NEURAL CIRCUITS FOR PERCEPTION AND DECISION-MAKING IN PRIMATES

My research group seeks to explain and alter perceptual decision-making from the level of single brain cells through to mental states. With this work, we aim to understand the neuronal code underlying conscious processes. One fundamental problem is that neuronal activity sometimes represents processes of which we are aware and sometimes codes for information to which we have no access (Krug et al. J. Neurophysiology 2004). Using electrical microstimulation of neurons in rhesus monkeys, we can show how the activity of neurons in visual cortex causally contributes to the perceptual appearance of visual objects. For instance, we have identified a strong cognitive signal in the activity of single neurons in extrastriate visual area V5/MT that shapes perceptual decisions about 3D-motion figures (Dodd et al. J. Neuroscience 2001; Krug et al. Current Biology 2013). This brain area in rhesus monkeys has a structural and functional homologue in humans (Large et al. Cerebral Cortex 2016). We have shown that contextual effects, like expected reward and social influence, interact with sensory signals in the brain and potentially affect visual perception (Cicmil el al. elife 2015; Large et al. PNAS 2019). This has profound implications for our understanding of decision-making in healthy individuals and in individuals with a psychiatric disorder.

In recent years, the closest experimental links between brain signals and perception have been established in awake primates between the activity of single neurons and perceptual decisions. Our current work builds on this powerful research platform my research group has built and extends it to increasingly naturalistic settings of perception and action. Specifically, our current research focuses on the continuity of perceptual activities. Rather than treating perception and behaviour as a sequence of discrete, finite episodes, each culminating in a decision, the new experimental paradigms will study of how the brain engages in active, continuous monitoring of the dynamically changing incoming flow of information. Linking the activity of brain cells in non-human primates with human MRI through common perceptual tasks and computational models, we investigate altered decision-making and perception in patients with psychological disorders, like autism and bipolar disorder.
My work has been funded by the DFG, the Wellcome Trust, the Royal Society, the BBSRC, and the Volkswagen Foundation.