A Multivariate Method for Dynamic System Analysis: Multivariate Detrended Fluctuation Analysis Using Generalized Variance

Authorea Preprints

The surgical procedure or Deep Brain Stimulation (DBS) is an established technique aimed at neuromodulation and is most often used for treating neurological and neuropsychiatric disorders. In clinical studies, Magnetoencephalography (MEG) is a widely used technique for characterizing the effects of Deep Brain Stimulation (DBS). A significant limitation of DBS stimulation is the inability to distinguish stimulation artifacts from actual neuronal activity, especially in the lower frequencies, where it may obscure the biological response and be a confounding factor. This paper aims to understand how to circumvent the DBS artifactual component in the summary metrics of DBS-corrupted MEG data. To do the same, we used a watermelon as a phantom model of the head to deploy DBS electrodes. The spectral signature of the artifactual component of DBS and it's power in different clinically significant bands of interest …

European Journal of Neuroscience

The pleasurable urge to move to music (PLUMM) activates motor and reward areas of the brain and is thought to be driven by predictive processes. Dopamine in motor and limbic networks is implicated in beat‐based timing and music‐induced pleasure, suggesting a central role of basal ganglia (BG) dopaminergic systems in PLUMM. This study tested this hypothesis by comparing PLUMM in participants with Parkinson's disease (PD), age‐matched controls, and young controls. Participants listened to musical sequences with varying rhythmic and harmonic complexity (low, medium and high), and rated their experienced pleasure and urge to move to the rhythm. In line with previous results, healthy younger participants showed an inverted U‐shaped relationship between rhythmic complexity and ratings, with preference for medium complexity rhythms, while age‐matched controls showed a similar, but weaker …

Closed form power estimation is only available for limited classes of models, requiring correct model specification for most applications. Simulation is used in other scenarios, but a general framework in computing required sample sizes for given power rates is still missing. We propose a new model-implied simulation-based power estimation (MSPE) method that makes use of the asymptotic normality property of estimates of a wide class of estimators, the M-estimators, and we give theoretical justification for the approach. M-estimators include maximum-likelihood estimates and least squares estimates, but also limited information estimators and estimators used for misspecified models, hence, the new power modeling method is widely applicable. We highlight its performance for linear and nonlinear structural equation models (SEM) and a moderated logistic regression model for correctly specified models and models under distributional misspecification. Simulation results suggest that the new power modeling method is unbiased and shows good performance with regard to root mean squared error and Type I error rates for the predicted required sample sizes and predicted power rates. Alternative approaches, such as the naıve approach of selecting arbitrary sample sizes with linear interpolation of power or simple logistic regression approaches, showed poor performance. The MSPE appears to be a valuable tool to estimate power for models without (asymptotic) analytical power estimation.

Cochlear implants (CIs) are optimized for speech perception but poor in conveying musical sound features such as pitch, melody, and timbre. Here, we investigated the early development of discrimination of musical sound features after cochlear implantation. Nine recently implanted CI users (CIre) were tested shortly after switch-on (T1) and approximately 3 months later (T2), using a musical multifeature mismatch negativity (MMN) paradigm, presenting four deviant features (intensity, pitch, timbre, and rhythm), and a three-alternative forced-choice behavioral test. For reference, groups of experienced CI users (CIex; n = 13) and normally hearing (NH) controls (n = 14) underwent the same tests once. We found significant improvement in CIre's neural discrimination of pitch and timbre as marked by increased MMN amplitudes. This was not reflected in the behavioral results. Behaviorally, CIre scored well above …

Journal of Occupational and Organizational Psychology

Job crafting refers to the self‐initiated work behaviours employees use to change their job characteristics. According to job design theory, these crafting‐induced changes in job characteristics should impact employee outcomes. Job characteristics can therefore be proposed as a key mechanism through which job crafting affects employee outcomes and we present cross‐sectional meta‐analytic structural equation modelling of this key mechanism (K = 58 independent samples, N = 20,347 employees). Results show significant indirect effects between task resource crafting and employee outcomes (well‐being and positive job attitudes) via task resources, and significant indirect effects between social job crafting and employee outcomes (well‐being and positive job attitudes) via social resources. Results also indicated that challenge and hindrance demand crafting increase job strain via increases in job demand …

Neuropsychologia

Language is a key part of human cognition, essential for our well-being at all stages of our lives. Whereas many neurocognitive abilities decline with age, for language the picture is much less clear, and how exactly speech comprehension changes with ageing is still unknown. To investigate this, we employed magnetoencephalography (MEG) and recorded neuromagnetic brain responses to auditory linguistic stimuli in healthy participants of younger and older age using a passive task-free paradigm and a range of different linguistic stimulus contrasts, which enabled us to assess neural processing of spoken language at multiple levels (lexical, semantic, morphosyntactic). Using machine learning-based classification algorithms to scrutinise intertrial phase coherence of MEG responses in cortical source space, we found that patterns of oscillatory neural activity diverged between younger and older participants across …

• Significant main effect of rhythm on urge to move and pleasure ratings, no significant main effect of group• Rhythm by group interaction observed for both ratings• Urge to move and pleasure ratings correlated across groups• Averaged PLUMM ratings show significant main effect of rhythm, no significant main effect of group, and a rhythm by group interaction

RESULTS Alberte B. Seeberg1, Tomas E. Matthews1, Andreas Højlund2, Peter Vuust1, Bjørn Petersen1 INTRODUCTION DISCUSSION METHO

Cortex; a journal devoted to the study of the nervous system and behavior

No selective action verb impairment in patients with Parkinson's disease: Evidence from Danish patients reading naturalistic texts, a Commentary on García et al., 2018 No selective action verb impairment in patients with Parkinson's disease: Evidence from Danish patients reading naturalistic texts, a Commentary on García et al., 2018 Cortex. 2023 Jan:158:176-180. doi: 10.1016/j.cortex.2022.07.006. Epub 2022 Sep 10. Authors Marie Louise Holm Møller 1 , Sabine Hagen Høj 2 , Karen Østergaard 3 , Mikkel Wallentin 2 , Andreas Højlund 4 Affiliations 1 Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Denmark; Dept. of Linguistics, Cognitive Science and Semiotics, Aarhus University, Denmark. Electronic address: marielouise@cfin.au.dk. 2 Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Denmark; …

International Journal of Clinical and Health Psychology

Background/objectivePatients with major depressive disorder (MDD) have altered learning rates for rewards and losses in non-social learning paradigms. However, it is not well understood whether the ability to learn from social interactions is altered in MDD patients. Using reinforcement learning during the repeated Trust Game (rTG), we investigated how MDD patients learn to trust newly-met partners in MDD patients.MethodSixty-eight MDD patients and fifty-four controls each played as ‘investor’ and interacted with ten different partners. We manipulated both the level of trustworthiness by varying the chance of reciprocity (10, 30, 50, 70 and 90%) and reputation disclosure, where partners’ reputation was either pre-disclosed or hidden.ResultsOur reinforcement learning model revealed that MDD patients had significantly higher learning rates for losses than the controls in both the reputation disclosure and non …

Beyond syncopation: the importance of rhythmic streams for the experience of groove — Aarhus University Skip to main navigation Skip to search Skip to main content Aarhus University Home Aarhus University Logo Help & FAQ English Dansk Home Profiles Research units Projects Research output Prizes Activities Courses Press/Media Search by expertise, name or affiliation Beyond syncopation: the importance of rhythmic streams for the experience of groove Alberte Baggesgaard Seeberg, Tomas Matthews, Andreas Højlund, Bjørn Petersen, Peter Vuust Department of Clinical Medicine - Center for Music In the Brain School of Communication and Culture - Cognitive Science Research output: Contribution to conference › Poster › Research › peer-review Overview Original language English Publication date 27 Aug 2023 Publication status Published - 27 Aug 2023 Event 17th International Conference on Music …

Parkinson’s disease is caused by degeneration of dopaminergic neurons, originating in the substantia nigra pars compacta and characterised by bradykinesia, rest tremor and rigidity. In addition, visual disorders and retinal abnormalities are often present and can be identified by decreased visual acuity, abnormal spatial contrast sensitivity or even difficulty in complex visual task completion. Because of their early onset in patients with de novo Parkinson’s disease, the anatomical retinal changes and electrophysiological modification could be valuable markers even at early stages of the disease. However, due to the concomitant occurrence of normal ageing, the relevance and specificity of these predictive values can be difficult to interpret. This review examines retinal dysfunction arising in Parkinson’s disease. We highlight the electrophysiological delays and decreased amplitude in the electroretinography …

Deep brain stimulation (DBS) is a therapeutic treatment used in pathological conditions, which is known to improve clinical state, but the effect-mechanisms are unclear. The electrophysiological study of effect-mechanisms is complicated by strong artifactual components blurring the boundary between brain activity and DBS-induced noise. To study the artifactual signatures and the effect of pre-processing steps such as spatiotemporal signal space separation (tSSS) and normalization on the DBS-corrupted MEG data, we deployed a watermelon-based phantom ‘implanted’ with DBS leads and stimulated the phantom with various DBS stimulation settings. We observe that tSSS can lead to a ‘spillover’ of artifacts between sensor types and bipolar stimulation leads to lower sub-harmonic (20 Hz) artifacts compared to monopolar stimulation. Normalized spectra, we show here, can be biased if artifactual spectral bins are …

bioRxiv

Our brain is constantly extracting, predicting, and recognising key spatiotemporal features of the physical world in order to survive. While neural processing of visuospatial patterns has been extensively studied, the hierarchical brain mechanisms underlying conscious recognition of auditory sequences and the associated prediction errors remain elusive. Using magnetoencephalography (MEG), we studied the brain functioning of 83 participants during recognition of previously memorised musical sequences and systematic variations. The results showed feedforward connections originating from auditory cortices, and extending to the hippocampus, anterior cingulate gyrus, and medial cingulate gyrus. Simultaneously, we observed backward connections operating in the opposite direction. Throughout the sequences, the hippocampus and cingulate gyrus maintained the same hierarchical level, except for the final tone, where the cingulate gyrus assumed the top position within the hierarchy. The evoked responses of memorised sequences and variations engaged the same hierarchical brain network but systematically differed in terms of temporal dynamics, strength, and polarity. Furthermore, induced-response analysis showed that alpha and beta power was stronger for the variations, while gamma power was enhanced for the memorised sequences. This study expands on the predictive coding theory by providing quantitative evidence of hierarchical brain mechanisms during conscious memory and predictive processing of auditory sequences.

Feel the beat and improve the groove: multimodal rhythm perception in cochlear implant users — Aarhus University Skip to main navigation Skip to search Skip to main content Aarhus University Home Aarhus University Logo Help & FAQ English Dansk Home Profiles Research units Projects Research output Prizes Activities Courses Press/Media Search by expertise, name or affiliation Feel the beat and improve the groove: multimodal rhythm perception in cochlear implant users Alberte Baggesgaard Seeberg, Peter Vuust, Andreas Højlund, Mark Fletcher, Samuel Perry, Kathleen F. Faulkner, Bjørn Petersen Department of Clinical Medicine - Center for Music In the Brain School of Communication and Culture - Cognitive Science Research output: Contribution to conference › Poster › Research › peer-review Overview Original language English Publication date May 2022 Publication status Published - May 2022 Event …

ObjectiveBipolar disorder is characterized by aberrant neurophysiological responses as measured with electroencephalography (EEG) and magnetoencephalography (MEG), including the 40-Hz auditory steady-state response (ASSR). 40-Hz ASSR deficits are also found in patients with schizophrenia and may represent a transdiagnostic biomarker of neuronal circuit dysfunction. In this systematic review and meta-analysis, we summarize and evaluate the evidence for 40-Hz ASSR deficits in patients with bipolar disorder.MethodsWe identified studies from PubMed, EMBASE, and SCOPUS. We assessed the risk of bias, calculated Hedges’ g meta-level effect sizes, and investigated small-study effects using funnel plots and Egger regression.ResultsSeven studies, comprising 396 patients with bipolar disorder and 404 healthy controls, were included in the meta-analysis. Studies displayed methodological …

European Psychiatry

IntroductionSchizophrenia (SZ) and bipolar disorder (BD) are severe mental illnesses with large overlapping heritability. Both disorders are associated with altered neurophysiological responses, as measured with magnetoencephalography (MEG) or electroencephalography (EEG), particularly reduced mismatch negativity (MMN) and 40 Hz auditory steady-state responses (ASSR). These deficits could potentially both serve as early markers of illness and provide insight into the underlying pathophysiology as endophenotypes. First-degree relatives to patients with SZ and BD also show some neurophysiological deficits, however whether these deficits can be detected in adolescent offspring of patients is undetermined.ObjectivesWe aim to investigate whether adolescents at familial high risk of schizophrenia and bipolar disorder show aberrant MMN and ASSR compared to population-based controls.MethodsWe will …

Topics in Cognitive Science

Successful spoken discourse requires a speaker to be informative to deliver a coherent, meaningful message. The informativeness of discourse can be conveyed by the variety of vocabulary produced (i.e., lexical diversity [LD]), the typicality of vocabulary items used (i.e., core lexicon [CL]), and the amount of relevant content produced (i.e., information units). Yet, it is well documented that older adults produce less informative content compared to younger adults despite relatively subtle changes to LD. The typicality of core lexical items has not been assessed in healthy aging. Paradoxically, these results indicate that some aspects of discourse informativeness remain stable or even improve across the adult lifespan, while other aspects decline. The purpose of the current study is to understand how microlinguistic processes of informativeness change across the adult lifespan. The cross‐sectional study included …

Topics in Cognitive Science

Collaboration requires agents to coordinate their behavior on the fly, sometimes cooperating to solve a single task together and other times dividing it up into sub‐tasks to work on in parallel. Underlying the human ability to collaborate is theory‐of‐mind (ToM), the ability to infer the hidden mental states that drive others to act. Here, we develop Bayesian Delegation, a decentralized multi‐agent learning mechanism with these abilities. Bayesian Delegation enables agents to rapidly infer the hidden intentions of others by inverse planning. We test Bayesian Delegation in a suite of multi‐agent Markov decision processes inspired by cooking problems. On these tasks, agents with Bayesian Delegation coordinate both their high‐level plans (e.g., what sub‐task they should work on) and their low‐level actions (e.g., avoiding getting in each other's way). When matched with partners that act using the same algorithm …

Topics in Cognitive Science

As organizations gravitate to group‐based structures, the problem of improving performance through judicious selection of group members has preoccupied scientists and managers alike. However, which individual attributes best predict group performance remains poorly understood. Here, we describe a preregistered experiment in which we simultaneously manipulated four widely studied attributes of group compositions: skill level, skill diversity, social perceptiveness, and cognitive style diversity. We find that while the average skill level of group members, skill diversity, and social perceptiveness are significant predictors of group performance, skill level dominates all other factors combined. Additionally, we explore the relationship between patterns of collaborative behavior and performance outcomes and find that any potential gains in solution quality from additional communication between the group members …

Topics in Cognitive Science

One of the most heated debates in psychological science concerns the concept of repressed memory. We discuss how the debate on repressed memories continues to surface in legal settings, sometimes even to suggest avenues of legal reform. In the past years, several European countries have extended or abolished the statute of limitations for the prosecution of sexual crimes. Such statutes force legal actions (e.g., prosecution of sexual abuse) to be applied within a certain period of time. One of the reasons for the changes in statutes of limitations concerns the idea of repressed memory. We argue that from a psychological standpoint, these law reforms can be detrimental, particularly when they are done to endorse unfounded psychological theories. The validity of testimonies is compromised many years after the alleged facts, and abolishing the statute of limitations increases the chance that even more (false …

Topics in Cognitive Science

One of the most heated debates in psychological science concerns the concept of repressed memory. We discuss how the debate on repressed memories continues to surface in legal settings, sometimes even to suggest avenues of legal reform. In the past years, several European countries have extended or abolished the statute of limitations for the prosecution of sexual crimes. Such statutes force legal actions (e.g., prosecution of sexual abuse) to be applied within a certain period of time. One of the reasons for the changes in statutes of limitations concerns the idea of repressed memory. We argue that from a psychological standpoint, these law reforms can be detrimental, particularly when they are done to endorse unfounded psychological theories. The validity of testimonies is compromised many years after the alleged facts, and abolishing the statute of limitations increases the chance that even more (false …

Topics in Cognitive Science

Motivation is the driving force that influences people's behaviors and interacts with many cognitive functions. Computationally, motivation is represented as a cost−benefit analysis that weighs efforts and rewards in order to choose the optimal actions. Shenhav and colleagues proposed an elegant theory, the Expected Value of Control (EVC), which describes the relationship between cognitive efforts, costs, and rewards. In this paper, we propose a more fine‐grained and detailed motivation framework that incorporates the principles of EVC into the ACT‐R cognitive architecture. Specifically, motivation is represented as a specific slot in the Goal buffer with a corresponding scalar value, M, that is translated into the reward value Rt that is delivered when the goal is reached. This implementation is tested in two models. The first model is a high‐level model that reproduces the EVC predictions with abstract actions. The …

Topics in Cognitive Science

Decades of research have established that learners benefit when instruction includes hand gestures. This benefit is seen when learners watch an instructor gesture, as well as when they are taught or encouraged to gesture themselves. However, there is substantial individual variability with respect to this phenomenon—not all individuals benefit equally from gesture instruction. In the current paper, we explore the sources of this variability. First, we review the existing research on individual differences that do or do not predict learning from gesture instruction, including differences that are either context‐dependent (linked to the particular task at hand) or context‐independent (linked to the learner across multiple tasks). Next, we focus on one understudied measure of individual difference: the learner's own spontaneous gesture rate. We present data showing rates of “non‐gesturers” across a number of studies and we …

Topics in Cognitive Science

Adverse early life experiences can have remarkably enduring negative consequences on mental health, with numerous, varied psychiatric conditions sharing this developmental origin. Yet, the mechanisms linking adverse experiences to these conditions remain poorly understood. Here, we draw on a principled model of interval timing to propose that statistically optimal adaptation of temporal representations to an unpredictable early life environment can produce key characteristics of anhedonia, a transdiagnostic symptom associated with affective disorders like depression and anxiety. The core observation is that early temporal unpredictability produces broader, more imprecise temporal expectations. As a result, reward anticipation is diminished, and associative learning is slowed. When agents with such representations are later introduced to more stable environments, they demonstrate a negativity bias …

Topics in Cognitive Science

I present a computational‐level model of language production in terms of a combination of information theory and control theory in which words are chosen incrementally in order to maximize communicative value subject to an information‐theoretic capacity constraint. The theory generally predicts a tradeoff between ease of production and communicative accuracy. I apply the theory to two cases of apparent availability effects in language production, in which words are selected on the basis of their accessibility to a speaker who has not yet perfectly planned the rest of the utterance. Using corpus data on English relative clause complementizer dropping and experimental data on Mandarin noun classifier choice, I show that the theory reproduces the observed phenomena, providing an alternative account to Uniform Information Density and a promising general model of language production which is tightly linked to …

Topics in Cognitive Science

Over two decades have passed since the publication of van Gelder's (1998) “dynamical hypothesis.” In that paper, van Gelder proposed that cognitive agents were not digital computers—per the representational computational approach—but dynamical systems. The evolution of the dynamical hypothesis was driven by parallel advances in three areas. Theoretically, a deeper understanding of genetics, biology, neuroscience, and cognitive science inspired questions about how systems within each domain dynamically interact and extend their effects across spatiotemporal scales. Methodologically, more sophisticated and domain‐general tools allowed researchers to discover, model, and quantify system dynamics, structure, and patterns across multiple scales to generate a more comprehensive system‐level understanding of behaviors. Empirically, we can analyze a system's behavior while preserving its natural …

Topics in Cognitive Science

Over two decades have passed since the publication of van Gelder's (1998) “dynamical hypothesis.” In that paper, van Gelder proposed that cognitive agents were not digital computers—per the representational computational approach—but dynamical systems. The evolution of the dynamical hypothesis was driven by parallel advances in three areas. Theoretically, a deeper understanding of genetics, biology, neuroscience, and cognitive science inspired questions about how systems within each domain dynamically interact and extend their effects across spatiotemporal scales. Methodologically, more sophisticated and domain‐general tools allowed researchers to discover, model, and quantify system dynamics, structure, and patterns across multiple scales to generate a more comprehensive system‐level understanding of behaviors. Empirically, we can analyze a system's behavior while preserving its natural …

Topics in Cognitive Science

Performance on the psychomotor vigilance test (PVT; Dinges & Powell, 1985)—a common index of sustained attention—is affected by the opposing forces of fatigue and sustained effort, where reaction times and error rates typically increase across trials and are sometimes offset by additional efforts deployed toward the end of the task (i.e., an “end‐spurt”; cf. Bergum & Klein, 1961). In ACT‐R (Adaptive Control of Thought‐Rational; Anderson et al., 2004), these influences on task performance have been modeled as latent variables that are inferred from performance (e.g., Jongman, 1998; Veksler & Gunzelmann, 2018) without connections to directly observable variables. We propose the use of frontal gamma (γ) spectral power as a direct measure of vigilant effort and demonstrate its efficacy in modeling performance on the PVT in both the aggregate and in individuals.

Topics in Cognitive Science

One of the most heated debates in psychological science concerns the concept of repressed memory. We discuss how the debate on repressed memories continues to surface in legal settings, sometimes even to suggest avenues of legal reform. In the past years, several European countries have extended or abolished the statute of limitations for the prosecution of sexual crimes. Such statutes force legal actions (e.g., prosecution of sexual abuse) to be applied within a certain period of time. One of the reasons for the changes in statutes of limitations concerns the idea of repressed memory. We argue that from a psychological standpoint, these law reforms can be detrimental, particularly when they are done to endorse unfounded psychological theories. The validity of testimonies is compromised many years after the alleged facts, and abolishing the statute of limitations increases the chance that even more (false …

Topics in Cognitive Science

This paper presents two studies in which a peer‐assisted learning condition was compared to an individual learning condition. The first study used the paired‐associates learning task and the second study used an incrementally more complex task—the remote associate test. Participants in the peer‐assisted learning condition worked in groups of four. They had to solve a given problem individually and give a first answer before being able to request to see their peers’ solutions; then, a second answer was issued. After six sessions of peer‐assisted practice, a final individual test was administered. Peer interaction was found to benefit learning in both studies but the benefit transferred to the final test only in the second study. Fine‐grained behavioral analyses and computational modeling suggested that the benefits of peer interaction were (partially) offset by its costs, particularly increased cognitive load and error …

Topics in Cognitive Science

Successful spoken discourse requires a speaker to be informative to deliver a coherent, meaningful message. The informativeness of discourse can be conveyed by the variety of vocabulary produced (i.e., lexical diversity [LD]), the typicality of vocabulary items used (i.e., core lexicon [CL]), and the amount of relevant content produced (i.e., information units). Yet, it is well documented that older adults produce less informative content compared to younger adults despite relatively subtle changes to LD. The typicality of core lexical items has not been assessed in healthy aging. Paradoxically, these results indicate that some aspects of discourse informativeness remain stable or even improve across the adult lifespan, while other aspects decline. The purpose of the current study is to understand how microlinguistic processes of informativeness change across the adult lifespan. The cross‐sectional study included …

Topics in Cognitive Science

As organizations gravitate to group‐based structures, the problem of improving performance through judicious selection of group members has preoccupied scientists and managers alike. However, which individual attributes best predict group performance remains poorly understood. Here, we describe a preregistered experiment in which we simultaneously manipulated four widely studied attributes of group compositions: skill level, skill diversity, social perceptiveness, and cognitive style diversity. We find that while the average skill level of group members, skill diversity, and social perceptiveness are significant predictors of group performance, skill level dominates all other factors combined. Additionally, we explore the relationship between patterns of collaborative behavior and performance outcomes and find that any potential gains in solution quality from additional communication between the group members …

Topics in Cognitive Science

Children's testimonial learning often occurs in epistemic collaborations with others. In this paper, we will discuss ways in which cultural learning emerges in social and interpersonal contexts, and is intrinsically supported and guided by children's collaborative capacities. Much work in cultural learning has focused on children's examination of speaker and model characteristics, but more recent research has investigated the interactive aspects of testimonial exchanges. We will review evidence that children (1) participate in the interpersonal commitments that are shared in testimonial transactions by way of direct address and epistemic buck passing, (2) participate in social groups that affect their selective learning in nuanced ways, and (3) may detect epistemic harms by listeners who refuse to believe sincere and accurate speakers. Implications for conceptualizing children's testimonial learning as an interactive …

Topics in Cognitive Science

Ruminative thinking, characterized by a recurrent focus on negative and self‐related thought, is a key cognitive vulnerability marker of depression and, therefore, a key individual difference variable. This study aimed to develop a computational cognitive model of rumination focusing on the organization and retrieval of information in memory, and how these mechanisms differ in individuals prone to rumination and individuals less prone to rumination. Adaptive Control of Thought‐Rational (ACT‐R) was used to develop a rumination model by adding memory chunks with negative valence to the declarative memory. In addition, their strength of association was increased to simulate recurrent negative focus, thereby making it harder to disengage from. The ACT‐R models were validated by comparing them against two empirical datasets containing data from control and depressed participants. Our general and …

Topics in Cognitive Science

Collaboration requires agents to coordinate their behavior on the fly, sometimes cooperating to solve a single task together and other times dividing it up into sub‐tasks to work on in parallel. Underlying the human ability to collaborate is theory‐of‐mind (ToM), the ability to infer the hidden mental states that drive others to act. Here, we develop Bayesian Delegation, a decentralized multi‐agent learning mechanism with these abilities. Bayesian Delegation enables agents to rapidly infer the hidden intentions of others by inverse planning. We test Bayesian Delegation in a suite of multi‐agent Markov decision processes inspired by cooking problems. On these tasks, agents with Bayesian Delegation coordinate both their high‐level plans (e.g., what sub‐task they should work on) and their low‐level actions (e.g., avoiding getting in each other's way). When matched with partners that act using the same algorithm …

Topics in Cognitive Science

Humans routinely form groups to achieve goals that no individual can accomplish alone. Group coordination often brings to mind synchrony and alignment, where all individuals do the same thing (e.g., driving on the right side of the road, marching in lockstep, or playing musical instruments on a regular beat). Yet, effective coordination also typically involves differentiation, where specialized roles emerge for different members (e.g., prep stations in a kitchen or positions on an athletic team). Role specialization poses a challenge for computational models of group coordination, which have largely focused on achieving synchrony. Here, we present the CARMI framework, which characterizes role specialization processes in terms of five core features that we hope will help guide future model development: Communication, Adaptation to feedback, Repulsion, Multi‐level planning, and Intention modeling. Although there …