The variability of practice hypothesis in motor learning: does it apply to Alzheimer's disease?

Based on Schmidt's (1975) variability of practice hypothesis, this study examined acquisition and transfer of a gross motor skill, namely tossing, in 58 patients with Alzheimer's disease (AD) and 58 healthy older adults under constant, blocked, and random practice conditions. While healthy older adults were able to learn the tossing task equally well under the three practice conditions, only AD patients receiving constant practice showed significant improvements. Tests of intermediate transfer yielded the expected random practice advantage in healthy controls but not AD patients. None of the practice conditions facilitated intermediate transfer in AD patients; however, constant practice did benefit these impaired individuals on tests of near transfer. These results indicate that the variability of practice hypothesis does not extend to AD patients. As motor learning and transfer were clearly a function of constant practice, future attempts to retrain basic activities of daily living in AD patients should emphasize consistency in training.     

Interfering neighbours: the impact of novel word learning on the identification of visually similar words

We assessed the impact of visual similarity on written word identification by having participants learn new words (e.g. BANARA) that were neighbours of familiar words that previously had no neighbours (e.g. BANANA). Repeated exposure to these new words made it more difficult to semantically categorize the familiar words. There was some evidence of interference following an initial training phase, and clear evidence of interference the following day (without any additional training); interference was larger still following more training on the second day. These findings lend support to models of reading that include lexical competition as a key process.     

Sex Differences in Social Support and Self-Efficacy Within a Recovery Community

This study examined similarities and differences in social support and self-efficacy for abstinence between women and men recovering from substance addiction. The sample consisted of 87 residents of Oxford House (OH) self-run, community-based recovery homes. Analyses revealed similarities between women and men in terms of the composition and utilization of support networks and abstinence self-efficacy. Also, for both sexes, length of residency in OH was significantly related to decreased social support for alcohol and drug use and increased self-efficacy for abstinence. However, multiple-group SEM analyses demonstrated that social support for alcohol/drug use fully mediated the link between length of residency and abstinence self-efficacy for women, but not for men. Findings suggest that the process of gaining self-efficacy to remain abstinent is distinct for women and men, and that social support plays a different role in women's recovery than it does in men's.     

Utility of the trauma symptom inventory's atypical response scale in detecting malingered post-traumatic stress disorder

The authors examined the Trauma Symptom Inventory's (TSI) ability to discriminate 88 student post-traumatic stress disorder (PTSD) simulators screened for genuine PTSD from 48 clinical PTSD-diagnosed outpatients. Results demonstrated between-group differences on several TSI clinical scales and the Atypical Response (ATR) validity scale. Discriminant function analysis using ATR revealed 75% correct patient classification but only 48% correct simulator classification, with an overall correct classification rate of 59% (positive predictive power [PPP] = .71; negative predictive power [NPP] = .51). Individual ATR cutoff scores did not yield impressive classification results, with the optimal cutoff (T score = 61) correctly classifying only 61% of simulators and patients (PPP = .66, NPP = .54). Although ATR was not developed as a malingered PTSD screen, instead serving as a general validity screen, caution is recommended in its current clinical use for detecting malingered PTSD.     

Do psychosocial and study skill factors predict college outcomes? A meta-analysis

This study examines the relationship between psychosocial and study skill factors (PSFs) and college outcomes by meta-analyzing 109 studies. On the basis of educational persistence and motivational theory models, the PSFs were categorized into 9 broad constructs: achievement motivation, academic goals, institutional commitment, perceived social support, social involvement, academic self-efficacy, general self-concept, academic-related skills, and contextual influences. Two college outcomes were targeted: performance (cumulative grade point average; GPA) and persistence (retention). Meta-analyses indicate moderate relationships between retention and academic goals, academic self-efficacy, and academic-related skills (ps =.340,.359, and.366, respectively). The best predictors for GPA were academic self-efficacy and achievement motivation (ps =.496 and.303, respectively). Supplementary regression analyses confirmed the incremental contributions of the PSF over and above those of socioeconomic status, standardized achievement, and high school GPA in predicting college outcomes.     

Dimensions of impulsivity and aggression associated with suicide attempts among bipolar patients: a preliminary study

Impulsivity and hostility are often thought to be interrelated among depressed patients with suicidal behavior, but few studies have examined this relationship empirically. In this study, we assessed trait impulsivity and hostility among 52 DSM-IV bipolar subjects with and without histories of suicide attempts. Impulsivity and hostility were correlated among attempters (r = .41, p = .03) but not non-attempters (r = .22, p = .28). As compared to non-attempters, attempters had significantly higher levels of overall hostility, more extensive subcomponents of hostility, and a trend toward higher overall impulsivity. Associations between lifetime suicide attempts and overall hostility were significant while controlling for current depression severity and lifetime illness duration. Aggression and impulsivity appear linked among bipolar patients with lifetime suicide attempts but may be independent constructs among non-attempters. The presence of both factors may elevate risk for suicidal behavior.     

The broth in my brother’s brothel: Morpho-orthographic segmentation in visual word recognition

Much research suggests that words comprising more than one morpheme are represented in a “decomposed” manner in the visual word recognition system. In the research presented here, we investigate what information is used to segment a word into its morphemic constituents and, in particular, whether semantic information plays a role in that segmentation. Participants made visual lexical decisions to stem targets preceded by masked primes sharing (1) a semantically transparent morphological relationship with the target (e.g.,cleaner-CLEAN), (2) an apparent morphological relationship but no semantic relationship with the target (e.g.,corner-CORN), and (3) a nonmorphological form relationship with the target (e.g.,brothel-BROTH). Results showed significant and equivalent masked priming effects in cases in which primes and targets appeared to be morphologically related, and priming in these conditions could be distinguished from nonmorphological form priming. We argue that these findings suggest a level of representation at which apparently complex words are decomposed on the basis of their morpho-orthographic properties. Implications of these findings for computational models of reading are discussed.     

Improving computer skill training: behavior modeling, symbolic mental rehearsal, and the role of knowledge structures

Effective computer skill training is vital to organizational productivity. Two experiments (N = 288) demonstrated that the behavior modeling approach to computer skill training could be substantially improved by incorporating symbolic mental rehearsal (SMR). SMR is a specific form of mental rehearsal that establishes a cognitive link between visual images and symbolic memory codes. As theorized, the significant effects of SMR on declarative knowledge and task performance were shown to be fully mediated by changes in trainees' knowledge structures. The mediational role of knowledge structures is expected to generalize to other training interventions and cognitive skill domains. Our findings have the immediate implications that practitioners should use SMR for improving the effectiveness of computer skill training.