Biomedical subjects

Anders Winman

Publications and source records attributed to Anders Winman.

7 recordsLinked to original sources

PubMed2006

Inferring causality assessments from predictive responses: cue interaction without cue competition.

The authors criticize the use of participants' predictive responses during a learning phase as a measure of causal assessments. Simulations demonstrate that a general aim to minimize error as required in the prediction task will produce results in accordance with those observed, in particular apparent cue interaction effects. It is argued that measures estimated from prediction responses do not reflect causal ratings, but are side-effects of learning explained by adaptation in strategy to changes in presented cell frequencies. The results are reinterpreted to be in line with a causal model view, not requiring dual processes or cue competition of lower level associative processes.

Association Learning↗

PubMed2005

Psychosocial factors and respiratory and cardiovascular parameters during psychophysiological stress profiling in working men and women.

The relationship between psychosocial factors and psychophysiological reactions to a situation including stressors and relaxation in a working population was examined. A sample of 115 working men and women aged 26-65 was used. Each participant was examined at baseline, during deep breathing, experimentally induced stress and relaxation. Heart rate, exhalation carbon dioxide, oxygen saturation and blood pressure were monitored. Significant variations across experimental conditions were observed for all physiological variables. There was a pronounced lowering of blood pressure during deep breathing. Women showed significantly more pronounced physiological variation than men. Participants with low education reacted with significantly more systolic blood pressure elevation during the stressful conditions than others. The implication of the results for therapeutic and preventive exercises with deep breathing are discussed.

Adult↗

PubMed2005

Evidence for rule-based processes in the inverse base-rate effect.

Three studies provide convergent evidence that the inverse base-rate effect (Medin & Edelson, 1988) is mediated by rule-based cognitive processes. Experiment 1 shows that, in contrast to adults, prior to the formal operational stage most children do not exhibit the inverse base-rate effect. Experiments 2 and 3 demonstrate that an adult sample is a mix of participants relying on associative processes who categorize according to the base-rate and participants relying on rule-based processes who exhibit a strong inverse base-rate effect. The distribution of the effect is bimodal, and removing participants independently classified as prone to rule-based processing effectively eliminates the inverse base-rate effect. The implications for current explanations of the inverse base-rate effect are discussed.

Adult↗

PubMed2004

Do perfume additives termed human pheromones warrant being termed pheromones?

Two studies of the effects of perfume additives, termed human pheromones by the authors, have conveyed the message that these substances can promote an increase in human sociosexual behaviour [Physiol. Behav. 75 (2003) R1; Arch. Sex. Behav. 27 (1998) R2]. The present paper presents an extended analysis of this data. It is shown that in neither study is there a statistically significant increase in any of the sociosexual behaviours for the experimental groups. In the control groups of both studies, there are, however, moderate but statistically significant decreases in the corresponding behaviour. Most notably, there is no support in data for the claim that the substances increase the attractiveness of the wearers of the substances to the other sex. It is concluded that more research using matched homogenous groups of participants is needed.

Adult↗

PubMed2004

Subjective probability intervals: how to reduce overconfidence by interval evaluation.

Format dependence implies that assessment of the same subjective probability distribution produces different conclusions about over- or underconfidence depending on the assessment format. In 2 experiments, the authors demonstrate that the overconfidence bias that occurs when participants produce intervals for an uncertain quantity is almost abolished when they evaluate the probability that the same intervals include the quantity. The authors successfully apply a method for adaptive adjustment of probability intervals as a debiasing tool and discuss a tentative explanation in terms of a naive sampling model. According to this view, people report their experiences accurately, but they are naive in that they treat both sample proportion and sample dispersion as unbiased estimators, yielding small bias in probability evaluation but strong bias in interval production.

Choice Behavior↗

PubMed2003

Cue abstraction and exemplar memory in categorization.

In this article, the authors compare 3 generic models of the cognitive processes in a categorization task. The cue abstraction model implies abstraction in training of explicit cue-criterion relations that are mentally integrated to form a judgment, the lexicographic heuristic uses only the most valid cue, and the exemplar-based model relies on retrieval of exemplars. The results from 2 experiments showed that, in lieu of the lexicographic heuristic, most participants spontaneously integrate cues. In contrast to single-system views, exemplar memory appeared to dominate when the feedback was poor, but when the feedback was rich enough to allow the participants to discern the task structure, it was exploited for abstraction of explicit cue-criterion relations.

Adolescent↗

PubMed2003

Can attentional theory explain the inverse base rate effect? Comment on Kruschke (2001).

In J. K. Kruschke's (2001; see record 2001-18940-005) study, it is argued that attentional theory is the sole satisfactory explanation of the inverse base rate effect and that eliminative inference (P. Juslin, P. Wennerholm, & A. Winman, 2001; see record 2001-07828-016) plays no role in the phenomenon. In this comment, the authors demonstrate that, in contrast to the central tenets of attentional theory, (a) rapid attention shifts as implemented in ADIT decelerate learning in the inverse base-rate task and (b) the claim that the inverse base-rate effect is directly caused by an attentional asymmetry is refuted by data. It is proposed that a complete account of the inverse base-rate effect needs to integrate attention effects with inference rules that are flexibly used for both induction and elimination.

Association Learning↗