NHBRU and IHR in Nottingham, PhD in Cognitive Neuroscience

Using EEG to measure cortical reorganisation after hearing loss

with Dr Jessica de Boer, Dr Katrin Krumbholz and Prof. Deborah Hall
jdb@ihr.mrc.ac.uk , katrin@ihr.mrc.ac.uk, deb.hall@nottingham.ac.uk

Hearing loss affects a large proportion of the population and can be associated with a severe reduction in the quality of life. A common, and particularly debilitating, consequence of hearing loss is tinnitus – the perception of phantom sounds in the absence of an external source. According to a widely-held hypothesis, tinnitus results from a reorganisation of cortical processing. This project aims to test this hypothesis using high-density electroencephalographic (EEG) measurements.

The cochlea in the inner ear separates sounds into their component frequencies. Given that the high-frequency part of the cochlea is more susceptible to noise- and age-related damage, hearing loss tends to affect high frequencies more than low frequencies, with a sloping transition between them. Animal studies have shown that sloping hearing loss can lead to cortical reorganisation, in that areas representing the damaged high frequencies get “taken over” by the intact low frequencies. It is commonly believed that it is this kind of cortical reorganisation that causes tinnitus (Pienkowski & Eggermont, 2011). This project will use high-density electro-encephalography (EEG) to investigate whether cortical reorganisation can also be observed in humans. If reorganisation takes place in humans, the EEG responses to tones with frequencies close to the hearing loss edge would be expected to be larger, and more selective, than the responses to tones with more remote frequencies.

This is an interdisciplinary project, aimed at graduates with a first- or upper second-class degree in the life sciences (e.g., biology or neuroscience), or in a more mathematical or technical subject (e.g., physics or computer science). You will be trained in advanced non-invasive neurorecording techniques, as well as psychophysical and audiological measurements of hearing impairment and tinnitus.

Pienkowski M & Eggermont JJ (2011). Cortical tonotopic map plasticity and behaviour. Neurosci Biobehav Rev 35, 2117-2128.