An implicit enumeration method for an exact test of weighted kappa

The kappa coefficient is one of the most widely used measures for evaluating the agreement between two raters asked to assign N objects to one of K nominal categories. Weighted versions of kappa enable partial credit to be awarded for near agreement, most notably in the case of ordinal categories. An exact significance test for weighted kappa can be conducted by enumerating all rater agreement tables with the same fixed marginal frequencies as the observed table, and accumulating the probabilities for all tables that produce a weighted kappa index that is greater than or equal to the observed measure. Unfortunately, complete enumeration of all tables is computationally unwieldy for modest values of N and K. We present an implicit enumeration algorithm for conducting an exact test of weighted kappa, which can be applied to tables of non‐trivial size. The algorithm is particularly efficient for ‘good’ to ‘excellent’ values of weighted kappa that typically have very small p‐values. Therefore, our method is beneficial for situations where resampling tests are of limited value because the number of trials needed to estimate the p‐value tends to be large.     

The Effect of Anxiety on the Cognitive Functioning in Non-clinical Schizotypal Individuals

Schizotypal personality disorder (SPD) is characterized by eccentric behavior and perceptual distortions that closely resemble the patterns observed in those with schizophrenia. Schizophrenia and related personality disorders (i.e., SPD) are associated with deficits in sustained attention, slower than normal reaction times, and manifestations of working memory deficits and erratic cognitive tasks. The present study used the schizotypal personality scale (STA) to compare cognitive abilities of self-reported low schizotypic tendency subjects with high schizotypic tendency subjects. The group scores on the STA differed significantly. Those with high STA scores also tended to have higher state and trait anxiety scores based on the State-Trait Anxiety Inventory (STAI). The groups did not significantly differ on any of the demographic variables tested, including age, education, self-rated health status, and medication. Along with an executive function test, two computerized tasks tested subjects on reaction time and memory. Even when covariates (i.e., state, trait anxiety scores) were analyzed, there were no significant differences between the groups and tasks, although the gathered data showed trends in the expected direction.     

Age-related differences in individual DSM criteria for borderline personality disorder

This study examined age-related effects of individual DSM criteria for borderline personality disorder (BPD) and symptoms of depression and anxiety in three groups: patients diagnosed with BPD, another personality disorder, or no personality disorder. The goal was to determine if distinctive age effects emerged within the BPD group. This mixed clinical and community sample (N = 380) ranged from 20-50 years old. Each participant was assessed for symptoms of axis I and II psychopathology. We found significant interactions for personality disorder group x age for the suicidal behavior and impulsivity criteria that reflected distinctive changes in the BPD group. The BPD group reported significantly more anxious and depressive symptoms. However, no main effect for age or personality disorder x age interaction emerged with symptoms. These results demonstrate that older individuals with BPD report less impulsivity and fewer suicidal behaviors, although symptoms of distress persist.     

Adapted motivational interviewing for women with binge eating disorder: a randomized controlled trial

In this randomized controlled trial, 108 women with binge-eating disorder (BED) recruited from the community were assigned to either an adapted motivational interviewing (AMI) group (1 individual AMI session + self-help handbook) or control group (handbook only). They were phoned 4, 8, and 16 weeks following the initial session to assess binge eating and associated symptoms (depression, self-esteem, quality of life). Postintervention, the AMI group participants were more confident than those in the control group in their ability to change binge eating. Although both groups reported improved binge eating, mood, self-esteem, and general quality of life 16 weeks following the intervention, the AMI group improved to a greater extent. A greater proportion of women in the AMI group abstained from binge eating (27.8% vs. 11.1%) and no longer met the binge frequency criterion of the Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.; American Psychiatric Association, 2000) for BED (87.0% vs. 57.4%). AMI may constitute a brief, effective intervention for BED and associated symptoms.     

The Effect of Anxiety on the Cognitive Functioning in Non-clinical Schizotypal Individuals

Schizotypal personality disorder (SPD) is characterized by eccentric behavior and perceptual distortions that closely resemble the patterns observed in those with schizophrenia. Schizophrenia and related personality disorders (i.e., SPD) are associated with deficits in sustained attention, slower than normal reaction times, and manifestations of working memory deficits and erratic cognitive tasks. The present study used the schizotypal personality scale (STA) to compare cognitive abilities of self-reported low schizotypic tendency subjects with high schizotypic tendency subjects. The group scores on the STA differed significantly. Those with high STA scores also tended to have higher state and trait anxiety scores based on the State-Trait Anxiety Inventory (STAI). The groups did not significantly differ on any of the demographic variables tested, including age, education, self-rated health status, and medication. Along with an executive function test, two computerized tasks tested subjects on reaction time and memory. Even when covariates (i.e., state, trait anxiety scores) were analyzed, there were no significant differences between the groups and tasks, although the gathered data showed trends in the expected direction.     

The Use of Stimulant Medication and Behavioral Interventions for the Treatment of Attention Deficit Hyperactivity Disorder: A Survey of Parents’ Knowledge, Attitudes, and Experiences

We examined parents’ knowledge, attitudes, and information sources regarding Attention-Deficit/Hyperactivity Disorder (ADHD), including treatment with stimulant medication and behavioral interventions. Responses from parents with a child diagnosed with ADHD and parents without a child diagnosed with ADHD were also compared. Participants consisted of 146 parents of elementary age children from Wisconsin. The surveyed parents were aware of issues surrounding ADHD and the use of stimulant medication, but there were several areas where they possessed inaccurate or incomplete factual information. Parents who had a child diagnosed with ADHD rated the effects of stimulant medication more positively and side effects as less severe than other parents. They also rated behavioral interventions as less effective on all questions. Implications of the study are discussed.     

Masked repetition priming and proportion effects under cognitive load.

The authors used a cognitive load manipulation (rehearsing a string of digits during the trial) to test the automaticity of (a) masked repetition priming and (b) the masked repetition proportion (RP) effect (i.e., greater priming when the proportion of repetition-prime trials is higher) in the lexical decision task. The RP (.2 vs. .8) was varied across blocks. Masked priming was not reduced under load compared with a no-load group. Surprisingly, only the load group showed an RP effect in response latencies, although the no-load group showed an RP effect in the error rates. Our results show that masked priming is automatic, yet the influence of masked primes can nonetheless be adjusted at an unconscious level. Implications for accounts of masked priming are discussed.     

CONCURRENT RESURGENCE AND BEHAVIORAL HISTORY

The contribution of past experiences to concurrent resurgence was investigated in three experiments. In Experiment 1, resurgence was related to the length of reinforcement history as well as the reinforcement schedule that previously maintained responding. Specifically, more resurgence occurred when key pecks had been reinforced on a variable-interval 1-min schedule than a variable-interval 6-min schedule, but this effect may have been due either to the differential reinforcement rates or differential response rates under the two schedules. When reinforcement rates were similar (Experiment 2), there was more resurgence of high-rate than low-rate responding. When response rates were similar (Experiment 3), resurgence was not related systematically to prior reinforcement rates. Taken together, these three experimental tests of concurrent resurgence illustrate that prior response rates are better predictors of resurgence than are prior reinforcement rates.     

Spatial memory in rats after 25 hours

We investigated the time course of spatial-memory decay in rats using an eight-arm radial maze. It is well established that performance remains high with retention intervals as long as 4 h, but declines to chance with a 24-h retention interval (Beatty, W. W., & Shavalia, D. A. (1980b). Spatial memory in rats: time course of working memory and effect of anesthetics. Behavioral & Neural Biology, 28, 454-462). It is possible that 24 h reflects a genuine retention limitation of rat spatial memory. Alternatively, it may be possible to identify factors that might support memory performance even after very long delays. The current experiment was conducted to test the above two hypotheses. We evaluated performance using two intertrial intervals (24 and 48 h) and two retention intervals (1 and 25 h). Increasing the intertrial interval produced an approximately constant increase in performance for both retention intervals. This improvement is consistent with a trial-spacing effect (i.e., the superiority of spaced over massed trials). Rat spatial memory apparently lasts at least 25 h.