Increased aggression after rapid eye movement sleep deprivation in Wistar rats is not influenced by reduction of dimensions of enclosure

Twelve female and twelve male Wistar rats were assigned to home groups, platform-control groups, and rapid eye movement sleep deprivation groups. The deprivation was performed with the cuff-pedestal method. Rats were tested in pairs in a shrinking chamber to increase proximity of the rats and to provoke interaction between them. An increase in boxing behavior was noted in the sleep-deprived groups. The result confirms that deprivation of rapid eye movement sleep increases aggressive behavior in the rat. However, this behavior is not influenced by the area of the testing arena. The sleep-deprived females explored each other more than the controls; the males' behavior did not differ in this respect. The amount of genital exploration decreased with diminishing area of enclosure, whereas boxing was not area dependent.     

Parent support is less effective in buffering cortisol stress reactivity for adolescents compared to children

The goal of the present study was to investigate developmental differences in the effectiveness of parent support to alleviate hypothalamic‐pituitary‐adrenal (HPA) axis stress responses of children (ages 9–10, N = 40) and adolescents (ages 15–16, N = 41). We experimentally manipulated the provision of parent support during the speech preparation period before a modified Trier Social Stress Test (TSST) and examined its effect on levels of salivary cortisol secreted in response to this laboratory stressor. Analyses revealed a significant interaction of condition and age group such that social support from the parent (versus a stranger) significantly eliminated the cortisol stress response in children, but had no effect on the response among adolescents.     

No decision‐maker is an Island: integrating expert advice with information acquisition

The present research examined the social context of information acquisition. The main purpose was to examine how decision‐makers' information acquisition processes changed when they were provided access to expert advice. Results indicated that all decision‐makers opted to acquire advice; however, they typically did so only after completing over 75% of their own information search. Decision‐makers agreed more with the advice as task complexity increased, but, in general, searched information in two stages—i.e., a pre‐advice “hypothesis generation” stage and a post‐advice “hypothesis testing” stage. To behave in an adaptive manner, decision‐makers could have used expert advice either to increase their decision accuracy or to reduce their effort expenditure (or both); they chose the former. Implications and further extensions are discussed. Copyright © 2006 John Wiley & Sons, Ltd.     

The effect of variations of emotional expressions on mnemonic discrimination and traditional recognition memory

Face recognition occurs when a face is recognised despite changes between learning and test exposures. Yet there has been relatively little research on how variations in emotional expressions influence people’s ability to recognise these changes. We evaluated the ability to discriminate old and similar expressions of emotions (i.e. mnemonic discrimination) of the same face, as well as the discrimination ability between old and dissimilar (new) expressions of the same face, reflecting traditional discrimination. An emotional mnemonic discrimination task with morphed faces that were similar but not identical to the original face was used. Results showed greater mnemonic discrimination for learned neutral expressions that at test became slightly more fearful rather than happy. For traditional discrimination, there was greater accuracy for learned happy faces becoming fearful, rather than those changing from fearful-to-happy. These findings indicate that emotional expressions may have asymmetrical influences on mnemonic and traditional discrimination of the same face.     

Basic psychological need satisfaction across the retirement transition: Changes and longitudinal associations with depressive symptoms

Motivation and Emotion - Drawing on self-determination theory, the present study examined how satisfaction of the basic psychological needs (autonomy, competence, and relatedness) changes across...     

The irreversibility of sensitive period effects in language development: evidence from second language acquisition in international adoptees

The question of a sensitive period in language acquisition has been subject to extensive research and debate for more than half a century. While it has been well established that the ability to learn new languages declines in early years, the extent to which this outcome depends on biological maturation in contrast to previously acquired knowledge remains disputed. In the present study, we addressed this question by examining phonetic discriminatory abilities in early second language (L2) speakers of Swedish, who had either maintained their first language (L1) (immigrants) or had lost it (international adoptees), using native speaker controls. Through this design, we sought to disentangle the effects of the maturational state of the learner on L2 development from the effects of L1 interference: if additional language development is indeed constrained by an interfering L1, then adoptees should outperform immigrant speakers. The results of an auditory lexical decision task, in which fine vowel distinctions in Swedish had been modified, showed, however, no difference between the L2 groups. Instead, both L2 groups scored significantly lower than the native speaker group. The three groups did not differ in their ability to discriminate non‐modified words. These findings demonstrate that L1 loss is not a crucial condition for successfully acquiring an L2, which in turn is taken as support for a maturational constraints view on L2 acquisition. A video abstract of this article can be viewed at: https://youtu.be/1J9X50aePeU     

Semantic processing without conscious identification: evidence from event-related potentials

Three event-related potential (ERP) experiments examined whether semantic content can be accessed from visually presented words that cannot be consciously identified. Category labels were shown to participants, followed by masked, briefly exposed words that were either exemplars of the category or not exemplars. The task was to verify the category, by guessing if necessary, and to identify the word, naming it if possible. Exposure durations were selected to allow identification in approximately half the trials. For identified words, there was a marked difference in the ERP response between in-category and out-of-category words because of an N400 component. For unidentified words, there was a similar although smaller difference. Conscious identification was defined using a variety of approaches: verbal report, 6-alternative forced choice, and binary categorization (in the context of the regression method; A. G. Greenwald, M. R. Klinger, & E. S. Schuh, 1995). By any definition, ERPs for unidentified words showed evidence of semantic processing. In addition, there were differences in the neuronal populations recruited to process above-threshold versus below-threshold words, suggesting qualitative differences.