AUTHOR=Chrobak Adrian Andrzej , Siuda-Krzywicka Katarzyna , Soltys Zbigniew , Bielak Sylwia , Nowaczek Dominik , Żyrkowska Aleksandra , Fafrowicz Magdalena , Marek Tadeusz , Pęcherzewska Ewa , Kużdżał Jan , Starowicz-Filip Anna , Gorostowicz Aleksandra , Dudek Dominika , Siwek Marcin TITLE=When practice does not make a perfect - paradoxical learning curve in schizophrenia and bipolar disorder revealed by different serial reaction time task variants JOURNAL=Frontiers in Psychiatry VOLUME=14 YEAR=2023 URL=https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2023.1238473 DOI=10.3389/fpsyt.2023.1238473 ISSN=1664-0640 ABSTRACT=Introduction

Our previous studies identified a paradoxical implicit motor learning curve in schizophrenia (SZ) and bipolar disorder (BD) patients. This study aimed to verify whether those previously observed deficits may be captured by a new version of the ambidextrous serial reaction time task (SRTT), prepared for use in the MRI.

Methods

This study involved 186 participants. A total of 97 participants (33 BD, 33 SZ, and 31 healthy controls, HCs) completed the original, unlimited time response variant of SRTT. A total of 90 individuals (30 BD, 30 SZ, and 30 HCs) underwent a newer, limited response time version of this procedure.

Results

There was no significant difference in terms of implicit motor learning indices between both limited and unlimited response time SRTT. Compared to HCs, SZ, and BD patients presented decreased indices of implicit motor learning. Both clinical groups showed a paradoxical learning pattern that differed significantly from the HCs. Moreover, in the SZ group, the pattern depended on the hand performing SRTT.

Discussion

The limited response time SRTT variant allowed us to replicate the findings of disrupted implicit motor learning in SZ and BD. The use of this paradigm in further neuroimaging studies may help to determine the neuronal underpinnings of this cognitive dysfunction in the abovementioned clinical groups.