Individual Differences In Adaptation Research Articles

Neural correlates of gait adaptation in younger and older adults

Mobility decline is a major concern for older adults. A key component of maintaining mobility with advancing age is the ability to learn and adapt to the environment. The split-belt treadmill paradigm is an experimental protocol that tests the ability to adapt to a dynamic environment. Here we examined the magnetic resonance imaging (MRI) derived structural neural correlates of individual differences in adaptation to split-belt walking for younger and older adults. We have previously shown that younger adults adopt an asymmetric walking pattern during split-belt walking, particularly in the medial-lateral (ML) direction, but older adults do not. We collected T_1-weighted and diffusion-weighted MRI scans to quantify brain morphological characteristics (i.e. in the gray matter and white matter) on these same participants. We investigated two distinct questions: (1) Are there structural brain metrics that are associated with the ability to adopt asymmetry during split-belt walking; and (2) Are there different brain-behavior relationships for younger and older adults? Given the growing evidence that indicates the brain has a critical role in the maintenance of gait and balance, we hypothesized that brain areas commonly associated with locomotion (i.e. basal ganglia, sensorimotor cortex, cerebellum) would be associated with ML asymmetry and that older adults would show more associations between split-belt walking and prefrontal brain areas. We identified multiple brain-behavior associations. More gray matter volume in the superior frontal gyrus and cerebellar lobules VIIB and VIII, more sulcal depth in the insula, more gyrification in the pre/post central gyri, and more fractional anisotropy in the corticospinal tract and inferior longitudinal fasciculus corresponded to more gait asymmetry. These associations did not differ between younger and older adults. This work progresses our understanding of how brain structure is associated with balance during walking, particularly during adaptation.

Comparing Psychoanalytic Process in Consulting Room and Teleconference: A Naturally Occurring Controlled Experiment.

In response to COVID-19, clinicians migrated psychoanalyses to videoconference platforms, creating an opportunity for a controlled empirical study in which only the site varied. There will be no differences in the quality of the psychoanalytic process (QAP) in the consulting room (CR) and in videoconference (VC). Individuals' defensive functioning (adaptive style) will be associated with their capacity to maintain the analytic process when treatment moves from CR to VC. Underlying was the concept that empirical research of clinical psychoanalysis is possible. Forty psychoanalysts of all ranks in the Accreditation Council for Psychoanalytic Education, Inc., accredited programs contributed 50 cases. Participants scored QAP at each site on a 0-to-100 scale. They reported patients' characteristic defense mechanisms using the Defensive Functioning Scale (DFS). To minimize bias, investigators calculated median DFS scores from data provided by clinicians. They compared QAP scores in CR and VC for the entire group without and with DFS scores, and for each DFS level (when feasible) using the related-samples Wilcoxon signed-rank test. There was no difference in QAP between CR and VC for the group as a whole; but QAP of the Minor Image Distorting group degraded significantly from CR to VC. This was the only group showing a significant difference. While statistical significance may not reflect clinical significance, individual differences in adaptation to telepsychoanalysis warrant further study. Empirical research of phenomena occurring naturally in clinical psychoanalysis appears feasible.

Individual Differences in Sensorimotor Adaptation Are Conserved Over Time and Across Force-Field Tasks.

Sensorimotor adaptation enables the nervous system to modify actions for different conditions and environments. Many studies have investigated factors that influence adaptation at the group level. There is growing recognition that individuals vary in their ability to adapt motor skills and that a better understanding of individual differences in adaptation may inform how motor skills are taught and rehabilitated. Here we examined individual differences in the adaptation of upper-limb reaching movements. We quantified the extent to which participants adapted their movements to a velocity-dependent force field during an initial session, at 24 h, and again 1-week later. Participants (n = 28) displayed savings, which was expressed as greater initial adaptation when re-exposed to the force field. Individual differences in adaptation across various stages of the experiment displayed weak-strong reliability, such that individuals who adapted to a greater extent in the initial session tended to do so when re-exposed to the force field. Our second experiment investigated if individual differences in adaptation are also present when participants adapt to different force fields or a force field and visuomotor rotation. Separate groups of participants adapted to position- and velocity-dependent force fields (Experiment 2a; n = 20) or a velocity-dependent force field and visuomotor rotation in a single session (Experiment 2b; n = 20). Participants who adapted to a greater extent to velocity-dependent forces tended to show a greater extent of adaptation when exposed to position-dependent forces. In contrast, correlations were weak between various stages of adaptation to the force-field and visuomotor rotation. Collectively, our study reveals individual differences in adaptation that are reliable across repeated exposure to the same force field and present when adapting to different force fields.

Metrics for quantifying cognitive factors that may underlie individual variation in exoskeleton use

Individual differences in adaptation to exoskeletons have been observed, but are not well understood. Kinematic, kinetic, and physiologic factors are commonly used to assess these systems. Parameters from experimental psychology and gait literature wereadapted to probe the lower extremity perception-cognition-action loop using measures of reaction times, gait task performance, and gait strategy. Parameters were measured in 15 subjects via two tasks: (1) a modified Simon task and (2) a speed-achievement task with secondary go/no-go cues on a self-paced treadmill. Outcome metrics were assessed for significantly different intra- versus inter-subject variability. Reaction time measures from the modified Simon task, as well two speed-achievement metrics and one gait-strategy characteristic we re found to show significant differenc es in intra- versus inter-subject variability. These results suggest that select cognitive factors may differentiate between individuals and be potential predictors for individual variation during exoskeleton system operation.

Neural Responses During Emotion Transitions and Emotion Regulation.

Why are some people more susceptible to interference from previous emotional stimuli? Neural mechanisms underlying emotion regulation are typically studied with one-off positive or negative stimuli. Less is known about how they operate during dynamic emotional experiences, which more closely resemble how emotions occur in real life. Therefore, we investigated the interaction among temporal context, stimulus content, and regulatory strategy. Image sequences included either neutral to negative emotion or negative to neutral emotion. Participants were instructed to either passively watch the emotional stimuli or apply cognitive reappraisal during the image sequences presentation. Participants also reported their habitual use of cognitive reappraisal in their daily lives on a standard scale. We measured functional connectivity (FC) with electroencephalography (EEG) source localization. A three-way interaction suggested that, in addition to momentary emotional content and regulatory effort, the temporal context of stimuli impacts the FC between the ventromedial prefrontal cortex (vmPFC) and the ventral anterior cingulate cortex (ACC) in both alpha and beta frequency bands. In the reappraisal condition—but not the passive watch conditions—, individual differences in habitual reappraisal were manifested in the FC of vmPFC-ACC in alpha band. Emotion transitions may be more demanding because prefrontal-posterior FC in the beta band decreased during emotion transitions regardless of emotional content or regulation efforts. Flexible emotion regulation enables the recruiting of neural activities in response to the content of dynamic, ever-changing experiences encountered in daily life. Studying brain responses to dynamic emotional stimuli may shed light on individual differences in adaptation and psychological health. It also provides a more ecologically valid assessment of emotion regulation.

Personality Traits and Changes in Health Behaviors and Depressive Symptoms during the COVID-19 Pandemic: A Longitudinal Analysis from Pre-pandemic to Onset and End of the Initial Emergency Conditions in Finland.

The COVID-19 pandemic and social distancing measures targeting the transmission of the virus impacted everyday life in 2020. This study investigated pre- to in-pandemic changes in health behaviors and depressive symptoms during the COVID-19 pandemic and the role of personality traits in these changes in Finland. Data from a larger population-based cohort study of 51–59-year-old Finnish women were used (n = 358). Self-reported questionnaires gathered information about depressive symptoms, eating behavior, physical activity, and alcohol consumption before the pandemic time, at the onset, and at the end of the COVID-19 emergency conditions. Information about personality traits (extraversion and neuroticism) and sociodemographic factors was available from the pre-pandemic baseline. Women reported more depressive symptoms and unhealthier eating habits at the end of the emergency conditions compared to the pre-pandemic time. An increase in depressive symptoms was associated with changing to unhealthier eating habits. Higher extraversion was associated with a perceived decrease in alcohol consumption and with changing to healthier eating habits. Women with higher neuroticism reported changing to either healthier or unhealthier eating habits. In general, some women reported healthier lifestyle changes while other women reported the opposite. Personality traits help to understand these individual differences in adaptation to the pandemic situation.

Restless nights? Nocturnal activity as a useful indicator of adaptability of shelter housed dogs

Shelter dogs face the challenge of adapting to a kennel environment. Individual differences in adaptation are known to exist. Resting patterns might be indicative of adaptability to such a novel environment, but need to be evaluated for its usefulness, like every potentially physiological and behavioural parameter. Here, we evaluated nocturnal activity patterns of dogs as indicators of adaptability to novel environments. We measured nocturnal activity (3-axial accelerometer, the Actical®) and two physiological stress parameters, i.e. urinary cortisol/creatinine ratio (UCCR) and body weight in 29 dogs relinquished to a shelter (SD group) in the first two days after intake at the shelter (n = 29), after a 12-day habituation period in the shelter (n = 28) and >6 weeks post-adoption (n = 17). A control group of 29 pet dogs kept at home (CPD group), matching the SD group characteristics, was also assessed for its nocturnal activity and UCCR. Linear mixed model analysis, t-tests and Friedman tests were used to analyse the data.The main findings are: 1) the SD group exhibited higher nocturnal activity (total activity counts, activity duration and number of rest bouts) the first two nights after intake than on night 12, with decreasing inter-individual variances. Compared to the CPD group they showed higher nocturnal activity on night 1 (all p < 0.001) and night 12 (all p ≤ 0.001) except for total activity counts on night 12. We found no ‘first-night effect’, where sleep is disturbed during the first night; nocturnal activity in the shelter did not significantly differ between nights 1 and 2 in the shelter. 2) In line with literature findings, SD group UCCRs were higher shortly after intake than after a 12-day habituation period and after adoption, and higher than in the CPD group. 3) An interaction was found between weight class and both nocturnal activity and UCCR levels: in their first days in the shelter, smaller dogs showing higher levels than larger dogs. 4) Dogs in the SD group lost, on average, 5% of their body weight between intake and the two-week habituation period.In conclusion, nocturnal activity, as measured by an accelerometer, may be a valid parameter to monitor adaptability of dogs to a kennel environment. Monitoring nocturnal activity in this way can be a useful and cost-effective additional indicator for assessing dog welfare.

Individual Differences in Adaptation to Sweet Taste

ObjectivesOver-consumption of sugar-sweetened beverages is associated with obesity and related conditions, but low-calorie alternatives are rejected by most consumers. Individual differences in sensitivity to off tastes of low-calorie sweeteners (LCS) have been considered as a factor in consumer choice. However, potential differences in adaptation, i.e., the tendency for sweetness to wane with repeated sips, has received less attention. This study measured sweetness adaption to a sugar and two LCS in the same sample of healthy adults to determine if there are stable individual differences in sweet adaptation. MethodsStimuli included three sweeteners at concentrations corresponding to the low (500 mM glucose, 246 μM sucralose, and 303 μM RebA) and high (1.08 M glucose, 870 μM sucralose, and 823 μM RebA) end of the sweetness spectrum for most commercially sold beverages in the US. Each trial participants (n = 38) tasted seven, 10 mL samples of the same stimulus (10 s between samples). For each sample, participants rated sweetness intensity using a general Labeled Magnitude Scale. Tests for all stimuli were repeated three times, on separate days, to assess stability. ResultsAll sweeteners showed significant reduction in sweetness with repeated sips, with the exception of the higher concentration glucose (no significant decrease across repeated sips). Sweetness waned with repeated sips more profoundly for the two LCS than for glucose, as expected given previous results. Importantly, there were substantial and stable (across test sessions) individual differences in sweet adaptation. ConclusionsSweetness faded more rapidly and completely for LCS than for glucose, and some individuals were more susceptible to sweetness adaptation than others. Whether these individual differences are stable across longer periods of time, or contribute to individual differences in acceptance of beverages sweetened with LCS is currently unclear. Funding SourcesFunded by a consortium of food and ingredient companies, including Asahi, Kellogg, Kraft, Mondelez, and Suntory. The views expressed are those of the authors, and do not necessarily reflect the views of the sponsors.

Differential Susceptibility to the Impact of the COVID-19 Pandemic on Working Memory, Empathy, and Perceived Stress: The Role of Cortisol and Resilience.

There are important individual differences in adaptation and reactivity to stressful challenges. Being subjected to strict social confinement is a distressful psychological experience leading to reduced emotional well-being, but it is not known how it can affect the cognitive and empathic tendencies of different individuals. Cortisol, a key glucocorticoid in humans, is a strong modulator of brain function, behavior, and cognition, and the diurnal cortisol rhythm has been postulated to interact with environmental stressors to predict stress adaptation. The present study investigates in 45 young adults (21.09 years old, SD = 6.42) whether pre-pandemic diurnal cortisol indices, overall diurnal cortisol secretion (AUCg) and cortisol awakening response (CAR) can predict individuals’ differential susceptibility to the impact of strict social confinement during the Coronavirus Disease 2019 (COVID-19) pandemic on working memory, empathy, and perceived stress. We observed that, following long-term home confinement, there was an increase in subjects’ perceived stress and cognitive empathy scores, as well as an improvement in visuospatial working memory. Moreover, during confinement, resilient coping moderated the relationship between perceived stress scores and pre-pandemic AUCg and CAR. In addition, in mediation models, we observed a direct effect of AUCg and an indirect effect of both CAR and AUCg, on change in perceived self-efficacy. These effects were parallelly mediated by the increase in working memory span and cognitive empathy. In summary, our findings reveal the role of the diurnal pattern of cortisol in predicting the emotional impact of the COVID-19 pandemic, highlighting a potential biomarker for the identification of at-risk groups following public health crises.

Evolution and revolution: Personality research for the coming world of robots, artificial intelligence, and autonomous systems

In forty years, human existence will be radically transformed by advances in information technology, including Artificial Intelligence, robots capable of social agency, and other autonomous physical and virtual systems. Future personality research must assess, understand, and apply individual differences in adaptation to these novel challenges. This review article discusses directions for future personality research. Cross-cultural research provides a model, in that both universal traits and those specific to future society are needed. Evolution of major “etic” trait models of today will maintain their relevance. There is also scope for defining a range of new “emic” dimensions for constructs such as trust in autonomy, mental models for robots, anthropomorphism of technology, and preferences for communication with machines. A more revolutionary perspective is that availability of big data on the individual will revive idiographic perspectives. Both nomothetic and idiographic accounts of personality may support applications such as design of intelligent systems and products that adapt to the individual.

Minimizing Precision-Weighted Sensory Prediction Errors via Memory Formation and Switching in Motor Adaptation

Humans predict the sensory consequences of motor commands by learning internal models of the body and of environment perturbations. When facing a sensory prediction error, should we attribute this error to a change in our body, and update the body internal model, or to a change in the environment? In the latter case, should we update an existing perturbation model or create a new model? Here, we propose that a decision-making process compares the models' prediction errors, weighted by their precisions, to select and update either the body model or an existing perturbation model. When no model can predict a perturbation, a new perturbation model is created and selected. When a model is selected, both the prediction's mean estimate and uncertainty are updated to minimize future prediction errors and to increase the precision of the predictions. Results from computer simulations, which we verified in an arm visuomotor adaptation experiment with subjects of both sexes, account for short aftereffects and large savings after adaptation to large, but not small, perturbations. Results also clarify previous data in the absence of errors (error-clamp): motor memories show an initial lack of decay after a large perturbation, but gradual decay after a small perturbation. Finally, qualitative individual differences in adaptation were explained by subjects selecting and updating either the body model or a perturbation model. Our results suggest that motor adaptation belongs to a general class of learning according to which memories are created when no existing memories can predict sensory data accurately and precisely.SIGNIFICANCE STATEMENT When movements are followed by unexpected outcomes, such as following the introduction of a visuomotor or a force field perturbation, or the sudden removal of such perturbations, it is unclear whether the CNS updates existing memories or creates new memories. Here, we propose a novel model of adaptation, and investigate, via computer simulations and behavioral experiments, how the amplitude and schedule of the perturbation, as well as the characteristics of the learner, lead to the selection and update of existing memories or the creation of new memories. Our results provide insights into a number of puzzling and contradictory motor adaptation data, as well as into qualitative individual differences in adaptation.

Assessing psychological adaptation during polar winter-overs: The isolated and confined environments questionnaire (ICE-Q)

Stressors in Isolated, Confined, Extreme environments (ICE environments) pose important challenges to psychological adaptation, whose assessment is therefore an important research issue. This article describes a standardized instrument, the ICE-Q, to help evaluate individual differences in adaptation to ICE environments.Several groups (n = 140), each spending one year in sub-Antarctic or Antarctic stations, completed a questionnaire. Factor analyses provided strong evidence for the construct validity of the ICE-Q. The most salient factors were (a) social (e.g., relationships, social support), (b) emotional (e.g., emotional changes, boredom) (c) occupational (e.g., level of investment in work and leisure activities), and (d) physical (e.g., fatigue, well-being).Complementing other methods, this short, quick, cost-effective and non-invasive measure could serve to (1) monitor psychological adaptation within the four key domains, and (2) assess methods used to facilitate adaptation to extreme situations and enhance the health and well-being of participants.

Burnout, Sleep, and Sleepiness during Day and Night Shifts in Transition from 8- to 12-Hour Shift Rosters among Airline Ground Crew Managers.

Organizational changes in shift scheduling provide rare opportunities for field studies aimed at investigating the effects of such changes on health and wellbeing. We studied the effects of a transition from 8-hour (8-h) to 12-hour (12-h) shift rosters in 39 airline ground crew managers on burnout, sleep quality, and sleepiness. Assessments were collected during the 8-h and were repeated three months after the transition to 12-h shift rosters. These assessments included the Shirom-Melamed Burnout Measure (SMBM), the Pittsburgh Sleep Quality Index (PSQI), actigraphy, the Karolinska Sleepiness Scale (KSS) completed hourly during one day and two night shifts, and caffeine intake. Findings demonstrated lower burnout, improved sleep quality, improved quality of naps, and increased afternoon sleepiness during the 12-h day shift. Napping was reported during 12-h night shifts by 36% of the sample. In nappers, increased night shift sleepiness was associated with increased caffeine intake on 8- and 12-h shifts. In non-nappers, increased night shift sleepiness was associated with decreased caffeine intake on the 8-h shift only. Change in shift length affects other structural and behavioral parameters in the workplace, making it challenging to isolate distinct characteristics of the two rosters and their relative effects on study outcomes. Individual differences in adaptation to shiftwork may also play a role.

Individual Differences in Sabahan Highland Farmers’ Adaptation towards Climate Change

This paper discusses the individual differences in adaptation towards climate change among Sabahan highland farmers. This study is quantitative in nature in the form of a cross-sectional survey. Via a simple random sampling, a total of 200 highland farmers in Kundasang and Moyog were selected as respondents. The analysis performed has concluded that the differences in education achievement have a significant influence on Sabahan highland farmers’ adaptation towards climate change, while factors such as age, income and the number of household members have a significant relationship with their adaptation towards climate change. A number of recommendations were highlighted and it is a hope that it can assist related parties in constructing a better community’s adaptation plan.

Articulation and adaptation to altered auditory feedback

Speakers listen to themselves while talking, and they use this auditory feedback to modify their speaking plans on-line [Houde and Jordan, Science 20;279(5354):1213-1216 (1998)]. This altered auditory feedback experiment uses ultrasound tongue imaging to investigate individual differences in adaptation under three conditions: (1) raising F1 in /ɛ/, (2) raising F2 in /ʊ/, (3) raising F3 in /r/. Pilot data suggest that speakers may change both F1 and F2 in response to an altered F1, replicating Katseff et al. (2010, JASA 127(3), 1955). Principal components analysis of the ultrasound data reveals that these two acoustic changes are independently controlled. We will also test the role of individual differences in vocal tract morphology. Hard palate curvature affects variability in both articulation and acoustics [Brunner et al. (2009, JASA 125(6), 3936-3949)]: flatter palates have less acoustic stability (and greater flexibility) [Bakst &amp; Johnson (2016, JASA 140(4), 3223-3223)], requiring greater articulatory precision to maintain acoustic consistency. We hypothesize that people with flatter palates will adapt to altered feedback faster and more completely because they (a) may have more detailed knowledge of their articulation-acoustics mapping and (b) have greater flexibility in their acoustic output.

Traits, cognitive processes and adaptation: An elegy for Hans Eysenck's personality theory

Hans Eysenck's personality theory has inspired several generations of researchers. However, it has substantial limitations as an account of the individual differences in performance and cognitive processing associated with personality traits. Three particular areas of concern are its handling of the complexity of processing, its attribution of performance effects to variation in cortical arousal, and its neglect of the adaptive significance of traits. The neurological concomitants of traits may be more consequential as indirect influences on skill acquisition than as direct influences on adaptation. Cognitive-adaptive theory provides a contrary perspective that sees traits as distributed across multiple processes and accommodates the dynamic nature of individual differences in adaptation. It may be time to laud the Eysenck theory for its historical contribution and lay it to rest with due respect.

PHANTOM PHENOMENA

Peter Brugger, born 1957 in Zurich, Switzerland. Acquired a teacher's Diploma for Elementary and High School levels before studying biology at Zurich University. Dissertation on Subjective Randomness: Implications for Neuropsychology...

Predictive validity of dispositional traits in diving

The peculiarities and environmental stressors of diving imply the requirement of physical, medical and psychological characteristics needed to adapt to its demands. From the first psychological studies the influence of the cognitive and personality traits to predict performance and adaptation of divers was analyzed, quantifying an effective relationship. Data from a large sample of military personnel performing diving courses have been analyzed, in order to verify the role of individual differences in adaptation to a hostile environment by checking the predictive validity of cognitive and non-cognitive traits. The results indicate the existence of psychological variables that predict performance ( R 2 = .303; F _11_522 = 19.980, p R 2 _ N = .513; X 2 _9 = 19.980, p

Prediction of human adaptation and performance in underwater environments.

Environmental stressors require the professional diver to undergo a complex process of psychophysiological adaptation in order to overcome the demands of an extreme environment and carry out effective and efficient work under water. The influence of cognitive and personality traits in predicting underwater performance and adaptation has been a common concern for diving psychology, and definitive conclusions have not been reached. In this ex post facto study, psychological and academic data were analyzed from a large sample of personnel participating in scuba diving courses carried out in the Spanish Navy Diving Center. In order to verify the relevance of individual differences in adaptation to a hostile environment, we evaluated the predictive validity of general mental ability and personality traits with regression techniques. The data indicated the existence of psychological variables that can predict the performance ( R² = .30, p <.001) and adaptation ( R²(N) = .51, p <.001) of divers in underwater environment. These findings support the hypothesis that individual differences are related to the probability of successful adaptation and effective performance in professional diving. These results also verify that dispositional traits play a decisive role in diving training and are significant factors in divers' psychological fitness.

Do Social Relationships Buffer the Effects of Widowhood? A Prospective Study of Adaptation to the Loss of a Spouse

The idea that strong social relationships can buffer the negative effects of stress on well-being has received much attention in existing literature. However, previous studies have used less than ideal research designs to test this hypothesis, making it difficult to draw firm conclusions regarding the buffering effects of social support. In this study, we examined the buffering hypothesis in the context of reaction and adaptation to widowhood in three large longitudinal datasets. We tested whether social relationships moderated reaction and adaptation to widowhood in samples of people who experienced loss of a spouse from three longitudinal datasets of nationally representative samples from Germany (N = 1,195), Great Britain (N = 562), and Australia (N = 298). We found no evidence that social relationships established before widowhood buffered either reaction or adaptation to the death of one's spouse. Similarly, social relationships that were in place during the first year of widowhood did not help widows and widowers recover from this difficult event. Social relationships acquired prior to widowhood, or those available in early stages of widowhood, do not appear to explain individual differences in adaptation to loss.