Mental rotation task in bipolar disorder. / Test rotacji mentalnych w chorobie afektywnej dwubiegunowej.

OBJECTIVES: Bipolar disorder (BD) significantly affects level of cognitive and motor functioning. Studies on cognitive function in BD shows i.a. deficits in visuospatial processing and visuospatial memory. However, studies have not used Mental Rotation Task to evaluate these functions so far. Our aim is to introduce this method to assess abovementioned deficits in euthymic BD patients. METHODS: 31 euthymic BD patients and 27 healthy volunteers matched for age and years of education were recruited. All participants performed digital version of Mental Rotation Task. In this task, participants were asked to compare two figures rotated against each other and declare its similarity or difference indicating whether the figures are identical or whether they constitute their own mirror image. RESULTS: The test revealed significantly longer reaction times in the group of BD patients when images were rotated by - 90, - 45, 45, 90 degrees, or not rotated at all. There was no significant difference in condition of - 135, 135 or 180 degrees. The accuracy rate was significantly lower in the patient group than in the control group for the entire test and in each condition. The correlation between the average response time and the accuracy rate turned out to be insignificant. CONCLUSIONS: Our results are consistent with studies presenting visuospatial deficits in bipolar disorder. In this study we show for the first time that mental rotation deficits are present in euthymic state of BD patients.

Disrupted implicit motor sequence learning in schizophrenia and bipolar disorder revealed with ambidextrous Serial Reaction Time Task.

BACKGROUND: Impairment of implicit motor sequence learning was shown in schizophrenia (SZ) and, most recently, in bipolar disorder (BD), and was connected to cerebellar abnormalities. The goal of this study was to compare implicit motor sequence learning in BD and SZ. METHODS: We examined 33 patients with BD, 33 patients with SZ and 31 healthy controls with a use of ambidextrous Serial Reaction Time Task (SRTT), which allows exploring asymmetries in performance depending on the hand used. RESULTS: BD and SZ patients presented impaired implicit motor sequence learning, although the pattern of their impairments was different. While BD patients showed no signs of implicit motor sequence learning for both hands, the SZ group presented some features of motor learning when performing with the right, but not with the left hand. CONCLUSIONS: To our best knowledge this is the first study comparing implicit motor sequence learning in BD and SZ. We show that both diseases share impairments in this domain, however in the case of SZ this impairment differs dependently on the hand performing SRTT. We propose that implicit motor sequence learning impairments constitute an overlapping symptom in BD and SZ and suggest further neuroimaging studies to verify cerebellar underpinnings as its cause.