The combination of brain stimulation and brain imaging technologies in the cognitive neurosciences: Problematizing the "Convergence Hypothesis"

It is one of the central goals of the cognitive neurosciences to establish causal relationships between brain states and all kinds of cognitive functions (e.g., visual attention, color perception, facial recognition). Brain imaging technologies like functional magnetic resonance imaging (fMRI) play an important role in this regard as they allow researchers to visualize brain activity but are also criticized for embodying a correlational logic. It has been proposed that the use of non-invasive brain stimulation (NIBS) technologies in combination with fMRI or electroencephalography (EEG) does enable direct epistemic access to causal relationships. The goal of this chapter is to critically evaluate if this claim is justified. On the basis of a case-study, I suggest that rather than reflecting how researchers combine brain stimulation and brain imaging technologies in practice, this claim should be understood as an example of a convergence hypothesis that serves as a discursive ideal that binds the different approaches to studying cognition together.