Two males participants with non-fluent aphasia took part in this study. The protocol was approved by Macquarie University and the participants and their primary caregivers gave informed consent. The Western Aphasia Battery (WAB) was used to assess both participants' speech and language function. Participant GOE was 65 years old and 18 months post left fronto-temporal stroke (see Figure 1 for structural image). The WAB assessment classified GOE as having moderate non-fluent Broca's aphasia. GOE also presented with moderate right hemiparesis. Participant AMC was 49 years old and 20 months post left fronto-temporal stroke (see Figure 1). AMC had a titanium mesh plate inserted in his temporal region following the stroke. The WAB assessment classified AMC as having moderate-to-severe non-fluent Broca's aphasia with difficulties in auditory-verbal comprehension. AMC also presented with moderate right hemiparesis and moderate right visual neglect. GOE had knowledge of MIT through his group therapy sessions and AMC had been undergoing MIT for a year prior to participating in the study. The participants were both asked to halt all speech and language therapy for the duration of this study. GOE and AMC were right-handed prior to the stroke and both were native speakers of English.
Language function was first assessed 1 week prior to commencing the study (baseline 1) and immediately before the first treatment session was conducted (baseline 2). After the study commenced, language testing was conducted after each treatment session and 1 week following the completion of the study. The language assessment tasks included the automatic production of verbal sequences (i.e., counting from 1 to 21, reciting the days of the week, reciting the months of the year, reciting the alphabet, and listing as many animals as possible within 1 min) and a phrase repetition task. There were 51 phrases in the phrase repetition task (see Table A1 for phrases). These phrases had no more than 4 syllables (e.g., "I love you," "Goodbye," "Pass the salt," "Hi"). The verbal output for both the phrase repetition and verbal fluency tasks was recorded and later transcribed.
The phrases used during the repetition task were divided into 3 lists of 17 phrases that were matched for utterance length, syntactic structure, and frequency/imageability. Each of these lists was randomly assigned to one of 3 conditions for each participant: rTMS-treated, sham-rTMS treated, and untreated. The rTMS-treated list was used by the clinician to provide MIT following rTMS, whilst the sham-rTMS treated list was used by the clinician to provide MIT following sham-rTMS. The untreated list was not practiced during MIT. The phrases practiced during MIT were, therefore, a subset of the phrases presented in the repetition task for language assessment.
Anatomical and functional images were collected at Macquarie University Hospital, Sydney, using a 3 Tesla Siemens MagnetonVerio scanner with a 32-channel head coil. First, an alignment scan was performed for head position adjustments so that the AC-PC reference line was as close as possible to the vertical axis of the scanner. Second, a T1-weighted anatomical image was obtained using the following parameters: TR/TE = 2000 ms/900 ms, FOV = 250 mm, flip angle = 9 degrees and voxel size = 1 mm3. Third, T2-weighted functional images were acquired using the following parameters: TR/TE = 3000 ms/32 ms, FOV = 240 mm, flip angle = 80 degrees, gap = 0.5, number of slices = 78 and voxel size = 2.5 mm2. The order of acquisition was ascending, interleaved. All sessions were started with 2 dummy scans. Brain activation was measured by adopting the blood oxygenation level-dependent (BOLD) effect with optimal contrast (Ogawa et al.,). The collected images were preprocessed using the Statistical Parametric Mapping software (SPM8; http://www.fil.ion.ucl.ac.uk/spm). Corrections were made for the time delay in acquisition of the different slices, and the images were realigned onto the mean image for head-motion correction and spatially normalized into a standard stereotaxic space with voxel size of 3 mm3 using the Montreal Neurological Institute (MNI) template. A spatial smoothing filter was employed for each volume by using an isotropic Gaussian kernel (FWHM = 6 mm).
Participants underwent an fMRI session one week prior to the start of the study and 1 week following the end of the study. The scans were used to localize Broca's homolog for targeted stimulation in the rTMS portion of the treatment and to track any functional cortical reorganization occurring during the study. Participants were asked to complete two tasks in the scanner: an automatic speech task and a naming/reading task. All stimuli were projected onto a screen and viewed through a mirror mounted on the head coil. Verbal responses were recorded using a FOMR-III MRI compatible microphone (Optoacoustics Ltd) attached to the head coil in the scanner. The overt responses were also transcribed at the time of scanning. Stimulus presentation and recording of the verbal responses was controlled by Presentation (Neurobehavioral Systems Inc). The participants were trained on each task prior to the fMRI sessions. A block-design was used to present the tasks in the scanner because it permits an examination of overt speech in participants with aphasia despite the false-starts and hesitations found in such participants (Martin et al.,). Such designs also have excellent statistical power (Aguirre et al.,).
In the automatic speech task, participants were required to count from 1 to 21 and recite the days of the week, months of the year and the alphabet. When completing this task (see Figure 2A), participants saw a category label appear on the screen for 3 s (e.g., NUMBERS) followed by three examples of the category sequence (e.g., 1, 2, 3) that appeared for 1.5 s each. Participants were given 20 s to recite (in correct order) each item in the category. The order of the categories was randomized. There were two runs of this task. Each run consisted of 4 trials that were separated by a 20 s fixation.
In the naming/reading task, participants were asked to name a picture or read a word. There were 10 items that appeared as both pictures and words. The items were selected from The International Picture Naming Project database (http://crl.ucsd.edu/experiments/ipnp/; Szekely et al.,) based on length (one syllable), frequency (high) and percent of dominant response (100% of participants produced the dominant name). When completing this task (see Figure 2B), participants saw an instruction label appear on the screen for 3 s (e.g., PICTURE or WORD) followed by 5 items (e.g., king, bat, leaf, map, egg) that each appeared for 1.5 s. Participants were given 4 s to name each picture or read each word. The pictures appeared in a separate block to the words. Block order was counterbalanced. Each block was separated by a 20 s fixation. There were four blocks in each run. Participants completed two runs.
Both GOE and AMC participated in two phases of the TMS protocol: rTMS and sham-TMS. The order of the two phases was counterbalanced across participants and was separated by a 1-week break. GOE first went through the rTMS phase, whereas AMC first went through the sham-TMS phase. Each phase consisted of three treatment sessions that were separated by 3 days (see Table 1 for treatment schedule).
Surface electromyography (EMG) electrodes were placed over the first dorsal interosseous (FDI) of the left hand. Single-pulse TMS was performed to establish active motor threshold (AMT) using a Magstim Rapid stimulator. Stimulation was conducted using a 70 mm figure-8 coil. The coil was placed with the handle pointing occipitally at an angle of approximately 45  to the mid-sagittal line over the primary motor cortex in the right hemisphere at the optimal site for obtaining an MEP in the FDI. After AMT was established, intermittent theta-burst stimulation (iTBS), a form of high frequency rTMS, was performed using Magstim Rapid2 with intensity set at 80% of AMT. The iTBS consisted of bursts of 3 pulses at 50 Hz given every 200 ms in 2 s trains, repeated every 10 s over 200 s for a total of 600 pulses. Coil position for iTBS was determined by examining the T2-weighted MRI scans of each participant. The target site for stimulation was selected by identifying a peak of frontal activity (separately for each participant) within the anatomical territory of pars triangularis (GOE) or pars opercularis (AMC) in the right inferior frontal gyrus. This peak voxel activity was elicited by the automatic speech task. The surface distance measurements method was used to identify the location of the selected region on the head of each participant (Weiduschat et al.,). The same iTBS procedure was used in the sham-rTMS phase, but a sham TMS coil was substituted for the real TMS coil. The sham coil mimics a real TMS coil by producing the same clicking sound, but, unlike a real TMS coil, the sham coil does not cause any change in neural activity. Each rTMS session lasted 5-min and was followed by a 5-min break. Participants completed a 40-min MIT session after the break, which was administered by a clinician. Participants and the clinician were blind to stimulation condition. The MIT session followed the format of a typical MIT protocol with phrases trained using a hierarchical series of steps (Norton et al.,). Each phrase was intoned on the minor third interval with regular syllable durations of 1 s.