Contributions of the Left and the Right Hemispheres on Language-Induced Grip Force Modulation of the Left Hand in Unimanual Tasks.

Background andObjectives: Language-induced grip force modulation (LGFM) can be used to better understand the link between language and motor functions as an expression of embodied language. However, the contribution of each brain hemisphere to LGFM is still unclear. Using six different action verbs as stimuli, this study evaluated the grip force modulation of the left hand in a unimanual task to characterize the left and right hemispheres' contributions. Materials and Methods: Left-hand LGFM of 20 healthy and consistently right-handed subjects was evaluated using the verbs "to write", "to hold", "to pull" (left-lateralized central processing actions), "to draw", "to tie", and "to drive" (bihemispheric central processing actions) as linguistic stimuli. The time between the word onset and the first interval of statistical significance regarding the baseline (here as reaction time, RT) was also measured. Results: The six verbs produced LGFM. The modulation intensity was similar for the six verbs, but the RT was variable. The verbs "to draw", "to tie", and "to drive", whose central processing of the described action is bihemispheric, showed a longer RT compared to the other verbs. Conclusions: The possibility of a given manual action being performed by the left hand in consistent right-handers does not interfere with the occurrence of LGFM when the descriptor verb of this action is used as a linguistic stimulus, even if the possibility is remote. Therefore, LGFM seems to mainly rely on the left hemisphere, while a greater activation of the right hemisphere in action processing appears to slow the increase in LGFM intensity.

Balance as an Additional Effect of Strength and Flexibility Aquatic Training in Sedentary Lifestyle Elderly Women.

OBJECTIVE: To evaluate the additional effects of on balance an aquatic muscle strengthening and flexibility training program in healthy sedentary lifestyle elderly women. METHOD: This controlled clinical trial included 56 healthy sedentary women, aged from 65 to 70 years, divided into two groups. The aquatic group (AG) underwent aquatic training (45 minutes/session, 32 sessions), and the control group (CG) received no intervention. Data were collected pre- and post-intervention, during a one-week period. Lower limb muscle strength was measured by a force sensor (myometer). Flexibility was measured by biophotogrammetry. Functional balance was evaluated by the Performance Oriented Mobility Assessment (POMA) and the Berg Balance Scale (BBS). RESULTS: Muscle strength, flexibility, and balance improved in AG (p < 0.001), but not in CG. CONCLUSION: The aquatic exercises program, which was originally developed to promote muscle strength and flexibility, also improved functional balance. Aquatic training is an option for physical health promotion for sedentary lifestyle elderly women.

Manual action verbs modulate the grip force of each hand in unimanual or symmetrical bimanual tasks.

Manual action verbs modulate the right-hand grip force in right-handed subjects. However, to our knowledge, no studies demonstrate the ability to accomplish this modulation during bimanual tasks nor describe their effect on left-hand behavior in unimanual and bimanual tasks. Using load cells and word playlists, we evaluated the occurrence of grip force modulation by manual action verbs in unimanual and symmetrical bimanual tasks across the three auditory processing phases. We found a significant grip force increase for all conditions compared to baseline, indicating the occurrence of modulation. When compared to each other, the grip force variation from baseline for the three phases of both hands in the symmetrical bimanual task was not different from the right-hand in the unimanual task. The left-hand grip force showed a lower amplitude for auditory phases 1 and 2 when compared to the other conditions. The right-hand grip force modulation became significant from baseline at 220 ms after the word onset in the unimanual task. This moment occurred earlier for both hands in bimanual task (160 ms for the right-hand and 180 for the left-hand). It occurred later for the left-hand in unimanual task (320 ms). We discuss the hypothesis that Broca's area and Broca's homologue area likely control the left-hand modulation in a unilateral or a bilateral fashion. These results provide new evidence for understanding the linguistic function processing in both hemispheres.

Effects of Excitatory Repetitive Transcranial Magnetic Stimulation of the P3 Point in Chronic Stroke Patients-Case Reports.

OBJECTIVE: To evaluate the effects of excitatory repetitive transcranial magnetic stimulation (rTMS) of the international 10⁻20 system P3 point (intraparietal sulcus region) in chronic patients with a frontal lesion and parietal sparing due to stroke on the impaired upper (UL) and lower limb (LL) as measured by the Fugl-Meyer Assessment (FMA). METHODS: Three patients (C1: 49.83/2.75, C2: 53.17/3.83, C3: 63.33/3.08-years-old at stroke/years post-stroke, respectively) received two weeks (five days/week) of rTMS at 10 Hz of P3. A patient was treated in similar conditions with a sham coil (S1: 56.58/4.33). Patients were evaluated before, after, and two months post-treatment (A1, A2, and A3, respectively). RESULTS: For LL, the scores of the motor function subsection of C1 and C3 as well as the sensory function of C2 increased by A2 and remained by A3. For UL, the score of the motor function of C2 and C3 also increased, but the score of C3 decreased by A3. The score of the range of motion subsection of C3 increased by the two follow-up evaluations. CONCLUSION: This study suggests excitatory rTMS over P3 may be of use for some chronic stroke patients, but these findings need to be verified in a future clinical trial.