Psychology, Department of

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Learning-Induced Changes in Attentional Allocation during Categorization: A Sizable Catalog of Attention Change as Measured by Eye Movements

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2014-01-31
Abstract: 

Learning how to allocate attention properly is essential for success at many categorization tasks. Advances in our understanding of learned attention are stymied by a chicken-and-egg problem: there are no theoretical accounts of learned attention that predict patterns of eye movements, making data collection difficult to justify, and there are not enough datasets to support the development of a rich theory of learned attention. The present work addresses this by reporting five measures relating to the overt allocation of attention across 10 category learning experiments: accuracy, probability of fixating irrelevant information, number of fixations to category features, the amount of change in the allocation of attention (using a new measure called Time Proportion Shift - TIPS), and a measure of the relationship between attention change and erroneous responses. Using these measures, the data suggest that eye-movements are not substantially connected to error in most cases and that aggregate trial-by-trial attention change is generally stable across a number of changing task variables. The data presented here provide a target for computational models that aim to account for changes in overt attentional behaviors across learning.

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Article
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The Emotional Toll of Hell: Cross-National and Experimental Evidence for the Negative Well-Being Effects of Hell Beliefs

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2014-01-22
Abstract: 

Though beliefs in Heaven and Hell are related, they are associated with different personality characteristics and social phenomena. Here we present three studies measuring Heaven and Hell beliefs' associations with and impact on subjective well-being. We find that a belief in Heaven is consistently associated with greater happiness and life satisfaction while a belief in Hell is associated with lower happiness and life satisfaction at the national (Study 1) and individual (Study 2) level. An experimental priming study (Study 3) suggests that these differences are mainly driven by the negative emotional impact of Hell beliefs. Possible cultural evolutionary explanations for the persistence of such a distressing religious concept are discussed.

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Article
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Proactive and Reactive Processes in the Medial Frontal Cortex: An Electrophysiological Study

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2014-01-03
Abstract: 

The posterior medial frontal cortex (pMFC) is known to be involved in adaptive goal-directed behavior, but its specific function is not yet clear. Most theories have proposed that the pMFC monitors performance in a reactive manner only, but it is possible that the pMFC also contributes to performance monitoring in a proactive manner. To date, the evidence for proactive pMFC activity is equivocal. Here, we investigated pMFC activity before, during and after the performance of a challenging motor task. Participants navigated a cursor through narrow and wide mazes in randomly intermixed trials. On each trial, participants saw previews of the actual maze display prior to gaining control of the cursor. Event-related potentials (ERPs) to the preview displays were compared to ERPs elicited by no-go signals and errors. Compared to the wider maze, the preview display for the more challenging narrow maze elicited a medial-frontal negativity (MFN) similar to the ERP components elicited by no-go signals and errors. Like these known ERP components, the preview-elicited MFN appeared to be generated from a source in pMFC. This is consistent with the hypothesis that the pMFC participates in adaptive behavior whenever there is a need for increased effort to maintain successful task performance

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Article
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Pharmacological Inhibition of O-GlcNAcase (OGA) Prevents Cognitive Decline and Amyloid Plaque Formation in Bigenic Tau/APP Mutant Mice

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2014
Abstract: 

Background

Amyloid plaques and neurofibrillary tangles (NFTs) are the defining pathological hallmarks of Alzheimer’s disease (AD). Increasing the quantity of the O-linked N-acetylglucosamine (O-GlcNAc) post-translational modification of nuclear and cytoplasmic proteins slows neurodegeneration and blocks the formation of NFTs in a tauopathy mouse model. It remains unknown, however, if O-GlcNAc can influence the formation of amyloid plaques in the presence of tau pathology.

Results

We treated double transgenic TAPP mice, which express both mutant human tau and amyloid precursor protein (APP), with a highly selective orally bioavailable inhibitor of the enzyme responsible for removing O-GlcNAc (OGA) to increase O-GlcNAc in the brain. We find that increased O-GlcNAc levels block cognitive decline in the TAPP mice and this effect parallels decreased β-amyloid peptide levels and decreased levels of amyloid plaques.

Conclusions

This study indicates that increased O-GlcNAc can influence β-amyloid pathology in the presence of tau pathology. The findings provide good support for OGA as a promising therapeutic target to alter disease progression in Alzheimer disease.

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Article
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Intimate Partner Abuse Before and During Pregnancy as Risk Factors for Postpartum Mental Health Problems

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2014
Abstract: 

Background

Although research has established the profound effects that intimate partner abuse can have on postpartum mental health, little is known regarding how this association may change as a function of the timing and type of abuse. This study examined associations of psychological, physical and sexual abuse experienced as adults before and during pregnancy with symptoms of postpartum mental health problems in a non-clinical sample of women.

Methods

English-speaking mothers aged 18 years and older in the metropolitan area of a large, Western Canadian city were recruited to participate in a study of women’s health after pregnancy. The study was advertised in hospitals, local newspapers, community venues, and relevant websites. One-hundred women completed standardized, self-report questionnaires during semi-structured interviews conducted by female research assistants at approximately 2 months postpartum. In addition to questions about their general health and well-being, participants answered questions about their experiences of intimate partner abuse and about their mental health during the postpartum period.

Results

Almost two-thirds (61.0%) of women reported postpartum mental health symptoms above normal levels, with 47.0% reporting symptoms at moderate or higher levels. The majority reported some form of intimate partner abuse before pregnancy (84.0%) and more than two-thirds (70.0%), during pregnancy; however, the abuse was typically minor in nature. Multivariate models revealed that women who experienced intimate partner abuse—whether before or during pregnancy—reported higher levels of postpartum mental health problems; however, associations differed as a function of the timing and type of abuse, as well as specific mental health symptoms. Multivariate models also showed that as the number of types of intimate partner abuse experienced increased, so did the negative effects on postpartum mental health.

Conclusions

Results of this study provide further evidence that intimate partner abuse is a risk factor for postpartum mental health problems. They also underscore the complex risks and needs associated with intimate partner abuse among postpartum women and support the use of integrated approaches to treating postpartum mental health problems. Future efforts should focus on the extent to which strategies designed to reduce intimate partner abuse also improve postpartum mental health and vice versus.

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Article
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Personalized Risk Assessment of Drug-Related Harm Is Associated with Health Outcomes

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2013
Abstract: 

Background

The Independent Scientific Committee on Drugs (ISCD) assigned quantitative scores for harm to 20 drugs. We hypothesized that a personalized, ISCD-based Composite Harm Score (CHS) would be associated with poor health outcomes in polysubstance users.

Methods

A prospective community sample (n=293) of adults living in marginal housing was assessed for substance use. The CHS was calculated based on the ISCD index, and the personal substance use characteristics over four weeks. Regression models estimated the association between CHS and physical, psychological, and social health outcomes.

Results

Polysubstance use was pervasive (95.8%), as was multimorbid illness (median 3, possible range 0–12). The median CHS was 2845 (interquartile range 1865–3977). Adjusting for age and sex, every 1000-unit CHS increase was associated with greater mortality (odds ratio [OR] 1.47, 95% confidence interval [CI] 1.07–2.01, p = 0.02), and persistent hepatitis C infection (OR 1.29, 95% CI 1.02–1.67, p = 0.04). The likelihood of substance-induced psychosis increased 1.39-fold (95% CI 1.13–1.67, p = 0.001). The amount spent on drugs increased 1.51-fold (1.40–1.62, p < 0.001) and the odds of having committed a crime increased 1.74-fold (1.46–2.10, p < 0.001). Multimorbid illness increased 1.43-fold (95% CI 1.26–1.63, p < 0.001).

Conclusions

Greater CHS predicts poorer physical, psychological, and social health, and may be a useful quantitative, personalized measure of risk for drug-related harm.

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Article
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Prosocial Bonuses Increase Employee Satisfaction and Team Performance

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2013
Abstract: 

In three field studies, we explore the impact of providing employees and teammates with prosocial bonuses, a novel type of bonus spent on others rather than on oneself. In Experiment 1, we show that prosocial bonuses in the form of donations to charity lead to happier and more satisfied employees at an Australian bank. In Experiments 2a and 2b, we show that prosocial bonuses in the form of expenditures on teammates lead to better performance in both sports teams in Canada and pharmaceutical sales teams in Belgium. These results suggest that a minor adjustment to employee bonuses – shifting the focus from the self to others – can produce measurable benefits for employees and organizations.

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Article
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Mental Rotational Ability Is Correlated with Spatial but Not Verbal Working Memory Performance and P300 Amplitude in Males

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2013
Abstract: 

This study investigated how both sex and individual differences in a mental rotation test (MRT) influence performance on working memory (WM). To identify the neural substrate supporting these differences, brain electrical activity was measured using the event-related potential technique. No significant sex differences were observed in a test of verbal WM, however males were significantly faster than females to respond to probe stimuli in a test of spatial WM. This difference was no longer significant after controlling for differences in MRT score, suggesting that rotational ability mediates performance in the spatial memory task for both sexes. A posterior P300 was observed in both tasks as participants encoded information into memory, however the amplitude of the P300 correlated with RT in the spatial task but not in the verbal task. Individual differences in the MRT also correlated with RT and with the amplitude of the P300, but again only in the spatial task. After splitting the analysis by sex, partial correlations controlling for MRT revealed that for males, individual differences in rotational ability completely mediated the correlation between the P300 and RT in the spatial task. This mediating effect was not observed for the female participants. The results therefore suggest a relatively stronger association in males between innate mental rotational ability, spatial memory performance, and brain electrophysiological processes supporting spatial memory.

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Article
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Photic and Pineal Modulation of Food Anticipatory Circadian Activity Rhythms in Rodents

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2013
Abstract: 

Restricted daily feeding schedules entrain circadian oscillators that generate food anticipatory activity (FAA) rhythms in nocturnal rodents. The location of food-entrainable oscillators (FEOs) necessary for FAA remains uncertain. The most common procedure for inducing circadian FAA is to limit food access to a few hours in the middle of the light period, when activity levels are normally low. Although light at night suppresses activity (negative masking) in nocturnal rodents, it does not prevent the expression of daytime FAA. Nonetheless, light could reduce the duration or magnitude of FAA. If so, then neural or genetic ablations designed to identify components of the food-entrainable circadian system could alter the expression of FAA by affecting behavioral responses to light. To assess the plausibility of light as a potential mediating variable in studies of FAA mechanisms, we quantified FAA in rats and mice alternately maintained in a standard full photoperiod (12h of light/day) and in a skeleton photoperiod (two 60 min light pulses simulating dawn and dusk). In both species, FAA was significantly and reversibly enhanced in the skeleton photoperiod compared to the full photoperiod. In a third experiment, FAA was found to be significantly attenuated in rats by pinealectomy, a procedure that has been reported to enhance some effects of light on behavioral circadian rhythms. These results indicate that procedures affecting behavioral responses to light can significantly alter the magnitude of food anticipatory rhythms in rodents.

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Article
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Winning Isn't Everything: Mood and Testosterone Regulate the Cortisol Response in Competition

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2013
Abstract: 

Dominance contests are recurrent and widespread causes of stress among mammals. Studies of activation of the stress axis in social defeat – as reflected in levels of adrenal glucocorticoid, cortisol – have generated scattered and sometimes contradictory results, suggesting that biopsychological individual differences might play an important mediating role, at least in humans. In the context of a larger study of the regulation of endocrine responses to competition, we evaluated the notion that mood states, such as self-assurance and hostility, may influence cortisol reactivity to dominance cues via an interplay with baseline testosterone, considered as a potential marker of individual differences in dominance. Seventy healthy male university students (mean age 20.02, range 18–26) provided saliva samples before and after competing for fifteen minutes on a rigged computer task. After a winner was determined, all participants were assessed on their mood states through a standardized psychometric instrument (PANAS-X). Among winners of a rigged videogame competition, we found a significant interaction between testosterone and self-assurance in relation to post-competition cortisol. Specifically, self-assurance was associated with lower post-competition cortisol in subjects with high baseline testosterone levels, but no such relationship was observed in subjects with lower baseline testosterone levels. In losers of the competition no interaction effect between basal testosterone and hostility was observed. However, in this subgroup a significant negative relationship between basal testosterone and post-competition cortisol was evident. Overall, these findings provide initial support for the novel hypothesis that biological motivational predispositions (i.e. basal testosterone) and state (i.e. mood changes) may interact in regulating the hypothalamic-pituitary-adrenal axis activation after a social contest.

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