The left column shows the
ERN and its combined EEG/MEG source localization. The right
column shows error-related dACC activation in the same
subjects and its hemodynamic time course. See Agam et al.
(2011): Multimodal functional imaging dissociates hemodynamic
and electrophysiological correlates of error processing. PNAS,
I am a cognitive neuroscientist interested in neural mechanisms of learning, memory and attention. I take a multimodal approach that combines different brain imaging methods such as EEG, MEG, fMRI and DTI. A major goal of my research is to understand the neural basis of error processing. Learning from errors is critical for adaptive behavior and, unfortunately, impaired in many neuropsychiatric disorders. My recent work has focused on two well-established neural markers of errors: The error-related negativity (ERN), an EEG potential seen after errors, and fMRI activation in the dorsal anterior cingulate cortex (dACC). Using multimodal neuroimaging, we have shown that contrary to the
widely-held assumption, these two signals likely index distinct underlying mechanisms, and that the generator of the ERN is in the dorsal posterior cingulate cortex (dPCC) and not dACC. We proposed a model in which dPCC detects
errors, giving rise to the ERN, whereas dACC activation reflects later processes related to error correction and to increased cognitive control following errors. If confirmed, this model could have profound implications
for theoretical models of error processing and, in turn, for our understanding of how humans adjust their behavior according to outcomes and why this ability might go awry in some populations.