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.     

Screening for eating disorders in primary care: EDE-Q versus SCOFF

OBJECTIVE AND METHODS: The comparative validity of the Eating Disorder Examination Questionnaire (EDE-Q) (22 items) and SCOFF (five items) in screening for cases of the more commonly occurring eating disorders was examined in a primary care sample of young adult women (n=257). Diagnoses were confirmed in a sub-group of interviewed participants (n=147). RESULTS: Twenty-five cases, primarily variants of bulimia nervosa (BN) not meeting formal diagnostic criteria, were identified in the interviewed sample. An EDE-Q global score of >or= 2.80 yielded the optimal trade-off between sensitivity (Se) (0.80) and specificity (Sp) (0.80) (positive predictive value (PPV)=0.44), whereas a score of two or more positive responses on the SCOFF was optimal (Se=0.72, Sp=0.73, PPV=0.35). Validity coefficients for both measures varied as a function of participants' age and body weight, although these effects were more pronounced for the SCOFF. CONCLUSIONS: Both measures performed well in terms of their ability to detect cases and to exclude non-cases of the more commonly occurring eating disorders in a primary care setting. The EDE-Q performed somewhat better than the SCOFF and was more robust to effects on validity of age and weight. These findings need to be weighed against the advantage of the SCOFF in terms of its brevity.     

Delivering phonological and phonics training within whole‐class teaching

Background Early, intensive phonological awareness and phonics training is widely held to be beneficial for children with poor phonological awareness. However, most studies have delivered this training separately from children's normal whole‐class reading lessons. Aims We examined whether integrating this training into whole class, mixed‐ability reading lessons could impact on children with poor phonological awareness, whilst also benefiting normally developing readers. Sample Teachers delivered the training within a broad reading programme to whole classes of children from Reception to the end of Year 1 (N = 251). A comparison group of children received standard teaching methods (N = 213). Method Children's literacy was assessed at the beginning of Reception, and then at the end of each year until 1 year post‐intervention. Results The strategy significantly impacted on reading performance for normally developing readers and those with poor phonological awareness, vastly reducing the incidence of reading difficulties from 20% in comparison schools to 5% in intervention schools. Conclusions Phonological and phonics training is highly effective for children with poor phonological awareness, even when incorporated into whole‐class teaching.     

Attentional resources in visual tracking through occlusion: the high-beams effect

A considerable amount of research has uncovered heuristics that the visual system employs to keep track of objects through periods of occlusion. Relatively little work, by comparison, has investigated the online resources that support this processing. We explored how attention is distributed when featurally identical objects become occluded during multiple object tracking. During tracking, observers had to detect small probes that appeared sporadically on targets, distracters, occluders, or empty space. Probe detection rates for these categories were taken as indexes of the distribution of attention throughout the display and revealed two novel effects. First, probe detection on an occluder’s surface was better when either a target or distractor was currently occluded in that location, compared to when no object was behind that occluder. Thus even occluded (and therefore invisible) objects recruit object-based attention. Second, and more surprising, probe detection for both targets and distractors was always better when they were occluded, compared to when they were visible. This new attentional high-beams effect indicates that the ability to track through occlusion, though seemingly effortless, in fact requires the active allocation of special attentional resources.     

Windows executable software for the progressive demasking task

The progressive demasking (PDM) task is a perceptual identification task using degraded stimulus presentation procedures, but with the advantage of providing response time (RT) measures on each trial. Participants simply press a response button whenever they recognize a word. In this article, we present newly developed, easy-to-use freeware for PDM. Considering the difficulty of programming such a paradigm with standard experimental software, we developed a program based on high-level C libraries to be executed on Windows XP computers. The program execution is millisecond accurate forRT measurements and generates the fewest possible display duration errors.     

An inexpensive infrared detector to verify the delivery of food pellets

The reproducibility of experimental outcomes depends on consistent control of independent variables. In food-maintained operant performance, it is of utmost importance that the quantity of food delivered is reliable. To that end, some commercial food pellet dispensers have add-on attachments to sense the delivery of pellets. Not all companies, however, offer such add-ons. Aside from availability, cost and temporary reduction in throughput may be a problem for smaller labs. The present paper outlines our recent development of a simple, inexpensive infrared device to detect and confirm the delivery of pellets. The in-line construction of the detector routes the falling pellet through a barrel so that it passes between an infrared emitter and receiver. The circuitry was designed to be compatible with all commercially available behavioral measurement systems, and so may be retrofit to any existing system. Our tests with the detector so far have shown that it is 100% accurate in detecting pellet delivery. The individual unit cost is approximately 25 dollars. The low cost and versatility of the device offer an easy method to ensure the integrity of food delivery in operant settings.     

Rethinking Cognition: On Coulter on Discourse and Mind

This paper responds to, and comments on, Coulter's (1999) critique of discursive psychology with particular reference to how cognition is conceptualised theoretically and analytically. It first identifies a number of basic misreadings of discursive psychological writings, which distort and, at times, reverse its position on the status of cognition. Second, it reviews the main ways in which cognition, mental states, and thoughts have been analytically conceptualised in discursive psychology (respecification of topics from mainstream psychology, studies of the psychological thesaurus in action, and studies of the way psychological issues are managed). Third, it considers two of Coulter's substantive issues: the role of correct usage and the role of conceptual vs. empirical analysis. A series of problems are identified with Coulter's development of both of these issues.