Behavioural and electrophysiological correlates of lightness contrast and assimilation.

Lightness contrast and assimilation are opposite phenomena: in contrast grey targets appear darker when bordering bright rather than dark surfaces; in assimilation grey targets appear lighter when bordering bright rather than dark surfaces. The underlying neurophysiological mechanisms of these phenomena are not known. The aim of this study was to investigate the relationship between contrast and assimilation, and the timing and levels of perceptual and cognitive processing using combined behavioural and electrophysiological methods. Thirty undergraduate students (23 female, age range 18-48 years) participated in a forced-choice (grey target is lighter/darker than a comparison square) task, using stimuli designed such that the inducers were in two configurations (small and large) and two shades (white and black). The behavioural data (more consistent and faster responses) corroborated previous findings of stronger contrast effects with white inducers and stronger assimilation effects with black inducers. According to the Event-Related Potentials (ERP) results the mean amplitude was larger in conditions with less consistent and slower behavioural responses. Thus, with contrast responses P1 amplitude was larger with black than white inducers, and N1 amplitude was larger to assimilation than contrast when the configuration of the stimulus was held constant. These results suggest contrast may occur as early as P1 (~ 110 ms) and assimilation may occur later in N2 (~ 220 ms), whereas in some conditions, differences in ERPs associated with contrast vs assimilation may happen as early as in N1 (~ 170 m), in occipital and parietal cortical sites.

Graphic imagery is not sufficient for increased attention to cigarette warnings: the role of text captions.

AIMS: The present study aims to assess the extent to which attention to UK cigarette warnings is attributable to the graphic nature of the content. DESIGN: A visual dot probe task was utilised, with the warnings serving as critical stimuli that were manipulated for the presence of graphic versus neutral image content, and the accompanying text caption. This mixed design yielded image content (graphic versus neutrally-matched images) and presence (versus absence) of text caption as within subjects variables and smoking status as a between-participants variable. SETTING: The experiment took place within the laboratories of a UK university. PARTICIPANTS: Eighty-six psychology undergraduates (51% smokers, 69% female), predominantly of Caucasian ethnicity took part. MEASUREMENTS: Reaction times towards probes replacing graphic images relative to probes replacing neutral images were utilised to create an index of attentional bias. FINDINGS: Bias scores (M = 10.20 ± 2.56) highlighted that the graphic image content of the warnings elicited attentional biases (relative to neutral images) for smokers. This only occurred in the presence of an accompanying text caption [t (43) = 3.950, P < 0.001] as opposed to when no caption was present [t (43) = 0.029, P = 0.977]. Non-smokers showed no biases in both instances. CONCLUSIONS: Graphic imagery on cigarette packets increases attentional capture, but only when accompanied by a text message about health risks.

Evidence that process simulations reduce anxiety in patients receiving dental treatment: randomized exploratory trial.

Process simulations--mental simulations that ask people to imagine the process of completing a task--have been shown to decrease anxiety in students facing hypothetical or psychological threats in the short term. The aim of the present study was to see whether process simulations could reduce anxiety in a sample of the general population attending a dental practice, and whether these effects could be sustained throughout treatment. Participants (N=75) were randomized to an experimental condition where they were asked to simulate mentally the process of seeing the dentist, or to a control condition where they were asked to simulate mentally the outcome of seeing the dentist. Findings showed that participants in the experimental condition were significantly less anxious both before and after their consultations. Self-efficacy and self-esteem remained unchanged. This study suggests that process simulation is one active ingredient in anxiety treatment programs and further research is required to enhance its effects.

Using implementation intentions to overcome the effects of social anxiety on attention and appraisals of performance.

The present research examines whether forming implementation intentions can help people with social anxiety to control their attention and make more realistic appraisals of their performance. In Experiment 1, socially anxious participants (relative to less anxious participants) exhibited an attentional bias toward social threat words in a Visual Dot Probe task. However, socially anxious participants who formed implementation intentions designed to control attention did not exhibit this bias. Using a spatial cuing task, Experiment 2 showed that forming implementation intentions also promoted rapid disengagement from threatening stimuli. Experiment 3 ruled out the possibility that implementation intentions were effective merely because they provided additional goal-relevant information. In Experiment 4, participants gave a speech and subsequently rated their performance. Forming implementation intentions prevented the underestimation of performance that characterizes socially anxious individuals. Together, the findings suggest that forming implementation intentions may provide an effective means of handling self-regulatory problems in social anxiety.

Use of mental simulations to change theory of planned behaviour variables.

OBJECTIVES: The predictive validity of the theory of planned behaviour is well established, but much less is known about: (a) whether there are causal relationships between key components of the model and (b) how to go about changing the theory of planned behaviour variables. This study tested the ability of outcome and process simulations to change variables specified in the theory of planned behaviour in relation to blood donation. DESIGN: Participants (N=146) were randomized to one of four conditions: outcome simulation only, process simulation only, process-plus-outcome simulation and a distractor control condition. The dependent variables were state anxiety, and intention attitude, subjective norm and perceived control from the theory of planned behaviour. METHODS: Participants were asked to empty their mind and visualize themselves: (a) after donating blood (outcome manipulation), (b) preparing to donate blood (process manipulation), (c) both preparing to donate blood and after having donated blood (process-plus-outcome manipulation) or (d) both preparing to get a high mark and after having got a high mark on their course (control condition). Following mental rehearsal, participants completed the dependent variables. RESULTS: There were no main effects of outcome simulation, but process simulation successfully increased intention, subjective norm and perceived control. There was also a significant outcome simulation x process simulation interaction for attitude. The effect of the process manipulation on intention was mediated by subjective norm and perceived control. CONCLUSIONS: The findings show promise for the use of mental simulations in changing cognitions and further research is required to extend the present findings to other health behaviours.