Colloquium Cognitive Systems

The number sense: Non-symbolic number cognition in humans.

Prof. em. David Burr (University of Florence)

Abstract: I will present evidence, largely from our own laboratory, investigating systems that process non-symbolic number in humans. For spatial arrays, three separate mechanisms operate, depending on numerosity and density. The number sense also acts on temporal sequences of visual, auditory and tactile stimuli, as well as on actions, pointing to a truly generalized number sense. Much evidence comes from psychophysical adaptation studies, but this is well supported by multi-disciplinary studies using psychophysics, EEG, pupillometry and eye-movements. The work has not been entirely uncontroversial, with claims that these studies reflect adaptation to visual texture, rather than numerosity, and a more recent challenge to the concept of adaptation itself. These controversies are discussed in the light of new and existing evidence. 

About:
David Burr is emeritus professor of psychology at the University of Florence, where he has worked for the last 30 years. He graduated in psychology from the University of Western Australia and received a PhD in psychology and physiology from Cambridge University. He has worked on various aspects of perception, notably visual motion, vision during eye movements, multi-sensory perception, generative vision and the perception of numerosity.