The role of expectation and probabilistic learning in auditory boundary perception: a model comparison

Grouping and boundary perception are central to many aspects of sensory processing in cognition. We present a comparative study of recently published computational models of boundary perception in music. In doing so, we make three contributions. First, we hypothesise a relationship between expectation and grouping in auditory perception, and introduce a novel information-theoretic model of perceptual segmentation to test the hypothesis. Although we apply the model to musical melody, it is applicable in principle to sequential grouping in other areas of cognition. Second, we address a methodological consideration in the analysis of ambiguous stimuli that produce different percepts between individuals. We propose and demonstrate a solution to this problem, based on clustering of participants prior to analysis. Third, we conduct the first comparative analysis of probabilistic-learning and rule-based models of perceptual grouping in music. In spite of having only unsupervised exposure to music, the model performs comparably to rule-based models based on expert musical knowledge, supporting a role for probabilistic learning in perceptual segmentation of music.     

Three approaches to religious education at Key Stages one and two in Wales: how different are church schools?

Survey data provided by 361 headteachers regarding religious education provision at Key Stages one and two within schools in Wales are modelled to distinguish between three main approaches to religious education, characterised as concerned with spiritual development, world religions, and Christian nurture. No differences in emphasis on these three approaches are found between non‐denominational schools and Church in Wales voluntary controlled schools. In Church in Wales voluntary aided schools greater emphasis is placed on the spiritual development dimension and on the Christian nurture dimension. In Roman Catholic voluntary‐aided schools greater emphasis is placed on the spiritual development dimension, greater emphasis is placed on the Christian nurture dimension, and less emphasis is placed on the world religions dimension.     

Spiritual development in church schools—a survey of Welsh head teachers’ perceptions

A questionnaire to assess views about spiritual development was completed by 112 of the 174 head teachers of church primary schools in Wales. The findings indicated that despite the seemingly ambiguous nature of the term ‘spiritual development’, head teachers had clear views about its meaning. While most head teachers emphasised the need for pupils to engage in their own personal spiritual search, their views differed in the extent to which they felt that promoting spiritual development meant encouraging pupils to adopt Christian beliefs. While the age and sex of head teachers was found to have no significant impact on their views; and the location and category of the school for which head teachers were responsible had only a limited impact on their view, the language of the school and the religiosity of the head teacher had a considerable impact on views regarding these matters.     

The development of metacognitive ability in adolescence

Introspection, or metacognition, is the capacity to reflect on our own thoughts and behaviours. Here, we investigated how one specific metacognitive ability (the relationship between task performance and confidence) develops in adolescence, a period of life associated with the emergence of self-concept and enhanced self-awareness. We employed a task that dissociates objective performance on a visual task from metacognitive ability in a group of 56 participants aged between 11 and 41 years. Metacognitive ability improved significantly with age during adolescence, was highest in late adolescence and plateaued going into adulthood. Our results suggest that awareness of one’s own perceptual decisions shows a prolonged developmental trajectory during adolescence.     

Probabilistic models of expectation violation predict psychophysiological emotional responses to live concert music

We present the results of a study testing the often-theorized role of musical expectations in inducing listeners’ emotions in a live flute concert experiment with 50 participants. Using an audience response system developed for this purpose, we measured subjective experience and peripheral psychophysiological changes continuously. To confirm the existence of the link between expectation and emotion, we used a threefold approach. (1) On the basis of an information-theoretic cognitive model, melodic pitch expectations were predicted by analyzing the musical stimuli used (six pieces of solo flute music). (2) A continuous rating scale was used by half of the audience to measure their experience of unexpectedness toward the music heard. (3) Emotional reactions were measured using a multicomponent approach: subjective feeling (valence and arousal rated continuously by the other half of the audience members), expressive behavior (facial EMG), and peripheral arousal (the latter two being measured in all 50 participants). Results confirmed the predicted relationship between high-information-content musical events, the violation of musical expectations (in corresponding ratings), and emotional reactions (psychologically and physiologically). Musical structures leading to expectation reactions were manifested in emotional reactions at different emotion component levels (increases in subjective arousal and autonomic nervous system activations). These results emphasize the role of musical structure in emotion induction, leading to a further understanding of the frequently experienced emotional effects of music.     

Contextual illusions reveal the limit of unconscious visual processing

The perception of even the most elementary features of the visual environment depends strongly on their spatial context. In the study reported here, we asked at what level of abstraction such effects require conscious processing of the context. We compared two visual illusions that alter subjective judgments of brightness: the simultaneous brightness contrast illusion, in which two circles of identical physical brightness appear different because of different surround luminance, and the Kanizsa triangle illusion, which occurs when the visual system extrapolates a surface without actual physical stimulation. We used a novel interocular masking technique that allowed us to selectively render only the context invisible. Simultaneous brightness contrast persisted even when the surround was masked from awareness. In contrast, participants did not experience illusory contours when the inducing context was masked. Our findings show that invisible context is resolvable by low-level processes involved in surface-brightness perception, but not by high-level processes that assign surface borders through perceptual completion.     

Coming to terms: quantifying the benefits of linguistic coordination

Sharing a public language facilitates particularly efficient forms of joint perception and action by giving interlocutors refined tools for directing attention and aligning conceptual models and action. We hypothesized that interlocutors who flexibly align their linguistic practices and converge on a shared language will improve their cooperative performance on joint tasks. To test this prediction, we employed a novel experimental design, in which pairs of participants cooperated linguistically to solve a perceptual task. We found that dyad members generally showed a high propensity to adapt to each other's linguistic practices. However, although general linguistic alignment did not have a positive effect on performance, the alignment of particular task-relevant vocabularies strongly correlated with collective performance. In other words, the more dyad members selectively aligned linguistic tools fit for the task, the better they performed. Our work thus uncovers the interplay between social dynamics and sensitivity to task affordances in successful cooperation.     

“It’s Really No Big Deal”: The Role of Social Supply Networks in Normalizing Use of Cannabis by Students at Canadian Universities

Cannabis (marijuana) has undergone a normalizing process as indicated by high use rates, social tolerance, and broader cultural acceptance of its use in many countries. Users also maintain access through extended friendship networks that facilitate the cultural diffusion of the practice. The social nature of supply is herein theorized in terms of Goffman’s understanding of activities that function to preserve a sense of normalcy as a collective achievement enabling predictable constructions of reality. Based on in-depth interviews with undergraduate students, we explore how social networks of supply—characterized by casual access, reciprocity, and sharing—contribute to shared meanings about using marijuana as an unremarkable or “normal” thing to do.     

Perceptual load alters visual excitability

Increasing perceptual load reduces the processing of visual stimuli outside the focus of attention, but the mechanism underlying these effects remains unclear. Here we tested an account attributing the effects of perceptual load to modulations of visual cortex excitability. In contrast to stimulus competition accounts, which propose that load should affect simultaneous, but not sequential, stimulus presentations, the visual excitability account makes the novel prediction that load should affect detection sensitivity for both simultaneous and sequential presentations. Participants fixated a stimulus stream, responding to targets defined by either a color (low load) or color and orientation conjunctions (high load). Additionally, detection sensitivity was measured for a peripheral critical stimulus (CS) presented occasionally. Increasing load at fixation reduced sensitivity to the peripheral CSs; this effect was similar regardless of whether CSs were presented simultaneously with central stimuli or during the (otherwise empty) interval between them. Controls ruled out explanations of the results in terms of strategic task prioritization. These findings support a cortical excitability account for perceptual load, challenging stimulus competition accounts.