How much information can be extracted from the BOLD signal?
Institute of Cognitive Neuroscience, UCL , UK
The biological applications of BOLD imaging typically rely on ascribing a functional role to a particular area on the basis of elevation in the BOLD signal associated with a change in mental state. Understanding what kind of neural activity BOLD indicates will also depend on an appreciation of this relationship. Here I will briefly reprise earlier work suggesting a close correspondence between changes in the BOLD signal in human visual cortex, and those observed in single units in monkey cortex. I will then present more recent findings that suggest that classic analytic approaches to the BOLD signal rather underestimate the amount of information it carries about mental states and therefore the underlying types of neural activity that evoke it.