Demographic and familial predictors of early executive function development: Contribution of a person-centered perspective

Executive function (EF) skills are integral components of young children’s growing competence, but little is known about the role of early family context and experiences in their development. We examined how demographic and familial risks during infancy predicted EF competence at 36 months of age in a large, predominantly low-income sample of nonurban families from Pennsylvania and North Carolina in the United States. Using latent class analysis, six ecological risk profiles best captured the diverse experiences of these families. Profiles with various combinations of family structure, income, and psychosocial risks were differentially related to EF. Much of the influence of early risks on later EF appears to be transmitted through quality of parent-child interactions during infancy. Findings suggest that early family environments may prove to be especially fruitful contexts for the promotion of EF development.     

Individual differences in ego depletion: The role of sociotropy-autonomy

In his cognitive theory of depression, Beck (1987) suggested that highly sociotropic individuals have a strong need for social acceptance whereas highly autonomous individuals have an excessive need for achievement. Research by Baumeister (2000) has suggested that a phenomenon known as ego depletion, the weakening of performance on tasks following active self-control, occurs because it depletes a limited inner resource. The present study examined whether individuals who are highly sociotropic or autonomous would respond differently when faced with tasks requiring self-control. Participants completed the Sociotropy-Autonomy Scale (Clark et al. 1995) and engaged in two active self-control tasks. The results revealed that sociotropy levels were negatively correlated with persistence on tasks that require self-control whereas autonomy was positively correlated to persistence on the same task. In addition, the results suggested that, following a task requiring self-control, highly sociotropic individuals expend less effort, whereas highly autonomous individuals expend more effort on subsequent tasks requiring self-control.     

Effects of acute stress and GluN2B-containing NMDA receptor antagonism on object and object–place recognition memory

The mechanisms underlying the complex effects of acute stress on memory are incompletely understood. Previous work suggests that the activation of N-methyl-d-aspartate (NMDA) receptors specifically containing GluN2B subunits may underlie the disruptions in spatial memory retrieval caused by acute stress (Wong et al., 2007 PNAS 104:11471). The present experiments were designed to assess whether a similar mechanism is involved in recognition memory. Recognition memory retrieval was assessed in Sprague–Dawley rats using an object recognition test and an object–place recognition test, both of which rely on patterns of spontaneous exploration. Exposure to acute stress for 30 min immediately before the test phase of either test disrupted memory retrieval. Administration of the GluN2B-selective antagonist Ro25-6981 (6 mg/kg; i.p.) enhanced memory in the object recognition test regardless of whether animals were exposed to acute stress. In the object–place test, Ro25-6981 had no effect on memory retrieval in the absence of stress but promoted memory following acute stress. These data highlight the specific contributions made by GluN2B-containing NMDA receptors to recognition memory for different types of stimuli.     

Religious Believers Do Not Distinguish Good from Poor Reasons for God’s Existence

Can people discriminate good from bad reasons for their beliefs about God? Research shows that religious believers favor intuitive processing, suggesting they may be less discriminating than nonbelievers. Indeed, in Experiment 1 and a replication, people listed 15 reasons for their beliefs about God, then evaluated the quality of either their first 3 reasons (presumably their best) or their last 3 (their worst); in both experiments, nonbelievers rated their good reasons as better than their bad reasons, whereas believers rated the 2 types of reasons equally. Experiments 2 and 3 revealed that this difference was limited to beliefs about God and was specific to believers’ own beliefs about God: Both believers and nonbelievers discriminated reasons for other people’s beliefs, as long as the reasons were congruent with their own. Whether cognitively or motivationally driven, our findings help explain why religious beliefs, in particular, are often immune to logical argument.     

Sadness and ruminative thinking independently depress people's moods

Depression and rumination often co‐occur in clinical populations, but it is not clear which causes which, or if both are manifestations of an underlying pathology. Does rumination simply exacerbate whatever affect a person is experiencing, or is it a negative experience in and of itself? In two experiments we answer this question by independently manipulating emotion and rumination. Participants were allocated to sad or neutral (in Experiment 1), or sad, neutral or happy (Experiment 2) mood conditions, via a combination of emotionally evocative music and autobiographical recall. Afterwards, in both studies, participants either ruminated by thinking about self‐relevant statements or, in a control group, thought about self‐irrelevant statements. Taken together, our data show that, independent of participants' mood, ruminators reported more negative affect relative to controls. The findings are consistent with theories suggesting that self‐focus is itself unpleasant, and illustrate that depressive rumination comprises both affective and ruminative components, which could be targeted independently in clinical samples.     

Teaching mands for information using speech generating devices: A replication and extension

Approximately 30% of individuals diagnosed with autism spectrum disorder (ASD) fail to develop vocal communication and, therefore, use some form of augmentative or alternative communication system. The current study replicates and extends previous research on teaching “Who?” and “Which?” mands for information to 3 young children diagnosed with ASD using a speech generating device. Procedures were evaluated using a multiple baseline across participants design. All participants learned to mand for information and, subsequently, used the information to access preferred items.     

Effects of physical fatigue and cognitive challenges on the potential for low back injury

There is no question that the motor control system will adapt under fatiguing conditions; however, there is documented evidence showing that when fatigued or challenged, the motor control system will, on occasion, perform inappropriate muscle sequencing, increasing the risk of injury, or directly causing injury. Knowing that inappropriate muscle activations can lead to injury, the purpose of this study was to investigate motor patterns during cognitive and physical challenges. Rather than ensure change with severe challenges, milder challenges were purposefully chosen. Eight male subjects performed a low external load task performed near end ROM while in an unchallenged state, and while in three challenged states: passive tissue creep, muscle fatigue and cognitive distraction. Data were collected using EMG of the trunk muscles and angular displacement of the lumbar spine. Comparison of motor control patterns between the unchallenged state and each of the three challenged conditions showed no systematic differences. However, several random anomalies were observed. A case study of a single subject was chosen to show inappropriate motor control during one trial under the cognitive distraction conditions. The response of the motor control system is very individualized and does on occasion produce inappropriate motor patterns. This supports the notion that injury may also occur as the result of random motor control errors as well as predictable, systematic changes.     

Random fluctuations of response rate

A simple model for fluctuating interresponse times is developed and studied. It involves a mechanism that generates regularly spaced excitations, each of which can trigger off a response after a random delay. The excitations are not observable, but their periodicity is reflected in a regular patterning of responses. The probability distribution of the time between responses is derived and its properties are analyzed. Several limiting cases are also examined.This paper was completed while the writer was a visiting summer scientist at the Lincoln Laboratory, Lexington, Mass.