[Eeglablist] phd position at university of aberdeen

Jasna Martinovic J.Martinovic at liverpool.ac.uk
Sun Mar 21 15:52:34 PDT 2010

Interactions between bottom-up and top-down biases in the processing of 
colour; a fully-funded PhD project at the School of Psychology, 
University of Aberdeen

Project description

The efficiency of attentional selection depends on two factors: the 
saliency of the stimulus (bottom-up processing, driven by exogenous 
cues) and the adopted perceptual set (top-down processing, driven by 
endogenous cues). Relations between these stimulus and task-driven 
factors are still poorly understood. However, it seems that in difficult 
tasks, when stimuli compete for limited perceptual resources, endogenous 
cueing interacts with exogenous cues such as stimulus saliency.  In 
real-life situations, the visual system is habitually presented with the 
difficult task of selecting stimuli from diverse and dynamic scenes. 
Therefore it is reasonable to assume that interactions between bottom-up 
and top-down biases are the norm, rather than an exception.  Preliminary 
work, using psychophysics and steady-state visual evoked potentials in 
the EEG, indicates multiplicative, independent effects of saliency and 
top-down selection in a continuous stimulus domain such as luminance. 
The aim of this project is to look for interactions between colour 
saliency and cueing in colour selection using the same methods. Due to 
the discontinuous nature of colour as a stimulus dimension, there may be 
interactions between bottom-up and top-down factors dependent on both 
low-level and high-level colour representations. This will extend the 
previous work on colour selection derived from visual search paradigms 
into the domain of complex dynamic displays and will complement it with 
insights into underlying neural processes through the use of EEG.

The project is based at the School of Psychology of the University of 
Aberdeen and will be supervised by Dr Jasna Martinovic and Prof Arash 

School of Psychology has state-of-the-art EEG facilities, including two 
64-electrode Biosemi ActiveTwo EEG systems. Vision Research Laboratories 
within the School are equipped with multiple psychophysical workstations 
and a high-resolution eye tracking system (EyeLink 1000). The succesful 
candidate will join an active group of vision researchers comprising of 
academic and research staff and students.

Information for applicants

Candidates must be eligible for UK/EU fee status and should hold a First 
or Upper Second Class Honours degree, a Masters degree or an equivalent 
qualification.  Candidates should have a background in visual  
perception, neuroscience, cognitive psychology or a related field. 
Programming skills (e.g. Matlab, C) and previous experience with 
electrophysiology, psychophysics and signal processing methods are 
highly desirable.

If you would like to be considered for this position, please send a 
cover letter, an up-to-date CV and names of two referees to Dr Jasna 
Martinovic  (j.martinovic at abdn.ac.uk).

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