Behavioural and neural correlates of binaural hearing

Sollini, Joseph A. (2013) Behavioural and neural correlates of binaural hearing. PhD thesis, University of Nottingham.

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Abstract

The work in this thesis involves two separate projects. The first project involves the behavioural measurement of auditory thresholds in the ferret (Mustela Putorius). A new behavioural paradigm using a sound localisation task was developed which produces reliable psychophysical detection thresholds in animals. Initial attempts to use the task failed and after further investigation improvements were made. These changes produced a task that successfully produced reliably low thresholds. Different methods of testing, and the number of experimental trials required, here then explored systemically. The refined data collection method was then used to investigate frequency resolution in the ferret. These data demonstrated that the method was suitable for measuring perceptual frequency selectivity. It revealed that the auditory filters of ferrets are broader than several other species. In some cases this was also broader than neural estimates would suggest.

The second project involved the measurement of neural data in the Guinea Pig (Cavia porecellus). More specifically the project aimed to test the ability of the primary auditory cortex (AI) to integrate high frequency spatial cues. Two experiments were required to elucidate these data. The first experiment demonstrated a relationship between frequency and space, though these data proved noisy. A second experiment was conducted, focussing on improving the quality of the data this allowed for a more quantitative approach to be applied. The results highlighted that though AI neurons are responsive over a broad frequency range, inhibitory binaural interactions integrate spatial information over a smaller range. Binaural interactions were only strong when sounds in either ear were closely matched in frequency. In contrast, excitatory binaural interactions did not generally depend on the interaural frequency difference. These findings place important constraints on the across frequency integration of binaural level cues.

Item Type: Thesis (University of Nottingham only) (PhD)
Supervisors: Sumner, C.
Subjects: Q Science > QP Physiology
Faculties/Schools: UK Campuses > Faculty of Medicine and Health Sciences > School of Biomedical Sciences
UK Campuses > Faculty of Medicine and Health Sciences > School of Life Sciences
Item ID: 13739
Depositing User: EP, Services
Date Deposited: 19 Mar 2014 10:58
Last Modified: 16 Sep 2016 06:35
URI: http://eprints.nottingham.ac.uk/id/eprint/13739

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