Sequential neural changes during motor learning in schizophrenia

Abstract

Positron emission tomography (PET) was used to investigate differences in neural plasticity associated with learning a unique motor task in patients with schizophrenia and healthy volunteers. Working with a robotic manipulandum, subjects learned reaching movements in a force field. Visual cues were provided to guide the reaching movements. PET rCBF measures were acquired while participants learned the motor skill over successive runs. The groups did not differ in behavioral performance but did differ in their rCBF activity patterns. Healthy volunteers displayed blood flow increases in primary motor cortex and supplementary motor area with motor learning. The patients with schizophrenia displayed an increase in the primary visual cortex with motor learning. Changes in these regions were positively correlated with changes in each group's motor accuracy, respectively. This is the first study to employ a unique arm-reaching motor learning test to assess neural plasticity during multiple phases of motor learning in patients with schizophrenia. The patients may have an inability to rapidly tune motor cortical neural populations to a preferred direction. The visual system, however, appears to be highly compensated in schizophrenia and the inability to rapidly modulate the motor cortex may be substantially corrected by the schizophrenic group's visuomotor adaptations.

Abnormal visuomotor processing in schizophrenia

“…There is a large amount of evidence for disruption to this balance in schizophrenia caused by GABAergic abnormalities (Lewis, 2014; Rowland et al, 2008), including reductions in levels of GAD, the enzyme necessary for synthesis of GABA from glutamate, and in the mRNA that codes for GAD and for the GABA transporter and receptors (Shin et al, 2011). There are also reductions in the volume of pyramidal neurons (Sweet et al, 2004) and in the number of parvalbumin expressing GABAergic inhibitory interneurons, which are involved in the generation of gamma oscillations (Lewis, 2014).…”

Motor Symptoms and Schizophrenia

“…reduced pre-SMA gray matter volume [168] or aberrant signal changes in ACC, and premotor and motor cortices in schizophrenia [169,170]. In addition, a variety of studies applied simple hand motor tasks, demonstrating reduced activation of SMA and M1 in schizophrenia [161,171].…”

Neuroscience-Based Rehabilitation for Stroke Patients

“…In addition, therapists have greater options for patients to have the possibility of an autonomous social life. However, we must understand the limitations and individual differences in functional recovery [85,86]. Thus, the application of the same therapy may not cause the same level of recovery.…”