Mental verb input for promoting children's theory of mind: A training study

An experimental study investigated the effect of the type of mental verb input (i.e., input with think, know, and remember) on preschoolers’ theory of mind development. Preschoolers (n = 72) heard 128 mental verb utterances presented in video format across four sessions over two weeks. The training conditions differed only in the way the mental verbs were presented: the form (statement or question), the referent (first person or other person), and the interaction style (overheard or interactive). Children who overheard the characters discussing the mental states of someone else, either in statement or question form, significantly improved in their false belief understanding. These experimental findings demonstrate mental verb utterances about other people, even when not directed to the child, scaffold children's attention to differing perspectives, thus more efficiently promoting some aspects of their ToM development.     

Change and Stability in Active and Passive Social Influence Dynamics during Natural Drinking Events: A Longitudinal Measurement-Burst Study

We examined the link between social norms and active social influences occurring during natural social drinking contexts. Across 4 yearly measurement-bursts, college students (N = 523) reported daily for 30-day periods on drinking norms, drinking offers, how many drinks they accepted, and personal drinking levels during social drinking events. In contexts where drinking norms were higher, students were more likely to both receive and comply with drinking offers. These acute social influences were highly stable throughout college, but affected men and women differently across time: Women received more drinking offers than men, especially at the beginning of college and when norms were higher, but men complied with more drinking offers per occasion. These effects were not attributable to between-person differences in social drinking motives or drinking levels, nor to within-person patterns of situation-selection. The present work suggests that context-specific drinking norms catalyze active social influence attempts, and further promote compliance drinking.     

Chronically stressed female rats show increased anxiety but no behavioral alterations in object recognition or placement memory: a preliminary examination

Stress, depending on intensity and duration, elicits adaptive or maladaptive physiological effects. Increasing evidence shows those patterns of advantageous versus deleterious physiologic stress effects also exist for some brain functions, including learning and memory. For example, short stress enhances, while chronic stress impairs, performance on numerous cognitive tasks in male rats. In contrast, performance of female rats is enhanced, or not altered, following both short-term and long-term stress exposure on the same behavioral tasks. The current study was designed to better characterize the behavioral effects of sustained chronic restraint stress in female rats. Female Sprague Dawley rats were assigned to a stress (restraint, 6 h/day, 35 days) or control (no stress) condition, weighed weekly, and then tested on open field (OF), object recognition (OR) and object placement (OP) tasks. Stressed females gained less weight during stress than controls. On the OF, there were no group differences in locomotor activity, but stressed females made fewer inner visits than controls, indicating increased anxiety. Both groups successfully performed the OP and OR tasks across all inter-trial delays, indicating intact non-spatial and spatial memory in both control and stress females. The current results provide preliminary evidence that the commonly used chronic restraint stress model may not be an efficient stressor to female rats.     

Task effects reveal cognitive flexibility responding to frequency and predictability: Evidence from eye movements in reading and proofreading

It is well-known that word frequency and predictability affect processing time. These effects change magnitude across tasks, but studies testing this use tasks with different response types (e.g., lexical decision, naming, and fixation time during reading; Schilling, Rayner, & Chumbley, 1998), preventing direct comparison. Recently, Kaakinen and Hyönä (2010) overcame this problem, comparing fixation times in reading for comprehension and proofreading, showing that the frequency effect was larger in proofreading than in reading. This result could be explained by readers exhibiting substantial cognitive flexibility, and qualitatively changing how they process words in the proofreading task in a way that magnifies effects of word frequency. Alternatively, readers may not change word processing so dramatically, and instead may perform more careful identification generally, increasing the magnitude of many word processing effects (e.g., both frequency and predictability). We tested these possibilities with two experiments: subjects read for comprehension and then proofread for spelling errors (letter transpositions) that produce nonwords (e.g., trcak for track as in Kaakinen & Hyönä) or that produce real but unintended words (e.g., trial for trail) to compare how the task changes these effects. Replicating Kaakinen and Hyönä, frequency effects increased during proofreading. However, predictability effects only increased when integration with the sentence context was necessary to detect errors (i.e., when spelling errors produced words that were inappropriate in the sentence; trial for trail). The results suggest that readers adopt sophisticated word processing strategies to accommodate task demands.     

Negative Life Events and Posttraumatic Stress Disorder among Incarcerated Boys with Callous-Unemotional Traits

Historically, researchers have searched extensively for biological explanations regarding causes of psychopathy and its theorized developmental precursor, callous-unemotional (CU) traits (i.e., lack of empathy/guilt, shallow affect). In consequence, environmental factors such as exposure to negative life events and posttraumatic stress that often follows have been relatively overlooked. The present study tests whether exposure to negative life events and related symptoms of posttraumatic stress disorder (PTSD) are associated with CU traits among a sample of 238 incarcerated boys. Additionally, youth high on CU traits were disaggregated into primary and secondary variants based on the presence of anxiety to examine differences in their experiences of negative life events and PTSD symptoms. Results suggest that CU traits are significantly positively associated with both the experience of negative life events as well as PTSD symptomatology. Additionally, high-anxious youth scoring high on CU traits (secondary variant) were significantly more likely to report a history of negative life events and PTSD symptoms than were lower anxious boys scoring high on CU traits (primary type) and non-psychopathic youth. Thus, study findings warrant further exploration of how trauma might impact or maintain the development of CU traits over time and indicate that issues of differential diagnosis must be considered in order to more effectively tailor treatment for trauma-exposed CU youth.