Publications by authors named "Alexander Demos"

Background: Passive sensing through smartphone keyboard data can be used to identify and monitor symptoms of mood disorders with low participant burden. Behavioral phenotyping based on mobile keystroke data can aid in clinical decision-making and provide insights into the individual symptoms of mood disorders.

Objective: This study aims to derive digital phenotypes based on smartphone keyboard backspace use among 128 community adults across 2948 observations using a Bayesian mixture model.

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Impulsivity can be a risk factor for serious complications for those with mood disorders. To understand intra-individual impulsivity variability, we analyzed longitudinal data of a novel gamified digital Go/No-Go (GNG) task in a clinical sample (n=43 mood disorder participants, n=17 healthy controls) and an open-science sample (n=121, self-reported diagnoses). With repeated measurements within-subject, we disentangled two aspects of GNG: reaction time and accuracy in response inhibition (i.

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Humans' complex behavior, such as speech, music, or dance, requires us to coordinate our actions with external sounds as well as with social partners. The presence of a partner can influence individuals' synchronization, and, in turn, social connection with the partner may depend on the degree of synchronization. We manipulated the synchronization quality in intervention conditions to address the causal relationship between observed temporal synchrony and perceived social interaction.

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We examine the feasibility of using accelerometer data exclusively collected during typing on a custom smartphone keyboard to study whether typing dynamics are associated with daily variations in mood and cognition. As part of an ongoing digital mental health study involving mood disorders, we collected data from a well-characterized clinical sample (N = 85) and classified accelerometer data per typing session into orientation (upright vs. not) and motion (active vs.

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Synchronization, the human tendency to align behaviors in time with others, is necessary for many survival skills. The ability to synchronize actions with rhythmic (predictable) sound patterns is especially well developed in music making. Recent models of synchrony in musical ensembles rely on pairwise comparisons between group members.

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The treatment of mood disorders, which can become a lifelong process, varies widely in efficacy between individuals. Most options to monitor mood rely on subjective self-reports and clinical visits, which can be burdensome and may not portray an accurate representation of what the individual is experiencing. A passive method to monitor mood could be a useful tool for those with these disorders.

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Objective: Examine the associations between smartphone keystroke dynamics and cognitive functioning among persons with multiple sclerosis (MS).

Methods: Sixteen persons with MS with no self-reported upper extremity or typing difficulties and 10 healthy controls (HCs) completed six weeks of remote monitoring of their keystroke dynamics (i.e.

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Important individual differences are observed in people's abilities to synchronize their body movements with regular auditory rhythms. We investigate whether synchronizing with a regular auditory cue is affected by each person's spontaneous production rate (SPR) and by hearing a partner's synchronization in a social context. Musically trained and untrained participants synchronized their tapping with an auditory cue presented at different rates (their own SPR or their partner's SPR) and in a Solo or Joint (turn-taking) condition.

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Humans tend to anticipate events when they synchronize their actions with sound (such as when they clap to music), which has puzzled scientists for decades. What accounts for this anticipation? We review two theoretical mechanisms for synchrony: predictive coding and dynamical systems. Both theories are grounded in neural activation patterns, but there are important distinctions.

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The causal relationship of interpersonal liking affecting interpersonal synchrony is inconsistently documented. This study tests whether (a) interpersonal liking increases both behavioural and perceived synchrony and (b) people will synchronise with an agreeable partner over a competing musical stimulus. We had college students ( = 25) shake an egg-shaker with an agreeable or disagreeable confederate without music, with music, and with specific instruction to synchronise.

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Research by our group and others have demonstrated the feasibility of using mobile phone derived metadata to model mood and cognition. Given the effects of age and mood on cognitive performance, it was hypothesized that using such data a model could be built to predict chronological age and that differences between predicted age and actual age could be a marker of pathology. These data were collected via the ongoing BiAffect study.

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Introduction: The parasympathetically derived marker of heart rate variability, root mean square of successive R-R differences (RMSSD), and the daily fluctuations as measured by the coefficient of variation (RMSSDCV) may be useful for tracking training adaptations in athletic populations. These vagally derived markers of heart rate variability may be especially pertinent when simultaneously considering a female athlete's menstrual cycle.

Purpose: The purpose of this study was to observe the perturbations in RMSSDCV, while considering RMSSD, across a season in the presence and absence of menses with training load in female collegiate rowers.

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Objective: The increase in smartphone usage has enabled the possibility of more accessible ways to conduct neuropsychological evaluations. The objective of this study was to determine the feasibility of using smartphone typing dynamics with mood scores to supplement cognitive assessment through trail making tests.

Methods: Using a custom-built keyboard, naturalistic keypress dynamics were unobtrusively recorded in individuals with bipolar disorder (n = 11) and nonbipolar controls (n = 8) on an Android smartphone.

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Interpersonal synchrony refers to the temporal coordination of actions between individuals and is a common feature of social behaviors, from team sport to ensemble music performance. Interpersonal synchrony of many rhythmic (periodic) behaviors displays dynamics of coupled biological oscillators. The current study addresses oscillatory dynamics on the levels of brain and behavior between music duet partners performing at spontaneous (uncued) rates.

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Background: Clinical research indicates that successful posttraumatic stress disorder (PTSD) treatment does not lead to improvements in alcohol use outcomes in comorbid PTSD and alcohol use disorder (AUD). Emerging theory suggests that treating PTSD may not disrupt an association between negative affect and alcohol craving, which underlies negative reinforcement drinking. The goal of the current study was to determine the respective influences of PTSD symptoms, coping motives, and negative affect on trauma and alcohol cue reactivity to inform theoretical models of co-occurring PTSD and AUD.

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Many studies of social perception and judgement have required individuals to make evaluations of social parameters based on static presentations of social stimuli. In the current study, we assessed whether individuals with a schizophrenia spectrum disorder and community controls differed in their judgements of others based on a series of computerized encounters designed to simulate impression formation over time. Twenty-eight community controls and 29 individuals with a schizophrenia spectrum disorder completed 25 gambling interactions with three different computer partners.

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The goal of the current research was to determine if conceptual metaphors are activated when people read idioms within a text. Participants read passages that included idioms that were consistent (blow your top) or inconsistent (bite his head off) with an underlying conceptual metaphor (ANGER IS HEATED FLUID IN A CONTAINER) followed by target words that were related (heat) or unrelated (lead) to the conceptual metaphor. Reading time (Experiment 1) or lexical decision time (Experiment 2) for the target words were measured.

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Despite support for the role of self-medication alcohol use in the etiology and maintenance of comorbid posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD), theoretical and empirical models of PTSD-AUD rarely account for the role of common comorbidities in risk processes, such as major depressive disorder (MDD). The current study examined the main and interactive effects of PTSD and depressive symptoms on patterns of trauma and alcohol cue reactivity to elucidate potential influences of depression on conditioned craving responses to trauma memories. It was hypothesized that depressive symptoms would be associated with greater cue reactivity (i.

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Objective: Ubiquitous technologies can be leveraged to construct ecologically relevant metrics that complement traditional psychological assessments. This study aims to determine the feasibility of smartphone-derived real-world keyboard metadata to serve as digital biomarkers of mood.

Materials And Methods: BiAffect, a real-world observation study based on a freely available iPhone app, allowed the unobtrusive collection of typing metadata through a custom virtual keyboard that replaces the default keyboard.

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To understand how individuals adapt to and anticipate each other in joint tasks, we employ a bidirectional delay-coupled dynamical system that allows for mutual adaptation and anticipation. In delay-coupled systems, anticipation is achieved when one system compares its own time-delayed behavior, which implicitly includes past information about the other system's behavior, with the other system's instantaneous behavior. Applied to joint music performance, the model allows each system to adapt its behavior to the dynamics of the other.

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A major question facing cognitive neuroscience is measurement of interbrain synchrony between individuals performing joint actions. We describe the application of a novel method for measuring musicians' interbrain synchrony: amplitude envelope correlations (AECs). Amplitude envelopes (AEs) reflect energy fluctuations in cortical oscillations over time; AE correlations measure the degree to which two envelope fluctuations are temporally correlated, such as cortical oscillations arising from two individuals performing a joint action.

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The target article makes the important case for making replicability mainstream. Yet, their proposal targets a symptom, rather than the underlying cause of low replication rates. We argue that psychological scientists need to devise stronger theories that are more clearly falsifiable.

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Although music performance has been widely studied in the behavioural sciences, less work has addressed the underlying neural mechanisms, perhaps due to technical difficulties in acquiring high-quality neural data during tasks requiring natural motion. The advent of wireless electroencephalography (EEG) presents a solution to this problem by allowing for neural measurement with minimal motion artefacts. In the current study, we provide the first validation of a mobile wireless EEG system for capturing the neural dynamics associated with piano performance.

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