Randy McIntosh

Department of Psychology, Rotman Research Institute

University of Toronto

Network Dynamics and Brain Noise: The Formula for Cognition

In relating brain signals to mental processes, the assumption is that engaging such processes will activate key regions of the brain. Much like a computer, the region is 'on' when the process it subserves is required and 'off' when it is not. Some critical features of brain organization suggest we need to rethink this mapping. First, the network architecture enables the pattern of information flow to change without appreciable activity changes. Second, as a nonlinear system, the brain relies on both signal and noise to ensure optimal function. Indeed, the noise may be vital for enabling a full exploration of the cognitive landscape. Considering these two features defines new principles of brain-behaviour linkages, which may also impact our conceptualization of the cognitive constructs.


Caplan JB, Luks TL, Simpson GV, Glaholt M, McIntosh AR (2006) Parallel networks operating across attentional deployment and motion processing: a multi-seed partial least squares fMRI study. Neuroimage 29:1192-202


Protzner AB, McIntosh AR (2007) The interplay of stimulus modality and response latency in neural network organization for simple working memory tasks. J Neurosci 27:3187-97