Predator (cat hair)-induced enhancement of hippocampal long-term potentiation in rats: involvement of acetylcholine

Extensive literature has demonstrated that arousal and fear modify memory acquisition and consolidation. Predator hair and odors increase arousal in rats and, therefore, may influence information encoding and synaptic plasticity in the rodent nervous system. In behavioral experiments, we confirm that laboratory-bred Long Evans rats avoid cat hair. Electrophysiological work in vivo showed that long-term potentiation (LTP) in the dentate gyrus induced by perforant path stimulation was enhanced for 5-7 days when LTP induction occurred in the presence of cat hair relative to fake hair. The muscarinic receptor antagonist scopolamine (i.p.) reversed the cat hair-elicited LTP enhancement without affecting weaker LTP elicited in the presence of fake hair. Thus, exposure to a predator stimulus elicits a cholinergically-dependent state of heightened plasticity that may serve to facilitate information storage in hippocampal circuits.     

Mothers' beliefs about listening: Implications for children's comprehension and conceptions of listening

Forty-four mothers offered their beliefs about listening and methods for encouraging listening in their 3- to 5-year-old children. Children's comprehension performance and conceptions of listening were also obtained. Mother perceived themselves as the primary agent responsible for children's development of basic listening competencies, such as figuring out the main point of what someone said to them, not interrupting others, and asking a question of the speaker when confused. Children who had strong comprehension skills had mothers who believed that listening is a complex set of activities, emphasized their own responsibility in ensuring that their children develop basic listening competencies, stressed comprehension processes and question asking in their conceptions of listening and in their techniques for enhancing children's listening, and began reading to their children at an early age.     

On the Robustness of Outcome Bias: No Constraint by Prior Culpability

Research on outcome bias has shown that blame attributions for behavioral decisions depend on the decision's consequences. Five studies of American undergraduates (N = 219, N = 83, N = 62, N = 279, and N = 45, respectively) demonstrated robust outcome effects across a variety of circumstances. A manipulation of prior negligence (Study 1), and attempts to keep prior negligence exceedingly low (Studies 2-4) produced converging results. In Study 5, a within-participants manipulation failed to eradicate outcome effects. Furthermore, outcome effects were not moderated by beliefs in a just world. Across all studies, mediational analyses suggested that participants adjusted estimates of negligence to match outcomes, which in turn led to more outcome-consistent attributions of blame. Study 5 showed that those low in belief in a just world were especially likely to adjust their negligence ratings in this way. These studies demonstrate that outcome effects contravene both the standards for rationality delineated by rational decision theorists, and also the more relaxed standards embodied in established legal doctrine.     

Perspectives on the Social Psychology of Creativity

Scholars began serious study into the social psychology of creativity about 25 years after the field of creativity research had taken root. Over the past 35 years, examination of social and environmental influences on creativity has become increasingly vigorous, with broad implications for the psychology of human performance, and with applications to education, business, and beyond. In this article, we revisit the origins of the social psychology of creativity, trace its arc, and suggest directions for its future.     

Similarity-based interference in a working memory numerical updating task: age-related differences between younger and older adults

Similarity among representations held simultaneously in working memory (WM) is a factor which increases interference and hinders performance. The aim of the current study was to investigate age-related differences between younger and older adults in a working memory numerical updating task, in which the similarity between information held in WM was manipulated. Results showed a higher susceptibility of older adults to similarity-based interference when accuracy, and not response times, was considered. It was concluded that older adults' WM difficulties appear to be due to the availability of stored information, which, in turn, might be related to the ability to generate distinctive representations and to the process of binding such representations to their context when similar information has to be processed in WM.     

Observational learning in mice can be prevented by medial prefrontal cortex stimulation and enhanced by nucleus accumbens stimulation

The neural structures involved in ongoing appetitive and/or observational learning behaviors remain largely unknown. Operant conditioning and observational learning were evoked and recorded in a modified Skinner box provided with an on-line video recording system. Mice improved their acquisition of a simple operant conditioning task by observational learning. Electrical stimulation of the observer's medial prefrontal cortex (mPFC) at a key moment of the demonstration (when the demonstrator presses a lever in order to obtain a reward) cancels out the benefits of observation. In contrast, electrical stimulation of the observer's nucleus accumbens (NAc) enhances observational learning. Ongoing cognitive processes in the demonstrator could also be driven by electrical stimulation of these two structures, preventing the proper execution of the ongoing instrumental task (mPFC) or stopping pellet intake (NAc). Long-term potentiation (LTP) evoked in these two cortical structures did not prevent the acquisition or retrieval process--namely, mPFC and/or NAc stimulation only prevented, or modified, the ongoing behavioral process. The dorsal hippocampus was not involved in either of these two behavioral processes. Thus, both ongoing observational learning and performance of an instrumental task require the active contribution of the mPFC and/or the NAc.     

Conditioned fear is modulated by D2 receptor pathway connecting the ventral tegmental area and basolateral amygdala

Excitation of the mesocorticolimbic pathway, originating from dopaminergic neurons in the ventral tegmental area (VTA), may be important for the development of exaggerated fear responding. Among the forebrain regions innervated by this pathway, the amygdala is an essential component of the neural circuitry of conditioned fear. The functional role of the dopaminergic pathway connecting the VTA to the basolateral amygdala (BLA) in fear and anxiety has received little attention. In vivo microdialysis was performed to measure dopamine levels in the BLA of Wistar rats that received the dopamine D(2) agonist quinpirole (1 μg/0.2 μl) into the VTA and were subjected to a fear conditioning test using a light as the conditioned stimulus (CS). The effects of intra-BLA injections of the D(1) antagonist SCH 23390 (1 and 2 μg/0.2 μl) and D(2) antagonist sulpiride (1 and 2 μg/0.2 μl) on fear-potentiated startle (FPS) to a light-CS were also assessed. Locomotor performance was evaluated by use of open-field and rotarod tests. Freezing and increased dopamine levels in the BLA in response to the CS were both inhibited by intra-VTA quinpirole. Whereas intra-BLA SCH 23390 did not affect FPS, intra-BLA sulpiride (2 μg) inhibited FPS. Sulpiride's ability to decrease FPS cannot be attributed to nonspecific effects because this drug did not affect motor performance. These findings indicate that the dopamine D(2) receptor pathway connecting the ventral tegmental area and the basolateral amygdala modulates fear and anxiety and may be a novel pharmacological target for the treatment of anxiety.     

The Relation Between Co-rumination, Maternal Depressive Symptoms and Child Psychopathology

Little is known about which processes explain the well-established link between maternal and child symptomatology. Interpersonal coping processes may be worth exploring, as depressed mothers have characteristic coping styles that may influence interactions with their children. We examined two interpersonal coping processes as potential factors explaining how depressive symptomatology in mothers impacts child psychopathology: parent-child co-rumination (dwelling on negative affect, over-analyzing problems) and impaired problem-solving. We analyzed 198 aggressive children (most of whom also had elevated internalizing symptoms) who engaged in structured discussions with their mothers. Coders rated the extent to which dyads problem-solved and co-ruminated during discussions, and mothers filled out questionnaires assessing maternal and child symptoms. Path analysis tested whether higher levels of co-rumination and poor problem-solving statistically mediated the relation between depressive symptoms in mothers and child internalizing and externalizing behaviour. Maternal depressive symptomatology was correlated with greater child symptoms, higher rates of co-rumination and poorer problem-solving. Statistical mediation was non-significant. Results support the established link between maternal depression and child psychopathology, and suggest that dysphoric mothers and their children engage in maladaptive coping interactions.     

The School and Community Study: Characteristics of Students Who Have Emotional and Behavioral Disabilities Served in Restructuring Public Schools

We present selected initial results from a study investigating the effects of school restructuring and reform activities on outcomes for students who are identified as having serious emotional and behavioral disabilities. A review of the literature revealed six key areas of reform for investigation: accountability, governance, parent involvement, includedness, curriculum and instruction, and pro-social discipline. Ten schools (five elementary, two K-8, one middle, and two high schools) actively engaged in school restructuring and reform efforts were selected to participate in the study, and their status related to these six areas is presented. Characteristics of the students identified as having emotional and behavioral disabilities and served in these schools in special education settings (N = 116) are described. Results from the administration of standardized assessments revealed that these students have significant levels of emotional and behavioral disabilities that impair their functioning at school and at home. Further, school staff are providing the majority of counseling services to these students during the school day, with non-school professionals providing services to 25% of the students.     

Tactile sensitivity in Asperger syndrome

People with autism and Asperger syndrome are anecdotally said to be hypersensitive to touch. In two experiments, we measured tactile thresholds and suprathreshold tactile sensitivity in a group of adults with Asperger syndrome. In the first experiment, tactile perceptual thresholds were measured. Two frequencies of vibrotactile stimulation were used: 30 and 200 Hz. The results demonstrated significantly lower tactile perceptual thresholds in the Asperger group at 200 Hz but not at 30 Hz, thus confirming tactile hypersensitivity but only for one class of stimulus. A second experiment investigated whether self-produced movement affected the perception of touch in a group of adults with Asperger syndrome. A suprathreshold tactile stimulus was produced either by the participant (self-produced condition) or by the experimenter (externally produced condition) and participants were asked to rate the perception of the tactile stimulation. The results demonstrated that, while both Asperger and control groups rated self-produced touch as less tickly than external touch, the Asperger group rated both types of tactile stimulus as significantly more tickly and intense than did the control group. This experiment confirms the finding of tactile hypersensitivity, but shows that the perceptual consequences of self-produced touch are attenuated in the normal way in people with Asperger syndrome. An abnormality in this process cannot therefore account for their tactile hypersensitivity.