Evidence that implementation intentions reduce self-harm in the community

Objectives

Implementation intentions are ‘IF-THEN’ plans that encourage goal-intended behaviour. This study was designed to test whether an intervention encouraging the formation of implementation intentions can reduce self-harm in the community.

Design

A randomized controlled design was used.

Methods

At pre-intervention, outcome variables (self-harm in both specified and unspecified critical situations and suicidality) and potential moderators of implementation intentions (goal intention, mental imagery, and exposure to self-harm) were measured using self-report questionnaires. The participants (N = 469, aged 18–66 years, 86.4% female, 6.8% male and 6.7% other) were then randomized to either an experimental (implementation intention) or control task. At three-months post-intervention, self-report questionnaires were used again to measure the outcome variables.

Results

There were no overall differences between the conditions at post-intervention. However, goal intention and mental imagery, but not exposure to self-harm, moderated the effects of condition on self-harm in specified critical situations. At high (mean + 1SD) levels of both goal intention and mental imagery, the experimental condition reported self-harming less frequently in the situations specified in their implementation intentions.

Conclusions

Implementation intentions therefore represent a useful intervention for reducing self-harm in specified critical situations for people in the community who wish to avoid self-harm and those who frequently experience self-harm and suicide related mental imagery.     

Evidence that maternal ventral skin substances promote suckling in infant rats.

Washing a lactating rat's ventral skin with acetone, alcohol and water markedly reduces the effectiveness with which her 2-week-old infants can initiate suckling on the anesthetized mother. Control experiments with detailed thermal and behavioral measures give evidence tending to rule out lowered skin temperature, altered thermal gradients, changed tactile characteristics of abdominal fur or nipples and aversion to remaining traces of the organic solvents as responsible for the infants' failure to find and attach to nipples. The data suggest that some substance(s) on the skin of the mother's ventrum act as olfactory and/or gustatory cues for the infants' orientation and attachment to nipples.     

A meta-analytic review of the effect of implementation intentions on physical activity

Abstract

Implementation intentions are a powerful strategy to promote health-related behaviours, but mixed results are observed regarding physical activity. The primary aim of this study was to systematically and quantitatively review the literature on the effectiveness of implementation intentions on physical activity. The second aim was to identify conditions under which effectiveness is optimal. A literature search was performed in several databases for published and non-published reports. The inverse variance method with random effect model was used for the meta-analysis of results. Effect sizes were reported as standard mean differences. Twenty-six independent studies were included in the systematic review. The overall effect size of implementation intentions was 0.31, 95% confidence intervals (CI) [0.11, 0.51] at post-intervention and 0.24, 95% CI [0.13, 0.35] at follow-up. The duration of follow-up had no significant effect on effect size (F(1, 18) = 0.21, p=0.66. This strategy was more effective among student and clinical samples, and when barrier management was part of implementation intentions. The present meta-analysis provides support for the use of implementation intentions to promote physical activity, even though the effect size is small to medium.     

Evidence that integrins contribute to multiple stages in the consolidation of long term potentiation in rat hippocampus

Three structurally distinct groups of antagonists were used to test the hypothesis that integrin adhesion receptors play an essential role in consolidating (stabilizing) long term potentiation of the Schaffer collaterals in rat hippocampus. Comparisons were made of percent potentiation at antagonist-treated versus control sites within CA1 stratum radiatum of the same hippocampal slice. Function blocking antibodies against the alpha5 subunit of the fibronectin receptor had no effect on baseline responses or initial potentiation but resulted in a >30% reduction, relative to within-slice control long term potentiation, 45 min later. Larger reductions were recorded in separate experiments continued for 4 h after the induction of potentiation. Alpha(v) and alpha2 subunit antibodies did not reliably affect the stabilization of potentiation. An antagonist peptide with preference for beta1 integrins produced a slowly developing decline of the type seen with alpha5 antibodies. A cyclic peptide antagonist reduced potentiation within 10 min of induction and caused an almost 40% decrease over 45 min. Two disintegrins (snake toxins that potently block integrins) were very effective in preventing the consolidation of long term potentiation: echistatin reduced potentiation by >70%, while triflavin caused approximately 50% decrease. The suppressing effects of echistatin were concentration-dependent, obtained with treatment after induction, and much more rapid than the effects of antibodies. Rapid declines in potentiation were particularly evident when the two disintegrins were applied together.These results indicate that hippocampal fibronectin receptors (alpha5/beta1 integrin) contribute importantly to a slowly developing phase of long term potentiation consolidation. They also suggest that other integrins are critical to aspects of consolidation occurring in the first few minutes after induction.     

Evidence for two genetic loci in Yersinia enterocolitica that can promote invasion of epithelial cells.

Virulent strains of Yersinia enterocolitica cause disease syndromes ranging from mild gastroenteritis to lymphadenitis and septicemia. The ability of these bacteria to invade intestinal epithelial cells to gain access to the reticuloendothelial system is thought to be an important aspect of their virulence. We report here on the cloning of two Y. enterocolitica chromosomal loci, inv and ail, each of which confers an invasive phenotype on Escherichia coli HB101. The inv locus allows a uniformly high level of invasion in several tissue culture lines and is homologous to the inv gene of Yersinia pseudotuberculosis. The second locus, ail, shows more host specificity than inv in that it allows invasion to a variable degree of some cell lines (e.g., HEp-2, HEC1B, and CHO cells) but allows no invasion of others (e.g., Madin-Darby canine kidney cells).     

Exercise motives and stages of change

The aim was to examine how exercise motives differ across stages of change. British government employees completed questionnaires measuring exercise motives and exercise stage of change at baseline (N = 425) and at 3-month follow-up (247 of the original sample). Discriminant analysis was used to determine whether exercise motives (and age and gender) could collectively discriminate between baseline stages of change; and whether exercise motives could discriminate between those who stayed inactive, stayed active, became active or became inactive over the 3 months. Taken as a whole, and with some qualifications, the results suggest that extrinsic (specifically bodily) motives dominate during the early stages of exercise adoption, but that intrinsic (specifically enjoyment) motives are important for progression to and maintenance of actual activity. This is consistent with Deci and Ryan's (1985) self- determination theory. The implications for exercise promotion are discussed.     

Increasing attendance for psychotherapy: implementation intentions and the self-regulation of attendance-related negative affect

The present study evaluated an implementation intention intervention that aimed to increase attendance at scheduled, initial appointments for psychotherapy by helping clients to manage negative feelings about attendance. Participants received a postal questionnaire that measured their views about attending psychotherapy. One half of the sample was randomly assigned to an implementation intention induction that was embedded in the questionnaire. Intention-to-treat analysis (N=390) indicated that participants who formed implementation intentions were more likely to attend compared to controls (75% vs. 63%), and this effect was even stronger among participants who returned the questionnaire (83% vs. 57%). Whereas anticipated affective costs (e.g., shame) had a negative impact on attendance for most participants, this effect was attenuated when participants formed implementation intentions and perceived that attendance would be beneficial. Thus, implementation intention formation can help clients to deal effectively with negative feelings that might otherwise prevent them attending their first psychotherapy appointment.     

Felt and potential ambivalence across the stages of change

This study tested discontinuity patterns across the stages of change. Fat intake, theory of planned behaviour (TPB) variables, and felt and potential ambivalence were assessed in 16-17 year olds (N = 187). Across the stages of change there were: (a) linear increases in TPB variables, (b) linear decreases in fat intake, and (c) quadratic relationships with felt and potential ambivalence. Although felt and potential ambivalence were moderately correlated, the correlation between the two was significantly higher in the action and maintenance stages. The findings are consistent with the idea that successful actors/maintainers are vigilant with respect to lapses.     

Theory-based processes that promote the remission of substance use disorders

Four related theories about the personal and social resources that shield individuals from developing substance use disorders and foster the process of remission from these disorders are described. These theories are social control theory, behavioral economics and behavioral choice theory, social learning theory, and stress and coping theory. Next, the social processes specified by these theories are highlighted, including the provision of support, goal direction, and monitoring; engagement in rewarding activities other than substance use, exposure to abstinence-oriented norms and models, and attempts to build self-efficacy and coping skills. Then, a review of the literature considers evidence about the association between the personal and social resources specified by the four theories and remission from substance use disorders. The discussion highlights several issues that need to be addressed to enhance our understanding of the protective resources involved in stable remission, such as how to develop integrated measures of the key resources and specify their associations with substance use outcomes, the extent to which the resources amplify or compensate for the influence of treatment, and how treatment and continuing care can be tailored to strengthen the protective resources that promote remission.     

Kinetic evidence that desensitized nAChR may promote transitions of active nAChR to desensitized states during sustained exposure to agonists in skeletal muscle

During prolonged exposure of postjunctional nicotinic acetylcholine receptors (nAChR) of skeletal muscle to acetylcholine (ACh), agonist-activated nAChR (nAChR_a) gradually fall into a refractory “desensitized” state (nAChR_d), which no longer supports the high-conductance channel openings characteristic of the initially active nAChR_a. In the present study, the possibility was examined that nAChR_d, rather than simply constituting a passive “trap” for nAChR_a, may actively promote further conversions of nAChR_a to nAChR_d in a formally autocatalytic manner. Single-ion whole-cell voltage-clamp currents (Na⁺ and Li⁺ in separate trials) were measured using two KCl-filled capillary electrodes (5–10 MΩ) implanted at the postjunctional locus of single frog skeletal muscle fibers (Rana pipiens) equilibrated in 30 mM K⁺ bath media to eliminate mechanical responses. Various nAChR agonists (carbamylcholine, acetylcholine, suberyldicholine) at different concentrations were delivered focally by positive pressure microjet. It was found that the decline of postmaximal agonist-induced currents under these different conditions (driven by the growth of the subpool of nAChR_d) consistently followed an autocatalytic logistic rule modified for population growth of fixed units in a planar array: (where y represents the remaining agonist-induced current at time t, A=initial maximum current, and n is a constant). Some further experimental features that might result from a self-promoting growth of nAChR_d were also tested, namely, (1) the effect of increased nAChR_a and (2) the effect of increased nAChR_d. Increase in agonist concentration of the superfusate, by increasing the planar density of active nAChR_a at the outset, should enhance the probability of autocatalytic interactions with emerging nAChR_d, hence, the rate of decline of agonist-induced current, and this was a consistent finding under all conditions tested. Raising the initial level of desensitized nAChR_d by pretreatment of fibers with very low concentrations of agonist would be another way to increase autocatalytic interactions with active nAChR_a, and this was also found to produce increased rates of decline of agonist-induced currents when tested in additional trials. It is concluded that several kinetic features of nAChR desensitization in skeletal muscle are consistent with an action of nAChR_d to promote further transitions of nAChR_a to desensitized forms. This could occur by a direct effect of nAChR_d on contiguous nAChR_a or perhaps through some intermediary membrane component or local intracellular pathway.     

Paving the path for habit change: Cognitive shielding of intentions against habit intrusion

Objective. The objective of the current study was to examine the cognitive processes that make it possible to use intentions to change one's habitual health‐related behaviour. Design. The study used an idiosyncratic approach to investigate personal existing habits and non‐habitual behaviours in a within‐participants experiment. Method. Participants first generated habitual and non‐habitual behaviours for various daily‐life goals (e.g., having lunch, playing sports). Next, they formed intentions to perform non‐habitual behaviours in order to attain these goals. Finally, we measured the cognitive accessibility of participants’ habitual and non‐habitual behaviours with a behaviour recognition task. Results. The findings showed that habitual behaviours were more accessible than the non‐habitual behaviours when no intentions were formed (control goals), showing that habits are more readily accessed in mind. However, when participants had formed intentions to use non‐habitual behaviours, habitual behaviours for the same goals were inhibited in mind. This could be the cognitive mechanism that shields intentions from habit intrusion and thus enables the pursuit of non‐habitual behaviours. Conclusion. The current study demonstrates the role of inhibitory processes in shielding non‐habitual intentions in memory. These findings are discussed in the context of success and failure in changing health‐related habits.     

Evidence that suggests a negative association between cigarette smoking and learning performance

The results of this study indicate that tobacco smoking may have a deleterious effect on the learning process. One hundred and fifteen male volunteers were assessed on four learning tasks. Those Ss who smoked in excess of 12 cigarettes per day did significantly less well, as a group, than nonsmokers and light smokers on three of the four learning tests.     

Evidence of differential mass change rates between human breast cancer cell lines in culture

Investigating the growth signatures of single cells will determine how cell growth is regulated and cell size is maintained. The ability to precisely measure such changes and alterations in cell size and cell mass could be important for applications in cancer and drug screening. Here, we measure the mass growth rate of individual benign (MCF-10A), non-invasive (MCF-7), and highly-invasive malignant (MDA-MB-231) breast cancer cells. A micro-patterning technique was employed to allow for the long-term growth of motile cells. Results show mass growth rates at 4.8%, 1.2%, and 2.8% for MCF-10A, MCF-7, and MDA-MB-231, demonstrating that normal cells have a higher mass growth rate than cancerous cells. All the cell lines show an increase in mass change rate indicating that the mass accumulation rate is exponential over a single cell cycle. The growth rates measured with our MEMS sensor are compared with doubling times obtained through conventional bulk analysis techniques, and exhibit excellent agreement.     

Efficacy of a brief worksite intervention to reduce smoking: the roles of behavioral and implementation intentions

The effectiveness of worksite interventions to reduce smoking needs to be enhanced because randomized controlled trials to date have produced mixed findings. The present study tested the ability of social-cognitive variables to mediate the past behavior-future behavior relationship and the effectiveness of implementation intentions to break the past behavior-future behavior relationship in a brief theory-based worksite intervention designed to reduce smoking. Smoking behavior and psychosocial orientation to quit (operationalized by theory of planned behavior variables and temptations) were measured at baseline; participants (N = 90) randomized to the experimental condition were also asked to form an implementation intention in their place of work. Identical measures taken 2 months postbaseline revealed that intention was a potent mediator of the past behavior-future behavior relationship. More important, significantly more people quit smoking in the experimental condition than in the control condition. Decomposition of these effects showed that implementation intentions worked best for individuals who were more motivated to quit at baseline and suggest that harnessing both motivational and volitional processes might enhance the effectiveness of worksite smoking cessation programs.     

In vitro culture methods for transition stages of filarial parasites: Evidence that host factors are important for parasite development

Simulium vittatum is a black fly that can serve as a surrogate intermediate host for the filarial parasite,Onchocerca lienalis. Use of media conditioned by excised thoraces ofS. vittatum led to the identification of a soluble chemical cue(s) used by the microfilariae to migrate to fly thoracic muscles, the site where continued differentiation occurs. Medium conditioned by a vertebrate cell line (LLCMK₂) supported vigorous culture of third-stage (L3) and fourth-stage larvae (L4), and provided an environment for uncomplicated screening of therapeutic drugs such as ivermectin.Abbreviations mf microfilaria - L1 first-stage larva - L2 second-stage larva - L3 third-stage larva - L4 fourth-stage larva - CCM cell-conditioned medium - TCM thorax-conditioned medium - ACM abdomen-conditioned medium - FBS fetal bovine serum - BSA bovine serum albumin - PBS phosphate buffered saline     

Identifying key processes of exercise behaviour change associated with movement through the stages of exercise behaviour change

This longitudinal study identified processes of exercise behaviour change (POC) associated with movement between the stages of exercise behaviour change (SOC). Participants' (N = 312) physical activity, SOC and POC were recorded at baseline, one, three, six and 12 months post-test. Following baseline, participants received one of three physical activity interventions. The process of self-liberation was important at each stage movement. The process of stimulus control appeared important when progressing from contemplation to preparation. Progression from action into maintenance was associated with increased use of social liberation and helping relationships. The study indicated the transtheoretical model is applicable to a British population.     

Two stages of excitability change of pontine pause neurons in the cat

Spikes of single pontine pause neurons (PNs) in the cat were recorded extracellularly and identified by observing cessation of tonic discharges before and during the fast phase of vestibular nystagmus. PNs were antidromically activated from the excitatory burst neuron area. Antidromic spikes were abolished or their peak latencies were prolonged during particular periods within a nystagmic cycle. The excitability change in PNs indicated by alteration of the antidromic responses occurred with two stages; i.e. a moderate decrease in excitability before the onset of the fast phase and an abrupt, intense decrease starting form the beginning of the fast phase.     

The general facilitation effect of implementation intentions on prospective memory performance in patients with schizophrenia

ABSTRACT

Introduction: Prospective memory (PM) refers to remembering to execute a planned intention in the future. It can be divided into event- and time-based, according to the nature of the PM cue. Event-based PM cues can be classified as focal or non-focal. Patients with schizophrenia (SCZ) have been found to be impaired in both event- and time-based PM. PM has been found to be improved by implementation intentions, which is an encoding strategy in the format of “if X then Y”. This study examined the effect of implementation intentions on a non-focal event-based and a time-based PM task in patients with SCZ.Methods: Forty-two patients with SCZ and 42 healthy controls were allocated to either an implementation intention or a control PM instruction condition and were asked to complete two PM tasks. Results: Implementation intentions was found to improve performance in both the non-focal event-based and time-based PM tasks in patients with SCZ and healthy controls, with no costs to the ongoing task. The improvement in time-based PM performance in the implementation intentions condition was partially mediated by the frequency of clock checking behaviour. Conclusions: Implementation intentions can facilitate PM performance in patients with SCZ and has the potential to be used as a clinical intervention tool.