Individual Differences and Task Behaviour

The Interactive Social Book Search track at CLEF has run the same experiment, task, and interface for two years. This provides an opportunity to study the individual differences between two separately recruited participant cohorts, rather than between sub-sets of a single cohort. Overall the results show no significant differences in how the participants used the three main stages of the interface for the two tasks. However, at the detail level there are some quite significant changes in exactly how participants use the available functionality

Identifying reliable traits across laboratory mouse exploration arenas: A meta-analysis

This study is a meta-analysis of 367 mice from a collection of behaviour neuroscience and behaviour genetic studies run in the same lab in Zurich, Switzerland. We employed correlation-based statistics to confirm and quantify consistencies in behaviour across the testing environments. All 367 mice ran exactly the same behavioural arenas: the light/dark box, the null maze, the open field arena, an emergence task and finally an object exploration task. We analysed consistency of three movement types across those arenas (resting, scanning, progressing), and their relative preference for three zones of the arenas (home, transition, exploration). Results were that 5/6 measures showed strong individual-differences consistency across the tests. Mean inter-arena correlations for these five measures ranged from +.12 to +.53. Unrotated principal component factor analysis (UPCFA) and Cronbach’s alpha measures showed these traits to be reliable and substantial (32-63% of variance across the five arenas). UPCFA loadings then indicate which tasks give the best information about these cross-task traits. One measure (that of time spent in “intermediate” zones) was not reliable across arenas. Conclusions centre on the use of individual differences research and behavioural batteries to revise understandings of what measures in one task predict for behaviour in others. Developing better behaviour measures also makes sound scientific and ethical sense

The effect of state core self-evaluations on task performance, organizational citizenship behaviour, and counterproductive work behaviour

Although the personality-performance relationship has been studied extensively, most studies focused on the relationship between between-person differences in the Big Five personality dimensions and between-person differences in job performance. The current paper extends this research in two ways. First, we build on core self-evaluations (CSEs): an alternative, broad personality dimension that has proven to be a good predictor of job performance. Second, we tested concurrent and lagged within-person relationships between CSEs and task performance, organizational citizenship behaviour (OCB), and counterproductive work behaviour (CWB). To this end, we conducted two experience sampling studies; the first one assessing the relationship between state CSEs and levels of momentary task performance and OCB, and a second study in which employees reported on their level of state CSEs and momentary CWB. Results showed that there is substantial within-person variability in CSEs and that these within-person fluctuations relate to within-person variation in task performance, OCB, and CWB towards the organization, and CWB towards the individual. Moreover, CSEs prospectively predicted within-person differences in task performance and CWB towards the organization, whereas the reversed effect did not hold. These findings tentatively suggest that state CSEs predict performance, rather than the other way around

Chimpanzees demonstrate individual differences in social information use

Studies of transmission biases in social learning have greatly informed our understanding of how behaviour patterns may diffuse through animal populations, yet within-species inter-individual variation in social information use has received little attention and remains poorly understood. We have addressed this question by examining individual performances across multiple experiments with the same population of primates. We compiled a dataset spanning 16 social learning studies (26 experimental conditions) carried out at the same study site over a 12-year period, incorporating a total of 167 chimpanzees. We applied a binary scoring system to code each participant’s performance in each study according to whether they demonstrated evidence of using social information from conspecifics to solve the experimental task or not (Social Information Score—‘SIS’). Bayesian binomial mixed effects models were then used to estimate the extent to which individual differences influenced SIS, together with any effects of sex, rearing history, age, prior involvement in research and task type on SIS. An estimate of repeatability found that approximately half of the variance in SIS was accounted for by individual identity, indicating that individual differences play a critical role in the social learning behaviour of chimpanzees. According to the model that best fit the data, females were, depending on their rearing history, 15–24% more likely to use social information to solve experimental tasks than males. However, there was no strong evidence of an effect of age or research experience, and pedigree records indicated that SIS was not a strongly heritable trait. Our study offers a novel, transferable method for the study of individual differences in social learning

Linearly integrating speed and accuracy to measure individual differences in theory of mind:Evidence from autistic and neurotypical adults

It has long been theorised that there is a direct link between individual differences in social cognition and behaviour. One of the most popular tests of this theory has involved examination of Theory of Mind (ToM) difficulties in Autism Spectrum Disorder (ASD). However, evidence for associations between ToM and social behaviour is mixed, both when testing the ToM explanation of ASD and when investigating individual differences in ToM in the general population. We argue that this is due to methodological limitations of many ToM measures, such as a lack of variability in task performance, inappropriate non-ToM control tasks, and a failure to account for general mental ability. To overcome these issues, we designed a novel task, which probed individual differences in ToM fluency through mental state attribution in response to cartoons (Cartoons Theory of Mind [CarToM] task). This task, enabling the linear combination of speed and accuracy, was used to quantify ToM ability and its association with self-reported (a)typical social behaviour in adults with and without ASD. In a large sample (N = 237), we found that having an ASD diagnosis and higher autistic traits predicted lower ToM ability, even after accounting for performance on a well-matched non-ToM condition and general mental ability. Overall, our findings provide fresh support for the existence of a link between individual differences in social cognition (specifically, ToM) and behaviour (specifically, autism). This has implications for social-cognitive theory and research, allowing large-scale, online assessment of individual differences in ToM in clinical groups and the general population

Individual Differences in the Effects of Physical Activity on Classroom Behaviour

Background: Promoting physical activity (PA) in children is associated with a wide range of desired outcomes. With children increasingly not meeting recommended levels of activity, the school setting offers many opportunities to improve this. Increasing children’s on-task behaviour is of particular importance to teachers, and while it has previously been suggested that PA can improve classroom behaviour, a consensus on the dose-response relationship of PA content, and its interaction with children’s individual differences, is yet to be reached. This study aimed to investigate this relationship more closely and assess the differences between objective and subjective measures of PA intensity. Method: Data was collected from 76 primary school-aged children (M age = 9.3 years, SD = 0.7 years; 46 females). The PE lesson intervention followed a 3 (intensity: low, medium, high) by 2 (complexity: low, high) within-person design. Children’s task-behaviour was observed pre- and post-the intervention PE lesson during “business as usual” classroom lesson. PA was measured objectively with wrist-worn accelerometer devices for 24 h before the intervention, and subjectively rated on a five-point Likert scale after each intervention lesson. Results: The results indicated a difference in subjective and objective measures of PA intensity on children’s on-task behaviour. Objective measures positively predicted task-behaviour at moderate to high intensities, whereas subjective ratings were beneficial only at sub-maximal intensity. Findings suggested that boys’ on-task behaviour improved at higher intensities, whereas girls were also responsive to lower intensity lessons. Less active children showed more improvement in on-task behaviour after a range of lessons, whereas more active children only benefited from the highest intensity lessons. Finally, children exhibiting the highest levels of off-task behaviour improved their on-task behaviour after all intervention lessons. Conclusion: The findings suggest that higher intensities of PA have a generally positive effect on children’s subsequent behaviour, although certain individual characteristics make children more responsive to lower PA intensities. Furthermore, passive off-task behaviours were less prevalent after lower-intensity PA. Thus, individual differences, as well as the target behaviour, are important factors to take into account when designing optimal PE lessons for improving classroom behaviour

Sonography data science

Fetal sonography remains a highly specialised skill in spite of its necessity and importance. Because of differences in fetal and maternal anatomy, and human pyschomotor skills, there is an intra- and inter-sonographer variability amoungst expert sonographers. By understanding their similarities and differences, we want to build more interpretive models to assist a sonographer who is less experienced in scanning. This thesis’s contributions to the field of fetal sonography can be grouped into two themes. First I have used data visualisation and machine learning methods to show that a sonographer’s search strategy is anatomical (plane) dependent. Second, I show that a sonographer’s style and human skill of scanning is not easily disentangled. We first examine task-specific spatio-temporal gaze behaviour through the use of data visualisation, where a task is defined as a specific anatomical plane the sonographer is searching for. The qualitative analysis is performed at both a population and individual level, where we show that the task being performed determines the sonographer’s gaze behaviour. In our population-level analysis, we use unsupervised methods to identify meaningful gaze patterns and visualise task-level differences. In our individual-level analysis, we use a deep learning model to provide context to the eye-tracking data with respect to the ultrasound image. We then use an event-based visualisation to understand differences between gaze patterns of sonographers performing the same task. In some instances, sonographers adopt a different search strategy which is seen in the misclassified instances of an eye-tracking task classification model. Our task classification model supports the qualitative behaviour seen in our population-level analysis, where task-specific gaze behaviour is quantitatively distinct. We also investigate the use of time-based skill definitions and their appropriateness in fetal ultrasound sonography; a time-based skill definition uses years of clinical experience as an indicator of skill. The developed task-agnostic skill classification model differentiates gaze behaviour between sonographers in training and fully qualified sonographers. The preliminary results also show that fetal sonography scanning remains an operator-dependent skill, where the notion of human skill and individual scanning stylistic differences cannot be easily disentangled. Our work demonstrates how and where sonographers look at whilst scanning, which can be used as a stepping stone for building style-agnostic skill models

Stable individual differences in strategies within, but not between, visual search tasks

A striking range of individual differences has recently been reported in three different visual search tasks. These differences in performance can be attributed to strategy, that is, the efficiency with which participants control their search to complete the task quickly and accurately. Here we ask if an individual's strategy and performance in one search task is correlated with how they perform in the other two. We tested 64 observers in the three tasks mentioned above over two sessions. Even though the test-retest reliability of the tasks is high, an observer's performance and strategy in one task did not reliably predict their behaviour in the other two. These results suggest search strategies are stable over time, but context-specific. To understand visual search we therefore need to account not only for differences between individuals, but also how individuals interact with the search task and context. These context-specific but stable individual differences in strategy can account for a substantial proportion of variability in search performance

A learning perspective on individual differences in skilled reading: Exploring and exploiting orthographic and semantic discrimination cues

The goal of the present study is to understand the role orthographic and semantic information play in the behaviour of skilled readers. Reading latencies from a self-paced sentence reading experiment in which Russian near-synonymous verbs were manipulated appear well-predicted by a combination of bottom-up sub-lexical letter triplets (trigraphs) and top-down semantic generalizations, modelled using the Naive Discrimination Learner. The results reveal a complex interplay of bottom-up and top-down support from orthography and semantics to the target verbs, whereby activations from orthography only are modulated by individual differences. Using performance on a serial reaction time task for a novel operationalization of the mental speed hypothesis, we explain the observed individual differences in reading behaviour in terms of the exploration/exploitation hypothesis from Reinforcement Learning, where initially slower and more variable behaviour leads to better performance overall

Willingness towards cognitive engagement: a preliminary study based on a behavioural entropy approach

Faced with a novel task some people enthusiastically embark in it and work with determination, while others soon lose interest and progressively reduce their efforts. Although cognitive neuroscience has explored the behavioural and neural features of apathy, the why’s and how’s of positive engagement are only starting to be understood. Stemming from the observation that the left hemisphere is commonly associated to a proactive (‘do something’) disposition, we run a preliminary study exploring the possibility that individual variability in eagerness to engage in cognitive tasks could reflect a preferred left- or right-hemisphere functioning mode. We adapted a task based on response-independent reinforcement and used entropy to characterize the degree of involvement, diversification, and predictability of responses. Entropy was higher in women, who were overall more active, less dependent on instructions, and never reduced their engagement during the task. Conversely, men showed lower entropy, took longer pauses, and became significantly less active by the end of the allotted time, renewing their efforts mainly in response to negative incentives. These findings are discussed in the light of neurobiological data on gender differences in behaviour