‘Top-down prediction’ enables humans to not be surprised by familiar events and items that are constantly presented to us. It is also prominent theme in cognitive neuroscience, yet its exact neural mechanisms remain elusive. Using transcranial magnetic stimulation, I intend to reveal if the prefrontal cortex can implement such mechanisms by modulating activity in visual processing areas, and whether this process determines what humans expect and perceive. In particular, I hope to reveal whether these mechanisms operate in a Bayesian-like fashion.
2013 – present. PS1015: Practical Psychology: Postgraduate tutor. I provide tutorials to first year Psychology undergraduates on writing practical reports and statistics, as well as marking assignments.
Full list of publications
Research topics and related papers
The ‘Bayesian Brain’
When attempting to incorporate Bayesian mechanisms in the human brain, it is argued that two distinct cell populations exist: representation units and error units. Error units propagate prediction error - a discrepancy between what is expected and what actually happens, forwards, whereas representation units encode causal relationships within the environment. These causal relationships are altered, and projected backwards following prediction error in order to reduce discrepancy between expectation and the physical events in the environment. In doing so, the brain would successfully match incoming sensory inputs with top-down predictions.
Clark, A. (2013). Whatever next? Predictive Brains, Situated Agents, and the Future of Cognitive Science. Behavioural and Brain Sciences, 36, 181 – 204.
The Prefrontal Cortex
Activation of the dorsolateral part of the prefrontal cortex (the DLPFC) is almost ubiquitous in some studies of cognitive control and perceptual decision-making. I hope to identify whether this region exerts top-down control on lower-level sensory processing in order to test a ‘top-down prediction’, or whether it simply computes ‘decision variables’ based on its inputs from lower-level sensory regions.
Heekeren, H. R., Marret, S., & Underleider, L. G. (2008). The neural systems that mediate perceptual decision-making. Nature Reviews Neuroscience, 9, 467 – 479.
Medical Research Council Doctoral Training Grant & PhD studentship from the School of Psychology, Cardiff University (50:50).
2009 – 2013: 2:1: BSc Psychology with Professional Placement (Hons.), Cardiff University, UK.
October 2011 – June 2012: Research Collaborator with Professor Jeff Brunstrom, Nutrition and Behaviour Unit, School of Experimental Psychology, University of Bristol, UK.
July 2012 – September 2012: Cardiff University Undergraduate Research Opportunities Scheme with Professor Lawrence Wilkinson, School of Psychology & School of Medicine, Cardiff University, UK.