The role of mechanism and covariation information in causal belief updating

The present study is aimed at identifying how prior causal beliefs and covariation information contribute to belief updating when evidence, either compatible or contradictory with those beliefs, is provided. Participants were presented with a cover story with which it was intended to activate or generate a causal belief. Variables related to the prior belief (the type of information, the strength of the cause-effect causal link, and how confident the participant was that the link existed) were assessed. Subsequently, participants were presented with covariational information and were asked to update their beliefs in light of the new evidence. Information reliability, prior belief's causal influence magnitude, and the cause-effect level of contingency portrayed by the new information--but not the type of the prior belief--are shown to directly determine belief updating.     

Two pathways to causal control: Use and availability of information in the environment in people with and without signs of depression

Perceiving one's causal control is important for adaptive behavior. Studying depression and other individual differences has provided insight into typical as well as pathological causal processing. We set out to study factors that have been shown to distinguish those with and without signs of depression and affect perceptions of causal control: levels of behavior, the availability of outcomes and learning about the environment or context. Two experiments were carried out in which participants, scoring low and high on the Beck Depression Inventory using established cutoffs, completed a causal control task, in which outcomes occurred with a low (.25) or high probability (.75). Behavior levels were either constrained (N₁ = 73) or unconstrained (N₂ = 74). Overall, findings showed that levels of behavior influenced people's experiences of the context in which events occurred. For all participants, very high behavior levels eliminated sensitivity to levels of outcomes occurring in the environment and lead to judgments that were consistent with conditional probabilities as opposed to the experimenter programmed contingency. Thus increased behavior increased perceived control via influence on context experience. This effect was also evident for those scoring high on the BDI. Overall conclusions are that behavior and context provide two important interlinked psychological pathways to perceived control. However, situations that constrain people's ability to respond freely can prevent people with signs of depression from taking control of a situation that would otherwise be uncontrollable.     

It's not what you play,it's how you play it: Timbre affects perception of emotion in music

Salient sensory experiences often have a strong emotional tone, but the neuropsychological relations between perceptual characteristics of sensory objects and the affective information they convey remain poorly defined. Here we addressed the relationship between sound identity and emotional information using music. In two experiments, we investigated whether perception of emotions is influenced by altering the musical instrument on which the music is played, independently of other musical features. In the first experiment, 40 novel melodies each representing one of four emotions (happiness, sadness, fear, or anger) were each recorded on four different instruments (an electronic synthesizer, a piano, a violin, and a trumpet), controlling for melody, tempo, and loudness between instruments. Healthy participants (23 young adults aged 18–30 years, 24 older adults aged 58–75 years) were asked to select which emotion they thought each musical stimulus represented in a four-alternative forced-choice task. Using a generalized linear mixed model we found a significant interaction between instrument and emotion judgement with a similar pattern in young and older adults (p < .0001 for each age group). The effect was not attributable to musical expertise. In the second experiment using the same melodies and experimental design, the interaction between timbre and perceived emotion was replicated (p < .05) in another group of young adults for novel synthetic timbres designed to incorporate timbral cues to particular emotions. Our findings show that timbre (instrument identity) independently affects the perception of emotions in music after controlling for other acoustic, cognitive, and performance factors.