Ambiguous animals: mutable mammal biases bird

Ambiguous figures were primed with picture context, movement, and by presentation of a prior ambiguous figure. We tested two mammal/bird figures to determine if the multiple primes would add or interfere. Picture priming was effective for both figures but diminished with the presentation of a prior ambiguous figure. For the 'swan/squirrel' there was little movement priming. However, 'rabbit/duck' showed strong movement priming which cancelled the reducing effect of prior presentation and added to the picture effect.     

Recollection training and transfer effects in Alzheimer's disease: effectiveness of the repetition-lag procedure

Objective

This study was designed to extend the use of a memory training technique, known as the repetition-lag procedure, to Alzheimer patients. The specificity of this procedure is to target the process of recollection for improvement.

Method

A group of 12 patients were trained individually for 6 h. The training procedure consisted of a series of yes/no recognition tasks in which some words were repeated throughout the test list across gradually increasing delays. Their performance was evaluated on pre-and-post tests and compared with a recognition practice group and a no contact control group.

Results

Initially, recollection training patients only performed accurately when the delay between repetitions consisted of one intervening word, but by the end of training their performance increased up to four-word intervals. Interestingly, these benefits generalized to other measures of memory, such as working memory, visual memory and source recognition.

Conclusions

Effectiveness of the repetition-lag procedure in Alzheimer’s disease is discussed.     

Classroom behavior and children with mental retardation: Comparison of children with and without ADHD

Thirty-four children (ages 6–12 years) with moderate to borderline mental retardation were studied in a laboratory classroom setting to determine whether children identified as having attention deficit hyperactivity disorder on the basis of Conners Questionnaires differed in classroom behavior. Half of the children scored 15 or greater on both the Parent and Teacher Conners; the remaining children scored 11 or less. All were participants in a Saturday Education Program serving children with mental retardation. Direct observation of the laboratory classroom documented significant differences between groups on measures of on-task behavior and fidgetiness, especially during situations where little direct teacher feedback or supervision was available. Saturday Education Program staff, while blind as to group designation, rated the two groups as differing significantly on all scales of two standardized behavior problem checklists. Checklists by parents and teachers appear to be valid measures of classroom behavior of children with moderate to borderline mental retardation.This research was supported by a grant to the first author from the National Institutes of Child Health and Human Development, U.S. Department of Health and Human Services, grant No. 1R29HD26186-01A1. The authors gratefully acknowledge the assistance of the staff of Children's Hospital of Pittsburgh's Saturday Education Program: Nancy Hall, Aimee Hart, Phyllis Loeffler, Robin Nelson, Christina Poljak, Kelley Sacco, Sarah Stewart, and Mary Zuberbuehler.     

A comparison of the classification capabilities of the 1-dimensional kohonen neural network with two pratitioning and three hierarchical cluster analysis algorithms

Neural Network models are commonly used for cluster analysis in engineering, computational neuroscience, and the biological sciences, although they are rarely used in the social sciences. In this study we compare the classification capabilities of the 1-dimensional Kohonen neural network with two partitioning (Hartigan and Späthk-means) and three hierarchical (Ward's, complete linkage, and average linkage) cluster methods in 2,580 data sets with known cluster structure. Overall, the performance of the Kohonen networks was similar to, or better than, the performance of the other methods.     

Long-Term Follow-Up of Children with Mental Retardation/Borderline Intellectual Functioning and ADHD

Fifty-two children (ages 7 to 14 years) with moderate mental retardation to borderline intellectual functioning were recontacted 12 to 65 months following participation in a double-blind, placebo-controlled trial of methylphenidate (MPH). Sixty-nine percent of subjects continued to be prescribed medication for behavior control at follow-up. While 72% of the sample evidenced improvement, over two-thirds continued to be rated at or above the 98th percentile on the Hyperactivity Index of the Parent Conners. In fact, 22% of subjects had received inpatient psychiatric treatment between the time of the initial MPH trial and follow-up. Finally, subjects with high initial ratings on the Parent Conners Conduct Problems scale were more likely to be suspended from school or receive inpatient psychiatric treatment than subjects with low initial ratings. The results suggested that children with ADHD and mental retardation or borderline intellectual functioning continued to exhibit significant symptoms associated with attention deficit hyperactivity disorder (ADHD) at follow-up and that early conduct problems were predictive of continuing behavioral difficulties.     

Frame-of-Reference Training: Overcoming the Effects of Organizational Citizenship Behavior on Performance Rating Accuracy

Frame-of-reference (FOR) training has been shown to increase rating accuracy. Studies suggest, however, that organizational citizenship behavior (OCB) can influence performance ratings insomuch as they are considered in the rating process. We examined the effects of OCB on the effectiveness of FOR training for improving performance rating accuracy. Results from 77 managers showed that OCB attenuates FOR training effectiveness because of rating inflation, unless the managers are trained to observe and evaluate the OCB.     

On the requirement of nitric oxide signaling in the amygdala for consolidation of inhibitory avoidance memory

Evidence suggests that the NO/sGC/PKG pathway plays a key role in memory processing but the actual participation of this signaling cascade in the amygdala during memory consolidation remains unknown. Here, we show that when infused in the amygdala immediately after inhibitory avoidance training, but not later, the NO synthase inhibitor L-NNA hindered long-term memory retention without affecting locomotion, exploratory behavior, anxiety state or retrieval of the avoidance response. The amnesic effect of L-NNA was not state-dependent and was mimicked by the soluble guanylyl cyclase inhibitor LY83583 and the PKG inhibitor KT-5823. On the contrary, post-training intra-amygdala infusion of the NOS substrate L-Arg, the NO-releasing compound SNAP or the non-hydrolysable analog of cGMP 8Br-cGMP increased memory retention in a dose-dependent manner. Co-infusion of 8Br-cGMP reversed the amnesic effect of L-NNA and LY83583 but not that of KT-5823. Our data indicate that the NO-induced activation of PKG in the amygdala is a necessary step for consolidation of inhibitory avoidance memory.     

COMT val158Met and executive control: a test of the benefit of specific deficits to translational research

The role of catechol-O-methyltransferase (COMT) val158met in prefrontal cortical deficits associated with the liability to schizophrenia remains controversial. This study evaluated 464 healthy adult participants using three measures of executive functions in working memory: a 3-back version of the N-back continuous performance task (CPT) and two variants of the AX-CPT. The interpretability of N-back performance was confounded by possible generalized deficits, whereas the AX variants included internal controls for uncovering specific deficits. There was no relationship between the COMT genotype and N-back performance, whereas val/val individuals had a specific deficit on a dot-pattern version of the AX-CPT. In this case, a specific executive function known as context processing appeared to be compromised. These data suggest that the interpretability gained by including task manipulations to uncover specific deficits can enhance associations between cognitive and genetic levels of analysis.