Effects of environmental enrichment on spatial memory and neurochemistry in middle-aged mice

The present study compared the effects of environmental enrichment on spatial memory, glutamic acid decarboxylase (GAD) activity, and synaptophysin levels in middle-aged male and female mice. Prior to testing, a subset of 18-month-old male and female C57BL/6 mice was housed with two to three toys and a running wheel in the home cage for up to 29 d. Adult mice (7 mo) of both sexes and the remaining middle-aged mice were group (social) housed, but not exposed to enriching objects. After the enrichment period, all mice were tested in a 1-day version of the Morris water maze, in which both spatial and nonspatial memory were assessed. Immediately after testing, the hippocampus and frontoparietal cortex were dissected, and GAD activity and synaptophysin levels were measured. Environmental enrichment reduced the age-related impairment in spatial acquisition and retention; relative to adult social controls, middle-aged enriched mice were unimpaired, whereas middle-aged social controls were impaired. This reduction was similar in middle-aged males and females. Enrichment did not affect cued memory in either sex. Although hippocampal GAD activity was increased by enrichment in males, all other neurochemical measurements were unaffected by enrichment or aging in either sex. These data suggest that environmental enrichment initiated at middle age can reduce age-related impairments in spatial memory in males and females, although the underlying neurobiological mechanisms of this effect remain unknown.     

“We want the world and we want it now”: Materialism,time perspectives and problem spending tendency of Chinese

Chinese consumers' spending has been expanding rapidly in the past decade, and along with it household and credit card debt. The present research collected evidence to triangulate the contention that materialism is positively related with Chinese's problem spending tendency (PST), and that present‐time‐perspective (PTP) and future‐time perspectives (FTP) interact systematically with materialism to affect PST. A survey of the general population in Macao, China (Study 1; N = 239) confirmed that materialism was positively correlated with PST. An interaction between materialism and PTP intensified the relationship, whereas an interaction with FTP weakened the relationship. Another survey with a sample of university students (Study 2; N = 223) again found positive relationships among PST, materialism, and PTP, as measured by temporal discount rate. But further exploration showed that PST was only related with temporal discounting among high materialists, but not among low materialists. Study 3 experimentally examined the causal effects of materialism and FTP on PST. When being primed of an orientation towards materialism (n = 33), the participants' planned consumption doubled that of the control group (n = 31). A FTP prime interacted with materialism prime and put a “damper” on participants' planned spending (n = 29), compared to their counterparts who were not primed of such a time perspective.     

Physiological and self-reported disgust reactions to obesity

There is accumulating evidence that disgust plays an important role in prejudice toward individuals with obesity, but that research is primarily based on self-reported emotions. In four studies, we examined whether participants displayed a physiological marker of disgust (i.e. levator labii activity recorded using facial electromyography) in response to images of obese individuals, and whether these responses corresponded with their self-reported disgust to those images. All four studies showed the predicted self-reported disgust response toward images of obese individuals. Study 1 further showed that participants exhibited more levator activity to images of obese individuals than to neutral images. However, Studies 2–4 failed to provide any evidence that the targets’ body size affected levator responses. These findings suggest that disgust may operate at multiple levels, and that the disgust response to images of obese individuals may be more of a cognitive-conceptual one than a physiological one.     

Facial memory deficits in children with fetal alcohol spectrum disorders

Prenatal exposure to alcohol may lead to a range of neurobehavioral effects, including impaired learning and memory. Although children with fetal alcohol spectrum disorders (FASD) exhibit both verbal and nonverbal memory impairments, their memory for faces has not been as thoroughly investigated and the extent literature provides inconsistent results. The aim of the current study was to determine whether difficulties in face memory exist in children with FASD and whether the difficulties are mediated by task demands. To address this, we used two measures of immediate and delayed facial recognition memory, the Children's Memory Scale (CMS) and Test of Memory and Learning (TOMAL). Compared to typically developing controls, children with FASD showed memory deficits on all tests and were more likely to perform in a clinically significant range. As well, children performed more poorly on the CMS compared to TOMAL, a finding consistent with the greater difficulty of the CMS task. Our results are consistent with our hypothesis that children with FASD show impairment in facial memory, particularly on demanding memory tasks.     

Cognitive Load Disrupts Implicit Theory-of-Mind Processing

Eye movements in Sally-Anne false-belief tasks appear to reflect the ability to implicitly monitor the mental states of other individuals (theory of mind, or ToM). It has recently been proposed that an early-developing, efficient, and automatically operating ToM system subserves this ability. Surprisingly absent from the literature, however, is an empirical test of the influence of domain-general executive processing resources on this implicit ToM system. In the study reported here, a dual-task method was employed to investigate the impact of executive load on eye movements in an implicit Sally-Anne false-belief task. Under no-load conditions, adult participants displayed eye movement behavior consistent with implicit belief processing, whereas evidence for belief processing was absent for participants under cognitive load. These findings indicate that the cognitive system responsible for implicitly tracking beliefs draws at least minimally on executive processing resources. Thus, even the most low-level processing of beliefs appears to reflect a capacity-limited operation.     

Have recent studies addressed methodological issues raised by five decades of television violence research? A critical review

Media violence continues to be a concern to parents, policy makers and researchers. In spite of confidence expressed by some that exposure to television violence causes serious aggression and violent crime, critics hold that serious flaws in research methodology limits or nullifies conclusions drawn from widely-cited studies. In this paper, we will examine a series of classic studies for lessons learned about conducting media violence research, and assess whether recent publications adhere to those standards. We conclude that empirical reports with serious flaws continue to be published, compromising our ability to understand this phenomenon.     

Eliciting and maintaining ruminative thought: the role of social-evaluative threat

This study tested whether a performance stressor characterized by social-evaluative threat (SET) elicits more rumination than a stressor without this explicit evaluative component and whether this difference persists minutes, hours, and days later. The mediating role of shame-related cognition and emotion (SRCE) was also examined. During a laboratory visit, 144 undergraduates (50% female) were randomly assigned to complete a speech stressor in a social-evaluative threat condition (SET; n = 86), in which an audience was present, or a nonexplicit social-evaluative threat condition (ne-SET; n = 58), in which they were alone in a room. Participants completed measures of stressor-related rumination 10 and 40 min posttask, later that night, and upon returning to the laboratory 3-5 days later. SRCE and other emotions experienced during the stressor (fear, anger, and sadness) were assessed immediately posttask. As hypothesized, the SET speech stressor elicited more rumination than the ne-SET speech stressor, and these differences persisted for 3-5 days. SRCE-but not other specific negative emotions or general emotional arousal-mediated the effect of stressor context on rumination. Stressors characterized by SET may be likely candidates for eliciting and maintaining ruminative thought immediately and also days later, potentially by eliciting shame-related emotions and cognitions.     

Should social savvy equal good spatial skills? The interaction of social skills with spatial perspective taking

Real-world perspective-taking problems frequently involve interactions among individuals, suggesting a potential social element to this seemingly spatial problem. Previous studies have suggested that the agency of the target in a perspective-taking task might influence reasoning. This hypothesis is tested directly by manipulating whether one takes the perspective of a potential agent or an object. The results were striking: Even though no overall differences in performance were observed with and without agents, performance was differentially associated with social skills. In particular, participants with better social skills were more accurate than less social peers when the target was a potential agent, whereas no such relationship was observed when the target was an object. These results suggest that bringing domain-specific investigations to bear on real-world problems requires understanding how that domain exists in the broader context of interacting skills and biases.     

The Illusion-of-Transparency and Episodic Memory: Are People Egocentric or Do People Think that Lies are Easy to Detect?

The illusion-of-transparency seems like an egocentric bias, in which people believe that their inner feelings, thoughts and perspectives are more apparent to others than they actually are. In Experiment 1, participants read out true and false episodic memories to an audience. Participants over-estimated the number of people who would think that they were the liar, and they overestimated how many would correctly identify the liar. Experiment 2 found that with lessened task demands, and by using a scale of doubt, participants distinguished lies from truthful statements (albeit with a degree of error). Over the two experiments, results indicated that people have some ability to distinguish lies from truth (in illusion-of-transparency tasks), although people often overestimate this ability, and participants sometimes think their own lies are easier to detect than is really the case.