Name recognition in autism: EEG evidence of altered patterns of brain activity and connectivity

Indistinguishable behavioural and neural correlates of perceptual self-other distinction in autistic and neurotypical adults

Previous research has suggested that self-bias (i.e., enhanced cognitive processing of self-versus other-relevant information) may be atypical in autism spectrum conditions (ASC), perhaps due to difficulties with self-other distinction. However, empirical evidence for this is inconsistent, and the neural basis of processing differences remains unknown. We present two experiments that aimed to test perceptual self-bias and familiarity effects in ASC using a perceptual-association task. Participants were asked to distinguish face/label associations of the self from those of other people of differing levels of familiarity (i.e., friend vs stranger). Experiment 1 took an individual differences approach by testing whether behavioural self-bias is associated with the number of autistic traits in a neurotypical adult sample (N = 59). Experiment 2 took a case-control approach by testing whether behavioural self-bias and associated ERP responses differ between neurotypical (N = 27) and autistic (N = 30) adults. Across both experiments, behavioural results showed that participants experienced a self-bias (self > friend and stranger) and a familiarity effect (e.g., friend > stranger); neither effect was affected by the number of autistic traits or autism diagnosis. In Experiment 2, analysis of N1, N2, and P3 ERP components revealed a typical self-bias in both groups (self distinct from friend and stranger), and only the autistic group showed evidence of a familiarity effect (N2 more negative-going for stranger than friend). The findings are discussed in relation to self-other distinction ability, and the relevance of other neuropsychological and psychiatric conditions such as anxiety and alexithymia are also considered.

Electrophysiological correlates of self-related processing in adults with autism

The term "self-bias" refers to the human propensity to prioritize self- over other-related stimuli and is believed to influence various stages of the processing stream. By means of event-related potentials (ERPs), it was recently shown that the self-bias in a shape-label matching task modulates early as well as later phases of information processing in neurotypicals. Recent claims suggest autism-related deficits to specifically impact later stages of self-related processing; however, it is unclear whether these claims hold based on current findings. Using the shape-label matching task while recording ERPs in individuals with autism can clarify which stage of self-related processing is specifically affected in this condition. Therefore, this study sought to investigate the temporal course of self-related processing in adults with and without autism. Thirty-two adults with autism and 27 neurotypicals completed a shape-label matching task while ERPs were concomitantly recorded. At the behavioral level, results furnished evidence for a comparable self-bias across groups, with no differences in task performance between adults with and without autism. At the ERP level, the two groups showed a similar self-bias at early stages of self-related information processing (the N1 component). Conversely, the autism group manifested a lessened differentiation between self- and other-related stimuli at later stages (the parietal P3 component). In line with recent claims of later phases of self-related processing being altered in autism, we found an equivalent self-bias between groups at an early, sensory stage of processing, yet a strongly diminished self-bias at a later, cognitive stage in adults with autism.

Differences in own-face but not own-name discrimination between autistic and neurotypical adults: A fast periodic visual stimulation-EEG study

Self-related processing is thought to be altered in autism, with several studies reporting that autistic individuals show a diminished neural response relative to neurotypicals for their own name and face. However, evidence remains scarce and is mostly based on event-related potential studies. Here, we used EEG to measure the neural activity of autistic adults (20 for faces, 27 for names) and neurotypical adults (24 for faces, 25 for names) while they were watching rapidly alternating faces and names, through a relatively new technique called Fast Periodic Visual Stimulation. We presented strangers' faces or names at a base frequency of 5.77 Hz, while one's own, a close other's, and a specific stranger's face/name was presented at an oddball frequency of 1.154 Hz. The neurotypical group showed a significantly greater response to their own face than both close other and stranger faces, and a greater response for close other than for stranger faces. In contrast, in the autism group, own and close other faces showed stronger responses than the stranger's face, but the difference between own and close other faces was not significant in a bilateral parieto-occipital cluster. No group differences in the enhanced response to familiar names were found. These results replicate and extend results obtained using traditional electroencephalographic techniques which suggest atypical responses to self-relevant stimuli in autism.

The relevance of familiarity in the context of self-related information processing

Humans are inclined to preferentially process self-related content, referred to as the "self-bias." Different paradigms have been used to study this effect. However, not all paradigms included a familiar other condition (but rather an unfamiliar other condition), needed to differentiate self-specific effects from the impact of familiarity. The primary goal of our study was to test the suitability for studying the self-bias of two paradigms that provide robust measures of salience effects-that is, the Repetition Blindness (RB) effect and the Emotional Stroop (ES) interference-while addressing the familiarity confound. We further explored whether self-bias effects were related to autism symptomatology, as a reduced self-bias in autism has been reported in previous research. In an online procedure, 82 adults performed an RB task and an ES task in a counterbalanced order, while being presented with both self- and familiar other-related stimuli. Results of both frequentist and Bayesian analyses did not provide evidence in favour of a specific self-bias on either task: we found no significant modulation of the RB effect, nor of the ES interference, for the own versus a close other's name. Moreover, no link with autism symptomatology was found. Tackling a crucial shortcoming from earlier studies, our investigation raises awareness on the importance of accounting for familiarity when investigating self-related processing.

Posterior theta activity reveals an early signal of self-face recognition

Self-related visual information, especially one's own face and name, are processed in a specific, prioritized way. However, the spatio-temporal brain dynamics of self-prioritization have remained elusive. Moreover, it has been unclear whether this prioritization is an effect of enhancement and amplification, or rather a facilitating automatization of processing self-referential information. In this EEG study, 25 married women (who changed their surnames after marriage, so that their past and present surnames could be used as stimuli) performed a detection task with faces and names from five categories: self, self from the past, friend, famous, and unknown person. The aim was to determine the temporal and spatial characteristics of early electrophysiological markers of self-referential processing. We report results of event-related component (ERP) and time-frequency analyses. In the ERPs, the earliest self-relevance effect was displayed only 300 ms after stimulus onset in the midfrontal N2, and later in the parietal P3b, independently of the stimulus type. No self-relevance effect was found on the N170 component. However, local theta power at the occipito-temporal (visual) areas and inter-regional theta phase coherence between the visual and midfrontal areas showed that self-relevance differentiation of faces began already about 100-300 ms after stimulus onset. No such early effects were found for names. The results are discussed in terms of the time-course, functional localization, stimulus-specificity, and automatization of self-prioritization.

EEG frequency tagging evidence of intact social interaction recognition in adults with autism

To explain the social difficulties in autism, many studies have been conducted on social stimuli processing. However, this research has mostly used basic social stimuli (e.g., eyes, faces, hands, single agent), not resembling the complexity of what we encounter in our daily social lives and what people with autism experience difficulties with. Third-party social interactions are complex stimuli that we come across often and are also highly relevant for social functioning. Interestingly, the existing behavioral studies point to altered social interaction processing in autism. However, it is not clear whether this is due to altered recognition or altered interpretation of social interactions. Here, we specifically investigated the recognition of social interaction in adults with and without autism. More precisely, we measured neural responses to social scenes depicting either social interaction or not with an electroencephalogram frequency tagging task and compared these responses between adults with and without autism (N = 61). The results revealed an enhanced response to social scenes with interaction, replicating previous findings in a neurotypical sample. Crucially, this effect was found in both groups, with no difference between them. This suggests that social interaction recognition is not atypical in adults with autism. Taken together with the previous behavioral evidence, our study thus suggests that individuals with autism are able to recognize social interactions, but that they might not extract the same information from those interactions or that they might use the extracted information differently.

The self and a close-other: differences between processing of faces and newly acquired information

Prioritization of self-related information (e.g. self-face) may be driven by its extreme familiarity. Nevertheless, the findings of numerous behavioral studies reported a self-preference for initially unfamiliar information, arbitrarily associated with the self. In the current study, we investigated the neural underpinnings of extremely familiar stimuli (self-face, close-other's face) and stimuli newly assigned to one's own person and to a close-other (abstract shapes). Control conditions consisted of unknown faces and unknown abstract shapes. Reaction times (RTs) to the self-face were shorter than to close-other's and unknown faces, whereas no RTs differences were observed for shapes. P3 amplitude to the self-face was larger than to close-other's and unknown faces. Nonparametric cluster-based permutation tests showed significant clusters for the self-face vs. other (close-other's, unknown) faces. However, in the case of shapes P3 amplitudes to the self-assigned shape and to the shape assigned to a close-other were similar, and both were larger than P3 to unknown shapes. No cluster was detected for the self-assigned shape when compared with the shape assigned to the close-other. Thus, our findings revealed preferential attentional processing of the self-face and the similar allocation of attentional resources to shapes assigned to the self and a close-other.

Equivalent own name bias in autism: An EEG study of the Attentional Blink

The “Attentional Blink” refers to difficulty in detecting the second of two target stimuli presented in rapid temporal succession. Studies have shown that salient target stimuli, such as one’s own name, reduce the magnitude of this effect. Given indications that self-related processing is altered in autism, it is an open question whether this attentional self-bias is reduced in autism. To investigate this, in the current study we utilised an Attentional Blink paradigm involving one’s own and others’ names, in a group of 24 autistic adults, and 22 neurotypical adults, while measuring EEG. In line with previous studies, the Attentional Blink was reduced when the participant’s own name was the second target, with no differences between autistic and neurotypical participants. ERP results show that the effect on the Attentional Blink of one’s own name was reflected in increased N2 and P3 amplitudes, for both autistic and nonautistic individuals. This is the first event-related potential study of own-name processing in the context of the Attentional Blink. The results provide evidence of an intact attentional self-bias in autism, both at the behavioural and neural level.

Neural correlates of own name and own face processing in neurotypical adults scoring low versus high on symptomatology of autism spectrum disorder

Previous event-related potential (ERP) research showed reduced self-referential processing in autism spectrum disorder (ASD). As different self-related stimuli were studied in isolation, it is unclear whether findings can be ascribed to a common underlying mechanism. Further, it is unknown whether altered self-referential processing is also evident in neurotypicals scoring high on ASD symptomatology. We compared ERPs in response to one's own name and face (versus other names/faces) between neurotypical adults scoring high versus low on ASD symptomatology. Conform previous research, the parietal P3 was enhanced, both for own name and face, indicating a self-referential effect. The N250 was only enhanced for one's own face. However, the self-referential parietal P3 effect did not correlate between the names and faces conditions, arguing against a common underlying mechanism. No group effects appeared, neither for names nor faces, suggesting that reduced self-referential processing is not a dimensional ASD feature in the neurotypical population.

Spontaneous State Detection Using Time-Frequency and Time-Domain Features Extracted From Stereo-Electroencephalography Traces

As a minimally invasive recording technique, stereo-electroencephalography (SEEG) measures intracranial signals directly by inserting depth electrodes shafts into the human brain, and thus can capture neural activities in both cortical layers and subcortical structures. Despite gradually increasing SEEG-based brain-computer interface (BCI) studies, the features utilized were usually confined to the amplitude of the event-related potential (ERP) or band power, and the decoding capabilities of other time-frequency and time-domain features have not been demonstrated for SEEG recordings yet. In this study, we aimed to verify the validity of time-domain and time-frequency features of SEEG, where classification performances served as evaluating indicators. To do this, using SEEG signals under intermittent auditory stimuli, we extracted features including the average amplitude, root mean square, slope of linear regression, and line-length from the ERP trace and three traces of band power activities (high-gamma, beta, and alpha). These features were used to detect the active state (including activations to two types of names) against the idle state. Results suggested that valid time-domain and time-frequency features distributed across multiple regions, including the temporal lobe, parietal lobe, and deeper structures such as the insula. Among all feature types, the average amplitude, root mean square, and line-length extracted from high-gamma (60–140 Hz) power and the line-length extracted from ERP were the most informative. Using a hidden Markov model (HMM), we could precisely detect the onset and the end of the active state with a sensitivity of 95.7 ± 1.3% and a precision of 91.7 ± 1.6%. The valid features derived from high-gamma power and ERP in this work provided new insights into the feature selection procedure for further SEEG-based BCI applications.

Impaired attentional bias toward one's own face in autism spectrum disorder: ERP evidence

Converging lines of evidence seem to indicate reduced self-referential processing in individuals with autism spectrum disorder (ASD). However, processing of one's own face has rarely been investigated in the context of ASD. Thus, the aim of the present study was to elucidate the role of attentional biases in the processing of self- and other faces in ASD. To achieve this goal we presented participants with images of their own face, the face of a close-other, and famous and unknown faces in a Stroop-like paradigm. Participants (22 with ASD, 22 typically developing [TD]) were instructed to indicate the color of presented faces while EEG was recorded. Our event-related potential results clearly showed that self-face was associated with larger P3 amplitudes than all other faces in the TD group, thus indicating a strong attentional bias toward one's own face. In the ASD group, P3 to the self-face and the close-other's face did not differ, suggesting similar attentional biases in both cases. In line with these P3 findings, nonparametric cluster-based permutation tests showed an analogous pattern of results: significant clusters for the self-face compared with all other faces in the TD group, and no significant cluster in the ASD group. Overall, our findings revealed impaired attentional bias to one's own face and diminished self versus other differentiation in individuals with ASD. The similar neural underpinnings of the self-face and other faces supports previous findings indicating reduced self-prioritization among individuals with ASD.

Differences in Performance of ASD and ADHD Subjects Facing Cognitive Loads in an Innovative Reasoning Experiment

We aim to investigate whether EEG dynamics differ in adults with ASD (Autism Spectrum Disorders) and ADHD (attention-deficit/hyperactivity disorder) compared with healthy subjects during the performance of an innovative cognitive task, Aristotle's valid and invalid syllogisms, and how these differences correlate with brain regions and behavioral data for each subject. We recorded EEGs from 14 scalp electrodes (channels) in 21 adults with ADHD, 21 with ASD, and 21 healthy, normal subjects. The subjects were exposed in a set of innovative cognitive tasks (inducing varying cognitive loads), Aristotle's two types of syllogism mentioned above. A set of 39 questions were given to participants related to valid-invalid syllogisms as well as a separate set of questionnaires, in order to collect a number of demographic and behavioral data, with the aim of detecting shared information with values of a feature extracted from EEG, the multiscale entropy (MSE), in the 14 channels ('brain regions'). MSE, a nonlinear information-theoretic measure of complexity, was computed to extract a feature that quantifies the complexity of the EEG. Behavior-Partial Least Squares Correlation, PLSC, is the method to detect the correlation between two sets of data, brain, and behavioral measures. -PLSC, a variant of PLSC, was applied to build a functional connectivity of the brain regions involved in the reasoning tasks. Graph-theoretic measures were used to quantify the complexity of the functional networks. Based on the results of the analysis described in this work, a mixed 14 × 2 × 3 ANOVA showed significant main effects of group factor and brain region* syllogism factor, as well as a significant brain region* group interaction. There are significant differences between the means of MSE (complexity) values at the 14 channels of the members of the 'pathological' groups of participants, i.e., between ASD and ADHD, while the difference in means of MSE between both ASD and ADHD and that of the control group is not significant. In conclusion, the valid-invalid type of syllogism generates significantly different complexity values, MSE, between ASD and ADHD. The complexity of activated brain regions of ASD participants increased significantly when switching from a valid to an invalid syllogism, indicating the need for more resources to 'face' the task escalating difficulty in ASD subjects. This increase is not so evident in both ADHD and control. Statistically significant differences were found also in the behavioral response of ASD and ADHD, compared with those of control subjects, based on the principal brain and behavior saliences extracted by PLSC. Specifically, two behavioral measures, the emotional state and the degree of confidence of participants in answering questions in Aristotle's valid-invalid syllogisms, and one demographic variable, age, statistically and significantly discriminate the three groups' ASD. The seed-PLC generated functional connectivity networks for ASD, ADHD, and control, were 'projected' on the regions of the Default Mode Network (DMN), the 'reference' connectivity, of which the structural changes were found significant in distinguishing the three groups. The contribution of this work lies in the examination of the relationship between brain activity and behavioral responses of healthy and 'pathological' participants in the case of cognitive reasoning of the type of Aristotle's valid and invalid syllogisms, using PLSC, a machine learning approach combined with MSE, a nonlinear method of extracting a feature based on EEGs that captures a broad spectrum of EEGs linear and nonlinear characteristics. The results seem promising in adopting this type of reasoning, in the future, after further enhancements and experimental tests, as a supplementary instrument towards examining the differences in brain activity and behavioral responses of ASD and ADHD patients. The application of the combination of these two methods, after further elaboration and testing as new and complementary to the existing ones, may be considered as a tool of analysis in helping detecting more effectively such types of disorders.

Self-Related Stimuli Decoding With Auditory and Visual Modalities Using Stereo-Electroencephalography

Name recognition plays important role in self-related cognitive processes and also contributes to a variety of clinical applications, such as autism spectrum disorder diagnosis and consciousness disorder analysis. However, most previous name-related studies usually adopted noninvasive EEG or fMRI recordings, which were limited by low spatial resolution and temporal resolution, respectively, and thus millisecond-level response latencies in precise brain regions could not be measured using these noninvasive recordings. By invasive stereo-electroencephalography (SEEG) recordings that have high resolution in both the spatial and temporal domain, the current study distinguished the neural response to one's own name or a stranger's name, and explored common active brain regions in both auditory and visual modalities. The neural activities were classified using spatiotemporal features of high-gamma, beta, and alpha band. Results showed that different names could be decoded using multi-region SEEG signals, and the best classification performance was achieved at high gamma (60–145 Hz) band. In this case, auditory and visual modality-based name classification accuracies were 84.5 ± 8.3 and 79.9 ± 4.6%, respectively. Additionally, some single regions such as the supramarginal gyrus, middle temporal gyrus, and insula could also achieve remarkable accuracies for both modalities, supporting their roles in the processing of self-related information. The average latency of the difference between the two responses in these precise regions was 354 ± 63 and 285 ± 59 ms in the auditory and visual modality, respectively. This study suggested that name recognition was attributed to a distributed brain network, and the subsets with decoding capabilities might be potential implanted regions for awareness detection and cognition evaluation.

Neural Evidence for Speech Processing Deficits During a Cocktail Party Scenario in Minimally and Low Verbal Adolescents and Young Adults with Autism

As demonstrated by the Cocktail Party Effect, a person's attention is grabbed when they hear their name in a multispeaker setting. However, individuals with autism (ASD) are commonly challenged in multispeaker settings and often do not respond to salient speech, including one's own name (OON). It is unknown whether neural responses during this Cocktail Party scenario differ in those with ASD and whether such differences are associated with expressive language or auditory filtering abilities. We measured neural responses to hearing OON in quiet and multispeaker settings using electroencephalography in 20 minimally or low verbal ASD (ASD-MLV), 27 verbally fluent ASD (ASD-V), and 27 neurotypical (TD) participants, ages 13-22. First, we determined whether TD's neural responses to OON relative to other names could be quantified with early frontal mismatch responses (MMRs) and late, slow shift parietal and frontal responses (LPPs/FNs). Second, we compared the strength of MMRs and LPPs/FNs across the three groups. Third, we tested whether participants with poorer auditory filtering abilities exhibited particularly weak neural responses to OON heard in a multispeaker setting. Our primary finding was that TDs and ASD-Vs, but not ASD-MLVs, had significant MMRs to OON in a multispeaker setting, and strength of LPPs positively correlated with auditory filtering abilities in those with ASD. These findings reveal electrophysiological correlates of auditory filtering disruption within a clinical population that has severe language and communication impairments and offer a novel neuroimaging approach to studying the Cocktail Party effect in neurotypical and clinical populations. Autism Res 2020, 13: 1828-1842. © 2020 International Society for Autism Research and Wiley Periodicals LLC. LAY SUMMARY: We found that minimally and low verbal adolescents and young adults with autism exhibit decreased neural responses to one's own name when heard in a multispeaker setting. In addition, decreased strength of neural responses in those with autism correlated with decreased auditory filtering abilities. We propose that these neural deficits may reflect the ineffective processing of salient speech in noisy settings and contribute to language and communication deficits observed in autism.

Motivational intensity and visual word search: Layout matters

Motivational intensity has been previously linked to information processing. In particular, it has been argued that affects which are high in motivational intensity tend to narrow cognitive scope. A similar effect has been attributed to negative affect, which has been linked to narrowing of cognitive scope. In this paper, we investigated how these phenomena manifest themselves during visual word search. We conducted three studies in which participants were instructed to perform word category identification. We manipulated motivational intensity by controlling reward expectations and affect via reward outcomes. Importantly, we altered visual search paradigms, assessing the effects of affective manipulations as modulated by information arrangement. We recorded multiple physiological signals (EEG, EDA, ECG and eye tracking) to assess whether motivational states can be predicted by physiology. Across the three studies, we found that high motivational intensity narrowed visual attentional scope by altering visual search strategies, especially when information was displayed sparsely. Instead, when information was vertically listed, approach-directed motivational intensity appeared to improve memory encoding. We also observed that physiology, in particular eye tracking, may be used to detect biases induced by motivational intensity, especially when information is sparsely organised.

Neural Correlates of Reflection on Present and Past Selves in Autism Spectrum Disorder

Previous studies indicate that autobiographical memory is impaired in individuals with autism spectrum disorder (ASD). Successful recollection of information referring to one’s own person requires the intact ability to re-activate representation of the past self. In the current fMRI study we investigated process of conscious reflection on the present self, the past self, and a close-other in the ASD and typically developing groups. Significant inter-group differences were found in the Past-Self condition. In individuals with ASD, reflection on the past self was associated with additional engagement of the posterior cingulate and posterior temporal structures. We hypothesize that this enhanced activation of widely distributed neural network reflects substantial difficulties in processes of reflection on one’s own person in the past.

Overlaps and distinctions between attention deficit/hyperactivity disorder and autism spectrum disorder in young adulthood: Systematic review and guiding framework for EEG-imaging research

Attention deficit/hyperactivity disorders (ADHD) and autism spectrum disorders (ASD) frequently co-occur. However, we know little about the neural basis of the overlaps and distinctions between these disorders, particularly in young adulthood - a critical time window for brain plasticity across executive and socioemotional domains. Here, we systematically review 75 articles investigating ADHD and ASD in young adult samples (mean ages 16-26) using cognitive tasks, with neural activity concurrently measured via electroencephalography (EEG) - the most accessible neuroimaging technology. The majority of studies focused on event-related potentials (ERPs), with some beginning to capitalise on oscillatory approaches. Overlapping and specific profiles for ASD and ADHD were found mainly for four neurocognitive domains: attention processing, performance monitoring, face processing and sensory processing. No studies in this age group directly compared both disorders or considered dual diagnosis with both disorders. Moving forward, understanding of ADHD, ASD and their overlap in young adulthood would benefit from an increased focus on cross-disorder comparisons, using similar paradigms and in well-powered samples and longitudinal cohorts.

Electrophysiological Biomarkers Predict Clinical Improvement in an Open-Label Trial Assessing Efficacy of Autologous Umbilical Cord Blood for Treatment of Autism

This study was a phase I, single-center, and open-label trial of a single intravenous infusion of autologous umbilical cord blood in young children with autism spectrum disorder (ASD). Twenty-five children between the ages of 2 and 6 with a confirmed diagnosis of ASD and a qualified banked autologous umbilical cord blood unit were enrolled. Safety results and clinical outcomes measured at 6 and 12 months post-infusion have been previously published. The purpose of the present analysis was to explore whether measures of electroencephalography (EEG) theta, alpha, and beta power showed evidence of change after treatment and whether baseline EEG characteristics were predictive of clinical improvement. The primary endpoint was the parent-reported Vineland adaptive behavior scales-II socialization subscale score, collected at baseline, 6- and 12-month visits. In addition, the expressive one word picture vocabulary test 4 and the clinical global impression-improvement scale were administered. Electrophysiological recordings were taken during viewing of dynamic social and nonsocial stimuli at 6 and 12 months post-treatment. Significant changes in EEG spectral characteristics were found by 12 months post-infusion, which were characterized by increased alpha and beta power and decreased EEG theta power. Furthermore, higher baseline posterior EEG beta power was associated with a greater degree of improvement in social communication symptoms, highlighting the potential for an EEG biomarker to predict variation in outcome. Taken together, the results suggest that EEG measures may be useful endpoints for future ASD clinical trials. Stem Cells Translational Medicine 2018;7:783-791.