Executive functions and social skills in survivors of pediatric brain tumor

Medical advances have resulted in increased survival rates for children with brain tumors. Consequently, issues related to survivorship have become more critical. The use of multimodal treatment, in particular cranial radiation therapy, has been associated with subsequent cognitive decline. Specifically, deficits in executive functions have been reported in survivors of various types of pediatric brain tumor. Survivors are left with difficulties, particularly in self-monitoring, initiation, inhibition, and planning, to name a few. Another domain in which survivors of pediatric brain tumor have been reported to show difficulty is that of social skills. Parents, teachers, and survivors themselves have reported decreased social functioning following treatment. Deficits in executive functions and social skills are likely interrelated in this population, as executive skills are needed to navigate various aspects of social interaction; however, this has yet to be studied empirically. Twenty-four survivors of pediatric brain tumor were assessed using a computerized task of executive functions, as well as paper-and-pencil measures of social skills and real-world executive skills. Social functioning was related to a specific aspect of executive functions, that is, the survivors' variability in response time, such that inconsistent responding was associated with better parent-reported and survivor-reported social skills, independent of intellectual abilities. Additionally, parent-reported real-world global executive abilities predicted parent-reported social skills. The implications of these findings for social skills interventions and future research are discussed.     

Selling and Sales Management in Action Examining the Bases Utilized for Evaluating Salespeoples' Performance

Evaluating salespeoples' performance is an important task for sales managers. However, little is known about what bases are used by sales managers to evaluate the performance of their salespeople. A study was conducted to determine the bases actually used by sales managers and the results were compared with a study conducted in 1983. Findings indicate more emphasis on profit and cost control, a continued reliance on qualitative measures, and a wide variety of bases being utilized to evaluate the performance of salespeople. Furthermore, the stability of results, across a wide variety of respondent job titles as well as business types and sizes, indicates a good deal of generalizability to other firms.     

Contextual cueing based on specific and categorical properties of the environment

Theories of visual search have generally assumed that rejected distractors are marked so as to avoid further processing of these items (memory-driven search). To test this assumption, Horowitz and Wolfe (1998) developed the randomized search paradigm, in which standard static search is compared to dynamic search where items are randomly replotted at new locations throughout a trial. Memory-driven search predicts that search slopes should double in the dynamic condition. After reviewing earlier findings that slopes were similar in the two conditions, we present two new experiments. Experiment 1 replicated and extended our previous findings using a larger range of set sizes, a slower rate of change, and adding a fixed location dynamic condition. Experiment 2 employed stimuli that required overt fixation. Neither experiment showed evidence for memory-driven search. We conclude that visual search is best understood as a series of successive judgements of the momentary probability of target presence.     

Time to guide: Evidence for delayed attentional guidance in contextual cueing

Contextual cueing experiments show that, when displays are repeated, reaction times (RTs) to find a target decrease over time even when the observers are not aware of the repetition. Recent evidence suggests that this benefit in standard contextual cueing tasks is not likely to be due to an improvement in attentional guidance (Kunar, Flusberg, Horowitz, & Wolfe, 2007). Nevertheless, we ask whether guidance can help participants find the target in a repeated display, if they are given sufficient time to encode the display. In Experiment 1 we increased the display complexity so that it took participants longer to find the target. Here we found a larger effect of guidance than in a condition with shorter RTs. Experiment 2 gave participants prior exposure to the display context. The data again showed that with more time participants could implement guidance to help find the target, provided that there was something in the search stimuli locations to guide attention to. The data suggest that, although the benefit in a standard contextual cueing task is unlikely to be a result of guidance, guidance can play a role if it is given time to develop.     

Coarse guidance by numerosity in visual search

In five experiments, we examined whether the number of items can guide visual focal attention. Observers searched for the target area with the largest (or smallest) number of dots (squares in Experiment 4 and “checkerboards” in Experiment 5) among distractor areas with a smaller (or larger) number of dots. Results of Experiments 1 and 2 show that search efficiency is determined by target to distractor dot ratios. In searches where target items contained more dots than did distractor items, ratios over 1.5:1 yielded efficient search. Searches for targets where target items contained fewer dots than distractor items were harder. Here, ratios needed to be lower than 1:2 to yield efficient search. When the areas of the dots and of the squares containing them were fixed, as they were in Experiments 1 and 2, dot density and total dot area increased as dot number increased. Experiment 3 removed the density and area cues by allowing dot size and total dot area to vary. This produced a marked decline in search performance. Efficient search now required ratios of above 3:1 or below 1:3. By using more realistic and isoluminant stimuli, Experiments 4 and 5 show that guidance by numerosity is fragile. As is found with other features that guide focal attention (e.g., color, orientation, size), the numerosity differences that are able to guide attention by bottom-up signals are much coarser than the differences that can be detected in attended stimuli.     

Neuropsychological Performance in Gulf War Era Veterans: Traumatic Stress Symptomatology and Exposure to Chemical–Biological Warfare Agents

Because complaints of diminished concentration and memory are among the most common health symptoms reported by Gulf War (GW) veterans with unexplained illnesses, this study investigated neuropsychological functions among GW veterans and controls. Relationships between neuropsychological performance, severity of posttraumatic stress disorder (PTSD) symptomatology, and exposure to chemical–biological warfare agents (CBW) were assessed. Participants were 225 veterans recruited from three cohorts: GW-deployed veterans from Ft. Devens, MA ( n = 141) and New Orleans, LA (n = 37), and Germany-deployed veterans from a Maine National Guard unit (n = 47). A comprehensive evaluation was completed. Severity of subclinical PTSD symptomatology was significantly related to scores on specific neuropsychological tests. PTSD symptom severity in GW-deployed veterans was found to be greater and associated with a broader range of neuropsychological deficits than in Germany-deployed veterans. PTSD severity was associated with lower performance on a range of neuropsychological tasks, whereas CBW exposure contributed to performance deficits on specific cognitive tasks.     

Why are there eccentricity effects in visual search? Visual and attentional hypotheses

In standard visual search experiments, observers search for a target item among distracting items. The locations of target items are generally random within the display and ignored as a factor in data analysis. Previous work has shown that targets presented near fixation are, in fact, found more efficiently than are targets presented at more peripheral locations. This paper proposes that the primary cause of this “eccentricity effect” (Carrasco, Evert, Chang, & Katz, 1995) is an attentional bias that allocates attention preferentially to central items. The first four experiments dealt with the possibility that visual, and not attentional, factors underlie the eccentricity effect. They showed that the eccentricity effect cannot be accounted for by the peripheral reduction in visual sensitivity, peripheral crowding, or cortical magnification. Experiment 5 tested the attention allocation model and also showed that RT X set size effects can be independent of eccentricity effects. Experiment 6 showed that the effective set size in a search task depends, in part, on the eccentricity of the target because observers search from fixation outward.