Professor Thoma's research interests are mainly in visual cognition, attention, and judgment and decision making.
A main line of studies concerns decision making and risk perception. One project investigates heuristics and reflective thinking in experts, such as professional traders or pension trustees. Here the results show that traders, but not bankers, show higher cognitive reflection performance, but no different risk-taking. Work with pension trustees (jointly with Professor Peter Ayton, Leeds University Business School) shows that trustees show considerable bias in decision-making.
Another line of inquiry looks at influences on consumer choice and preference, such as spatial location of products or the familiarity of brands. Items presented centrally are preferred over other positions in certain conditions (with Dr Paul Rodway, Chester). In other research, Professor Thoma showed that the familiarity of products or objects is a major determinant of preferential choice even in the context of negative information (such as consumer star ratings).
Professor Thoma's work also used behavioural and neuroimaging techniques to investigate the role of attention in object recognition (in collaboration with Prof. John Hummel, University of Illinois; Alan Richardson-Klavehn, Magdeburg; John-Dylan Haynes & Philipp Sterzer, Humboldt University Berlin) and face perception (with Jan de Fockert, Goldsmiths).
In particular, Volker's work found that spatially unattended objects can be processed without attention, in particular, if objects are depicted in familiar views. He also showed that the capacity for face perception is limited only by the number of other faces (not other stimuli) present in a scene. Finally, work using non-invasive brain stimulation shows that transcranial Alternating Current Stimulation (tACS) of the occipito-temporal areas can improve object and face perception (with Dr Davide Rivolta, University of Bari; and Prof. Michael Nitsche, TU Dortmund).
Professor Thoma also investigates cognitive processes in decision-making using non-invasive brain stimulation. One project showed that tDCS to the right dorsolateral pre-frontal cortex improves reflective decision-making. A related line of research shows that tDCS modulates risk-taking in gambling-like tasks.
Volker is a committee member and honorary treasurer of the British Association of Cognitive Neuroscience (BACN). He serves as the coordinator of UEL's UoA 4 (REF 2021) and committee member of the School's ethics committee. He is Review Editor for Frontiers in Psychology and Frontiers in Neuroimaging and Stimulation.