Influencing health decision-making: A study of colour and message framing

Objective: Previous research has provided evidence that colour associations and frame can influence behavioural intentions to engage in vaccination behaviours. In this study, the extension of these effects to sunscreen application behaviours was investigated. Additional colours and the manner in which colour primes were employed were also explored.

Design: Two hundred and eighty-six college students were primed with either short wavelength colours (blue/purple) or long wavelength colours (red/orange) as part of goal framed sunscreen information pamphlets.

Main outcome measures: Self-reported behavioural intentions to apply sunscreen, immediate affective reaction to stimuli material, anticipated affect towards sunscreen use, and perceived efficacy of preventing skin cancer were measured.

Results: Individuals with no prior intention to use sunscreen expressed greater behavioural intentions to do so after reading a positively framed sunscreen pamphlet that was designed using short wavelength colours. The negatively framed messages and those presented in long wavelength colours did not enhance persuasion.

Conclusions: In accordance with the Unification Theory of Framing, a match between the representations of the target behaviour, the colour prime, and the frame resulted in the greatest amount of persuasion. Creating communications with representations that match the target behaviour could be a powerful tool to increase compliance.     

Motivational incentives modulate age differences in visual perception

This study examined whether motivational incentives modulate age-related perceptual deficits. Younger and older adults performed a perceptual discrimination task in which bicolored stimuli had to be classified according to their dominating color. The valent color was associated with either a positive or negative payoff, whereas the neutral color was not associated with a payoff. Effects of incentives on perceptual efficiency and response bias were estimated using the diffusion model (Ratcliff, 1978). Perception of neutral stimuli showed age-related decline, whereas perception of valent stimuli, both positive and negative, showed no age difference. This finding is interpreted in terms of preserved top-down control over the allocation of perceptual processing resources in healthy aging.     

Waking and dreaming: related but structurally independent. Dream reports of congenitally paraplegic and deaf-mute persons

Models of dream analysis either assume a continuum of waking and dreaming or the existence of two dissociated realities. Both approaches rely on different methodology. Whereas continuity models are based on content analysis, discontinuity models use a structural approach. In our study, we applied both methods to test specific hypotheses about continuity or discontinuity. We contrasted dream reports of congenitally deaf-mute and congenitally paraplegic individuals with those of non-handicapped controls. Continuity theory would predict that either the deficit itself or compensatory experiences would surface in the dream narrative. We found that dream form and content of sensorially limited persons was indifferent from those of non-handicapped controls. Surprisingly, perceptual representations, even of modalities not experienced during waking, were quite common in the dream reports of our handicapped subjects. Results are discussed with respect to feedforward mechanisms and protoconsciousness theory of dreaming.     

Mathematics and Theology: A Stroll through the Garden of Mathaphors

Mathematics has long been considered the language of science and has even been acknowledged as the universal language of the future. Yet mathematics also plays a less-recognized religious role in that metaphors drawn from mathematics (mathaphors) can influence our spiritual perspectives by helping us to entertain new religious ideas and to challenge old ones. Mathaphors are therefore useful tools in matheology (the study of mathematics and theology). This essay explores ten ways in which contemporary mathaphors affect our spiritual lives. Specifically, mathaphors are: changing our metaphors for God; challenging our human role in the universe; helping us accept ambiguity; revamping our understanding of the one and the many; revising our thoughts about free will and determinism; moving us toward pluralistic, multi-world views; pushing the envelope on what consciousness is; altering our expectations for afterlife; offering the hope of a more compassionate future; encouraging faith perspectives that are always incomplete and in process.     

Interpreting the parameters of the diffusion model: an empirical validation

The diffusion model (Ratcliff, 1978) allows for the statistical separation of different components of a speeded binary decision process (decision threshold, bias, information uptake, and motor response). These components are represented by different parameters of the model. Two experiments were conducted to test the interpretational validity of the parameters. Using a color discrimination task, we investigated whether experimental manipulations of specific aspects of the decision process had specific effects on the corresponding parameters in a diffusion model data analysis (see Ratcliff, 2002; Ratcliff & Rouder, 1998; Ratcliff, Thapar, & McKoon, 2001, 2003). In support of the model, we found that (1) decision thresholds were higher when we induced accuracy motivation, (2) drift rates (i.e., information uptake) were lower when stimuli were harder to discriminate, (3) the motor components were increased when a more difficult form of response was required, and (4) the process was biased toward rewarded responses.     

Some antiepileptic compounds impair learning by rats in a Morris water maze

In the present experiments, we investigated the effects of several commonly employed antiepileptic drugs on the performance of adult rats in a Morris water maze task. We found that phenytoin treatment produced the most deleterious performance impairments across all days of training, and that these performance deficits are not likely due to any general sensorimotor impairments. Carbamazepine had milder, but detectable negative effects, as carbamazepine-treated animals exhibited initial acquisition deficits, but rapidly achieved escape levels comparable to controls. In marked contrast, valproate and ethosuximide had no detectable effects on learning in the water maze. These results parallel previous findings in rats treated with these compounds and tested in an instrumental learning task, and are in general agreement with the human clinical literature. To the extent that one might wish to minimize learning deficits associated with maintenance on antiepileptic drugs, phenytoin is definitely not the treatment of choice, while valproate or ethosuximide are apparently much less disruptive.     

The influence of adaptation and stochastic fluctuations on spontaneous perceptual changes for bistable stimuli

Spontaneous perceptual change was studied by measuring the probabilities of the first two spontaneous pattern switches as a function of time following the onset of a bistable apparent quartet for which either horizontal or vertical motion is perceived. Contrary to the classical satiation hypothesis (Köhler & Wallach, 1944),differential time-dependent adaptation of the perceived compared with the unperceived motion directions was not necessary to account for the first spontaneous switch. In addition, adaptation of the perceived motion accompanied by recovery from adaptation of the unperceived motion was not necessary to account for the increased probability of the second spontaneous switch. It was concluded that regardless of possible adaptation effects, stochastic fluctuations are necessary for the actual reversal of activation levels that produces the spontaneous switch. When the difference in detector activation is reduced by differential adaptation of competing motion detectors (or by the occurrence of a prior spontaneous pattern change), smaller stochastic fluctuations are sufficient to reverse the relative activation of competing detectors. Thus, adaptation can increase the probability of spontaneous switches without directly causing them.     

APPROXIMATING CHAOTIC BEHAVIOR

Abstract— Human subjects received feedback showing how closely their responses approximated the chaotic output of the logistic difference function. In Experiment 1, subjects generated analog responses by placing a pointer along a line. In Experiment 2, they generated digital responses in the form of three-digit numbers. In Experiment 3, feedback was sometimes provided and other times withheld. Responses came to approximate three defining characteristics of logistic chaos: Sequences were "noisy," they were extremely sensitive 10 initial conditions, and lag I autocorrelation functions were parabolic in form. Chaos theory may describe some highly variable although precisely determined human behaviors.