4 YEAR PhD IN NEUROSCIENCE
Institute of Cognitive Neuroscience
The Visual Cognition lab is currently engaged in a series of experiments extending its work on visual search and eye movements (Juan et al., 2008; Muggleton et al., 2008; Silvanto et al, 2008) to vision and search in real scenes. The lab uses a variety of techniques (e.g.TMS, tDCS, eye movement recording, fMRI) and collaborates with several groups within the ICN
(see Visual Cognition Group).
Examples of projects that may be considered are:
1. Eye movements in real scenes. A great deal is known, or at least is published, about the visual search abilities of humans – how one finds an person, book, food item in a visual noisy environment. The vast majority of work addresses lab-based tasks with simple displays and eye and head movements restricted. We are engaged in testing how much of this knowledge transfers to the real world and in describing eye movements and search abilities as subjects view and move through real scenes. This work involves learning how to analyze real scene components, how to collect and analyse eye movement data and how to apply lab knowledge to ecologically valid tasks.
2. Does the visual system use scene statistics? It is widely believed that the visual system somehow calculates values of the stimulus features in a scene (mean size, velocity, shape, colour etc). Our pilot data to date suggest that this is only true in impoverished visual environments and that our ability to make statistical inferences about scene properties breaks down very quickly. We are keen to explore the limits of the human visual system and projects are available on a range of psychophysical and brain stimulation projects which aim to explore the limits of visual statistical processing, the influence of scene familiarity on statistical processing and the brain areas that may be involved in making such inferences. Depending on the current stage of work, involvement in scene statistics work may include psychophysics, TMS, eye movement recording or fMRI.
3. The Visual Cognition Group has recently set up sleep recording facilities in the ICN and has begun sleep fMRI-EEG recordings in BUCNI. The goals are to provide a description of BOLD states in different stages of sleep, to examine the role of sleep in learning and consolidation and to enhance consolidation by using AC brain stimulation during sleep.
Brascamp, J., Kanai, R., Walsh, V., & Van Ee, R. (2010) Human MT+, perceptual bias and perceptual memory for ambiguous 3D motion. Journal of Neuroscience 30: 760-766.
Cohen Kadosh, R., Soskic, S., Iucalano, T., Kanai, R., & Walsh, V. (2010) Modulating neuronal activity produces specific and long lasting changes in numerical competence. Current Biology 20: 2016-2020
Banissy, M.J., Garrido, L., Kusnir, F., Duchaine, B., Walsh, V., & Ward, J. (2011) Superior facial expression, but not identity recognition, in mirror-touch synaesthesia. Journal of Neuroscience 31: 1820-1824.
Bueti, D., Bahrami, B., Walsh, V., & Rees, G. (2010) Encoding of temporal probabilities in the human brain. J Neuroscience 30: 4343-4352
Machizawa, M.G., Kalla, R., Walsh,V., & Otten, L.J. (2010) The time course of ventrolateral prefrontal cortex involvement in memory formation. Journal of Neurophysiology 103: 1569-1579.