Towards a neural basis of music perception

Music perception involves complex brain functions underlying acoustic analysis, auditory memory, auditory scene analysis, and processing of musical syntax and semantics. Moreover, music perception potentially affects emotion, influences the autonomic nervous system, the hormonal and immune systems, and activates (pre)motor representations. During the past few years, research activities on different aspects of music processing and their neural correlates have rapidly progressed. This article provides an overview of recent developments and a framework for the perceptual side of music processing. This framework lays out a model of the cognitive modules involved in music perception, and incorporates information about the time course of activity of some of these modules, as well as research findings about where in the brain these modules might be located.     

Hypersomnia and the perception of sleep-wake states: some preliminary findings

35 hypersomniacs (20 with obstructive sleep apnea and 15 with narcolepsy) and 15 controls estimated sleep latency during systematic trials of attempting to remain awake during the day. The error in subjective assessment of sleep latency was more variable for both patient groups than for controls. In addition, narcoleptics could not provide a determination of sleep latency or differentiate sleep-wake states on nearly 23% of all trials. Ratings on a subjective sleepiness scale did not covary with objective sleep latency for any hypersomniac. The findings suggested that patients with either sleep apnea or narcolepsy had difficulty differentiating sleep and quiet wakefulness during the day.     

Duplex perception: a comparison of monosyllables and slamming doors

Duplex perception has been interpreted as revealing distinct systems for general auditory perception and speech perception. The systems yield distinct experiences of the same acoustic signal, the one conforming to the acoustic structure itself and the other to its source in vocal-tract activity. However, this interpretation has not been tested by examining whether duplex perception can be obtained for nonspeech sounds that are not plausibly perceived by a specialized system. In five experiments, we replicate some of the phenomena associated with duplex perception of speech using the sound of a slamming door. Similarities between subjects' responses to syllables and door sounds are striking enough to suggest that some conclusions in the speech literature should be tempered that (a) duplex perception is special to sounds for which there are perceptual modules and (b) duplex perception occurs because distinct systems have rendered different percepts of the same acoustic signal.     

The cutaneous saltatory area and its presumed neural basis

The saltatory area, defined as that region of the skin within which two successive and spatinily separated signals will interact to produce apparent mislocalization of the prior signal, is measured by a campimetric technique applied to the palm, finger pad, and volar forearm. As contrasted with earlier measures on larger anatomical units, saltatory areas of the hand region are considerably compressed. Comparisons between cortical receptive fields and saltatory areas lead to speculation concerning the operation of the neural principle of “magnification” in the establishment of saltatory limits. The correspondence of configurational properties of both receptive fields and saltatory areas suggests a commonality of principles underlying both, but demands more information on the temporal dimensions of cortical interaction to confirm the parallelism.     

Duplex perception of cues for stop consonants: Evidence for a phonetic mode

When the (vocalic) formant transitions appropriate for the stops in a synthetic approximation to [spa] or [sta] are presented to one ear and the remainder of the acoustic pattern to the other, listeners report a duplex percept. One side of the duplexity is the same coherent syllable ([spa] or [sta]) that is perceived when the pattern is presented in its original, undivided form; the other is a nonspeech chirp that corresponds to what the transitions sound like in isolation. This phenomenon is here used to determine why, in the case of stops, silence is an important cue. The results show that the silence cue affects the formant transitions differently when, on the one side of the duplex percept, the transitions support the perception of stop consonants, and when, on the other, they are perceived as nonspeech chirps. This indicates that the effectiveness of the silence cue is owing to distinctively phonetic (as against generally auditory) processes.     

Asymptotic log-linear analysis: some cautions concerning sparse frequency tables

Traditional asymptotic probability values resulting from log-linear analyses of sparse frequency tables are often much too large. Asymptotic probability values for chi-squared and likelihood-ratio statistics are compared to nonasymptotic and exact probability values for selected log-linear models. The asymptotic probability values are all too often substantially larger than the exact probability values for the analysis of sparse frequency tables. An exact nondirectional permutation method is presented to analyze combined independent multinomial distributions. Exact nondirectional permutation methods to analyze hypergeometric distributions associated with r-way frequency tables are confined to r = 2.     

The neural basis of cognitive development: a constructivist manifesto

How do minds emerge from developing brains? According to "neural constructivism," the representational features of cortex are built from the dynamic interaction between neural growth mechanisms and environmentally derived neural activity. Contrary to popular selectionist models that emphasize regressive mechanisms, the neurobiological evidence suggests that this growth is a progressive increase in the representational properties of cortex. The interaction between the environment and neural growth results in a flexible type of learning: "constructive learning" minimizes the need for prespecification in accordance with recent neurobiological evidence that the developing cerebral cortex is largely free of domain-specific structure. Instead, the representational properties of cortex are built by the nature of the problem domain confronting it. This uniquely powerful and general learning strategy undermines the central assumption of classical learnability theory, that the learning properties of a system can be deduced from a fixed computational architecture. Neural constructivism suggests that the evolutionary emergence of neocortex in mammals is a progression toward more flexible representational structures, in contrast to the popular view of cortical evolution as an increase in innate, specialized circuits. Human cortical postnatal development is also more extensive and protracted than generally supposed, suggesting that cortex has evolved so as to maximize the capacity of environmental structure to shape its structure and function through constructive learning.     

Cognitions associated with initial medical consultations concerning recurrent breathing difficulties: A community-based study

Abstract

A two-stage community survey identified 568 respondents reporting recurrent breathing difficulties over a one-year period. Subsequent interviews allowed comparison of (i) 21 respondents who had never consulted a doctor about frequent wheezing (i.e., on more than 30 days) or serious breathing difficulties (i.e., disrupting everyday activities) over the past year with (ii) a randomly selected group of 22 who had seen their doctor concerning breathing difficulties in the past year. These groups were found to be similar with respect to demographic and lung function measures. An extended health belief model framework including causal attributions for breathing difficulties and consulting self-efficacy was used to explore cognitions which might distinguish between the two groups. Logistic regression suggested that lower perceived relative severity of symptoms (in relation to other problems). attribution of wheezing to smoking and lower self-efficacy in relation to explaining breathing difficulties to a doctor distinguished between those who did and did not consult. Health education implications. including initiatives to encourage medical help-seeking amongst those with recurrent, frequent or serious breathing difficulties are discussed.     

Toward the neural basis of verbal priming: A cognitive-neuropsychological synthesis

Repetition priming is a mnemonic phenomenon that has attracted considerable attention from neuropsychologists and cognitive scientists. In an attempt at elucidating the putative mechanisms of priming, the present review draws on evidence from both domains. The review is restricted to verbal priming of visually presented stimuli—an area that accounts for the majority of empirical studies of priming. A number of theoretical accounts are presented. The interim conclusion is that neither multiple systems nor unitary system-multiple process theories can adequately explain the data on priming, although both contain many valid components. An integrative model is proposed to improve the explanation of the empirical evidence. The central assertion of the proposed model is that repetition priming depends on perceptual processes that can be mapped on specific neural systems. It is postulated that individual differences in perceptual processing ability predict variability in memory performance. It is proposed that data-driven priming of verbal stimuli critically depends on the activity of primary and secondary visual cortices in the right hemisphere, whereas conceptually-driven priming is hypothesized to rely on the activities of higher order tertiary association cortices in language areas and more anterior neocortical areas.     

The neural basis of cognitive control: Response selection and inhibition

The functional neuroanatomy of tasks that recruit different forms of response selection and inhibition has to our knowledge, never been directly addressed in a single fMRI study using similar stimulus–response paradigms where differences between scanning time and sequence, stimuli, and experimenter instructions were minimized. Twelve right-handed participants were scanned on two standard cognitive control tasks, a stimulus–response incompatibility task, and a response inhibition task. A compound trial design allowed comparison of preparing to inhibit an upcoming automatic response to wholly inhibiting an automatic response. Furthermore, inhibiting an automatic response to perform an alternative task-relevant response was compared to wholly inhibiting an automatic response. No differences were found in prefrontal activity when preparing to inhibit an automatic response was compared to wholly inhibiting an automatic response, suggesting a mostly common network. The left inferior frontal gyrus was found to be commonly recruited during both tasks when controlled responses were required, likely due to its role in response selection. In contrast, the right inferior frontal gyrus was found to be more involved when task demands were stronger for response inhibition. Our results are largely consistent with models of cognitive control that postulate that separate psychological constructs, such as response selection and inhibition, are related processes largely served by a common prefrontal network. This prefrontal network is recruited to a greater or lesser extent depending on specific task demands.