Sweet spot in music-Is predictability preferred among persons with psychotic-like experiences or autistic traits?

People prefer music with an intermediate level of predictability; not so predictable as to be boring, yet not so unpredictable that it ceases to be music. This sweet spot for predictability varies due to differences in the perception of predictability. The symptoms of both psychosis and Autism Spectrum Disorder have been attributed to overestimation of uncertainty, which predicts a preference for predictable stimuli and environments. In a pre-registered study, we tested this prediction by investigating whether psychotic and autistic traits were associated with a higher preference for predictability in music. Participants from the general population were presented with twenty-nine pre-composed music excerpts, scored on their complexity by musical experts. A participant's preferred level of predictability corresponded to the peak of the inverted U-shaped curve between music complexity and liking (i.e., a Wundt curve). We found that the sweet spot for predictability did indeed vary between individuals. Contrary to predictions, we did not find support for these variations being associated with autistic and psychotic traits. The findings are discussed in the context of the Wundt curve and the use of naturalistic stimuli. We also provide recommendations for further exploration.

Seeing minds - a signal detection study of agency attribution along the autism-psychosis continuum.

INTRODUCTION: Diametrically aberrant mentalising biases, namely hypermentalising in psychosis and hypomentalising in autism, are postulated by some theoretical models. To test this hypothesis, we measured psychotic-like experiences, autistic traits and mentalising biases in a visual chasing paradigm. METHODS: Participants from the general population (N = 300) and psychotic patients (N=26) judged the absence or presence of a chase during five-second long displays of seemingly randomly moving dots. Hypermentalising is seeing a chase where there is none, whereas hypomentalising is missing to see a chase. RESULTS: Psychotic-like experiences were associated with hypermentalising. Autistic traits were not associated with hypomentalising, but with a reduced ability to discriminate chasing from non-chasing trials. Given the high correlation (τ = .41) between autistic traits and psychotic-like experiences, we controlled for concomitant symptom severity on agency detection. We found that all but those with many autistic and psychotic traits showed hypomentalising, suggesting an additive effect of traits on mentalising. In the second study, we found no hypermentalising in patients with psychosis, who performed also similarly to a matched control group. CONCLUSIONS: The results suggest that hypermentalising is a cognitive bias restricted to subclinical psychotic-like experiences. There was no support for a diametrically opposite mentalising bias along the autism-psychosis continuum.

Overestimation of volatility in schizophrenia and autism? A comparative study using a probabilistic reasoning task.

BACKGROUND AND OBJECTIVES: A plethora of studies has investigated and compared social cognition in autism and schizophrenia ever since both conditions were first described in conjunction more than a century ago. Recent computational theories have proposed similar mechanistic explanations for various symptoms beyond social cognition. They are grounded in the idea of a general misestimation of uncertainty but so far, almost no studies have directly compared both conditions regarding uncertainty processing. The current study aimed to do so with a particular focus on estimation of volatility, i.e. the probability for the environment to change. METHODS: A probabilistic decision-making task and a visual working (meta-)memory task were administered to a sample of 86 participants (19 with a diagnosis of high-functioning autism, 21 with a diagnosis of schizophrenia, and 46 neurotypically developing individuals). RESULTS: While persons with schizophrenia showed lower visual working memory accuracy than neurotypical individuals, no significant group differences were found for metamemory or any of the probabilistic decision-making task variables. Nevertheless, exploratory analyses suggest that there may be an overestimation of volatility in subgroups of participants with autism and schizophrenia. Correlations revealed relationships between different variables reflecting (mis)estimation of uncertainty, visual working memory accuracy and metamemory. LIMITATIONS: Limitations include the comparably small sample sizes of the autism and the schizophrenia group as well as the lack of cognitive ability and clinical symptom measures. CONCLUSIONS: The results of the current study provide partial support for the notion of a general uncertainty misestimation account of autism and schizophrenia.

Insufficient evidence for habituation in Mimosa pudica. Response to Gagliano et al. (2014).

Gagliano et al. (Oecologia 175(1):63-72, 2014) reported that Mimosa pudica habituates to repeated stimulation, as shown by a reduction in response, dishabituation, and stimulus specificity. I argue that Gagliano et al.'s data show an absence of dishabituation, that their experimental design needs an additional condition to test whether there is stimulus specificity, and that most of their data can be explained by motor fatigue. Some data are not easily explained by fatigue, and I suggest a further analysis that may clarify the issue. The status of habituation in Mimosa remains uncertain.