## 3 Materials and Methods  
### Case Description  
This study is concerned with the case of a 50-year-old right-handed female who suffered from conduction aphasia after a left ischemic stroke involving white matter of the fronto-parietal lobe and left temporo-occipital areas. She had surgery to replace the aortic valve with a mechanical prosthesis one week before the stroke. She arrived at the rehabilitative unit of IRCCS Centro Neurolesi Bonino-Pulejo (Messina) one month after the stroke. Neurological, neuropsychological and logopedic assessments were carried out. The patient was attentive, cooperative, and time- and space-oriented. Neurological examination showed a right facio-bracho-crural hemiparesis. The patient followed a drug therapy of oral anticoagulants and antihypertensive. The rehabilitative treatment combined different types of training. In particular: physiotherapeutic training, including balance and gait exercises, Bobath and task-oriented exercises, robotic rehabilitation; neuropsychological training, which provided psychological support to improve the patient's emotional-behavioral control, strategies to improve patient motivation during rehabilitation, problem-solving strategies; logopedic training, which consisted of sentence repetition therapy, stimulation-facilitation therapy, and group communication treatment. The rehabilitation was carried out every day for a session of 60 min for each type of treatment. The tasks performed during training were different from those used for the assessment before and after the treatment. EEG data were acquired by means of the 256-channel HydroCel Geodesic Sensor Net, belonging to the Electrical Geodesics (EGI) EEG system (Figure 1). The electrode impedance was kept <50 k\(\Omega\), on the basis of EGI guidelines. The reference electrode was Cz, placed in the middle of the scalp. The sampling rate was 250 Hz. The EEG data were band-pass filtered between 1 and 40 Hz by means of EGI's Net Station EEG software and cleaned from artifacts by visual inspection. The signals from sensors placed on the face and the neck were affected by muscle artifacts, so only 173 electrodes from the starting 256 were considered. In addition, the LORETA-KEY software used for our study required only cephalic (no face, no neck) electrodes to be considered. Finally, the EEG recordings were average referenced and segmented into artifact-free non-overlapping epochs of 1 s. HD-EEG were acquired at baseline (T0) and after a rehabilitative treatment of two months (T1). HD-EEG were recorded while the patient was performing specific language tasks displayed on a computer screen in order to set the time and use a standard method without the influence of external stimuli. The task paradigm was created by means of E-prime 3.0, a leading software for designing, collecting and analyzing data for behavioral research. E-Prime provides a complete environment for building experiments with text, images, sound, and videos through an easy-to-use graphical interface. E-prime provides a millisecond accuracy for subject responses and sound onset times. The EEG recordings were carried out during time blocks consisting of three task periods with alternating rest periods. Specifically, the experimental setup included the following tasks: naming, repetition, and reading. During the naming task, the subject had to mention 24 images, each displayed on the computer screen for 3 s. The images were divided into two groups of 12, alternating with 10 s of rest. The total duration of the naming task is 72 s. The repetition task consisted of repeating 16 words of 5 s, played by speakers. The words were divided into two groups of 8, alternating with 10 s of rest. The total duration of the repetition task was 80 s. The reading task consisted of reading 16 words of 3 s, displayed on the computer screen. The words were divided into two groups of 8, alternating with 10 s of rest. The total duration of the naming task was 48 s. Each task at T0 and the corresponding one at T1 have the same duration.