Continuous Behavioural Measures Research Articles

From pre-processing to advanced dynamic modeling of pupil data

The pupil of the eye provides a rich source of information for cognitive scientists, as it can index a variety of bodily states (e.g., arousal, fatigue) and cognitive processes (e.g., attention, decision-making). As pupillometry becomes a more accessible and popular methodology, researchers have proposed a variety of techniques for analyzing pupil data. Here, we focus on time series-based, signal-to-signal approaches that enable one to relate dynamic changes in pupil size over time with dynamic changes in a stimulus time series, continuous behavioral outcome measures, or other participants’ pupil traces. We first introduce pupillometry, its neural underpinnings, and the relation between pupil measurements and other oculomotor behaviors (e.g., blinks, saccades), to stress the importance of understanding what is being measured and what can be inferred from changes in pupillary activity. Next, we discuss possible pre-processing steps, and the contexts in which they may be necessary. Finally, we turn to signal-to-signal analytic techniques, including regression-based approaches, dynamic time-warping, phase clustering, detrended fluctuation analysis, and recurrence quantification analysis. Assumptions of these techniques, and examples of the scientific questions each can address, are outlined, with references to key papers and software packages. Additionally, we provide a detailed code tutorial that steps through the key examples and figures in this paper. Ultimately, we contend that the insights gained from pupillometry are constrained by the analysis techniques used, and that signal-to-signal approaches offer a means to generate novel scientific insights by taking into account understudied spectro-temporal relationships between the pupil signal and other signals of interest.

Audience immersion: validating attentional and physiological measures against self-report

When an audience member becomes immersed, their attention shifts towards the media and story, and they allocate cognitive resources to represent events and characters. Here, we investigate whether it is possible to measure immersion using continuous behavioural and physiological measures. Using television and film clips, we validated dual-task reaction times, heart rate, and skin conductance against self-reported narrative engagement. We find that reaction times to a secondary task were strongly positively correlated with self-reported immersion: slower reaction times were indicative of greater immersion, particularly emotional engagement. Synchrony in heart rate across participants was associated with self-reported attentional and emotional engagement with the story, although we found no such relationship with skin conductance. These results establish both dual-task reaction times and heart rate as candidate measures for the real-time, continuous, assessment of audience immersion.

Behavior and wear of the hooves of confined sheep in different types of floors

The objective of this work was to evaluate the thermal environment, the surface temperature of the floor, wear of the hooves, ingestive behavior, and the productive performance of Santa Inês sheep, confined in facilities with individual pen, with three types of floor (masonry, rubber, and sand). The research was developed in the dry period in the Brazilian Semiarid region, using 18 females with 120 days of age and weighing 21.33 ± 2.62 kg. It was used a completely randomized design with three treatments and six replications. A 3 × 4 factorial was used for the surface temperature, with three types of floor and four collection times, applying the Tukey test at 5% probability and regression analysis by the SAS software. For the morphometric measures, ingestive behavior, and performance of the animals, the Tukey test at 5% was applied through the PROC GLM, and the continuous behavioral measures had their frequencies compared by the Chi-square test at the level of 5% through the PROC FREQ. The sand floor had the highest surface temperature concerning the other floors, regardless of the time. The animals kept on the masonry floor had a reduction of 6.17 and 5.56 cm in the upper length of the front hull and a reduction of 3.37 and 3.36 cm in the rear hull, respectively. The ingestive behavior and performance of the animals (90 g animal-1 day-1) were not affected by the type of floor used.

Tracking continuities in the flanker task: From continuous flow to movement trajectories.

Since its introduction nearly a half century ago, the Eriksen flanker task has prompted multiple theoretical and methodological advancements in the study of attention and control. Early research with the task inspired the continuous flow model of information processing, which in turn prompted researchers to investigate the dynamics of response competition using continuous behavioral measures. In recent years, the use of such measures in psychological research has increased dramatically as hand-tracking techniques have become more widely accessible. The current article highlights commonly overlooked links between Eriksen and colleagues' pioneering research investigating the continuous flow model and recent hand-tracking research investigating the dynamics of attention and control. After providing an overview of two hand-tracking techniques frequently used in psychological research, we review a series of recent studies that have used these techniques to investigate how the processes underlying attention and control (a) unfold over the course of a response (within-trial dynamics), (b) are impacted by recent experience (cross-trial dynamics), and (c) contribute to age-related changes observed across the life span (developmental dynamics). In addition to highlighting the central role that the flanker task has played in advancing psychological research and theory, this review underscores the advantages of collecting continuous behavioral measures, both in Eriksen's seminal work and in contemporary hand-tracking studies.

Beyond diagnosis: Cross-diagnostic features in canonical resting-state networks in children with neurodevelopmental disorders

Children with neurodevelopmental disorders (NDDs) share common behavioural manifestations despite distinct categorical diagnostic criteria. Here, we examined canonical resting-state network connectivity in three diagnostic groups (autism spectrum disorder, attention-deficit/hyperactivity disorder and paediatric obsessive–compulsive disorder) and typically developing controls (TD) in a large single-site sample (N = 407), applying diagnosis-based and dimensional approaches to understand underlying neurobiology across NDDs. Each participant’s functional network graphs were computed using five graph metrics. In diagnosis-based comparisons, an analysis of covariance was performed to compare all NDDs to TD, followed by pairwise comparisons between NDDs. In the dimensional approach, participants’ functional network graphs were correlated with continuous behavioural measures, and a data-driven k-means clustering analysis was applied to determine if subgroups of participants were seen, without diagnostic information having been included. In the diagnosis-based comparisons, children with NDDs did not differ significantly from the TD group and the NDD categorical groups also did not differ significantly from each other, across all graph metrics. In the dimensional, diagnostic-independent approach, however, subcortical functional connectivity was significantly correlated with participants’ general adaptive functioning across all participants. The clustering analysis identified an optimal solution of two clusters, and participants assigned in the same data-driven cluster were highly heterogeneous in diagnosis. Neither cluster exclusively contained a specific diagnostic group, nor did NDDs separate cleanly from TDs. Each participant’s distance ratio between the two clusters was significantly correlated with general adaptive functioning, social deficits and attentional problems. Our results suggest the neurobiological similarity and dissimilarity between NDDs need to be investigated beyond DSM/ICD-based, behaviourally-defined diagnostic categories.

Step by step: Harvesting the dynamics of delay discounting decisions.

People show a tendency to devalue rewards when they are delayed in time. This so-called delay discounting often happens to an extent that seems irrational from an economical perspective. Research studying outcomes of delay discounting decisions has successfully derived descriptive models for such choice preferences. However, this outcome-based approach faces limitations in integrating the influence of contextual factors on the decision. Recently, this outcome-centred perspective on delay discounting has been complemented by a focus on the process dynamics leading to delay discounting decisions. Here, we embrace and add to this approach: We show how an attractor model can extend discounting descriptive discounting curves into the temporal dimension. From the model, we derive three predictions and study the predictions in a delay discounting experiment based on mouse tracking. We find differences in discounting depending on the order of option presentation and more direct movements to options presented first. Together with the analysis of specific temporal patterns of information integration, these results show that considering the continuous process dynamics of delay discounting decisions and harvesting them with continuous behavioural measures allow the integration of contextual factors into existing models of delay discounting, not as noise but as a signal on their own.

The effects of phonological similarity on the semantic categorisation of pictorial and lexical stimuli: evidence from continuous behavioural measures

ABSTRACTBehavioural and neuroimaging studies provide evidence of automatic activation of phonology (e.g., covert speech) during the recognition of lexical stimuli. Implicit processing of phonological information was investigated in a kinematic study of semantic categorisation of pictures (session A) or words (session B). Participants clicked one of two items (target and distractor) based on their semantic congruency (artefact or natural) with a cued-word. Phonological similarity between cued-word and distractor was varied. The presence of the phonological distractor produced trajectories with greater curvature towards the competing semantic category than did the presence of a distractor not phonologically related. This suggests that the semantic categorisation of pictorial and lexical stimuli is influenced by the automatic activation of phonological information. Trajectories’ curvature reveals competition between partially activated phonological and semantic representations suggesting that phonological codes involved in linguistic processing influence the dynamic competition underlying the semantic categorisation of lexical and pictorial.

Using affective and behavioural sensors to explore aspects of collaborative music making

Our research considers the role that new technologies could play in supporting emotional and non-verbal interactions between musicians during co-present music making. To gain a better understanding of the underlying affective and communicative processes that occur during such interactions, we carried out an exploratory study where we collected self-report and continuous behavioural and physiological measures from pairs of improvising drummers. Our analyses revealed interesting relationships between creative decisions and changes in heart rate. Self-reported measures of creativity, engagement, and energy were correlated with body motion; whilst EEG beta-band activity was correlated with self-reported positivity and leadership. Regarding co-visibility, lack of visual contact between musicians had a negative influence on self reported creativity. The number of glances between musicians was positively correlated with rhythmic synchrony, and the average length of glances was correlated with self-reported boredom. Our results indicate that ECG, motion, and glance measurements could be particularly suitable for the investigation of collaborative music making.

Estimating latent attentional states based on simultaneous binary and continuous behavioral measures.

Cognition is a complex and dynamic process. It is an essential goal to estimate latent attentional states based on behavioral measures in many sequences of behavioral tasks. Here, we propose a probabilistic modeling and inference framework for estimating the attentional state using simultaneous binary and continuous behavioral measures. The proposed model extends the standard hidden Markov model (HMM) by explicitly modeling the state duration distribution, which yields a special example of the hidden semi-Markov model (HSMM). We validate our methods using computer simulations and experimental data. In computer simulations, we systematically investigate the impacts of model mismatch and the latency distribution. For the experimental data collected from a rodent visual detection task, we validate the results with predictive log-likelihood. Our work is useful for many behavioral neuroscience experiments, where the common goal is to infer the discrete (binary or multinomial) state sequences from multiple behavioral measures.

Functional approach to the integration of kinematic and dynamic variables in causal perception: Is there a link between phenomenology and behavioral responses?1

Abstract: The study of perceptual causality has seen a resurgence of interest ever since continuous behavioral measures, and not just perceptual reports, were proposed. As one such measure, representational momentum (RM) was recently applied by Hubbard (Hubbard, Blessum, & Ruppel, 2001; Hubbard & Ruppel, 2002) to Michotte's launching paradigm (Michotte, 1954). Among the several open issues regarding this use of RM stand the following three: (a) how the joint actions of dynamic and kinematic variables are integrated in RM; (b) the effect of specific response modalities; and (c) how RM relates to causal phenomenology. In the present experiment, launcher‐target velocities and launcher's size (implied mass) were fully crossed in three integration tasks, requiring target localization responses with a mouse cursor or a pointer (Mouse and Pointer Tasks) and numerical estimates of how far the target would travel as a result of the collision (Numerical Ratings Task). An additive integration rule for size and velocity was found across all experiments and derived functional scales of size (but not of velocity) exhibited a linear relation between phenomenological ratings and both sorts of localization responses.

Serotonin transporter intron 2 polymorphism associated with rigid‐compulsive behaviors in Dutch individuals with pervasive developmental disorder

Two putatively functional polymorphisms of the serotonin transporter gene (HTT, SLC6A4) were examined for associations with risk for pervasive developmental disorders (PDDs) and specific autism phenotypes. Dutch patients diagnosed with PDD (N = 125, age range 5-20 years, DSM-IV-TR based criteria, ADI-R and ADOS behavioral assessments) and their parents (N = 230) were genotyped for promoter ins/del (5-HTTLPR) and intron 2 variable number of tandem repeats (VNTR) alleles. Using the transmission disequilibrium test (TDT), no disorder-specific preferential transmission of promoter (long and short) or intron 2 (10- and 12-repeat) alleles was observed. However, multivariate analysis of continuous autism-related behavioral measures revealed that subjects with intron 2 12/12 genotype were significantly more impaired in the rigid-compulsive domain (P = 0.008). Quantitative TDT (QTDT) analysis also showed significant association of the intron 2 VNTR 12-repeat allele with rigid-compulsive behavior (P = 0.015). These results suggest that intron 2 VNTR alleles or nearby polymorphisms in linkage disequilibrium may play a role in specific aspects of the behavioral phenotype of autism.

Refining Genetic Approaches for Identifying Behavioral Loci

Two decades of linkage and association studies with candidate genes have attempted to decipher the genetic contributions of complex behavioral disorders such as Schizophrenia and Substance Use Disorders with only limited success. We suggest refining these efforts by: 1) using association studies on epidemiologically sound, general population samples with large sample sizes (2000 - 5000) to detect small effect loci, 2) developing continuous behavioral measures that “cut at natures joint”, 3) capitalizing on DNA haplotypes showing evidence of positive selection as “candidate gene” regions and 4) integrating the results with translational biological methodologies. We review our studies of a large, conserved Xq13 haplotype and discuss directions for future studies in genetic dissection integrating across complementary linkage, association, and microarray strategies. Keywords: microarray strategies, DNA haplotypes, Schizophrenia

Sex role orientation and social skill: A naturalistic assessment of assertion and conversational skill

This study evaluated the relationship between sex role orientation and social skill, improving upon previous research by utilizing a more naturalistic role-play assessment, and by assessing both assertion and conversational skills. Fifty-nine female psychology students were classified as masculine, feminine, androgynous, or undifferentiated based on the PRF-ANDRO scale. These subjects interacted with a confederate who engaged them in a standardized conversation including requests to borrow psychology class notes. The masculine, feminine, and androgynous groups displayed similar levels of assertion and conversational skill, even though masculine subjects rated themselves as more skillful and had fewer negative thoughts associated with being assertive than feminine subjects. Correlational analyses among continuous sex role and behavioral measures revealed that both masculinity and femininity scores were positively correlated with overall conversational skill. These results are interpreted in light of methodological difficulties in previous research, and in light of recent evidence that both masculine and feminine capabilities contribute to social competence in certain behavioral domains.