Approximate entropy used to assess sitting postural sway of infants with developmental delay

Infant sitting postural sway provides a window into motor development at an early age. The approximate entropy, a measure of randomness, in the postural sway was used to assess developmental delay, as occurs in cerebral palsy. Parameters used for the calculation of approximate entropy were investigated, and approximate entropy of postural sway in early sitting was found to be lower for infants with developmental delay in the anterior-posterior axis, but not in the medial-lateral axis. Spectral analysis showed higher frequency features in the postural sway of early sitting of infants with typical development, suggesting a faster control mechanism is active in infants with typical development as compared to infants with delayed development, perhaps activated by near-fall events.     

The interplay between value and relatedness as bases for metacognitive monitoring and control: evidence for agenda-based monitoring

Two experiments are reported examining how value and relatedness interact to influence metacognitive monitoring and control processes. Participants studied unrelated and related word pairs, each accompanied by point values denoting how important the items were to remember. These values were presented either before or after each pair in a between-subjects design, and participants made item-by-item judgments of learning (JOLs) predicting the likelihood that each item would be remembered later. Results from Experiment 1 showed that participants used value and relatedness as cues to inform their JOLs. Interestingly, JOLs increased as a function of value even in the after condition in which value had no impact on cued recall. Participants in Experiment 2 were permitted to control study time for each item. Results showed that value and relatedness were simultaneously considered when allocating study time. These results support a cue-weighting process in which JOLs and study time allocation are based on multiple cues, which may or may not be predictive of future memory performance, and complements the agenda-based regulation model of study time (Ariel, Dunlosky, & Bailey, 2009) by providing evidence for agenda-based monitoring.     

Aging and the structure and long-term stability of the internalizing spectrum of personality and psychopathology

Structural psychopathology research has identified two broad factors--internalizing and externalizing--that account for comorbidity among many common mental disorders. Evaluating the utility of these factors for nosology, research, and treatment entails expanding beyond a cross-sectional understanding to how these factors evolve over time. We tested factorial invariance of internalizing in three age cohort groups--35 years and under (n = 1,729), 36-50 years (n = 2,719), and over 50 years (n = 2,601)--as well as the long-term stability of internalizing within individuals. Internalizing showed a notable degree of invariance between cohorts and within cohorts over time; long-term internalizing stability was equivalently moderate-to-high in each cohort.     

Mating interest improves women's accuracy in judging male sexual orientation

People can accurately infer others' traits and group memberships across several domains. We examined heterosexual women's accuracy in judging male sexual orientation across the fertility cycle (Study 1) and found that women's accuracy was significantly greater the nearer they were to peak ovulation. In contrast, women's accuracy was not related to their fertility when they judged the sexual orientations of other women (Study 2). Increased sexual interest brought about by the increased likelihood of conception near ovulation may therefore influence women's sensitivity to male sexual orientation. To test this hypothesis, we manipulated women's interest in mating using an unobtrusive priming task (Study 3). Women primed with romantic thoughts showed significantly greater accuracy in their categorizations of male sexual orientation (but not female sexual orientation) compared with women who were not primed. The accuracy of judgments of male sexual orientation therefore appears to be influenced by both natural variations in female perceivers' fertility and experimentally manipulated cognitive frames.     

Adolescent recognition of parental affect: influence of depressive symptoms

This study examined depressive biases in adolescents' labeling of parental affect. Adolescents (151 girls; 82 boys) and their parents engaged in videotaped problem-solving interactions. Adolescents then participated in a video-mediated recall procedure in which they watched the videotaped interaction and indicated how they thought their parents were feeling. Indices of parents' affect during the problem-solving interactions were also provided by parent self-report and behavioral observations. Adolescent depressive symptoms were associated with overreporting of parental aggressive affect and underreporting of parental happy and neutral affects, relative to both directly observed and self-reported parental affect. Depressive symptoms were not associated with overreporting of parental dysphoric affect. Given the importance of accurately reading affective cues for negotiating interpersonal interactions, these findings likely have implications for understanding processes that contribute to adverse relationships among the families of adolescents with depressive symptoms.     

Data-based decision making: the impact of data variability, training, and context

The current study examines agreement among individuals with varying expertise in behavior analysis about the length of baseline when data were presented point by point. Participants were asked to respond to baseline data and to indicate when to terminate the baseline phase. When only minimal information was provided about the data set, experts and Board Certified Behavior Analyst participants generated baselines of similar lengths, whereas novices did not. Agreement was similar across participants when variability was low but deteriorated as variability in the data set increased. Participants generated shorter baselines when provided with information regarding the independent or dependent variable. Implications for training and the use of visual inspection are discussed.     

Manifestations of personality in Online Social Networks: self-reported Facebook-related behaviors and observable profile information

Despite the enormous popularity of Online Social Networking sites (OSNs; e.g., Facebook and Myspace), little research in psychology has been done on them. Two studies examining how personality is reflected in OSNs revealed several connections between the Big Five personality traits and self-reported Facebook-related behaviors and observable profile information. For example, extraversion predicted not only frequency of Facebook usage (Study 1), but also engagement in the site, with extraverts (vs. introverts) showing traces of higher levels of Facebook activity (Study 2). As in offline contexts, extraverts seek out virtual social engagement, which leaves behind a behavioral residue in the form of friends lists and picture postings. Results suggest that, rather than escaping from or compensating for their offline personality, OSN users appear to extend their offline personalities into the domains of OSNs.     

Prefrontal and hippocampal contributions to encoding and retrieval of spatial memory

The prefrontal cortex is thought to be critical for goal-directed action and the hippocampus is known to be importantly involved in spatial memory. Several studies have been suggestive of a role for the orbitofrontal cortex (OFC) in spatial navigation. However, the medial prefrontal cortex (mPFC) receives projections directly from the intermediate CA1 (iCA1) region of hippocampus and this link may be critical for spatial navigation. The purpose of the present investigation was to test the performance of rats receiving bilateral or disconnection infusions of lidocaine into OFC, mPFC, or iCA1 to determine the contribution of these structures to encoding and retrieval of spatial memory using the Hebb–Williams maze. A total of 92 male Long-Evans rats received chronic bilateral, contralateral, or ipsilateral implantation of cannulas into OFC, mPFC, or iCA1. Prior to testing on day 1 or day 2, subjects received central infusions of saline or lidocaine. The number of errors committed on the first five trials compared to the second five trials of day 1 was used to determine encoding, whereas retrieval was determined by comparing the second five trials of day 1 with the first five trials of day 2. The present findings suggest that mPFC and iCA1 are necessary and interact during encoding and retrieval; however, the OFC does not appear to be essential for either process. While the nature of the interaction between mPFC and iCA1 during encoding and retrieval is unclear, it may be supported by the integration of goals and spatial cues or strategy switching.     

A balancing act: Physical balance, through arousal, influences size perception

Previous research has demonstrated that manipulating vision influences balance. Here, we question whether manipulating balance can influence vision and how it may influence vision--specifically, the perception of width. In Experiment 1, participants estimated the width of beams while balanced and unbalanced. When unbalanced, participants judged the widths to be smaller. One possible explanation is that unbalanced participants did not view the stimulus as long as when balanced because they were focused on remaining balanced. In Experiment 2, we tested this notion by limiting viewing time. Experiment 2 replicated the findings of Experiment 1, but viewing time had no effect on width judgments. In Experiment 3, participants' level of arousal was manipulated, because the balancing task likely produced arousal. While jogging, participants judged the beams to be smaller. In Experiment 4, participants completed another arousing task (counting backward by sevens) that did not involve movement. Again, participants judged the beams to be smaller when aroused. Experiment 5A raised participants' level of arousal before estimating the board widths (to control for potential dual-task effects) and showed that heightened arousal still influenced perceived width of the boards. Collectively, heightened levels of arousal, caused by multiple manipulations (including balance), influenced perceived width.