Rats use a sense of direction to alternate on T-mazes located in adjacent rooms

Lister hooded rats were trained on a forced-sample T-maze alternation task in an environment lacking spatial landmarks. An early study of spontaneous alternation on the T-maze had shown that rats use a "spatial sense" to select alternate maze arms across mazes. As this phenomenon may provide a useful tool for studying the neural substrates of a directional sense, we wished to confirm this finding on a different version of the T-maze task, with well-trained animals. We found that rats successfully selected the appropriate maze arm when the choice phase of the task was presented on a second maze, oriented in the same direction, and located in an adjacent room. However, choice performance fell to chance level when the second maze was oriented 90° relative to the first. This result suggests that the rats do not simply alternate turns across the two environments, but rather that they rely on a sense of direction that is carried across environments. Electronic Publication     

Body checking and avoidance and the core features of eating disorders among obese men and women seeking bariatric surgery

This study examined two aspects of body checking and avoidance, and their relations to the core psychopathology of eating disorders (EDs), in severely obese men and women seeking bariatric surgery. A consecutive series of 260 (44 male and 216 female) gastric bypass candidates were administered measures to assess body checking and avoidance, binge eating, restraint, and overevaluation of weight and shape. The majority of patients reported regularly pinching areas of their body to check for fatness and avoided wearing clothing that made them particularly aware of their body. Significant associations were observed between checking and restraint, and between avoidance and binge eating. Both checking and avoidance behaviors were significantly associated with overevaluation of weight and shape. The positive associations between each of the two behaviors (body checking and avoidance) with overevaluation of weight/shape remained significant even after controlling for the effects of avoidance on body checking and vice versa. Stepwise multiple regression analyses revealed that binge eating, body checking, and avoidance behaviors made significant unique contributions and jointly accounted for 22-25% of the variance in overevaluation of weight and shape, respectively. This study documents the presence of eating disorder psychopathology among severely obese patients seeking bariatric surgery. The findings support the view that body checking and avoidance behaviors are manifestations of overevaluation of weight and shape and disordered eating.     

Teamwork in multiteam systems

The authors examined how networks of teams integrate their efforts to succeed collectively. They proposed that integration processes used to align efforts among multiple teams are important predictors of multiteam performance. The authors used a multiteam system (MTS) simulation to assess how both cross-team and within-team processes relate to MTS performance over multiple performance episodes that differed in terms of required interdependence levels. They found that cross-team processes predicted MTS performance beyond that accounted for by within-team processes. Further, cross-team processes were more important for MTS effectiveness when there were high cross-team interdependence demands as compared with situations in which teams could work more independently. Results are discussed in terms of extending theory and applications from teams to multiteam systems.     

Aggression and self-esteem: a diary study of children's reactivity to negative interpersonal events

The study employs a daily diary design to assess self-esteem reactivity and its association with children's aggressive behavior. We test the hypothesis that the self-esteem of aggressive children will be more reactive to negative interpersonal events than the self-esteem of nonaggressive children. Results provide partial support for the aggression/reactivity hypothesis. Aggressive children's self-esteem was more reactive to negative peer events but less reactive to negative adult events than the self-esteem of less aggressive children. These findings are discussed in relation to the experimental literature relating self-esteem instability and ego-threat to aggression and in relation to the extensive body of research on childhood aggression. Intervention implications are also considered.     

The consequences of race for police officers' responses to criminal suspects

The current work examined police officers' decisions to shoot Black and White criminal suspects in a computer simulation. Responses to the simulation revealed that upon initial exposure to the program, the officers were more likely to mistakenly shoot unarmed Black compared with unarmed White suspects. However, after extensive training with the program, in which the race of the suspect was unrelated to the presence of a weapon, the officers were able to eliminate this bias. These findings are discussed in terms of their implications for the elimination of racial biases and the training of police officers.     

Assessing the effectiveness of jail diversion programs for persons with serious mental illness and co-occurring substance use disorders

In recent years, jail diversion programs for people with serious mental illness and co-occurring substance use disorders have received increasing attention and have rapidly grown in number. Previous studies suggest that jail diversion programs have the potential to achieve positive outcomes. The present study reports findings from 6 jail diversion programs (3 pre-booking and 3 post-booking) participating in a federally-funded research initiative to assess the effectiveness of jail diversion programs for people with co-occurring disorders. Diverted and non-diverted groups were compared on self-reported outcomes at 12 months following diversion. The findings suggest that jail diversion reduces time spent in jail without increasing the public safety risk, while linking participants to community-based services. Jail diversion costs and the implications of these results for jail diversion programs and future research are discussed.     

Relationship between short- and long-term memory and short- and long-term extinction

Both the acquisition and the extinction of memories leave short- and long-term mnemonic traces. Here, we show that in male Wistar rats, the short-term memory for a step-down inhibitory avoidance task (IA) is resistant to extinction, and that its expression does not influence retrieval or extinction of long-term memory. It has been known for some time that short- and long-term inhibitory avoidance memory involve separate and parallel processes. Here we show that, instead, short-term extinction of IA long-term memory is the first step towards its long-term extinction, and that this link requires functional NMDA receptors and protein synthesis in the CA1 region of the dorsal hippocampus at the time of the first CS-no US presentation.     

Attention and inhibition in bilingual children: evidence from the dimensional change card sort task

In a previous study, a bilingual advantage for preschool children in solving the dimensional change card sort task was attributed to superiority in inhibition of attention (Bialystok, 1999). However, the task includes difficult representational demands to encode and interpret the task stimuli, and bilinguals may also have profited from superior representational abilities. This possibility is examined in three studies. In Study 1, bilinguals outperformed monolinguals on versions of the problem containing moderate representational demands but not on a more demanding condition. Studies 2 and 3 demonstrated that bilingual children were more skilled than monolinguals when the target dimensions were perceptual features of the stimulus and that the two groups were equivalent when the target dimensions were semantic features. The conclusions are that bilinguals have better inhibitory control for ignoring perceptual information than monolinguals do but are not more skilled in representation, confirming the results of the original study. The results also identify the ability to ignore an obsolete display feature as the critical difficulty in solving this task.     

An analysis of initial acquisition and maintenance of sight words following picture matching and copy cover, and compare teaching methods

This study compared the copy, cover, and compare method to a picture-word matching method for teaching sight word recognition. Participants were 5 kindergarten students with less than preprimer sight word vocabularies who were enrolled in a public school in the Pacific Northwest. A multielement design was used to evaluate the effects of the two interventions. Outcomes suggested that sight words taught using the copy, cover, and compare method resulted in better maintenance of word recognition when compared to the picture-matching intervention. Benefits to students and the practicality of employing the word-level teaching methods are discussed.