls using an interactive eye-tracking paradigm in which participants initiated and responded to joint attention bids with an on-screen avatar. Compared to control participants, autistic adults completed fewer trials successfully. They were also slower to respond to joint attention bids in the first block of testing but performed as well as controls in the second block. There were no group differences in responding to spatial cues on a non-social task with similar attention and oculomotor demands. These experimental results were mirrored in the subjective reports given by participants, with some commenting that they initially found it challenging to communicate using eye gaze, but were able to develop strategies that allowed them to achieve joint attention. Our study indicates that for many autistic individuals, subtle difficulties using eye-gaze information persist well into adulthood.

Detecting communicative intent in a computerised test of joint attention.

The successful navigation of social interactions depends on a range of cognitive faculties-including the ability to achieve joint attention with others to share information and experiences. We investigated the influence that intention monitoring processes have on gaze-following response times during joint attention. We employed a virtual reality task in which 16 healthy adults engaged in a collaborative game with a virtual partner to locate a target in a visual array. In the Search task, the virtual partner was programmed to engage in non-communicative gaze shifts in search of the target, establish eye contact, and then display a communicative gaze shift to guide the participant to the target. In the NoSearch task, the virtual partner simply established eye contact and then made a single communicative gaze shift towards the target (i.e., there were no non-communicative gaze shifts in search of the target). Thus, only the Search task required participants to monitor their partner's communicative intent before responding to joint attention bids. We found that gaze following was significantly slower in the Search task than the NoSearch task. However, the same effect on response times was not observed when participants completed non-social control versions of the Search and NoSearch tasks, in which the avatar's gaze was replaced by arrow cues. These data demonstrate that the intention monitoring processes involved in differentiating communicative and non-communicative gaze shifts during the Search task had a measurable influence on subsequent joint attention behaviour. The empirical and methodological implications of these findings for the fields of autism and social neuroscience will be discussed.