More on the fragility of performance: choking under pressure in mathematical problem solving

In 3 experiments, the authors examined mathematical problem solving performance under pressure. In Experiment 1, pressure harmed performance on only unpracticed problems with heavy working memory demands. In Experiment 2, such high-demand problems were practiced until their answers were directly retrieved from memory. This eliminated choking under pressure. Experiment 3 dissociated practice on particular problems from practice on the solution algorithm by imposing a high-pressure test on problems practiced 1, 2, or 50 times each. Infrequently practiced high-demand problems were still performed poorly under pressure, whereas problems practiced 50 times each were not. These findings support distraction theories of choking in math, which contrasts with considerable evidence for explicit monitoring theories of choking in sensorimotor skills. This contrast suggests a skill taxonomy based on real-time control structures.     

Suicide surveillance in the U.S. Military--reporting and classification biases in rate calculations

The military has a well-defined population with suicide prevention programs that have been recognized as possible models for civilian suicide prevention efforts. Monitoring prevention programs requires accurate reporting. In civilian settings, several studies have confirmed problems in the reporting and classification of suicides. This analysis evaluated whether suicides were underreported or misclassified under accident or undetermined manner of death in the military system. We reviewed all 1998 and 1999 military deaths using official death reports and compared these data with additional sources, most importantly the DoD Medical Mortality Registry. We assessed for evidence of expressed suicidal intent and past psychiatric history among deaths classified as undetermined and accidents due to gunshot, overdose, drowning, falls, or asphyxia. Using sources other than official records, we found 17% more suicides than were reported, and an additional 4% of deaths that were suspicious for suicide. This study suggests that reporting and classification errors may account for 21% additional suicides in the military. These findings are comparable to rates seen in civilian studies and add to the literature regarding the problems inherent in using administrative death classification data for medical surveillance purposes.     

Tasks of a feather flock together: Similarity effects in task switching

Recent research on task switching has paid little attention to how tasks are represented and how the relations between task representations might affect the executive processes engaged to achieve a task switch. Two experiments investigated the effect of task similarity on task switching. Similarity was defined in terms of shared component operations--attentional control settings in Experiment 1 and response modality in Experiment 2--with tasks sharing more component operations said to be more similar to each other than tasks sharing fewer component operations. Across both experiments, task similarity facilitated task switching, seen in reduced switch costs for switching between similar tasks as opposed to dissimilar tasks. These results indicate that task similarity defined in terms of component operations can be used to define a multidimensional task space in which the executive processes of task selection and implementation are active.     

An ER-fMRI investigation of morphological inflection in German reveals that the brain makes a distinction between regular and irregular forms

The hypothesis that morphological processing is supported by a mental dictionary of stored entries plus a set of mental computations based on rules is examined using event-related fMRI. If a rules-plus-memory model () reflects the actual organization of the language faculty, two distinct patterns of brain activation should be observed for production of German irregular and regular noun and verb inflections. If a connectionist alternative to the rules-and-memory model (, and many others since), which seeks to explain the production of both irregular and regular forms within a single associative memory mechanism, is correct, there should be no neural differentiation between German regular and irregular inflection. The results we report support the existence of substantially differing patterns of activation for regulars vs. irregulars, an outcome that is consistent with the two-component rules-plus-memory account.     

On the displacement of leisure items by food during multiple-stimulus preference assessments

Previous studies have demonstrated that when food and leisure stimuli are combined in multiple-stimulus preference assessments, individuals typically select food more often, although the leisure stimuli also have known reinforcing properties. The purpose of the current study was to replicate this effect and determine its durability by examining the effect after mealtimes. Four adults who had been diagnosed with severe mental retardation were given three initial multiple-stimulus (without replacement) preference assessments (i.e., food, leisure stimuli, and combined). All participants selected food items as the most preferred stimuli in the combined assessments. Combined assessments were then administered immediately before and after the evening meal for each participant for 1 week. The results showed similar data both before and after mealtimes.     

CREATING SINGLE-SUBJECT DESIGN GRAPHS WITH MICROSOFT EXCEL™

Because single-subject design methodology is the cornerstone of behavior-analytic research, behavior analysts are often engaged in the practice of graph production. There are a variety of computer software packages on the market that can be used to create graphs; however, not all of them are suitable for producing single-subject design line graphs. Microsoft Excel 97 for Windows 95/NT and MacOS operating systems contains a variety of features that are conducive to producing reversal, multiple baseline, and multielement graphs (among others) that conform to many of the technical recommendations for publication in the Journal of Applied Behavior Analysis. We present detailed instructions on creating these graphs using Microsoft Excel.     

ON THE EFFECTS OF NONCONTINGENT DELIVERY OF DIFFERING MAGNITUDES OF REINFORCEMENT

We conducted a parametric analysis of response suppression associated with different magnitudes of noncontingent reinforcement (NCR). Participants were 5 adults with severe or profound mental retardation who engaged in a manual response that was reinforced on variable-ratio schedules during baseline. Participants were then exposed to NCR via multielement and reversal designs. The fixed-time schedules were kept constant while the magnitude of the reinforcing stimulus was varied across three levels (low, medium, and high). Results showed that high-magnitude NCR schedules produced large and consistent reductions in response rates, medium-magnitude schedules produced less consistent and smaller reductions, and low-magnitude schedules produced little or no effect on responding. These results suggest that (a) NCR affects responding by altering an establishing operation (i.e., attenuating a deprivation state) rather than through extinction, and (b) magnitude of reinforcement is an important variable in determining the effectiveness of NCR.     

The Inclusion of Fathers In Family Therapy: A Research Based Perspective

This paper summarizes the results of research on the role of fathers in families and family therapy with particular reference to preparation for fatherhood, father involvement in family life as a protective factor, fathers' deviant behaviour as a risk factor, fathers' communication and coping styles, fatherhood and different types of marriages, and the effects of the workplace on fathers' behaviour within the family. Available research suggests that, with respect to problem formation, the behaviour of fathers may serve as either a risk factor or as a protective factor. With respect to problem resolution, fathers may be a powerful therapeutic resource or seriously compromise effectiveness of family therapy. The implications of research for clinical practice are discussed.