Attention and Communication Following TBI: Making the Connection through a Meta-Narrative Systematic Review

Neuropsychology Review - Background and aim: Communication difficulties are one of the hallmark characteristics of adults following traumatic brain injury (TBI), a difficulty that incorporates...     

Screening for Muir-Torre Syndrome Using Mismatch Repair Protein Immunohistochemistry of Sebaceous Neoplasms

Screening for the Muir-Torre variant of Lynch Syndrome (LS) using Mismatch Repair (MMR) gene immunohistochemistry (IHC) on sebaceous neoplasms (SNs) is technically feasible. To date, research into the clinical utility of MMR IHC for this indication is limited. We conducted a retrospective chart review of 90 patients with MMR IHC completed on at least one SN from January 2005 to May 2010. SNs included were adenomas, epitheliomas, carcinomas and basal and squamous cell carcinomas with sebaceous differentiation. Of the 90 patients, 13 (14 %) had genetically confirmed or fulfilled clinical criteria for a diagnosis of MTS and 51 patients (57 %) presented with an abnormal MMR IHC result (loss of one or more MMR proteins) on at least one SN. Abnormal IHC had a sensitivity of 85 %, specificity of 48 %, positive predictive value (PPV) of 22 % and negative predictive value (NPV) of 95 % when evaluating for MTS. When personal or family history of colorectal cancer (≥2 family members with a history of colorectal cancer) was taken into consideration, ignoring IHC results, sensitivity was 92 %, specificity was 99 %, PPV was 92 % and NPV was 99 %. MMR IHC on SNs when used to screen for MTS has poor diagnostic utility. We recommend that MMR IHC not be performed routinely on SNs when the patient does not have either personal or family history of colorectal cancer.     

Building Meaningful Parasocial Relationships Between Toddlers and Media Characters to Teach Early Mathematical Skills

Very young children have difficulty transferring what they view onscreen to their offscreen worlds. This study examined whether familiarizing toddlers with a character would improve toddlers' performance on a subsequent seriation task. Toddlers were randomly assigned to one of three conditions: (1) a familiarized character condition where toddlers viewed character-based videos and engaged in character-based play over a 3-month period before viewing the seriation video demonstration; (2) an unfamiliarized character condition where the toddler only saw the seriation video demonstration; and (3) a no-exposure control group where the toddler did not see the seriation video demonstration or have any involvement with the character. All toddlers were tested on the same seriation task at age 21 months, with the familiarized character group beginning the study at age 18 months and the other groups participating only at age 21 months. Toddlers in the familiarized character condition, but not the unfamiliarized character condition, completed the seriation task significantly better than the no-exposure control group. Within the familiarized character condition, toddlers who nurtured the character during play subsequently had higher seriation scores. The results suggest that meaningful relationships with media characters can help toddlers learn early mathematical skills.     

Heroic DVD portrayals: What US and Taiwanese adolescents admire and understand

Viewing media aggression can be a risk factor for the long-term well being of viewers, and heroes have been targeted as a major risk factor in this relationship because they commit justified acts of aggression. However, little is known about the specific aspects of heroic conduct that viewers find worthy of emulation. We examined US and Taiwanese adolescents' and college students' identification with, and perceptions of, heroic characters portrayed in a DVD narrative as well as their comprehension of the narrative. Those who thought that certain characters were heroes were more likely to identify with them. However, the qualities that viewers found attractive in heroes were compassion and thinking before using force, not aggression or vengeance. Those who did not understand the program well were more likely to identify with the villain, and they were also more likely to misattribute prosocial qualities to the villain. The results suggest that at least for older viewers, heroic behavior is admired and emulated for prosocial rather than antisocial conduct, and that poor plot-comprehension is one factor that contributes to younger viewers' identification with, and imitation of, antisocial role models.     

Pigeons' discounting of probabilistic and delayed reinforcers

Pigeons' discounting of probabilistic and delayed food reinforcers was studied using adjusting-amount procedures. In the probability discounting conditions, pigeons chose between an adjusting number of food pellets contingent on a single key peck and a larger, fixed number of pellets contingent on completion of a variable-ratio schedule. In the delay discounting conditions, pigeons chose between an adjusting number of pellets delivered immediately and a larger, fixed number of pellets delivered after a delay. Probability discounting (i.e., subjective value as a function of the odds against reinforcement) was as well described by a hyperboloid function as delay discounting was (i.e., subjective value as a function of the time until reinforcement). As in humans, the exponents of the hyperboloid function when it was fitted to the probability discounting data were lower than the exponents of the hyperboloid function when it was fitted to the delay discounting data. The subjective values of probabilistic reinforcers were strongly correlated with predictions based on simply substituting the average delay to their receipt in each probabilistic reinforcement condition into the hyperboloid discounting function. However, the subjective values were systematically underestimated using this approach. Using the discounting function proposed by Mazur (1989), which takes into account the variability in the delay to the probabilistic reinforcers, the accuracy with which their subjective values could be predicted was increased. Taken together, the present findings are consistent with Rachlin's (Rachlin, 1990; Rachlin, Logue, Gibbon, & Frankel, 1986) hypothesis that choice involving repeated gambles may be interpreted in terms of the delays to the probabilistic reinforcers.     

Delay discounting of qualitatively different reinforcers in rats

Humans discount larger delayed rewards less steeply than smaller rewards, whereas no such magnitude effect has been observed in rats (and pigeons). It remains possible that rats' discounting is sensitive to differences in the quality of the delayed reinforcer even though it is not sensitive to amount. To evaluate this possibility, Experiment 1 examined discounting of qualitatively different food reinforcers: highly preferred versus nonpreferred food pellets. Similarly, Experiment 2 examined discounting of highly preferred versus nonpreferred liquid reinforcers. In both experiments, an adjusting-amount procedure was used to determine the amount of immediate reinforcer that was judged to be of equal subjective value to the delayed reinforcer. The amount and quality of the delayed reinforcer were varied across conditions. Discounting was well described by a hyperbolic function, but no systematic effects of the quantity or the quality of the delayed reinforcer were observed.