Individual Differences In Behavioral Responses Research Articles

Discrete prefrontal neuronal circuits determine repeated stress-induced behavioral phenotypes in male mice

Chronic stress is a major risk factor for psychiatric disorders, including depression. Although depression is a highly heterogeneous syndrome, it remains unclear how chronic stress drives individual differences in behavioral responses. In this study, we developed a subtyping-based approach wherein stressed male mice were divided into four subtypes based on their behavioral patterns of social interaction deficits and anhedonia, the core symptoms of psychiatric disorders. We identified three prefrontal cortical neuronal projections that regulate repeated stress-induced behavioral phenotypes. Among them, the medial prefrontal cortex (mPFC)→anterior paraventricular thalamus (aPVT) pathway determines the specific behavioral subtype that exhibits both social deficits and anhedonia. Additionally, we identified the circuit-level molecular mechanism underlying this subtype: KDM5C-mediated epigenetic repression of Shisa2 transcription in aPVT projectors in the mPFC led to social deficits and anhedonia. Thus, we provide a set of biological aspects at the cellular, molecular, and epigenetic levels that determine distinctive stress-induced behavioral phenotypes.

Shelter fidelity and exploratory behaviours of juvenile Haliotis discus hannai in response to different stressors

Individual differences in behavioural responses to stressors are categorised as adaptive variation and serve as a foundation for devising improvements in animal health and welfare. However, the existence of different coping styles in response to stress has not been demonstrated in marine gastropods. To evaluate individual differences in shelter fidelity and exploratory levels of abalones in response to stress, the behaviours of juvenile Pacific abalones (Haliotis discus hannai) housed in tanks were observed; several behavioural parameters such as forage duration and un-sheltering behaviour were also measured and analysed. To test differences in survival rates between individuals that showed staying (returning to home shelters after foraging) and wandering (not returning to home shelters after foraging) behaviours in response to poor water quality, 90 1-year-old abalones were exposed to hypoxia stress caused by interrupted water flow. To assess the individuals’ exploratory behaviours, 150 1.5-year-old abalones were supplied with excess food inside their shelters, and their movement between the shelters was recorded. Differences in behavioural parameters between the exploratory and nonexploratory individuals in the presence of resident intruders were also tested. Our results showed that (1) staying abalones exhibited higher survival rates than their wandering counterparts under hypoxic stress; (2) the number of shelters visited in one night could be considered as an exploratory activity under conditions of sufficient food availability within the shelters; and (3) in the presence of intruders, both the exploratory and nonexploratory abalones displayed reduced shelter-seeking activity, although the reduction was more pronounced in the exploratory than the nonexploratory abalones.

Boredom is the root of all evil-or is it? A psychometric network approach to individual differences in behavioural responses to boredom.

Functional accounts of boredom propose that boredom serves as an impartial signal to change something about the current situation, which should give rise to adaptive and maladaptive behaviour alike. This seemingly contrasts with research on boredom proneness, which has overwhelmingly shown associations with maladaptive behaviour. To shed light on this discrepancy, we disentangled boredom proneness from individual differences in (i) the urge to avoid and escape boredom and (ii) adaptive and maladaptive ways of dealing with boredom by developing corresponding trait scales. In a study with N = 636 participants, psychometric network modelling revealed tight associations between boredom proneness and less adaptive and (especially) more maladaptive ways of dealing with boredom. However, its associations with the urge to avoid and escape boredom were rather weak. Importantly, a higher urge to avoid and escape boredom was linked not only to more maladaptive but also to more adaptive ways of dealing with boredom. This pattern of results was robust across various specific behaviours that have previously been linked to boredom. Our findings provide novel evidence for functional accounts of boredom from an individual difference perspective, cautioning against a shallow view of boredom as being associated with purely maladaptive behaviour.

Limitations and challenges of adapting subjective keeper questionnaires to non-Western sanctuary settings

In the past decade, there has been substantial growth in the number of animal personality studies published, however relatively little work has been conducted on different species of bears. Personality structure can provide insight into individual differences in behavioural responses, and in the context of captive management, may be valuable for improving welfare through individualised monitoring and care. The goal of this study was to assess the relationship between personality and welfare in Asiatic black bears (‘moon bear’, Ursus thibetanus) and sun bears (Helarctos malayanus). In collaboration with bear behaviour specialists, we adapted existing personality, subjective well-being, and welfare surveys originally designed for other captive mammal species to be appropriate and specific for bears. Surveys were written in English and translated to Khmer, with backtranslation checked for retention of the original meaning. The surveys were delivered verbally to 16 experienced bear keepers working within a bear rescue centre in Cambodia. In total, 36 Asiatic black bears and 41 sun bears were rated. Each bear was assessed by two keepers who were familiar with the individual animal. Although this approach has been successfully used with an array of captive species, in the current study, observer agreement was found to be very low as determined by intraclass correlations of rating scores. Because of this, we were unable to determine the personality structures in these species and thus could not examine the relationship between personality and welfare. The cause of this low agreement is unclear however in this paper we discuss potential cross-cultural or logistical reasons, and suggest that future studies using questionnaires to assess animal personality, welfare, or subjective well-being may benefit from consideration of these challenges in their study design.

The Impact of Interpretation Biases on Psychological Responses to the COVID-19 Pandemic: a Prospective Study.

BackgroundThis study investigates the longitudinal role of interpretation biases in the development and maintenance of health anxiety during the pandemic. Individual differences in behavioural responses to the virus outbreak and decision-making were also examined.MethodsTwo hundred seventy-nine individuals from a pre-pandemic study of interpretation bias and health anxiety completed an online survey during the third wave of the COVID-19 pandemic in Hong Kong. Participants’ health anxiety, interpretation biases, and COVID-specific behaviours (i.e. practice of social distancing, adherence to preventive measures, information seeking), and health decision-making were assessed.ResultsPre-pandemic tendencies to interpret ambiguous physical sensations as signals for illness did not predict health anxiety during the pandemic, b = −0.020, SE = 0.024, t = −0.843, p = .400, 99% CI [−0.082, 0.042], but were associated with a preference for risky treatment option for COVID-19, b = 0.026, SE = 0.010, Wald = 2.614, p = .009, OR = 1.026, 99% CI [1.001, 1.054]. Interpretation biases and health anxiety symptoms during the pandemic were associated with each other and were both found to be significant predictors of practice of social distancing, adherence to preventive measures, and information seeking behaviour.ConclusionsThis study adds to the growing evidence of the role of interpretation biases in health anxiety and the way that people respond to the ongoing pandemic.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12529-022-10079-5.

Studi Tempramental Pada Mahasiswa Suku Jawa dan Madura di Kota Malang

Temperament is individual differences in behavioral responses or characteristics that have been present since birth but can change and develop along with the experiences experienced by individuals. The individual's temperament affects the individual's tendency to behave and perceive something. This cross-cultural comparative study aims to determine the temperamental of students from the Javanese and Madurese ethnic groups, whether there are cross-cultural differences in the distribution of temperament levels. The results showed that the cultural environment greatly affects the temperamental of individuals, Javanese students tend to have a lower temperament attitude than Madurese students.

Individual differences in the behavioral responsiveness of F1 Holstein-Gyr heifers to the training for milking routine

The objective of this study was to assess individual differences in behavioral responses of F1 Holstein-Gyr heifers subjected to habituation protocols to humans and milking procedures. Training was divided in two phases (P1 and P2): habituation to humans (P1), and to the milking parlor and human physical contact (P2). Flight distances (FD) were assessed during P1, and numbers of steps and kicks (as binary) were recorded during P2. The last two measurements and milking reactivity (scored from 1 = cow stands quietly to 8 = cow is very agitated) were recorded during the first four days of milking. Repeated behavioral measurements were used to evaluate individual changes fitting a linear regression for each animal, and the b-coefficients were used to classify heifers as habituated, neutral or sensitized. The percentages of assessment days that each heifer/cow kicked during P2, and during the first four days of milking were calculated. Pearson’s correlation coefficients between b-coefficients were estimated. General linear models were fitted to assess the effects of interval classes (defined by the number of days between the last day in training and the first day in miking) and behavioral responses during P1 and P2 on milking reactivity and number of steps on the first day of milking and on b-coefficients of these variables. Individual differences in behavioral responses were observed. Most heifers (∼87 %) habituated during P1 and ∼ 44 % of them reduced number of steps during P2. Almost 52 % of the heifers did not step or exhibit only one step, and ∼93 % of them did not kick when fitting the milking cluster in the first day of milking. Around 56 % of them increased the number of steps along milking assessments, while ∼33 % reduced it. The b-coefficients of FD and for the number of steps in P2 were not associated to the b-coefficients of milking assessed variables. The b-coefficient and the number of steps on the first assessment day of P2 showed a significant effect (P < 0.05) on milking reactivity scores (F = 6.06 and 6.54, respectively) and number of steps (F = 5.73 and 7.88, respectively) assessed in the first day of milking. None of the other independent variables showed significant effect on b-coefficients of milking reactivity scores and number of steps during milking. We conclude that training reduces fear to humans and cows’ reactivity to milking, and that individual differences between heifers play an important role in the training results.

Individual differences in behavioural responses to the financial threat posed by the COVID-19 pandemic

Using a representative sample of 400 Slovaks, the present study investigated the mediating role of subjective perception of financial threat to the relation between psychological resources and behavioural responses in the adaptation to financial stress posed by the COVID-19 pandemic. The results of structural equation modelling analyses showed that greater neuroticism and uncertainty intolerance were positively related to aggravated perception of financial threat. This, in turn, led to greater willingness to change consumption patterns and use of mostly problem-focused coping strategies. The model remained robust after controlling for chronic financial hardship moderators, including the absence of savings and indebtedness. In contrast, the acute financial hardship caused by the deterioration of one's financial situation during the COVID-19 pandemic showed to significantly moderate the relation between one's psychological resources and perceived financial threat.

Individual Differences in Behavioural Responses to the Financial Threat Posed by the COVID-19 Pandemic

Using a representative sample of 400 Slovaks, the study investigated the mediating role of subjective perception of financial threat to the relation between psychological resources and behavioural responses in the adaptation to financial stress posed by the COVID-19. The results showed that greater neuroticism and uncertainty intolerance were positively related to aggravated perception of financial threat. This led to greater willingness to change consumption patterns and use of mostly problem-focused coping strategies. The model remained robust after controlling for chronic financial hardship moderators, including the absence of savings and indebtedness. In contrast, acute financial hardship caused by the deterioration of one’s financial situation during the pandemic showed to significantly moderate the relation between one’s psychological resources and perceived financial threat.

Widespread Behavioral Responses by Mammals and Fish to Zoo Visitors Highlight Differences between Individual Animals.

Simple SummaryIt is important to understand the impacts that humans have on zoo animals to ensure that zoo animal welfare is not compromised. We conducted multiple short-term studies of the impact of zoo visitors on 16 animal species and found that 90.9% of the mammal species and 60.0% of the fish species studied exhibited some change in behavior related to zoo visitors. Animals with behavioral changes were housed in exhibits with no direct contact with humans and exhibits with direct contact. These changes in behaviors were not always consistent across species, and often individual animals of the same species and living within the same exhibit had varied behavioral responses. We recommend (1) using short-term assessments to identify behavioral responses that may be of concern; (2) monitoring individual responses of zoo animals to humans; and (3) creating refuges where animals may choose to retreat.The impact that humans have on zoo animals can vary based on the species of animal, exhibit design, and individual differences in behavioral responses. We independently analyzed data from 10 never-published studies that examined the impact of zoo visitors on zoo animal behavior. Of the 16 species studied, 90.9% of the mammal species and 60.0% of the fish species demonstrated a change in at least one behavior based on zoo visitor abundance or visitor behavior (e.g., noise, solicitation of interactions from zoo animals). In addition, behavioral changes associated with zoo visitors were present in animals housed in exhibits where there was direct contact with zoo visitors, as well as in exhibits where there was indirect contact and no direct contact. Individuals often varied in their behavioral responses, and some individuals appeared to seek out interactions with visitors. Our findings demonstrate that short-term research projects can provide valuable insight into individual animal-level and species-level responses to visitor abundance and visitor behavior in the zoo setting. We recommend that behavioral assessments focus on the analysis of behaviors of individual animals whenever possible, and we recommend that exhibits provide areas that allow for animals to retreat from the public view.

Dissociable effects of tDCS polarity on latent decision processes are associated with individual differences in neurochemical concentrations and cortical morphology

Applying a weak electrical current to the cortex has the potential to modulate neural functioning and behaviour. The most common stimulation technique, transcranial direct current stimulation (tDCS), has been used for causal investigations of brain and cognitive functioning, and to treat psychiatric conditions such as depression. However, the efficacy of tDCS in modulating behaviour varies across individuals. Moreover, despite being associated with different neural effects, the two polarities of electrical stimulation – anodal and cathodal – can result in similar behavioural outcomes. Here we employed a previously replicated behavioural paradigm that has been associated with polarity non-specific disruption of training effects in a simple decision-making task. We then used the linear ballistic accumulator model to quantify latent components of the decision-making task. In addition, magnetic resonance imaging measures were acquired prior to tDCS sessions to quantify cortical morphology and local neurochemical concentrations. Both anodal and cathodal stimulation disrupted learning-related task improvement relative to sham (placebo) stimulation, but the two polarities of stimulation had distinct effects on latent task components. Whereas anodal stimulation tended to affect decision thresholds for the behavioural task, cathodal stimulation altered evidence accumulation rates. Moreover, performance variability with anodal stimulation was related to cortical thickness of the inferior frontal gyrus, whereas performance variability with cathodal stimulation was related to cortical thickness in the inferior precentral sulcus, as well as to prefrontal neurochemical excitability. Our findings demonstrate that both cortical morphology and local neurochemical balance are important determinants of individual differences in behavioural responses to electrical brain stimulation.

Brain-Derived Neurotrophic Factor in the Nucleus Accumbens Mediates Individual Differences in Behavioral Responses to a Natural, Social Reward.

BDNF-oxytocin interactions in the brain are implicated in mammalian maternal behavior. We found that BDNF gene expression is increased in the hippocampus of rat mothers that show increased pup licking/grooming (high LG mothers) compared to low LG mothers. High LG mothers also showed increased BDNF protein levels in the nucleus accumbens (nAcc). Immunoneutralization of BDNF in the nAcc eliminated the differences in pup LG between high and low LG mothers. Oxytocin antagonist in the ventral hippocampus significantly decreased the frequency of maternal LG behavior. Oxytocin antagonist significantly prevented the oxytocin-induced BDNF gene expression in primary hippocampal cell cultures. We suggest that oxytocin-induced regulation of BDNF in the nAcc provides a neuroendocrine basis for both individual differences in maternal behavior and resilience to the stress of reproduction in female mammals.

Individual Differences in Behavioral Responses to Palatable Food or to Cholecystokinin Predict Subsequent Diet-Induced Obesity.

Objective:This study investigated whether individual differences in behavioral responses to palatable food and to the satiation signal cholecystokinin (CCK) in outbred chow-maintained Sprague Dawley rats enabled prediction of individual differences in weight gained after subsequent high-fat/high-sugar diet (HFHSD) maintenance.Methods:Meal size, meal number and early dark cycle intake during initial HFHSD exposure were measured as was early dark cycle sucrose solution and chow intake, chow meal size and meal number, the intake suppressive effect of 0.5μg/kg CCK injection, and CCK-induced c-Fos activation in the nucleus tractus solitarius (NTS). Subsequently, rats were maintained on HFHSD for five weeks and weight gain determined.Results:Rats that took larger and less frequent meals on the first day of HFHSD exposure, whose early dark cycle intake (HFHSD and sucrose) was larger during initial HFHSD exposure, gained more weight after HFHSD maintenance. Rats with lesser sucrose intake suppression in response to CCK gained more weight after HFHSD maintenance and also displayed reduced CCK-induced c-Fos activation in the NTS.Conclusions:Together, these data identify individual differences in behavioral responses to palatable food and to CCK as novel predictors of diet-induced obesity.

Approach, avoidance, and the detection of conflict in the development of behavioral inhibition

Motivation has played an integral role in understanding personality development. Two motivational systems, one associated with seeking reward (approach motivation) and one associated with avoidance of threat (avoidance motivation), have been theorized to represent individual differences in behavioral responses to the environment. However, contextual factors, particularly those with a high degree of novelty, ambiguity, and unpredictability, may simultaneously activate both systems, thereby causing approach–avoidance conflict. The resulting behavior, commonly called inhibition, is characterized by an inability to engage in motivated, goal-directed behavior and is theorized to reflect a core component of anxiety. A form of inhibition observed in childhood, behavioral inhibition (BI), is a relatively stable temperamental profile characterized by negative affect in response to unfamiliar and unpredictable contexts and is a risk factor for anxiety. Our review draws from findings in clinical and cognitive neuroscience to argue that BI reflects an increased sensitivity of both approach and avoidance motivational systems, thereby increasing the likelihood of approach–avoidance conflict within the context of unfamiliar or unpredictable stimuli and environments. Such motivational conflict activates neural systems associated with conflict monitoring, which leads to increases in arousal (e.g., sympathetic nervous system activity) and onlooking behavior, two commonly observed characteristics of childhood BI.

Atomoxetine restores the response inhibition network in Parkinson's disease.

Parkinson's disease impairs the inhibition of responses, and whilst impulsivity is mild for some patients, severe impulse control disorders affect ∼10% of cases. Based on preclinical models we proposed that noradrenergic denervation contributes to the impairment of response inhibition, via changes in the prefrontal cortex and its subcortical connections. Previous work in Parkinson's disease found that the selective noradrenaline reuptake inhibitor atomoxetine could improve response inhibition, gambling decisions and reflection impulsivity. Here we tested the hypotheses that atomoxetine can restore functional brain networks for response inhibition in Parkinson's disease, and that both structural and functional connectivity determine the behavioural effect. In a randomized, double-blind placebo-controlled crossover study, 19 patients with mild-to-moderate idiopathic Parkinson's disease underwent functional magnetic resonance imaging during a stop-signal task, while on their usual dopaminergic therapy. Patients received 40 mg atomoxetine or placebo, orally. This regimen anticipates that noradrenergic therapies for behavioural symptoms would be adjunctive to, not a replacement for, dopaminergic therapy. Twenty matched control participants provided normative data. Arterial spin labelling identified no significant changes in regional perfusion. We assessed functional interactions between key frontal and subcortical brain areas for response inhibition, by comparing 20 dynamic causal models of the response inhibition network, inverted to the functional magnetic resonance imaging data and compared using random effects model selection. We found that the normal interaction between pre-supplementary motor cortex and the inferior frontal gyrus was absent in Parkinson's disease patients on placebo (despite dopaminergic therapy), but this connection was restored by atomoxetine. The behavioural change in response inhibition (improvement indicated by reduced stop-signal reaction time) following atomoxetine correlated with structural connectivity as measured by the fractional anisotropy in the white matter underlying the inferior frontal gyrus. Using multiple regression models, we examined the factors that influenced the individual differences in the response to atomoxetine: the reduction in stop-signal reaction time correlated with structural connectivity and baseline performance, while disease severity and drug plasma level predicted the change in fronto-striatal effective connectivity following atomoxetine. These results suggest that (i) atomoxetine increases sensitivity of the inferior frontal gyrus to afferent inputs from the pre-supplementary motor cortex; (ii) atomoxetine can enhance downstream modulation of frontal-subcortical connections for response inhibition; and (iii) the behavioural consequences of treatment are dependent on fronto-striatal structural connections. The individual differences in behavioural responses to atomoxetine highlight the need for patient stratification in future clinical trials of noradrenergic therapies for Parkinson's disease.

The influence of AVPR1A genotype on individual differences in behaviors during a mirror self-recognition task in chimpanzees (Pan troglodytes).

The mark/rouge test has been used to assess mirror self-recognition (MSR) in many species. Despite consistent evidence of MSR in great apes, genetic or non-genetic factors may account for the individual differences in behavioral responses that have been reported. We examined whether vasopressin receptor gene (AVPR1A) polymorphisms are associated with MSR-related behaviors in chimpanzees since vasopressin has been implicated in the development and evolution of complex social relations and cognition and chimpanzees are polymorphic for the presence of the RS3-containing DupB region. We compared a sample of DupB+/- and DupB-/- chimpanzees on a mark test to assess its role on social behavior toward a mirror. Chimpanzees were administered two, 10-min sessions where frequencies of mirror-guided self-directed behaviors, contingent actions and other social behaviors were recorded. Approximately one-third showed evidence of MSR and these individuals exhibited more mirror-guided self-exploratory behaviors and mouth contingent actions than chimpanzees not classified as passers. Moreover, DupB+/- males exhibited more scratching and agonistic behaviors than other male and female cohorts. Our findings support previous studies demonstrating individual differences in MSR abilities in chimpanzees and suggest that AVPR1A partly explains individual differences in MSR by influencing the behavioral reactions of chimpanzees in front of a mirror.

Relative Changes In Diet And Neat In Response To Initiating A Walking Exercise Program

Variability in the efficacy of structured exercise to achieve targeted levels of weight loss or maintenance appears to be primarily due to individual differences in behavioral responses that increase energy intake (EI) or decrease non-exercise activity thermogenesis (NEAT). However, the relative importance of each type of compensatory behavior remains incompletely characterized. PURPOSE: To quantify and compare changes in EI and NEAT that occur when women initiate a structured exercise program. METHODS: Previously sedentary women (n=98, 35.9±6.1 y, 75% white non-Hispanic, 29.8±8.2 kg/m2) completed an 8-week exercise-only intervention with the goal of achieving 150 min/week of moderate intensity walking. ActiGraph GT3X+ monitors were worn during waking hours for 1-week at baseline and throughout the intervention to measure exercise energy expenditure (ExEE) and changes in NEAT (kcal/d). Changes in EI (kcal/d) were measured via the National Cancer Institute’s ASA24 program on three randomly selected days at baseline and six days during the intervention. RESULTS: The exercise intervention directly increased ExEE by a mean of 103.3 kcal/d above baseline values. Reflecting the observation that 50% of women reported an intention to diet during the exercise intervention, there was a significant decrease in average EI (-185.3±558.1 kcal/d, p<.01), but no change in relative macronutrient intake (p>.35 for all). However, 27.6% of women reported increases in EI greater than their ExEE, including 20.4% of intended dieters. Modest average decreases in NEAT (-46.4±69.5 kcal/d, p<.01) were observed although 9.2% of women had decreases which exceeded their increased ExEE. Overall, combined changes in EI and NEAT totally offset ExEE for 28.6% of women. A smaller percentage of overweight and obese women (23.1%) than healthy weight women (39.4%) had compensatory changes exceeding ExEE, although these differences were not statistically significant (p=.09). CONCLUSIONS: Among women initiating a structured exercise program, changes in total daily EI are of greater magnitude than changes in NEAT. For approximately a quarter of participating women, compensatory behavioral changes appear to totally offset the additional ExEE. Supported by NHLBI-1R21HL113742-01

Temporal stability of personality traits in group-housed gestating sows

The movement of sows (Sus scrofa domesticus) out of individual gestation stalls and into group housing can introduce new sources of stress due to the enhanced environmental and social complexity. Some sows may have the behavioral capacity to adapt to these changes better than others. However, little is known about individual differences in behavioral responses, or personality traits, in gestating sows and how they impact the animal’s ability to cope with group housing. The temporal consistency in the assessment of an animal’s behavior is a prerequisite to the establishment of personality traits and was addressed at an interval of approximately five months during two consecutive gestation periods in the present study. Forty-six group-housed sows from a commercially available genetic line were assessed for aggressive and social behaviors at mixing into a group, reaction to human approach, ease of handling, exploration of an open field, and reaction to a novel object. Principal component analysis revealed the presence of three traits accounting for over 60% of the variance in behaviors: aggressive/dominant, avoidant of humans and active/exploratory. Individual component scores were significantly correlated between pregnancies demonstrating temporal stability of trait assessment. Significant relationships were found between aggressive/dominant component scores and individual feed rank at electronic sow feeding stations and skin lesion scores, as well as between avoidant of humans component scores and average number of stillbirths per litter. These findings provide evidence for the temporal stability of distinct behaviors contributing to personality traits within a group of genetically similar sows and demonstrate how these traits may be useful in identifying individuals likely to succeed in group housing.

Structural Organization of the Corpus Callosum Predicts Attentional Shifts after Continuous Theta Burst Stimulation

Repetitive transcranial magnetic stimulation (rTMS) applied over the right posterior parietal cortex (PPC) in healthy participants has been shown to trigger a significant rightward shift in the spatial allocation of visual attention, temporarily mimicking spatial deficits observed in neglect. In contrast, rTMS applied over the left PPC triggers a weaker or null attentional shift. However, large interindividual differences in responses to rTMS have been reported. Studies measuring changes in brain activation suggest that the effects of rTMS may depend on both interhemispheric and intrahemispheric interactions between cortical loci controlling visual attention. Here, we investigated whether variability in the structural organization of human white matter pathways subserving visual attention, as assessed by diffusion magnetic resonance imaging and tractography, could explain interindividual differences in the effects of rTMS. Most participants showed a rightward shift in the allocation of spatial attention after rTMS over the right intraparietal sulcus (IPS), but the size of this effect varied largely across participants. Conversely, rTMS over the left IPS resulted in strikingly opposed individual responses, with some participants responding with rightward and some with leftward attentional shifts. We demonstrate that microstructural and macrostructural variability within the corpus callosum, consistent with differential effects on cross-hemispheric interactions, predicts both the extent and the direction of the response to rTMS. Together, our findings suggest that the corpus callosum may have a dual inhibitory and excitatory function in maintaining the interhemispheric dynamics that underlie the allocation of spatial attention. The posterior parietal cortex (PPC) controls allocation of attention across left versus right visual fields. Damage to this area results in neglect, characterized by a lack of spatial awareness of the side of space contralateral to the brain injury. Transcranial magnetic stimulation over the PPC is used to study cognitive mechanisms of spatial attention and to examine the potential of this technique to treat neglect. However, large individual differences in behavioral responses to stimulation have been reported. We demonstrate that the variability in the structural organization of the corpus callosum accounts for these differences. Our findings suggest novel dual mechanism of the corpus callosum function in spatial attention and have broader implications for the use of stimulation in neglect rehabilitation.

基于个体差异的大样本脑影像数据在心理学研究中的应用

Psychological research frequently uses cognitive neuroscience technologies to reveal the brain mechanisms underlying the psychological structure of personality, cognition, and emotion. However, previous research has often been constrained by small samples and other features of the experimental design and data analysis. Additionally, individual differences in behavioral responses and cognitive or emotional processing have often been considered confounding factors or random error, so they are usually controlled in data analysis. Human activity is the result of interactions between genes, environment, and the brain. Therefore, the investigation of environmental factors and individual life experiences, the collection of large samples of behavior, and the use of multimodal brain imaging data measuring cognition, emotion, and personality can help to address several questions from an individual differences perspective: (1) the neural basis of personality; (2) the brain mechanisms of emotion; (3) the brain mechanisms of cognition; (4) the construction of a model to predict interactions between the environment, personality, the brain, and behavior. This article summarizes recent domestic and international studies on the relationship between brain imaging and behavior within a large sample, and it is a good way to understand the neural basis of behavior, personality, emotions, and cognitive ability from the perspective of individual differences.