A role for olfaction in object recognition by normal and hippocampal-damaged rats

To examine how olfactory and visual factors affect object discriminations in rats with and without hippocampus damage, the authors trained Long-Evans rats on simple object discriminations. They then examined how these discriminations were affected by rotations of the objects, by coating the objects in a transparent acrylic coating, or by both rotating and coating the objects in acrylic. The rats displayed no impairments when the objects were only sprayed in acrylic, and they displayed minor impairments when the objects were rotated. However, when the objects were both rotated and acrylic coated, the rats displayed severe impairments. This suggests that the rats are solving the rotated-only phase based on surface features of the objects (probably odor) and not based on the visual information. Such species' biases for obtaining object information are important factors to consider when designing and interpreting visual memory experiments across species. There was no difference in performance between the rats with hippocampus damage and the sham rats, and this is consistent with the literature on similar tasks.     

Homework,stress, and mood disturbance in senior high school students

This study aimed at investigating the relationship between hours of homework, stress, and mood disturbance in senior high school students, 141 boys and 228 girls, recruited from high schools across Victoria, Australia. Participants' ages ranged from 16 to 18 years (M = 16.6, SD = .6). A 1-wk. homework diary, a Self-reported Stress scale, and the Profile of Mood States were administered to students. Analysis showed that the number of hours spent completing homework ranged from 10 to 65 hours per week (M = 37.0, SD = 12.2). Independent samples t-test analyses showed significant sex differences, with female students scoring higher on hours of homework, stress, and mood disturbance compared to male students. Pearson product-moment correlations were significant and positive for hours of homework with stress and for hours of homework with mood disturbance.     

Beyond monoamines: glutamatergic function in mood disorders

The monoamine theory has implicated abnormalities in serotonin and norepinephrine in the pathophysiology of major depression and bipolar illness and contributed greatly to our understanding of mood disorders and their treatment. Nevertheless, some limitations of this model still exist that require researchers and clinicians to seek further explanation and develop novel interventions that reach beyond the confines of the monoaminergic systems. Recent studies have provided strong evidence that glutamate and other amino acid neurotransmitters are involved in the pathophysiology and treatment of mood disorders. Studies employing in vivo magnetic resonance spectroscopy have revealed altered cortical glutamate levels in depressed subjects. Consistent with a model of excessive glutamate-induced excitation in mood disorders, several antiglutamatergic agents, such as riluzole and lamotrigine, have demonstrated potential antidepressant efficacy. Glial cell abnormalities commonly associated with mood disorders may at least partly account for the impairment in glutamate action since glial cells play a primary role in synaptic glutamate removal. A hypothetical model of altered glutamatergic function in mood disorders is proposed in conjunction with potential antidepressant mechanisms of antiglutamatergic agents. Further studies elucidating the role of the glutamatergic system in the pathophysiology of mood and anxiety disorders and studies exploring the efficacy and mechanism of action of antiglutamatergic agents in these disorders, are likely to provide new targets for the development of novel antidepressant agents.     

Location serves as a conditional cue when harp seals (Pagophilus groenlandicus) solve object discrimination reversal problems.

We examined the capacity of harp seals (Pagophilus groenlandicus) to use spatial context (i.e., their tank) as a conditional cue to solve a two-choice visual discrimination reversal task. Seals were trained to touch one of two 3D objects. Two of four seals experienced a context shift that coincided with each of five reversals in the reward value of the two stimuli (i.e., a reversal of S+ and S-); these seals solved the six discriminations in significantly fewer trials than did seals that did not experience a context shift with the contingency reversal. Thus, harp seals use contextual cues when encoding information. The findings are discussed in terms of harp seals' adaptations to the pack-ice environment, the constraints of the learning tasks, and the nature of the subjects that were raised in captivity.     

Spousal caregiver confidence and recovery from ambulatory activity limitations in stroke survivors.

OBJECTIVE: This study examined whether spousal confidence in care-recipient recovery can predict recovery from activity limitations following stroke and how spousal confidence relates to stroke survivor self-efficacy for recovery. DESIGN: A prospective design was used. Measures were gathered from stroke survivor/spouse dyads at two time points, both postdischarge from the hospital following stroke (N=109). MAIN OUTCOME MEASURES: The dependent variable was recovery from ambulatory activity limitations over 6 weeks, as measured by the Functional Limitations Profile. A single spousal confidence item was tailored to an ambulatory behavior that the stroke survivors could not perform at Time 1. RESULTS: Spousal confidence was correlated with ambulation recovery (r=-0.23, p<.05) and stroke survivor self-efficacy for recovery (r=.25, p<.05). Higher spousal confidence was associated with a better recovery and greater stroke survivor self-efficacy for recovery, but not with initial health status or practical support received. CONCLUSION: The relationship between caregiver confidence, care-recipient self-efficacy for recovery, and recovery outcomes needs further elucidation.     

The Questionnaire Big Six in 26 Nations: Developing Cross‐Culturally Applicable Big Six,Big Five and Big Two Inventories

The Big Five is a useful model of attributes now commonly used in cross‐cultural research, but without the support of strong measurement invariance (MI) evidence. The Big Six has been proposed as a cross‐culturally informed update, and the broader Big Two (Social Self‐Regulation and Dynamism) draws on even more cross‐cultural evidence. However, neither has been rigorously tested for cross‐cultural MI. Here a Big Six inventory (36QB6) and measures of the Big Five and Big Two derived from it were tested and refined for cross‐cultural usability in samples from 26 nations, divided into three subsets. Confirmatory factor analysis of the models in the first subset of nations demonstrated fit as strong in translation as typical personality measures achieve in their nation of origin (although poor per standard benchmarks). Items that performed inconsistently across cultures were removed, and alternates considered in a second subset of nations. Fit and invariance were improved for refined 30‐item QB6, 25‐item Big Five and 14‐item Big Two measures in the third subset of nations. For all models, decrease in comparative fit index between MI levels was larger than .01, indicating lack of support for higher levels. Configural and factorial invariance were relatively stronger, compared to scalar and full. Copyright © 2014 European Association of Personality Psychology