A nonparametric test for the two-sample problem

Moses [3] has proposed a nonparametric test of the null hypothesis that two samples, say a treatment and a control group, have been drawn from the same population; his test is designed to be sensitive to the alternative hypothesis that the treatment group is extreme in either or both directions as compared with the controls. This paper presents a test of similar character, except that rather than being based on a range of the control group ranks, it depends upon the variance of those ranks. This has the advantage of making ties less troublesome. Tables of significance values are presented for some small sample sizes. A normal approximation is developed and seen to be useful.This research was partially sponsored by a Public Health Biostatistics Training Grant at Stanford University.I wish to thank Professor Lincoln E. Moses of Stanford University for suggesting the problem, and for his invaluable assistance in the preparation of this paper.     

Seeing double: the role of meaning in alphanumeric-colour synaesthesia

When PD, an alphanumeric-colour synaesthete, is shown black digits or letters, each grapheme elicits a highly specific colour, called a "photism" (e.g., a 2 induces green, a Z induces brown). Previous experiments showed that photisms interfere with video-colour naming when the photism colour and the video colour are incongruent. Here we used coloured ambiguous graphemes that could be interpreted as either digits or letters depending on context (e.g., an ambiguous grapheme was interpreted as a 2 if presented within a block of digit trials, but as a Z if presented within a block of letter trials). Ambiguous graphemes were presented in video colours that were either congruent or incongruent with PD's photisms. Crucially, what was a congruent trial in one context was an incongruent trial in the other context. PD's pattern of response times indicated that identical graphemes could induce differently coloured photisms depending on their interpretation. This suggests that the meaning of graphemes ultimately determines their synaesthetic colour.     

Vicarious Experiences of Major Discrimination and the Life Satisfaction of Black and White Adults from a Community Sample

The racism-related stress framework argues that racism can influence the well-being of individuals through personal and vicarious experiences of discrimination, but studies on racism and health have primarily focused on understanding how personally experienced discrimination shapes these outcomes. Using data from the Nashville Stress and Health Study (N?=?1,252) the present study examines the racial differences in vicarious experiences of major discrimination among Black and non-Hispanic White adults from a community sample. Additionally, given longstanding evidence of racial disparities in life satisfaction, this study assesses whether the effects of vicarious experiences of discrimination influence overall life satisfaction of both Black and White adults. Results reveal significant racial differences in the types of vicarious discrimination that both groups are exposed to, and that Black adults are more exposed to vicarious experiences of major discrimination relative to White adults. Furthermore, findings indicate that vicarious experiences of discrimination, in addition to personal experiences of discrimination, are associated with lower levels of overall life satisfaction among Black adults, but not for White adults. This study extends the broader literature on racism-related stress and offers new insights for understanding racial differences in overall life satisfaction and well-being.

     

The Gap Between Science and Practice: How Therapists Make Their Clinical Decisions

Recent surveys have found that many patients are not receiving empirically supported treatments and that therapists may not update their knowledge of research. Studies have found that therapists prefer to use their clinical experience rather than research findings to improve their practice, although cognitive behavioral (CB) practitioners have been found to use research more frequently than therapists of other theoretical orientations. The organization in which therapists work has been shown to impact attitudes toward working practices, but studies have not examined whether workplace requirements to use research affect therapists’ practice. Studies to date have mainly been conducted in North America. These findings may not be generalizable to the United Kingdom where there is a National Health Service (NHS), which requires the use of empirically supported treatments. The first part of this study aimed to investigate which factors were influential in therapists’ choice of theoretical orientation and to see whether CB practitioners differed from other therapists in the factors that influenced their choice of theoretical orientation. The second part tested whether therapists’ theoretical orientation or their workplace influenced the frequency with which they used research in their clinical decision-making. The final part investigated whether being a CB practitioner or working in the NHS was associated with having a favorable attitude toward research. An online survey was sent to 4,144 psychological therapists in England; 736 therapists responded (18.5%). Therapists reported that research had little influence over their choice of theoretical orientation and clinical decision-making compared to other factors, specifically clinical experience and supervision. CB practitioners and NHS therapists, regardless of their orientation, were significantly more likely to use research than other therapists and were more likely to have a positive attitude toward research.     

Moral worry and religiosity in US and Canadian college samples

The objective of this study was to investigate the presence of worry about personal moral attitudes and behaviors in two college samples, and to check associations with religiosity, age, gender, personality traits, and geographic region. The study sample was drawn from college students in Minneapolis, Minnesota (N?=?333) and Sydney, Nova Scotia (N?=?137). Instruments consisted of moral worry and religiosity questionnaires, and the Eysenck Personality Questionnaire. Principal-components analysis was used to develop components for the worry and religiosity scales, and MANOVA for correlations between variables. Moral worry emerged as a domain distinct from worry about practical issues. Moral worry was not related to religiosity, age, gender, or Eysenck personality traits. Whereas the US sample scored higher in religiosity than the Canadian sample, the Canadian sample scored higher on moral worry. The present study supports our previous work and that of others that worry about one's moral emotions and behaviors is an important aspect of daily life. As such, consideration should be given to including some inquiry about moral worries (guilt, shame, regret, remorse, and others) in psychiatric assessments.     

Hand-eye coordination: The role of “motor memory”

Ten Ss attempted to track a visual target, which was moved either by hand (test run) or by a tape recording of the same hand movements (control run). On some test runs, movement of the target lagged behind that of the hand by a fixed amount (.18, .36, .72, or 1.44 sec). The number of saccades occurring on a given test run was divided by the number on the matched control run, and the test/control ratio was studied as a function of the hand-to-target lag time. With lag times of .36 sec or less, the test/control ratios were less than 1. indicating that manual control of the target had a significant effect on oculomotor performance. This effect disappeared at a lag close to .72 sec. The results are discussed in terms of a hypothetical “motor memory.”