Muhammad A. Parvaz

Background: Traditional scalp electroencephalography (EEG), though clinically validated, presents significant limitations, including lengthy setup, patient discomfort, and limited mobility. These factors hinder its utility for long-term ambulatory monitoring. In-ear EEG offers a promising alternative by leveraging the ear canal’s anatomical proximity to the temporal lobes and natural mechanical stability. To address this, we developed SeizEAR, a standardized, three-size in-ear EEG system using paste-based electrodes with cross-ear referencing. Methods: This pilot study evaluated SeizEAR devices featuring small, medium, and large earpieces with superior and inferior paste-based electrodes in each ear, configured in a cross-ear reference scheme. It included five healthy adults who underwent recording sessions of approximately three hours (2.4 to 3.3 h). Electrode impedance was monitored against the acquisition system’s threshold indicator, with simultaneous scalp EEG from T7/T8 electrodes serving as the reference. Participants rated comfort on a 0–5 Likert scale every 30 min. Results: In-ear recordings showed moderate, band-dependent correspondence with ipsilateral temporal scalp electrodes, strongest in the delta and alpha bands and weakest in beta, and correspondence was consistently higher against a geometrically matched T7–T8 bipolar derivation than against a single referenced electrode. In-ear alpha reactivity to eye closure was present but attenuated relative to scalp. Comfort ratings remained high over the final two hours of wear, with no reported adverse events. Conclusions: SeizEAR acquired in-ear EEG that corresponded moderately with temporal scalp EEG and was well-tolerated over multi-hour wear in healthy adults. These preliminary findings support further development of a standardized in-ear EEG system and require confirmation in an adequately powered sample.

Introduction: Adolescent alcohol experimentation is a rising concern given its links to future problematic drug use. Difficulty with inhibitory control (i.e., the ability to suppress unwanted behaviors) is a well-known risk factor for early alcohol use onset. Nevertheless, little is known about the neurobiology of inhibitory control during early development (i.e., preadolescence), especially in relation to minimal early low-level alcohol use. The current study will reveal neural and behavioral differences in inhibitory control that differentiate youth will go on to engage in low-level alcohol experimentation compared with youth who remain alcohol naïve. Methods: The current study examined 80 pairs of demographically and developmentally matched youth from the Adolescent Brain Cognitive Development Study to predict early alcohol experimentation, consuming at least one full drink, but no regular use, prospectively (ages 10–14 years old). To identify the underlying neural mechanisms differentiating youth who endorsed alcohol experimentation (AE) and those who did not (AN), we utilized impulsive personality trait markers and neurobehavioral markers from the Stop Signal Task. Results: AE and AN youth showed no difference in task performance nor in impulsive personality traits but differed in patterns of neural engagement during the Stop Signal task. When compared to AN youth, AE youth displayed significantly higher activation in the right paracentral lobule and the left isthmus gyrus during the correct stop versus correct go contrast (indexing inhibitory control). Moreover, our findings indicated that, unlike in AN, a greater lack of planning in AE youth was associated with lower inhibitory control-related activation in the fusiform gyrus. Discussion: This study demonstrates a possible role of neural correlates of inhibitory control that are associated with substance use initiation. Despite behavioral similarities, the study detects differential neural markers of inhibitory control between AE and AN youth, an effect potentially driven by impulsive personality trait markers. As these markers could be both constitutionally and environmentally based, our results suggest that early substance use is accompanied by detectable differences in brain activation in key regions, which may be similar to those in later stages of use, highlighting the importance of delaying the age of alcohol onset.

Schizophrenia spectrum disorders (SCZ) are a group of psychiatric disorders that can severely impact social and occupational functioning. Social cognition plays a key role in social functioning, with deficits in social cognition potentially revealing social deficits. However, existing tests of social cognition are lengthy to administer and only measure one or two aspects of social cognition. The Edinburgh Social Cognition Test (ESCoT) is a newly developed brief assessment that evaluates multiple domains of social cognition, including cognitive Theory of Mind (ToM), affective ToM, and interpersonal and intrapersonal understandings of social norms. However, the ESCoT has not been utilized before to examine social cognition in SCZ. This observational study analyzed 18 individuals with SCZ and 19 healthy controls (HC), all of whom completed the ESCoT and several social functioning scales, including the Lubben Social Network Scale (LSNS), the Pinkham Social Skill Rating (PSSR), the Role Function Scale (RFS), and the Social Disconnectedness Scale (SDS). Between-group comparisons revealed significantly reduced scores in the participants with SCZ on cognitive and affective ToM but comparable scores on interpersonal and intrapersonal understandings of social norms, compared to HC. Additionally, the participants with SCZ showed reduced scores on the LSNS, PSSR, RFS, and SDS. Furthermore, ESCoT-derived cognitive ToM scores were positively correlated with scores on the LSNS, PSSR, and SDS, whereas affective ToM scores were positively correlated with the LSNS and PSSR. Interpersonal understanding of social norms was positively correlated with the LSNS and RFS score. The current study showed deficits in cognitive and affective ToM alongside other aspects of social functioning in SCZ compared to HC participants. The ESCoT sub-scores were correlated with scores from validated questionnaires of social functioning, thus validating the utility of the ESCoT to study social cognition in SCZ. Further investigation is recommended to replicate these findings in larger and more heterogeneous samples of SCZ individuals for a better generalization of these findings.

Background: Family history of substance use (FHSU), along with sociodemographic and psychosocial factors, has been identified as a key risk factor for adolescent substance use and progression to substance use disorders (SUD). However, the interaction between distinct sociodemographic and psychosocial profiles in adolescents with FHSU and constitutional factors, such as psychopathological symptom severity, impulsivity, and reward processing, remains unclear. Given the complexity of these factors, it is crucial to explore how these elements contribute to the differential vulnerability to SUD among youth with family history of substance use. Particularly as, the identification of clinically relevant subgroups of at-risk youth may inform precision prevention and treatment approaches to reduce adverse outcomes related to SUDs. Methods: Here, we used data from the Adolescent Brain Cognitive Development (ABCD) study and grouped the participants (age: 9–10 years) into positive and negative FHSU [i.e., FHSU-P ( n = 1955; female 49.7%, White 57.95%), and FHSU-N ( n = 4,369; female 48.33%, White 61.16%), respectively]. We used K-means clustering to identify latent subgroups in the FHSU-P population based on psychosocial variables and then compared the resulting subgroups on internalizing, externalizing, and total psychopathology, impulsivity, and reward prediction errors. Results: K-means clustering revealed five subgroups within FHSU-P: Subgroups 1 ( n = 744) and 2 ( n = 300) exhibited favorable psychosocial profiles, marked by higher school involvement, social engagement, and parental acceptance. Subgroups 3 ( n = 267), 4 ( n = 201), and 5 ( n = 443) were characterized by lower engagement across peer, school, and parental domains. Group comparisons showed that Subgroups 1 and 2 had comparable levels of psychopathology and impulsivity, while Subgroups 3, 4, and 5 displayed higher psychopathology and impulsivity. Reward prediction errors were similar across all subgroups. Other group differences are also presented and discussed in the main text. Conclusion: These findings highlight significant heterogeneity within the FHSU-P group and emphasize the importance of stratifying adolescents based on sociodemographic and psychosocial factors. Such stratification can help identify adolescents at higher risk for psychopathologies, including SUDs, offering insights for targeted prevention and intervention strategies.

Reinforcement learning studies propose that decision-making is guided by a tradeoff between computationally cheaper model-free (habitual) control and costly model-based (goal-directed) control. Greater model-based control is typically used under highly rewarding conditions to minimize risk and maximize gain. Although prior studies have shown impairments in sensitivity to reward value in individuals with frequent alcohol use, it is unclear how these individuals arbitrate between model-free and model-based control based on the magnitude of reward incentives. In this study, 81 individuals (47 frequent Alcohol Users and 34 Alcohol Non-Users) performed a modified 2-step learning task where stakes were sometimes high, and other times they were low. Maximum a posteriori fitting of a dual-system reinforcement-learning model was used to assess the degree of model-based control, and a utility model was used to assess risk sensitivity for the low- and high-stakes trials separately. As expected, Alcohol Non-Users showed significantly higher model-based control in higher compared to lower reward conditions, whereas no such difference between the two conditions was observed for the Alcohol Users. Additionally, both groups were significantly less risk-averse in higher compared to lower reward conditions. However, Alcohol Users were significantly less risk-averse compared to Alcohol Non-Users in the higher reward condition. Lastly, greater model-based control was associated with a less risk-sensitive approach in Alcohol Users. Taken together, these results suggest that frequent Alcohol Users may have impaired metacontrol, making them less flexible to varying monetary rewards and more prone to risky decision-making, especially when the stakes are high.

Bulimia nervosa (BN) is a disabling eating disorder that is associated with costly medical morbidity and often follows a chronic course. Novel treatments are needed, particularly those that directly target symptom-maintaining mechanisms. One such mechanism may be reduced activation of the prefrontal cortex (PFC) during attempts to control behavioral responses. In this proof-of-principle project, we propose to develop, establish feasibility, and preliminarily test a novel neurofeedback procedure that is intended to increase PFC activation and enhance the ability to control the consumption of common binge foods. We will compare the effects of one session of real and sham neurofeedback during eating on neural activation, inhibitory control, and clinical symptoms in women with BN. To our knowledge, this will be the first test of neurofeedback in BN to date. Results will establish this new technique’s potential to clarify causal mechanisms of BN symptoms and inform future clinical trials. Trial Registration: NCT05614024.