New analysis of variance formulas for treating data from mutually paired subjects

The experimental design considered in this paper is one in which each of a group of several subjects is observed in the presence of each of the other subjects of the group, the entire set of possible pairings being repeated or replicated on several occasions. Analysis of variance formulas are described for this somewhat unusual design. Both the model of constants and mixed model are considered. Reliability formulas growing out of the analysis of variance calculations are developed.This work was supported in part by grants M-627; M-627C from the National Institutes of Health, Public Health Service.     

The effect of repetition on the perception of single letters)

Single letters were presented for from one to five flashes, with S required to report what he saw after each f1ash. The clarity of the letter increased sharply with repetition. Since the letters were no larger than one-third of a degree in size, clarity could not have .been increased by S making different fixations from f1ash to f1ash and combining them into a total percept. Nor was S guessing, since this could be ruled out by other indicators. Thus, it was concluded that repetition of the stimulus can have a direct effect on the clarity of a S’s percept of that stimulus.     

Processing emotional facial expressions: The role of anxiety and awareness

In this paper, the role of self-reported anxiety and degree of conscious awareness as determinants of the selective processing of affective facial expressions is investigated. In two experiments, an attentional bias toward fearful facial expressions was observed, although this bias was apparent only for those reporting high levels of trait anxiety and only when the emotional face was presented in the left visual field. This pattern was especially strong when the participants were unaware of the presence of the facial stimuli. In Experiment 3, a patient with right-hemisphere brain damage and visual extinction was presented with photographs of faces and fruits on unilateral and bilateral trials. On bilateral trials, it was found that faces produced less extinction than did fruits. Moreover, faces portraying a fearful or a happy expression tended to produce less extinction than did neutral expressions. This suggests that emotional facial expressions may be less dependent on attention to achieve awareness. The implications of these results for understanding the relations between attention, emotion, and anxiety are discussed.     

Comparison of Scoring Criteria for Clock Drawing Test

This study compared clock drawings by 42 medically hospitalized patients with a mean age of 51.9 (SD = 10.1) years, using four sets of published scoring criteria to determine comparability of classification and to assess validity by comparison to other measures of cognitive functioning. We found impairment in 20 of 42 cases using the criteria of Mendez et al. (1992); 11 of 42 cases by Sunderland et al. (1989); 9 of 42 cases with Freedman et al. (1994); and 8 of 42 cases according to Rouleau et al. (1992). Kappa coefficients of impairment status between sets of scoring criteria ranged from .41 to .86. Pearson correlations of raw scores between schemes ranged from .72 to .94. All except Sunderland et al. were significantly correlated with the Standardized Mini-Mental State Examination. All correlated significantly with the Wechsler Adult Intelligence Scale–Revised Block Design; however, only Mendez et al. correlated significantly with the Neurobehavioral Cognitive Status Examination. On the basis of these results and our experience, we recommend using the Freedman scoring scheme.     

Dual n-back training increases the capacity of the focus of attention

Working memory (WM) training has been reported to benefit abilities as diverse as fluid intelligence (Jaeggi et al., Proceedings of the National Academy of Sciences of the United States of America, 105:6829–6833, 2008) and reading comprehension (Chein & Morrison, Psychonomic Bulletin & Review, 17:193–199, 2010), but transfer is not always observed (for reviews, see Morrison & Chein, Psychonomics Bulletin & Review, 18:46–60, 2011; Shipstead et al., Psychological Bulletin, 138:628–654, 2012). In contrast, recent WM training studies have consistently reported improvement on the trained tasks. The basis for these training benefits has received little attention, however, and it is not known which WM components and/or processes are being improved. Therefore, the goal of the present study was to investigate five possible mechanisms underlying the effects of adaptive dual n-back training on working memory (i.e., improvements in executive attention, updating, and focus switching, as well as increases in the capacity of the focus of attention and short-term memory). In addition to a no-contact control group, the present study also included an active control group whose members received nonadaptive training on the same task. All three groups showed significant improvements on the n-back task from pretest to posttest, but adaptive training produced larger improvements than did nonadaptive training, which in turn produced larger improvements than simply retesting. Adaptive, but not nonadaptive, training also resulted in improvements on an untrained running span task that measured the capacity of the focus of attention. No other differential improvements were observed, suggesting that increases in the capacity of the focus of attention underlie the benefits of adaptive dual n-back training.     

Dreaming and hallucinations - continuity or discontinuity? Perspectives from dementia with Lewy bodies

Comparing the phenomenology, neurochemical pathology, and psychopharmacology of hallucinations and dreaming is limited by the available data. Evidence to date reveals no simple correspondence between the two states. Differences in the phenomenology of visual hallucinations and the visual component of dreams may reflect variations in visual context acting on the same underlying mechanism – the minimal visual input during dreaming contrasts with the more substantial perceived context in hallucinations. Variations in cholinergic, dopaminergic and serotonergic neurotransmitter function during sleep and during hallucinations in Lewy body dementias, together with relevant drug effects suggest that, on the whole, different, potentially opposite, changes characterise the two states. A similar analysis of other psychotic features in Lewy body dementia and other disorders suggests that, in contrast to hallucinations, there may be more convincing parallels between dreaming and delusional states.