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1.
Brain Topogr ; 37(6): 1055-1067, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38874853

RESUMO

The ability to comprehend the intention conveyed through human body movements is crucial for effective interpersonal interactions. If people can't understand the intention behind other individuals' isolated or interactive actions, their actions will become meaningless. Psychologists have investigated the cognitive processes and neural representations involved in understanding action intention, yet a cohesive theoretical explanation remains elusive. Hence, we mainly review existing literature related to neural correlates of action intention, and primarily propose a putative Three-stage Dynamic Brain-cognitive Model of understanding action intention, which involves body perception, action identification and intention understanding. Specifically, at the first stage, body parts/shapes are processed by those brain regions such as extrastriate and fusiform body areas; During the second stage, differentiating observed actions relies on configuring relationships between body parts, facilitated by the activation of the Mirror Neuron System; The last stage involves identifying various intention categories, utilizing the Mentalizing System for recruitment, and different activation patterns concerning the nature of the intentions participants dealing with. Finally, we delves into the clinical practice, like intervention training based on a theoretical model for individuals with autism spectrum disorders who encounter difficulties in interpersonal communication.


Assuntos
Encéfalo , Cognição , Intenção , Humanos , Encéfalo/fisiologia , Cognição/fisiologia , Movimento/fisiologia , Compreensão/fisiologia
2.
Clin Psychol Psychother ; 31(4): e3031, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39036831

RESUMO

OBJECTIVE: There has been an increasing interest in understanding what contributes to the development and what maintains posttraumatic stress disorder (PTSD). The cognitive model emphasizes that it is a disturbance of the autobiographical memory for the trauma, cognitive beliefs and maladaptive behaviour that maintain trauma symptoms. Interventions are based on cognitive restructuring and behaviour experiments to modify these beliefs. In contrast, the metacognitive model emphasizes that it is the metacognitive beliefs that give rise to the cognitive attentional syndrome (CAS) that maintain trauma symptoms. The focus of treatment is reducing CAS and working on metacognitive beliefs. The aim of this study was to explore the contribution of cognitions and metacognitive beliefs to trauma symptoms and investigate what predicts symptom burden in traumatized patients. METHOD: Participants (N = 290) diagnosed with PTSD were included, and hierarchical multiple regression analyses were performed to explore if cognitions and metacognitive beliefs explained additional and independent variance in trauma symptoms while controlling for age and gender. RESULTS: Both cognitions and metacognitive beliefs contributed independently and significantly to predicting trauma symptoms. CONCLUSION: The results provide further support for investigating what maintains trauma symptoms and what to target in treatment. This may have clinical implications for our theoretical and practical understanding of PTSD.


Assuntos
Metacognição , Transtornos de Estresse Pós-Traumáticos , Humanos , Transtornos de Estresse Pós-Traumáticos/psicologia , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Cognição , Adulto Jovem , Adolescente
3.
Learn Individ Differ ; 1102024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38405100

RESUMO

Dweck's social-cognitive model has long been used as a basis for achievement motivation research. However, few studies have examined the comprehensive model with interactions between perceived ability and achievement goals, and even fewer studies have focused on this model in a science academic context. With a sample of undergraduates (n = 1,036), the relations among mindsets, science academic self-efficacy, achievement goals, and achievement-related outcomes in science were examined. Fixed mindset related to performance goals. Growth mindset related to mastery goals and the number of courses completed. There was a significant indirect effect of growth mindset on interest value via mastery goals. Contrary to Dweck's model, the relation of performance goals to outcomes did not vary as a function of science academic self-efficacy. The findings provide empirical evidence for a more nuanced understanding of Dweck's model. They provide practical insights for how to support undergraduate students who are pursuing science-related career.

4.
BMC Psychiatry ; 23(1): 702, 2023 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-37759204

RESUMO

BACKROUND: Dysfunctional interpersonal beliefs (DIBs) are a key symptom domain in numerous mental disorders. Because DIBs exert a strong influence on social experience and behavior, they play an important role in a mental disorder's development and progression. To date, only the Interpersonal Cognitive Distortions Scale (ICDS) captures DIBs independently of specific disorders, populations, or contexts. The present study's aim was to psychometrically evaluate and validate a German translation of the ICDS. METHODS: The ICDS was administered along with indicators of convergent (rejection sensitivity, depressive expectations, interpersonal trust, interpersonal problems, perceived social support), discriminant (self-efficacy, perseverative negative thinking, optimism), and clinical validity (psychopathology, perceived stress, well-being) to a pooled sample incorporating non-clinical (N = 114) and clinical (N = 94) participants. RESULTS: An exploratory factor analysis (EFA) suggested a five-factor solution (factor loadings: .44 to .85). Correlational analyses demonstrated acceptable convergent (ρ = -.29 to -.35, ρ = .27 to .59), suboptimal discriminant (ρ = -.27 to -.38, ρ = .52), and acceptable clinical validity (ρ = -.21, ρ = .36 to .44) at the total-scale level. However, results at the subscale level were mixed and required nuanced interpretation. Likewise, internal consistency was acceptable at the total-scale level (α = .76), but ranged from good to poor at the subscale level (α = .61 to .80). DIBs mediated the negative relationship between mental disorder onset and psychopathology levels. DISCUSSION: Our results imply DIBs' relevance to mental health and related outcomes. When working with the ICDS's German version, we recommend employing only the "insecurity" subscale, as this was the only scale revealing acceptable psychometric properties. Future studies should improve the construct validity of the ICDS (and its subscales), e.g., by adding more items to the respective subscales and further classes of DIBs.


Assuntos
Disfunção Cognitiva , Psicopatologia , Humanos , Análise Fatorial , Saúde Mental , Otimismo
5.
Mem Cognit ; 51(2): 455-472, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36190659

RESUMO

The acquisition and retention of knowledge is affected by a multitude of factors including amount of practice, elapsed time since practice occurred, and the temporal distribution of practice. The third factor, temporal distribution of practice, is at the heart of research on the spacing effect. This research has consistently shown that separating practice repetitions by a delay slows acquisition but enhances retention. The current study addresses an empirical gap in the spacing effects literature. Namely, how does the allocation of a fixed number of practice repetitions among multiple sessions impact learning and retention? To address this question, we examined participants' acquisition and retention of declarative knowledge given different study schedules in which the number of practice repetitions increased, decreased, or remained constant across multiple acquisition sessions. The primary result was that retention depended strongly on the total number of sessions in which an item appeared, but not on how practice repetitions were distributed among those sessions. This outcome was consistent with predictions from a computational cognitive model of skill acquisition and retention called the Predictive Performance Equation (PPE). The success of the model in accounting for the patterns of performance across a large set of study schedules suggests that it can be used to tame the complexity of the design space and to identify schedules to enhance knowledge acquisition and retention.


Assuntos
Aprendizagem , Retenção Psicológica , Humanos , Conhecimento
6.
Aging Ment Health ; 27(8): 1644-1651, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36809116

RESUMO

Objectives: Knowledge about the mechanism of the personal stigma of depression may inform strategies to reduce stigma and promote help-seeking. We examined the dimensionality and risk factors of the personal stigma of depression in older adults at risk of depression.Methods: Seven-hundred and one Hong Kong adults aged 50 years and older at risk of depression completed the personal stigma subscale of the depression Stigma Scale (DSS-personal) at two-time points. We used exploratory factor analysis (EFA) to explore the factor structure of DSS personal and confirmatory factor analysis to examine the model fit of the EFA-informed factor structure and structures proposed in previous studies. Regression analyses examined the relationships between risk factors and personal stigma dimensions.Results: Factor analyses identified a 3-factor structure of DSS-personal resembling the social-cognitive model consistent over time and included stereotype, prejudice, and discrimination (CFI = 0.95, TLI = 0.92, RMSEA = 0.05). Regression analyses indicated all stigma dimensions were associated with older age, less education, and no personal history of depression (B = -0.44 to 0.06); discrimination was also associated with more depressive symptoms (B = 0.10 to 0.12).Conclusion: Findings illustrated the potential theoretical underpinning of DSS-personal. Stigma reduction interventions could target and tailor to older adults with risk factors to enhance effectiveness and promote help-seeking.


Assuntos
Depressão , Estigma Social , Humanos , Pessoa de Meia-Idade , Idoso , Depressão/epidemiologia , Depressão/psicologia , Inquéritos e Questionários , Estereotipagem , Fatores de Risco
7.
Psychol Med ; 52(3): 538-547, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-32646525

RESUMO

BACKGROUND: Cognitive models propose that behavioural responses to voices maintain distress by preventing disconfirmation of negative beliefs about voices. We used Experience Sampling Methodology (ESM) to examine the hypothesized maintenance role of behavioural responses during daily life. METHOD: Thirty-one outpatients with frequent voices completed a smartphone-based ESM questionnaire 10 times a day over 9 days, assessing voice-related distress; resistance and compliance responses to voices; voice characteristics (intensity and negative content); appraisals of voice dominance, uncontrollability and intrusiveness. RESULTS: In line with predictions, behavioural responses were associated with voice appraisals (dominance and uncontrollability), but not voice characteristics. Greater resistance and compliance were reported in moments of increased voice distress, but these associations did not persist after controlling for concurrent voice appraisals and characteristics. Voice distress was predicted by appraisals, and, unexpectedly, also by voice characteristics. As predicted, compliance and resistance were related to increases in distress at subsequent timepoints, whilst antecedent voice appraisals and characteristics had no such effect. Compliance, but not resistance, additionally predicted subsequent increases in voice uncontrollability. In both cases, the reverse models showed no association, indicating directional effects of responses on subsequent distress, and of compliance on uncontrollability appraisals. CONCLUSIONS: These results provide support for the cognitive model by suggesting that momentary behavioural and emotional responses to voices are associated with concurrent negative voice appraisals. Findings suggest that behavioural responses may be driven by voice appraisals, rather than directly by distress, and may in turn maintain voice appraisals and associated distress during the course of daily life.


Assuntos
Alucinações , Voz , Cognição , Avaliação Momentânea Ecológica , Emoções , Alucinações/psicologia , Humanos
8.
Brain Cogn ; 158: 105850, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35183884

RESUMO

The antisaccade paradigm is frequently applied to measure inhibitory control. Typically, simple, perceptually neutral stimuli are used as cues. Recently, emotional versions of this paradigm have also been employed. In our study, we used both versions of the paradigm. In addition, scrambled faces served to control for stimulus size and emotional valence. We applied a hierarchical extension to the Linear Approach to Threshold Ergodic Rate (LATER) process model, which allows the estimation of two latent cognitive parameters: speed of information accumulation (accretion rate) and the amount of information needed before a saccadic movement (caution threshold). We hypothesized a faster accretion rate and lower caution threshold for circular and scrambled compared to emotional face stimuli as well as meaningful differences between individual emotions. Our results showed a faster accretion rate and lower caution threshold for emotional compared to circular stimuli, though. In contrast, scrambled faces had a lower accretion rate and lower caution threshold. Furthermore, the LATER model uncovered subtle differences between different emotions. Happy faces tend to receive a faster accretion rate and higher caution threshold than neutral ones, while for fearful faces it was the other way around. Our results contradict earlier research on emotional stimuli interfering inhibitory control.


Assuntos
Síndrome de DiGeorge , Movimentos Sacádicos , Sinais (Psicologia) , Emoções , Medo , Humanos , Tempo de Reação
9.
Hum Factors ; : 187208221132740, 2022 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-36259529

RESUMO

OBJECTIVE: This study investigated the use of human performance modeling (HPM) approach for prediction of driver behavior and interactions with in-vehicle technology. BACKGROUND: HPM has been applied in numerous human factors domains such as surface transportation as it can quantify and predict human performance; however, there has been no integrated literature review for predicting driver behavior and interactions with in-vehicle technology in terms of the characteristics of methods used and variables explored. METHOD: A systematic literature review was conducted using Compendex, Web of Science, and Google Scholar. As a result, 100 studies met the inclusion criteria and were reviewed by the authors. Model characteristics and variables were summarized to identify the research gaps and to provide a lookup table to select an appropriate method. RESULTS: The findings provided information on how to select an appropriate HPM based on a combination of independent and dependent variables. The review also summarized the characteristics, limitations, applications, modeling tools, and theoretical bases of the major HPMs. CONCLUSION: The study provided a summary of state-of-the-art on the use of HPM to model driver behavior and use of in-vehicle technology. We provided a table that can assist researchers to find an appropriate modeling approach based on the study independent and dependent variables. APPLICATION: The findings of this study can facilitate the use of HPM in surface transportation and reduce the learning time for researchers especially those with limited modeling background.

10.
Hum Factors ; : 187208221143028, 2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36473708

RESUMO

OBJECTIVE: This study develops a computational model to predict drivers' response time and understand the underlying cognitive mechanism for freeway exiting takeovers in conditionally automated vehicles (AVs). BACKGROUND: Previous research has modeled drivers' takeover response time in emergency scenarios that demand a quick response. However, existing models may not be applicable for scheduled, non-time-critical takeovers as drivers take longer to resume control when there is no time pressure. A model of driver response time in non-time-critical takeovers is lacking. METHOD: A computational cognitive model of driver takeover response time is developed based on Queuing Network-Model Human Processor (QN-MHP) architecture. The model quantifies gaze redirection in response to takeover request (ToR), task prioritization, driver situation awareness, and driver trust to address the complexities of drivers' takeover strategies when sufficient time budget exists. RESULTS: Experimental data of a preliminary driving simulator study were used to validate the model. The model accounted for 97% of the experimental takeover response time for freeway exiting. CONCLUSION: The current model can successfully predict drivers' response time for scheduled, non-time-critical freeway exiting takeovers in conditionally AVs. APPLICATION: This model can be applied to the human-machine interface design with respect to ToR lead time for enhancing safe freeway exiting takeovers in conditionally AVs. It also provides a foundation for future modeling work towards an integrated driver model of freeway exiting takeover performance.

11.
Behav Cogn Psychother ; : 1-12, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-35166196

RESUMO

BACKGROUND: Many patients with mental health disorders become increasingly isolated at home due to anxiety about going outside. A cognitive perspective on this difficulty is that threat cognitions lead to the safety-seeking behavioural response of agoraphobic avoidance. AIMS: We sought to develop a brief questionnaire, suitable for research and clinical practice, to assess a wide range of cognitions likely to lead to agoraphobic avoidance. We also included two additional subscales assessing two types of safety-seeking defensive responses: anxious avoidance and within-situation safety behaviours. METHOD: 198 patients with psychosis and agoraphobic avoidance and 1947 non-clinical individuals completed the item pool and measures of agoraphobic avoidance, generalised anxiety, social anxiety, depression and paranoia. Factor analyses were used to derive the Oxford Cognitions and Defences Questionnaire (O-CDQ). RESULTS: The O-CDQ consists of three subscales: threat cognitions (14 items), anxious avoidance (11 items), and within-situation safety behaviours (8 items). Separate confirmatory factor analyses demonstrated a good model fit for all subscales. The cognitions subscale was significantly associated with agoraphobic avoidance (r = .672, p < .001), social anxiety (r = .617, p < .001), generalized anxiety (r = .746, p < .001), depression (r = .619, p < .001) and paranoia (r = .655, p < .001). Additionally, both the O-CDQ avoidance (r = .867, p < .001) and within-situation safety behaviours (r = .757, p < .001) subscales were highly correlated with agoraphobic avoidance. The O-CDQ demonstrated excellent internal consistency (cognitions Cronbach's alpha = .93, avoidance Cronbach's alpha = .94, within-situation Cronbach's alpha = .93) and test-re-test reliability (cognitions ICC = 0.88, avoidance ICC = 0.92, within-situation ICC = 0.89). CONCLUSIONS: The O-CDQ, consisting of three separate scales, has excellent psychometric properties and may prove a helpful tool for understanding agoraphobic avoidance across mental health disorders.

12.
Curr Psychol ; : 1-10, 2022 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-35153460

RESUMO

The experience of socially aversive events is proposed to be a critical etiological factor in the development of social anxiety symptoms even though the experience itself is also common among healthy individuals. Rather than the event itself, accompanying factors such as maladaptive processing might be associated with higher levels of social anxiety symptoms. One-hundred-seventy-four individuals participated in this online-survey comprising questionnaires regarding social anxiety symptoms and retrospective reports concerning maladaptive processing of the worst socially aversive event. Structural equation modelling was used to analyze the hypothesized mediation of maladaptive processing and fear of negative evaluation by intrusive re-experiencing and social phobic beliefs. The positive association between retrospectively evaluated maladaptive processing after the worst socially aversive event and fear of negative evaluation was mediated by social phobic beliefs but not by intrusive re-experiencing. These results point towards the relevance of further investigating processing strategies after socially aversive events as a potential influencing factor for SAD development. Trial registration. The trial was registered at the German Clinical Trial Register (DRKS00021502) on June 3rd, 2020. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12144-022-02805-9.

13.
Clin Case Stud ; 21(6): 588-605, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38603092

RESUMO

A small but clinically significant number of people experience delayed-onset Post-traumatic stress disorder (PTSD); symptoms of trauma years after the events which are now being re-experienced. The following case report describes the use of the cognitive-behavioural treatment for PTSD with a woman experiencing flashbacks to domestic abuse endured more than 20 years ago. Mask-wearing mandated as a result of the COVID-19 pandemic triggered non-contextualised memories of life-threatening physical violence by an abuser who covered his face. She had been managing her flashbacks and intrusive thoughts with both behavioural and experiential forms of avoidance. An 18-session intervention was provided in her own home due to physical health difficulties. Treatment focused on managing hyper-arousal, reducing thought suppression, in-vivo exposure, stimulus-discrimination and re-contextualising traumatic memories. Regular outcome measurements were kept and results are presented as a single-case experimental design in 'AB' format (i.e. baseline period pre intervention). Symptoms of trauma fell to levels non-indicative of PTSD and speak to the evidence base for this modality, even when applied to delayed-onset difficulties in a non-traditional therapy setting. This conclusion is lent extra credence by an experimental design with good internal validity.

14.
Soins Psychiatr ; 43(340): 29-32, 2022.
Artigo em Francês | MEDLINE | ID: mdl-36109135

RESUMO

Recovering from a mental disorder is a process by which the affected person will develop a new life project, based on the optimal use of personal and environmental resources. This involves adapting and managing certain symptoms better, in order to be able to rebuild oneself psychologically. This may be the case for delusions, which need to be distanced and accepted in order to develop this new life stage in. In this perspective, the notions of mourning for the self and mourning for delusional beliefs seem to be necessary steps in the reconstruction of a self that is favourable to recovery.


Assuntos
Delusões , Transtornos Psicóticos , Pesar , Humanos
15.
J Aging Phys Act ; 29(6): 931-940, 2021 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-34135127

RESUMO

Improving the capacity for physical activity interventions to maintain behavior change is a key public health concern and an important strategy for the health and independence of older adults. Ways of ensuring effective maintenance of physical activity levels in older adults are unclear. This study includes the objective measure of moderate-to-vigorous physical activity (MVPA); self-reported self-efficacy; and self-regulation at four timepoints (baseline, intervention completion at 4 months, 12-, and 18-month follow-up) from the SITLESS study, a clinical trial conducted with a cohort of community-dwelling older adults (≥65 years) from Denmark, Germany, Spain, and the United Kingdom. A cross-lagged analysis found that self-regulation and self-efficacy may be key determinants of MVPA behavior in community-dwelling older adults. More specifically, the use of behavioral support strategies represents an important correlate of MVPA behavior, and its association with MVPA may be mediated by self-regulation and self-efficacy in older adults in the short and long term.


Assuntos
Autoeficácia , Autocontrole , Idoso , Exercício Físico , Humanos , Vida Independente , Atividade Motora
16.
Behav Cogn Psychother ; : 1-11, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34651570

RESUMO

BACKGROUND: According to Clark and Wells' cognitive model (Clark and Wells, 1995), social anxiety is maintained by both a negative self-image and self-focused attention (SFA). Although these maintaining factors were investigated extensively in previous studies, the direction of this relationship remains unclear, and so far, few studies have investigated self-image and SFA together within a current social interaction situation. AIMS: The aim of this experiment is to investigate the influence of a negative versus positive self-image on social anxiety and on SFA during a social interaction. METHOD: High (n = 27) and low (n = 36) socially anxious participants, holding a manipulated negative versus positive self-image in mind, had a real-time video conversation with a confederate. Social anxiety, SFA and state anxiety before and during the conversation were measured with questionnaires. RESULTS: An interaction between negative self-image and social anxiety showed that high socially anxious individuals with a negative self-image in mind were more anxious than those with a positive self-image in mind during the conversation. They were also more anxious compared with low socially anxious individuals. Furthermore, high socially anxious individuals reported higher SFA; however, SFA was not affected by negative or positive self-image. CONCLUSION: The present results confirm once again the strong influence of self-image and SFA on social anxiety, highlighting that a negative self-image has more impact on socially anxious individuals. Moreover, the present results suggest that SFA is not necessarily affected by a negative self-image, indicating that therapies should focus on both.

17.
Behav Res Methods ; 53(1): 78-95, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32572844

RESUMO

It is commonly assumed that a specific testing occasion (task, design, procedure, etc.) provides insights that generalize beyond that occasion. This assumption is infrequently carefully tested in data. We develop a statistically principled method to directly estimate the correlation between latent components of cognitive processing across tasks, contexts, and time. This method simultaneously estimates individual-participant parameters of a cognitive model at each testing occasion, group-level parameters representing across-participant parameter averages and variances, and across-task correlations. The approach provides a natural way to "borrow" strength across testing occasions, which can increase the precision of parameter estimates across all testing occasions. Two example applications demonstrate that the method is practical in standard designs. The examples, and a simulation study, also provide evidence about the reliability and validity of parameter estimates from the linear ballistic accumulator model. We conclude by highlighting the potential of the parameter-correlation method to provide an "assumption-light" tool for estimating the relatedness of cognitive processes across tasks, contexts, and time.


Assuntos
Cognição , Simulação por Computador , Humanos , Modelos Lineares , Tempo de Reação , Reprodutibilidade dos Testes
18.
Environ Dev Sustain ; 23(11): 16588-16616, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34720690

RESUMO

Appreciating and dealing with the plurality of farmers' perceptions and their contextual knowledge and perspectives of the functioning and performance of their agroecosystems-in other words, their 'mental models'-is central for appropriate and sustainable agricultural development. In this respect, the sustainable development goals (SDGs) aim to eradicate poverty and food insecurity by 2030 by envisioning social inclusivity that incorporates the preferences and knowledge of key stakeholders, including farmers. Agricultural development interventions and policies directed at sustainable intensification (SI), however, do not sufficiently account for farmers' perceptions, beliefs, priorities, or interests. Considering two contrasting agroecological systems in coastal Bangladesh, we used a fuzzy cognitive mapping (FCM)-based simulation and sensitivity analysis of mental models of respondents of different farm types from 240 farm households. The employed FCM mental models were able to (1) capture farmers' perception of farming system concepts and relationships for each farm type and (2) assess the impact of external interventions (drivers) on cropping intensification and food security. We decomposed the FCM models' variance into the first-order sensitivity index (SVI) and total sensitivity index (TSI) using a winding stairs algorithm. Both within and outside polder areas, the highest TSIs (35-68%) were observed for effects of agricultural extension on changes in other concepts in the map, particularly food security and income (SI indicators), indicating the importance of extension programs for SI. Outside polders, drainage and micro-credit were also influential; within polders, the availability of micro-credit appears to affect farmer perceptions of SI indicators more than drainage. This study demonstrated the importance of reflection on the differing perspectives of farmers both within and outside polders to identify entry points for development interventions. In addition, the study underscores the need for micro-farming systems-level research to assess the context-based feasibility of introduced interventions as perceived by farmers of different farm types. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10668-021-01342-y.

19.
J Neurosci ; 39(30): 5910-5921, 2019 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-31123103

RESUMO

The speed of motor reaction to an external stimulus varies substantially between individuals and is slowed in aging. However, the neuroanatomical origins of interindividual variability in reaction time (RT) remain unclear. Here, we combined a cognitive model of RT and a biophysical compartment model of diffusion-weighted MRI (DWI) to characterize the relationship between RT and microstructure of the corticospinal tract (CST) and the optic radiation (OR), the primary motor output and visual input pathways associated with visual-motor responses. We fitted an accumulator model of RT to 46 female human participants' behavioral performance in a simple reaction time task. The non-decision time parameter (Ter) derived from the model was used to account for the latencies of stimulus encoding and action initiation. From multi-shell DWI data, we quantified tissue microstructure of the CST and OR with the neurite orientation dispersion and density imaging (NODDI) model as well as the conventional diffusion tensor imaging model. Using novel skeletonization and segmentation approaches, we showed that DWI-based microstructure metrics varied substantially along CST and OR. The Ter of individual participants was negatively correlated with the NODDI measure of the neurite density in the bilateral superior CST. Further, we found no significant correlation between the microstructural measures and mean RT. Thus, our findings suggest a link between interindividual differences in sensorimotor speed and selective microstructural properties in white-matter tracts.SIGNIFICANCE STATEMENT How does our brain structure contribute to our speed to react? Here, we provided anatomically specific evidence that interindividual differences in response speed is associated with white-matter microstructure. Using a cognitive model of reaction time (RT), we estimated the non-decision time, as an index of the latencies of stimulus encoding and action initiation, during a simple reaction time task. Using an advanced microstructural model for diffusion MRI, we estimated the tissue properties and their variations along the corticospinal tract and optic radiation. We found significant location-specific correlations between the microstructural measures and the model-derived parameter of non-decision time but not mean RT. These results highlight the neuroanatomical signature of interindividual variability in response speed along the sensorimotor pathways.


Assuntos
Cognição/fisiologia , Tratos Piramidais/diagnóstico por imagem , Tratos Piramidais/fisiologia , Tempo de Reação/fisiologia , Substância Branca/diagnóstico por imagem , Substância Branca/fisiologia , Tomada de Decisões/fisiologia , Imagem de Tensor de Difusão/métodos , Feminino , Humanos , Masculino , Distribuição Aleatória , Adulto Jovem
20.
J Neurophysiol ; 124(4): 1056-1071, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32845769

RESUMO

Mounting evidence suggests that the role of sensory cortices in perceptual decision making goes beyond the mere representation of the discriminative stimuli and additionally involves the representation of nonsensory variables such as reward expectation. However, the relevance of these representations for behavior is not clear. To address this issue, we trained rats to discriminate sounds in a single-interval forced-choice task and then confronted the animals with unsignaled blockwise changes of reward probabilities. We found that unequal reward probabilities for the two choice options led to substantial shifts in response bias without concomitant reduction in stimulus discrimination. Although decisional biases were on average less extreme than required to maximize overall reinforcement, a model-based analysis revealed that rats managed to harvest >97% of rewards. Neurons in auditory cortex recorded during task performance weakly differentiated the discriminative stimuli but more strongly the subsequent goal-directed movement. Although 10-20% of units exhibited significantly different firing rates between task epochs with different response biases, control experiments showed this to result from inflated false positive rates due to unspecific temporal correlations of spiking activity rather than changing reinforcement contingencies. Transient pharmacological inactivation of auditory cortex reduced sound discriminability without affecting other measures of performance, whereas inactivation of medial prefrontal cortex affected both discriminability and bias. Together, these results suggest that auditory cortex activity only weakly reflects decisional variables during flexible updating of stimulus-response-outcome contingencies and does not play a crucial role in sound-cued adaptive behavior, beyond the representation of the discriminative stimuli.NEW & NOTEWORTHY Recent evidence suggests that sensory cortex represents nonsensory variables such as reward expectation, but the relevance of these representations for behavior is not well understood. We show that rat auditory cortex (AC) is modulated during movement and reward anticipation in a sound-cued reward tracking task, whereas AC inactivation only impaired discrimination without affecting reward tracking, consistent with a predominantly sensory role of AC.


Assuntos
Adaptação Psicológica , Córtex Auditivo/fisiologia , Objetivos , Movimento , Recompensa , Animais , Percepção Auditiva , Comportamento de Escolha , Sinais (Psicologia) , Discriminação Psicológica , Masculino , Córtex Pré-Frontal/fisiologia , Ratos , Ratos Long-Evans
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