Randomized controlled trial of an intervention to prevent adherence failure among HIV-infected patients initiating antiretroviral therapy.

OBJECTIVE: Compare the efficacy of a multicomponent social support intervention to standard-of-care counseling on medication adherence among HIV-infected patients initiating antiretroviral therapy. DESIGN: Randomized controlled trial. Generalized estimating equations tested for differences in the percentage of participants achieving 90% adherence. MAIN OUTCOME MEASURES: Pill-taking, electronically monitored over 6 consecutive months; plasma viral load (VL), assessed at 3 and 6 months following initiation of therapy. RESULTS: Of 226 participants who were randomized and began the trial, 87 (38%) were lost to the study by 6 months. The proportion of adherent participants declined steadily over time, with no time by group interaction. Sustained adherence was associated with increased odds of achieving an undetectable VL (OR=1.78; 95% CI=1.01, 3.13). In intention-to-treat analyses, a larger proportion of the intervention group than the control group was adherent (40.15% vs. 27.59%, p=.02) and achieved an undetectable VL p=.04). However, the majority of participants who remained on study experienced some reduction in VL (>or=1-log drop or undetectable), regardless of experimental condition. CONCLUSION: The multicomponent social support intervention significantly improved medication adherence over standard-of-care counseling; evidence for improved virologic outcomes was inconsistent. Early discontinuation of care and treatment may be a greater threat to the health of HIV patients than imperfect medication-taking.     

Differential effects of prime-probe duration on positive and negative location priming: Evidence for opponent facilitatory and inhibitory influences in priming tasks

A series of four spatial localization experiments is reported that examined the effects of display duration and presentation mode on positive and negative priming using an attended-repetition and an ignored-repetition paradigm, respectively. Experiment 1 showed larger positive priming with response-dependent than with 150 ms display durations while negative priming remained unaffected. Experiments 2-4 were performed to further elucidate the effects of prime-probe durations. Data suggest largely independent effects of prime and probe duration on priming effects. Manipulation of prime duration affected facilitation due to repetition of the prime distractor location as well as inhibitory effects associated with ignored repetition. Furthermore, anticipated probe duration modulated the effectiveness of inhibition of return. Findings are discussed within a framework proposing two major components of priming effects—a stimulus-driven or automatic component, and a strategic component related to the participant's expectations towards the probe.     

The role of illness uncertainty on coping with fibromyalgia symptoms.

This study examined the role of illness uncertainty in pain coping among women with fibromyalgia (FM), a chronic pain condition of unknown origin. Fifty-one FM participants completed initial demographic and illness uncertainty questionnaires and underwent 10-12 weekly interviews regarding pain, coping difficulty, and coping efficacy. Main outcome measures included weekly levels of difficulty coping with FM symptoms and coping efficacy. Multilevel analyses indicated that pain elevations for those high in illness uncertainty predicted increases in coping difficulty. Furthermore, when participants had more difficulty coping, they reported lower levels of coping efficacy. Results were consistent with hypothesized effects. Illness uncertainty accompanied by episodic pain negatively influenced coping efficacy, an important resource in adaptation to FM.     

Perceived racism and cardiovascular reactivity and recovery to personally relevant stress.

This study evaluated cardiovascular responses (CVR) to an active speech task with blatantly discriminatory (BRC) versus neutral (NRC) stimuli and an anger recall task in a sample of Black men (N = 73; age 18 to 47). Diastolic blood pressure scores were higher for NRC versus BRC stimuli during anger recall (p = .05). Moreover, persons in the NRC group who perceived high levels of racism (vs. no racism or BRC group) during active speech showed larger increases in blood pressure across postspeech rest, anger recall, and subsequent rest (p = .03). The notable elevation in CVR in response to an ambiguous event extends current models of racism suggesting that subtle racism is a psychosocial stressor that erodes health through chronically elevated CVR.     

The Influence of Shared Visual Context on the Successful Emergence of Conventions in a Referential Communication Task

Human communication is thoroughly context bound. We present two experiments investigating the importance of the shared context, that is, the amount of knowledge two interlocutors have in common, for the successful emergence and use of novel conventions. Using a referential communication task where black‐and‐white pictorial symbols are used to convey colors, pairs of participants build shared conventions peculiar to their dyad without experimenter feedback, relying purely on ostensive‐inferential communication. Both experiments demonstrate that access to the visual context promotes more successful communication. Importantly, success improves cumulatively, supporting the view that pairs establish conventional ways of using the symbols to communicate. Furthermore, Experiment 2 suggests that dyads with access to the visual context successfully adapt the conventions built for one color space to another color space, unlike dyads lacking it. In linking experimental pragmatics with language evolution, the study illustrates the benefits of exploring the emergence of linguistic conventions using an ostensive‐inferential model of communication.     

Reinforcement and the organisation of behaviour in golden hamsters: Differential overshadowing of a CS by different responses

Are different responses differentially associable with their consequences? An overshadowing design was used to try to answer this question for three responses previously studied in golden hamsters. In Experiment I, scrabbling was rapidly suppressed by electric shock punishment, and it overshadowed a tone which occurred between scrabbling and shock. In Experiment II, no evidence of response-shock association was obtained when open rearing was the punished response, and open rearing did not overshadow the tone. Punishment had some effect on face washing, but there was no statistically significant overshadowing with this response. These results are consistent with the idea that differences in punishment suppression among these three responses have an associative basis. They also demonstrate the usefulness of a novel paradigm for studying “preparedness” of response-reinforcer associations.