Psychological and Behavioural Within-participant Predictors of Adherence to Oral HIV Pre-Exposure Prophylaxis (PrEP).

Oral PrEP's effectiveness relies on adequate adherence during periods of substantial HIV risk. Since most PrEP users will miss doses, understanding predictors within participants can help to explain adherence. We used a cross-sectional, within-participant design with 67 gay, bisexual, and other men who have sex with men taking PrEP daily. Using a questionnaire, informed by the Information Motivation Behavioral Skills Model, participants were asked about an adherent and a non-adherent episode. PrEP non-adherence was associated with non-normality of the day (p < .001), being out of the home (p < .001), weekend days (p = .01), having company (p = .02), using substances (p = 0.02), not using reminders (p = .03), lower PrEP information (p = .04), lower behavioural skills (p < .001) and less positive affect (p = .002). PrEP adherence assessment could focus on situational variations, supporting the construction of alternative strategies to facilitate adherence in these situations.

Object labeling activates young children's scale errors at an early stage of verb vocabulary growth.

Scale errors are intriguing developmental phenomena in which young children attempt to perform impossible object-specific actions toward miniature-sized objects. Of several related cognitive abilities, lexical development during toddlerhood enhances scale error production by making objects' semantic representations dominant over perceptual information. To directly address the effect of activated semantic representations on scale errors, we examined whether and when object labeling affected scale errors. Toddlers aged 18 to 30 months (N = 72) performed a body-based scale error task twice: in one session with specific object labels provided (e.g., "chair") and in the other session with general pronouns provided (e.g., "this"). Using different developmental indices, including chronological age and productive vocabulary size of nouns, verbs, and adjectives, the enhancement effect of object labeling was detected only for children whose verb vocabulary size was classified into the medium group (3-26 words). Moreover, verb vocabulary size was determined to be the best predictor of scale error production among the candidate developmental indices. We also found that toddlers produced more scale errors in the first session that they performed the task compared with the second session. In addition to revealing that careful control of relevant factors (e.g., developmental indices, labeling, task repetition) is required for scale error research, this study sheds light on the relevance of verb vocabulary on scale errors.

The effect of distinctive facial features on destination memory.

Destination memory involves remembering to whom we told information. Low accuracy of this memory is linked to higher self-focus and lower attentional resources allocated to the recipient of the information. The present paper aimed to investigate whether the existence of distinctive features (e.g., tattoos) of destination face would improve destination memory, in a within- (Experiment 1 and 2) and between-participants (Experiment 3) design. In a destination memory task, participants had to tell proverbs to faces that presented a distinctive feature and to other faces that did not. Results showed that a destination memory advantage only occurs when faces with different distinctive features are compared to faces without distinctive features (Experiment 1). These results are in accordance with the existing theoretical framework on destination memory and distinctiveness; highlighting the importance of personal attributes, namely, the distinctiveness of the destination face and the relativity of distinctiveness in destination memory.

Corrigendum: Linear mixed-effects models for within-participant psychology experiments: an introductory tutorial and free, graphical user interface (LMMgui).

[This corrects the article DOI: 10.3389/fpsyg.2015.00002.].

Linear mixed-effects models for within-participant psychology experiments: an introductory tutorial and free, graphical user interface (LMMgui).

Linear mixed-effects models (LMMs) are increasingly being used for data analysis in cognitive neuroscience and experimental psychology, where within-participant designs are common. The current article provides an introductory review of the use of LMMs for within-participant data analysis and describes a free, simple, graphical user interface (LMMgui). LMMgui uses the package lme4 (Bates et al., 2014a,b) in the statistical environment R (R Core Team).