Experimental Psychology Seminar - Rick Adams

Abstract: Over recent decades, the theory that there is an imbalance between excitation and inhibition in cortical circuits in people with psychosis has become increasingly popular. The exact nature of this imbalance is still unclear, however. One issue is that it is conceptually ill-defined. Another reason is that it is hard to measure in vivo. We have found, using rodent recordings of simultaneous LFP and cell spiking data, that most ‘traditional’ measures of E/I imbalance (e.g., gamma power, 1/f power spectrum slope, etc) are not reliable. We have used computational modelling of Me/EEG (and fMRI) data to show that there is hypofunction of excitatory neurone in both established schizophrenia and in the prodromal period (NAPLS2 dataset), although this pathology may not be present in all subgroups of psychosis (analysing ‘biotypes’ from the BSNIP consortium dataset). Symptoms such as hallucinations, however, seem to relate to disinhibition (the opposite effect). I discuss why this might be, and what this might mean for treatments.