Research Fellows Directory
Dr Jennifer Bizley
University College London
We effortlessly integrate the signals provided by our eyes and ears to form our perception of the world around us. Even when we consider only one sense – hearing, for example, we perceive a three dimensional acoustical scene in which we can recognize the voice of a colleague behind us, a printer buzzing to our right, and a car passing by the window. Our ears breakdown these sounds into their individual sound waves, or frequency components, meaning that the brain must somehow deduce how these sound waves relate the acoustic ‘objects’ in our environment. To do this the brain must first group these frequencies appropriately before it can begin to reconstruct and localize the individual objects that may have emitted the sound waves in the first place. We believe that the auditory cortex is crucial for enabling us to identify and localize a sound in space and so my research asks how it is that nerve cells in auditory cortex might be responsible for shaping our perception of the sounds that we hear – with distinct pitches, identities, and spatial locations. To do this I train ferrets in listening tasks, such as discriminating a rising pitch from a falling pitch, or an “ae” from an “ih”. By recording neural activity whilst they perform such tasks we can try to correlate the neural activity with the sound that the animal heard, and their judgment about its pitch or identity. For this sort of work an animal model is necessary as recording the activity of single nerve cells requires implanting recording electrodes. However, as Parkinsonian patients fitted with electrodes for deep brain stimulation demonstrate, implanting recording electrodes is a relatively painless procedure and allows us to measure neural activity and behaviour simultaneously. We record activity from large numbers of nerve cells in this manner, and then use computer algorithms to try to decode the neural signals to explore how they might be ‘read out’ in the brain to create perception.
Interests and expertise (Subject groups)