Adrian Andrzej Chrobak1, Katarzyna Siuda-Krzywicka2, Grzegorz Przemysław Siwek1, Aleksandra Arciszewska3, Marcin Siwek3, Anna Starowicz-Filip4, Dominika Dudek3. 1. Faculty of Medicine, Jagiellonian University Medical College, Poland. 2. Faculty of Medicine, Jagiellonian University Medical College, Poland; Department of Psychophysiology, Faculty of Psychology, Jagiellonian University, Poland. Electronic address: siuda.krzywicka@gmail.com. 3. Department of Affective Disorders, Chair of Psychiatry, Jagiellonian University Medical College, Poland. 4. Medical Psychology Department, Jagiellonian University Medical College, Poland.
Abstract
OBJECTIVES: A growing number of publications describe cerebellar abnormalities in patients with bipolar disorder (BD). The aim of the following paper was to examine the functional aspects of that issue by focusing on implicit learning - a cognitive function with significant cerebellar underpinnings. METHODS: 27 patients with BD and 26 healthy controls (HC), matched for age and sex took part in the study. Implicit motor learning was assessed by the serial reaction time task (SRTT), in which participants were unconsciously learning a sequence of motor reactions. The indicators of procedural learning were the decrease of reaction time (RT) across the repetition of the sequence and the rebound of RT when the sequence changed into a random set of stimuli. RESULTS: BD patients did not present any indicators of the implicit learning, their RT increased across repetitions of the sequence and it decreased when the sequence changed to random. Contrary, in the control group RT decreased across the sequence repetitions and increased when the stimuli begun to appear randomly. LIMITATIONS: A low subject count and a non-drug naïve patients group, medicated with atypical antipsychotic and mood stabilizers, are the most significant limitations of this study. CONCLUSIONS: BD patients did not acquire procedural knowledge while performing the task, whereas HC did. To our knowledge this is the first study that shows the impairment of implicit motor learning in patients with BD. This indicates the possible cerebellar dysfunction in this disease and may provide a new neuropsychiatric approach to bipolar disorder.
OBJECTIVES: A growing number of publications describe cerebellar abnormalities in patients with bipolar disorder (BD). The aim of the following paper was to examine the functional aspects of that issue by focusing on implicit learning - a cognitive function with significant cerebellar underpinnings. METHODS: 27 patients with BD and 26 healthy controls (HC), matched for age and sex took part in the study. Implicit motor learning was assessed by the serial reaction time task (SRTT), in which participants were unconsciously learning a sequence of motor reactions. The indicators of procedural learning were the decrease of reaction time (RT) across the repetition of the sequence and the rebound of RT when the sequence changed into a random set of stimuli. RESULTS: BD patients did not present any indicators of the implicit learning, their RT increased across repetitions of the sequence and it decreased when the sequence changed to random. Contrary, in the control group RT decreased across the sequence repetitions and increased when the stimuli begun to appear randomly. LIMITATIONS: A low subject count and a non-drug naïve patients group, medicated with atypical antipsychotic and mood stabilizers, are the most significant limitations of this study. CONCLUSIONS: BD patients did not acquire procedural knowledge while performing the task, whereas HC did. To our knowledge this is the first study that shows the impairment of implicit motor learning in patients with BD. This indicates the possible cerebellar dysfunction in this disease and may provide a new neuropsychiatric approach to bipolar disorder.
Authors: Casey P Johnson; Gary E Christensen; Jess G Fiedorowicz; Merry Mani; Joseph J Shaffer; Vincent A Magnotta; John A Wemmie Journal: Bipolar Disord Date: 2018-01-07 Impact factor: 6.744
Authors: Allan Peter Davis; Thomas C Wiegers; Benjamin L King; Jolene Wiegers; Cynthia J Grondin; Daniela Sciaky; Robin J Johnson; Carolyn J Mattingly Journal: PLoS One Date: 2016-05-12 Impact factor: 3.240