Impaired discrimination learning in mice lacking the NMDA receptor NR2A subunit

N-Methyl-D-aspartate receptors (NMDARs) mediate certain forms of synaptic plasticity and learning. We used a touchscreen system to assess NR2A subunit knockout mice (KO) for (1) pairwise visual discrimination and reversal learning and (2) acquisition and extinction of an instrumental response requiring no pairwise discrimination. NR2A KO mice exhibited significantly retarded discrimination learning. Performance on reversal was impaired in NR2A KO mice during the learning phase of the task; with no evidence of heightened perseverative responses. Acquisition and extinction of an instrumental behavior requiring no pairwise discrimination was normal in NR2A KO mice. The present findings demonstrate a significant and selective deficit in discrimination learning following loss of NR2A.     

Moving From Efficacy to Effectiveness in Eating Disorders Prevention: The Sorority Body Image Program

Although eating disorders prevention research has begun to produce programs with demonstrated efficacy, many such programs simply target individuals as opposed to engaging broader social systems (e.g., schools, sororities, athletic teams) as participant collaborators in eating disorders prevention. Yet, social systems ultimately will be responsible for the real-world delivery of eating disorder prevention programs, suggesting that an important issue has yet to be addressed. Namely, it is unclear to what degree efficacious individual-focused eating disorder prevention programs remain effective when incorporated into critical social systems under real-world conditions. Over the past 5 years, we have collaborated with the campus sororities in the development of a sustainable eating disorders prevention program that is based on the prevention efficacy literature. This paper describes both challenges and helpful strategies that we encountered in tailoring an evidence-based eating disorders prevention program to the needs of a relevant social system.     

Parallel non-verbal enumeration is constrained by a set-based limit

Adults can represent approximate numbers of items independently of language. This approximate number system can discriminate and compare entities as varied as dots, sounds, or actions. But can multiple different types of entities be enumerated in parallel and stored as independent numerosities? Subjects who were prevented from verbally counting watched an experimenter hide sequences of objects in two locations. The number of object types, which contrasted in category membership, color, shape, and texture, varied from 1 to 5, and object types were completely temporally intermixed. Subjects were then asked how many objects of each type were in each location. In three experiments, subjects successfully enumerated the objects of each type in each location when 1-3 types were presented, but failed with 4 or 5 types, regardless of the total number of objects seen. Thus, adults can perform simultaneous enumeration of multiple sets that unfold in temporally intermixed fashion, but are limited to 3 such sets at a time. Furthermore, they perform these parallel enumerations in the absence of training or instruction, and can do so for sets of objects that are hidden in distinct locations. The convergence of this 3-set capacity limit with the 3-item capacity limit widely observed in studies of working memory suggests that each enumeration requires a single slot in memory, and that storage in memory is required before enumeration can occur.     

Lexical and sublexical processes in the perception of transposed-letter anagrams

Evidence from priming and lexical decision tasks suggests that nonwords created by transposing adjacent letter pairs (TL nonwords) are very effective in activating lexical representations of their base words, because the process of orthographic matching tolerates minor changes in letter position. However, this account disregards the possible role of sublexical processing in reading. TL nonwords are perceptually ambiguous, with lexical and sublexical processing giving rise to conflicting interpretations. The consequences of this ambiguity were investigated in a lexical decision experiment with primes that were either high or low bigram frequency TL versions of target words. Priming effects were much larger for low BF primes (e.g., pucnh-PUNCH) than for high BF primes (e.g., panit-PAINT). This finding is interpreted as evidence that lexical activation can be inhibited by competing output resulting from sublexical processing of TL letter string. We conclude that phonological processing is an important determinant of responses to TL stimuli, and we consider how this interpretation might be accommodated within the dual-route cascaded (DRC) model of word recognition.     

Developmental change in the acuity of the "Number Sense": The Approximate Number System in 3-, 4-, 5-, and 6-year-olds and adults

Behavioral, neuropsychological, and brain imaging research points to a dedicated system for processing number that is shared across development and across species. This foundational Approximate Number System (ANS) operates over multiple modalities, forming representations of the number of objects, sounds, or events in a scene. This system is imprecise and hence differs from exact counting. Evidence suggests that the resolution of the ANS, as specified by a Weber fraction, increases with age such that adults can discriminate numerosities that infants cannot. However, the Weber fraction has yet to be determined for participants of any age between 9 months and adulthood, leaving its developmental trajectory unclear. Here we identify the Weber fraction of the ANS in 3-, 4-, 5-, and 6-year-old children and in adults. We show that the resolution of this system continues to increase throughout childhood, with adultlike levels of acuity attained surprisingly late in development.     

Social Support Opinions1

This research introduces the Social Support Opinion Survey (SSOS), the first measure of social support from the provider's perspective. Studies 1–3 developed the SSOS and confirmed that support opinions can be reliably characterized as directive (attempting to govern how others cope) and nondirective (facilitating without governing how others cope). Studies 4–6 showed that social support opinions relate to more basic cognitive, emotional, and interpersonal styles. Directive opinions were related to cognitive rigidity (need for structure, need for certainty, and just‐world beliefs) and to an exchange orientation. Nondirective opinions, in contrast, were related to emotional differentiation, use of emotions as information, empathy, and a communal orientation. Thus, people may reveal who they are by how they help.     

Differential effects of regulatory fit on category learning

Motivation affects the degree to which people engage in tasks as well as the processes that they bring to bear. We explore the proposal that a fit between a person’s situationally induced self-regulatory focus and the reward structure of the task that they are pursuing supports greater flexibility in processing than does a mismatch between regulatory focus and reward structure. In two experiments, we prime regulatory focus and manipulate task reward structure. Our participants perform a rule-based learning task whose solution requires flexible strategy testing as well as an information-integration task for which flexible strategy use hinders learning. Across two experiments, we predict and obtain a three-way interaction between regulatory focus, reward structure, and task. Relative to a mismatch, a match leads to better rule-based task performance, but worse performance on the information-integration task. We relate these findings to other work on motivation and choking under pressure.     

Comparison of inhibition in two timed reaction tasks: the color and emotion Stroop tasks

The authors examined the cross-task consistency of the ability to inhibit the processing of irrelevant information. They compared interference scores on 2 widely used inhibition tasks and found that color word Stroop interference scores correlated with emotion word Stroop interference scores. An examination of physiological reactivity showed that, in general, the color Stroop was more arousing than was the emotion Stroop, most likely due to increased response conflict.