Multifractality in postural sway supports quiet eye training in aiming tasks: A study of golf putting.

The 'quiet eye' (QE) approach to visually-guided aiming behavior invests fully in perceptual information's potential to organize coordinated action. Sports psychologists refer to QE as the stillness of the eyes during aiming tasks and increasingly into self- and externally-paced tasks. Amidst the 'noisy' fluctuations of the athlete's body, quiet eyes might leave fewer saccadic interruptions to the coupling between postural sway and optic flow. Postural sway exhibits fluctuations whose multifractal structure serves as a robust predictor of visual and haptic perceptual responses. Postural sway generates optic flow centered on an individual's eye height. We predicted that perturbing the eye height by attaching wooden blocks below the feet would perturb the putting more so in QE-trained participants than participants trained technically. We also predicted that QE's efficacy and responses to perturbation would depend on multifractality in postural sway. Specifically, we predicted that less multifractality would predict more adaptive responses to the perturbation and higher putting accuracy. Results showed that lower multifractality led to more accurate putts, and the perturbation of eye height led to less accurate putts, particularly for QE-trained participants. Models of radial error (i.e., the distance between the ball's final position and the hole) indicated that lower estimates of multifractality due to nonlinearity coincided with a more adaptive response to the perturbation. These results suggest that reduced multifractality may act in a context-sensitive manner to restrain motoric degrees of freedom to achieve the task goal.

The Impact of Using Documented but Uncharged Offense Data on JSORRAT-II Predictive Validity.

Following the implementation of sexual offender notification laws, researchers have found a drop in the rate of prosecutions and an increase in plea bargains for sexual offenses committed by male juveniles. This type of prosecutorial hesitation has implications for the predictive validity of sexual recidivism risk assessments, such as the Juvenile Sexual Offender Recidivism Risk Assessment Tool-II (JSORRAT-II), that require data from officially adjudicated offenses in the scoring of several items. The present study sought to test the impact of including data from documented but uncharged (DBU) sexual offenses in the scoring of the JSORRAT-II on its predictive validity using an exhaustive sample of 1,095 juveniles who offended sexually from the states of Iowa and Utah. Although sexual recidivists had significantly more DBU data, the inclusion of those data did not improve the predictive validity of the tool. The authors discuss additional reasons why changes in prosecutorial practice might remain confound in risk assessment studies and suggest future research to investigate those hypotheses.

Cross-Validation of the JSORRAT-II in Iowa.

The predictive validity of the Juvenile Sexual Offense Recidivism Risk Assessment Tool-II (JSORRAT-II) was evaluated using an exhaustive sample of 11- to 17-year-old male juveniles who offended sexually (JSOs) between 2000 and 2006 in Iowa (n = 529). The validity of the tool in predicting juvenile sexual recidivism was significant (area under the receiver operating characteristic curve [AUC] = .70, 99% confidence interval [CI] = [.60, .81], d = 0.70). Non-significant predictive validity coefficients were observed for the prediction of non-sexual forms of recidivism. Additional analyses were undertaken to test hypotheses about the tool's performance with various subsamples. The age of the JSO at the time of the index sexual offense and time at risk outside secure facility placements interacted significantly with JSORRAT-II scores to predict juvenile sexual recidivism. The implications of these findings for practice and research on the validation of risk assessment tools are discussed.

Development and Validation of the Juvenile Sexual Offense Recidivism Risk Assessment Tool-II.

This article describes the development and initial validation of the Juvenile Sexual Offense Recidivism Risk Assessment Tool-II (JSORRAT-II). Potential predictor variables were extracted from case file information for an exhaustive sample of 636 juveniles in Utah who sexually offended between 1990 and 1992. Simultaneous and hierarchical logistic regression analyses were used to identify the group of variables that was most predictive of subsequent juvenile sexual recidivism. A simple categorical scoring system was applied to these variables without meaningful loss of accuracy in the development sample for any sexual (area under the curve [AUC] = .89) and sexually violent (AUC = .89) juvenile recidivism. The JSORRAT-II was cross-validated on an exhaustive sample of 566 juveniles who had sexually offended in Utah in 1996 and 1997. Reliability of scoring the tool across five coders was quite high (intraclass correlation coefficient [ICC] = .96). Relative to the development sample, however, there was considerable shrinkage in the indices of predictive accuracy for any sexual (AUC = .65) and sexually violent (AUC = .65) juvenile recidivism. The reduced level of accuracy was not explained by severity of the index sexual offense, time at risk, or missing data. Capitalization on chance and other explanations for the possible reduction in predictive accuracy are explored, and potential uses and limitations of the tool are discussed.

Predictive validity of adult risk assessment tools with juveniles who offended sexually.

An often-held assumption in the area of sexual recidivism risk assessment is that different tools should be used for adults and juveniles. This assumption is driven either by the observation that adolescents tend to be in a constant state of flux in the areas of development, education, and social structure or by the fact that the judicial system recognizes that juveniles and adults are different. Though the assumption is plausible, it is largely untested. The present study addressed this issue by scoring 2 adult sexual offender risk assessment tools, the Minnesota Sex Offender Screening Tool-Revised and the Static-99, on an exhaustive sample (N = 636) of juveniles who had sexually offended (JSOs) in Utah. For comparison, 2 tools designed for JSOs were also scored: the Juvenile-Sex Offender Assessment Protocol-II and the Juvenile Risk Assessment Scale. Recidivism data were collected for 2 time periods: before age 18 (sexual, violent, any recidivism) and from age 18 to the year 2004 (sexual). The adult actuarial risk assessment tools predicted all types of juvenile recidivism significantly and at approximately the same level of accuracy as juvenile-specific tools. However, the accuracy of longer term predictions of adult sexual recidivism across all 4 tools was substantially lower than the accuracy achieved in predicting juvenile sexual recidivism, with 2 of the tools producing nonsignificant results, documenting the greater difficulty in making longer term predictions on the basis of adolescent behavior.

In-use peroxide kinetics of 10% hydrogen peroxide whitening strips.

OBJECTIVE: Clinical research was conducted to establish the peroxide degradation profile of a very thin 10% hydrogen peroxide bleaching gel delivered on a flexible polyethylene strip. METHODS: Sixteen subjects participated in this study of Crest Whitestrips Premium, a thin layer of 10% hydrogen peroxide gel. Application was supervised, and strips were removed after five, 10, 30, and 60 minutes. Samples were collected from the strips, teeth, gingiva, and saliva, and peroxide levels were derived using a colorimetric peroxide assay. RESULTS: At five minutes, median peroxide concentrations were 7.3%, 6.4%, and 0.7% for strips, teeth, and gingiva, respectively, declining to 4.6%, 2.9%, and 0.1% at 30 minutes. Salivary samples never exceeded a median concentration of 0.014% at any time point. Samples differed significantly (p < 0.01) with respect to the 30- and 60-minute area-under-the-curve calculations, with the highest concentrations on the strip and teeth, and the lowest on the gingiva and in saliva. Median peroxide concentrations on strips and teeth remained above 2% over 60 minutes. At all post-treatment time points, the gingival peroxide concentration was an order of magnitude lower than the teeth samples. CONCLUSION: Use of 10% hydrogen peroxide whitening strips yielded appreciable peroxide on teeth over a 60-minute period, with rapid peroxide degradation on the gingiva, and exceedingly low accumulation in saliva anytime during use.