This Research Topic is part of the Hemispheric Asymmetries in the Auditory Domain series:
Hemispheric Asymmetries in the Auditory Domain, Volume IFunctional and structural asymmetries are present in many regions of the brain which control various types of sensory processing, cognitive functions, and motor activity. The present issue focuses on hemispheric asymmetries in the auditory system. The first evidence for auditory system asymmetries came from early studies of dichotic listening, done by Philip Bryden and Doreen Kimura, who noticed the presence of a right ear advantage for verbal auditory material processing and the presence of a left ear advantage for non-verbal material such as pitch and melody processing. This evidence, together with earlier findings concerning the pathophysiology of speech by some well-known nineteenth-century neurologists, such as Paul Broca and Carl Wernicke, has given rise to a huge amount of scientific work utilizing behavioral, neuropsychological, electrophysiological, neuroimaging and non-invasive brain stimulation techniques. This literature ranges from the study of the asymmetric responses to simple auditory stimuli, to the differential specialization of the hemispheres in the various aspects of language, to the latest evidence of asymmetries arising during social interactions.
The processing of complex auditory stimuli in the form, for example, of speech and music requires the analysis of several basic acoustic parameters such as duration and frequency. Different hypotheses exist that address the different specialization of the left and right auditory cortices for the different acoustic properties of sound, among which one of the best known proposes the existence of a higher temporal resolution in the neural systems of the left auditory cortex, and a higher spectral resolution in those present in the right auditory cortex. However, many aspects of the relations between the hemispheres during sound processing are still unknown. Unanswered questions comprise, for example:
• What neural mechanisms allow the left hemisphere to have a higher temporal resolution and the right one to have a higher spectral resolution?
• Which part of the auditory environment is processed preferentially in the left, or in the right hemisphere?
• Is the lateralization of auditory information processing static, or does it undergo asymmetric dynamics?
• What is the role of top-down attention, or of a subjective listening strategy?
• Do plastic processes interact with hemispheric asymmetries, e.g. during learning?
• Does the representation of an auditory object in one hemisphere have a counterpart in the other one?
In this Research Topic, we ask contributors to address the above as well as similar open issues in the field and submit them to the closest journal section.
Suitable research works include studies derived from the outcomes of experimental research, review articles of related scientific literature that offer novel insights into this field as well as opinion articles on the topic.
