MMN in  Psychosis

Duration MMN in emerging psychosis

Auditory Mismatch Negativity (MMN) is an event related potential that is elicited by unexpected irregularities in a constant auditory stream, e.g. during an oddball paradigm, where repetitive standard sounds are interspersed with infrequent randomly presented deviants.

Reductions in MMN-responses are well established in chronic schizophrenia. However, evidence for MMN impairments in Clinical High Risk for Psychosis (CHR-P) and First Episode Psychosis (FEP) patients groups is less consistent. 

In this work, we examined recorded neuromagnetic responses to duration deviants to establish whether MMN responses are impaired during early stage psychosis. 

Contrary to our hypothesis, MMN-responses were intact, suggesting that MMN may not constitute a biomarker for early detection and diagnosis of psychosis. 

Here is my poster summarising this work

Relevant Publication

• Pradeep D, Tineke Grent-‘t-Jong, Ruchika Gajwani, Joachim Gross, Andrew I Gumley,  Rajeev Krishnadas, Stephen M Lawrie, Matthias Schwannauer, Frauke Schultze-Lutter, Peter J Uhlhaas, "Intact Mismatch Negativity Responses in Clinical High-Risk for Psychosis and First-Episode Psychosis: Evidence from Source-Reconstructed Event-Related Fields and Time-Frequency Data", Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, vol. 9 (1), pp.121-131, 2024 (pdf)  https://www.biologicalpsychiatrycnni.org/article/S2451-9022(23)00244-6/fulltext

Frequency MMN in early Schizophrenia

We investigated frequency deviant Mismatch Negativity (f-MMN) responses in the auditory cortex of Early Schizophrenia (ESZ) patients and matched healthy controls using high-field 7T fMRI. We aimed to assess differences in cortical laminar-specific microcircuits active during f-MMN. We also manipulated participant’s attention either towards (irrelevant auditory feature) or away (concurrent visual stimulation) from the auditory stimulation.