Cognitive training with action-related verbs induces neural plasticity in the action representation system as assessed by gray matter brain morphometry.

Embodied cognition theories of semantic memory still face the need for multiple sources of converging evidence in support of the involvement of sensory-motor systems in action-related knowledge. Previous studies showed that training manual actions improves semantic processing of verbs referring to the trained actions. The present work aimed to provide complementary evidence by measuring the brain plasticity effects of a cognitive training requiring sustained lexical-semantic processing of action-related verbs. We included two groups of participants, namely the Proximal Group (PG) and the Distal Group (DG), which underwent a 3-week training with verbs referring to actions involving the proximal and the distal upper limb musculature, respectively. Before and after training, we measured gray matter voxel brain morphometry based on T1 structural magnetic resonance imaging. By means of this 2 (Group: PG, DG) × 2 (Time: pre-, post-training) factorial design, we tested whether sustained cognitive experience with specific action-related verbs induces congruent brain plasticity modifications in target regions of interest pertaining to the action representation system. We found significant post- versus pre-training gray matter volume increases, specifically for PG in the left dorsal precentral gyrus, and for DG in the right cerebellar lobule VIIa. These preliminary results suggest that a cognitive training can induce structural plasticity modifications in brain regions specifically coding for the distal and proximal motor actions the trained verbs refer to.

Improving hand functional use in subjects with multiple sclerosis using a musical keyboard: a randomized controlled trial.

BACKGROUND AND PURPOSE: Playing an instrument implies neuroplasticity in different cerebral regions. This phenomenon has been described in subjects with stroke, suggesting that it could play a role in hand rehabilitation. The aim of this study is to analyse the effectiveness of playing a musical keyboard in improving hand function in subjects with multiple sclerosis. METHODS: Nineteen hospitalized subjects were randomized in two groups: nine played a turned-on musical keyboard by sequences of fingers movements (audio feedback present) and 10 performed the same exercises on a turned-off musical keyboard (audio feedback absent). Training duration was half an hour per day for 15 days. Primary outcome was the perceived hand functional use measured by ABILHAND Questionnaire. Secondary outcomes were hand dexterity, measured by Nine-Hole Peg Test, and hand strength, measured by Jamar and Pinch dynamometers. Two-way analysis of variance was used for data analysis. RESULTS: The interaction time × group was significant (p = 0.003) for ABILHAND Questionnaire in favour of experimental group (mean between-group difference 0.99 logit [IC95%: 0.44; 1.54]). The two groups showed a significant time effect for all outcomes except for Jamar measure. DISCUSSION: Playing a musical keyboard seems a valid method to train the functional use of hands in subjects with multiple sclerosis.

Action observation and motor imagery in performance of complex movements: evidence from EEG and kinematics analysis.

Motor imagery (MI) and action observation (AO) are considered effective cognitive tools for motor learning, but little work directly compared their cortical activation correlate in relation with subsequent performance. We compared AO and MI in promoting early learning of a complex four-limb, hand-foot coordination task, using electroencephalographic (EEG) and kinematic analysis. Thirty healthy subjects were randomly assigned into three groups to perform a training period in which AO watched a video of the task, MI had to imagine it, and Control (C) was involved in a distracting computation task. Subjects were then asked to actually perform the motor task with kinematic measurement of error time with respect to the correct motor performance. EEG was recorded during baseline, training and task execution, with task-related power (TRPow) calculation for sensorimotor (alpha and beta) rhythms reactive with respect to rest. During training, the AO group had a stronger alpha desynchronization than the MI and C over frontocentral and bilateral parietal areas. However, during task execution, AO group had greater beta synchronization over bilateral parietal regions than MI and C groups. This beta synchrony furthermore demonstrated the strongest association with kinematic errors, which was also significantly lower in AO than in MI. These data suggest that sensorimotor activation elicited by action observation enhanced motor learning according to motor performance, corresponding to a more efficient activation of cortical resources during task execution. Action observation may be more effective than motor imagery in promoting early learning of a new complex coordination task.