Defining the boundary of childhood amnesia

When adults are asked to recall their earliest autobiographical memories most can recall nothing about their infancy and early childhood, a phenomenon commonly referred to as childhood amnesia. There is general consensus regarding the existence of childhood amnesia, but there remains considerable debate over its boundary. Most researchers have argued that the boundary of childhood amnesia occurs between the ages of 3 and 4 years, but in 1993 Usher and Neisser published a highly influential paper, which has subsequently been used to argue that the boundary may be as low as 2 years. In the present experiment we examined how changes in scoring criteria influence our estimates of the age of adults' earliest memories. We conclude that some coding criteria are more valid than others and that the best estimates of childhood amnesia will include measures of free recall in addition to the specific questions that have dominated prior research in this area.     

Cross-national comparisons of the association between alcohol consumption and deliberate self-harm in adolescents

How differences in drinking patterns may affect the impact of alcohol consumption on deliberate self-harm among adolescents is explored in this international comparative study. Schools in Australia, Belgium, England, Hungary, Ireland, the Netherlands, and Norway (N = 30,532) were surveyed. In all countries the risk of deliberate self-harm was significantly elevated among adolescents who reported some or numerous episodes of intoxication, controlling for confounding factors. The results support the assumption that intoxication is significantly related to the association between alcohol consumption and deliberate self-harm in adolescents.     

Response inhibition and interference control: Effects of schizophrenia,genetic risk,and schizotypy

The ability to inhibit inappropriate responses and suppress irrelevant information is a core feature of executive control. In this study, we provide a detailed analysis of prepotent response inhibition and interference in patients with schizophrenia. To further test the role of genetic factors and subclinical schizophrenia‐like traits, we additionally studied clinically unaffected, first‐degree relatives of schizophrenia patients and assessed dimensions of schizotypy in both relatives and healthy controls. Inhibition and interference control were assessed using a battery comprising the antisaccade, Stroop, stop signal, go/no‐go, flanker, and Simon tasks. Schizophrenia patients differed from both relatives and controls in making more errors on the antisaccade task and having longer response times on the Stroop task, especially the incongruent condition. Patients also had general, that is, condition independent, increases in reaction times on the go/no‐go and flanker tasks and made more errors on the flanker and Simon tasks, suggesting general performance impairments independent of inhibitory demand. Relatives were characterized by hypometric antisaccade amplitude gain despite normal prosaccades, suggesting a selective deficit in non‐standard sensorimotor transformations. Schizotypy was correlated with inhibitory performance across a number of tasks in both relatives and controls. Generally, these effects were independent of verbal intelligence levels. Overall, the findings point to rather selective impairments of inhibitory control in the schizophrenia spectrum and confirm a previously observed deficit in antisaccade spatial accuracy as an endophenotype of schizophrenia.     

The role of perception, language, and preference in the developmental acquisition of basic color terms

When learning basic color vocabulary, young children show a selective delay in the acquisition of brown and gray relative to other basic color terms. In this study, we first establish the robustness of this finding and then investigate the extent to which perception, language, and color preference may influence color conceptualization. Experimental tasks were designed to measure different aspects of perceptual color processing (discrimination and saliency), color preference and objective counts of color term frequency in preschool-directed language (books and mothers' speech) were used to compare the acquisition of three groups of colors: primary colors, secondary colors (orange, pink, and purple) that appear at the same time as the primary colors, and secondary colors (brown and gray) that appear late. Although our results suggest that perception does not directly shape young children's color term acquisition, we found that children prefer brown and gray significantly less than basic colors and that these color terms appear significantly less often in child-directed speech, suggesting that color preference, linguistic input, and developing color cognition may be linked.     

Why I did Not do What I Felt Like Doing When I Felt Hurt: An REBT-Based Investigation of Reasons Why Hurt-Based Action Tendencies are Not Acted On

In our previous study (Dryden and Hurton in J Ration Emot Cogn Behav Ther 29, 2013), we investigated the action tendencies that 100 people reported having, but did not act on in specific episodes where they felt hurt. In this study, we examine the reasons given by this same group of people for not so acting. Understanding the types of reasons why people do not act on their hurt-based action tendencies will first help REBT therapists to distinguish between constructive and unconstructive factors contained in these expressed reasons and thence to use this information to encourage their clients to act on their constructive tendencies and to discourage their clients from acting on their hurt feelings when it is unconstructive for them to do so.     

Running with emotion: When affective content hampers working memory performance

This study tested the hypothesis that affective content may undermine rather than facilitate working memory (WM) performance. To this end, participants performed a running WM task with positive, negative and neutral words. In typical running memory tasks, participants are presented with lists of unpredictable length and are asked to recall the last three or four items. We found that accuracy with affective words decreased as lists lengthened, whereas list length did not influence recall of neutral words. We interpreted this pattern of results in terms of a limited resource model of WM in which valence represents additional information that needs to be manipulated, especially in the context of difficult trials.     

Whistle rates of wild bottlenose dolphins (Tursiops truncatus): influences of group size and behavior

In large social groups acoustic communication signals are prone to signal masking by conspecific sounds. Bottlenose dolphins (Tursiops truncatus) use highly distinctive signature whistles that counter masking effects. However, they can be found in very large groups where masking by conspecific sounds may become unavoidable. In this study we used passive acoustic localization to investigate how whistle rates of wild bottlenose dolphins change in relation to group size and behavioral context. We found that individual whistle rates decreased when group sizes got larger. Dolphins displayed higher whistle rates in contexts when group members were more dispersed as in socializing and in nonpolarized movement than during coordinated surface travel. Using acoustic localization showed that many whistles were produced by groups nearby and not by our focal group. Thus, previous studies based on single hydrophone recordings may have been overestimating whistle rates. Our results show that although bottlenose dolphins whistle more in social situations they also decrease vocal output in large groups where the potential for signal masking by other dolphin whistles increases.