| Authors | Griffis JC, Nenert R, Allendorfer JB, Szaflarski JP |
| Title | Linking left hemispheric tissue preservation to fMRI language task activation in chronic stroke patients |
| Reference | Cortex 2017; 96: 1-18 |
| PMID | 28961522 |
| DOI | 10.1016/j.cortex.2017.08.031 |
| Language | US English |
| Inclusion criteria | — |
| Number of individuals with aphasia | 43 |
| Number of control participants | 43 |
| Were any of the participants included in any previous studies? | Yes (same dataset as Griffis et al. (2017) Hum Brain Mapp) |
| Is age reported for patients and controls, and matched? | Yes (mean 53 ± 15 years, range 23-90 years) |
| Is sex reported for patients and controls, and matched? | Yes (males: 25; females: 18) |
| Is handedness reported for patients and controls, and matched? | Yes (right: 41; left: 2) |
| Is time post stroke onset reported and appropriate to the study design? | Yes (range 1-14 years) |
| To what extent is the nature of aphasia characterized? | Not at all |
| Language evaluation | BNT, semantic fluency, phonemic fluency |
| Aphasia severity | Not stated |
| Aphasia type | Not stated |
| First stroke only? | Yes |
| Stroke type | Not stated |
| To what extent is the lesion distribution characterized? | Lesion overlay |
| Lesion extent | Mean 105.2 ± 76.3 cc |
| Lesion location | L |
| Participants notes | — |
| Modality | fMRI |
| Is the study cross-sectional or longitudinal? | Cross-sectional |
| If longitudinal, at what time point(s) were imaging data acquired? | — |
| If longitudinal, was there any intervention between the time points? | — |
| Is the scanner described? | No (Siemens Allegra 3 Tesla or Philips 3 Tesla; model not stated) |
| Is the timing of stimulus presentation and image acquisition clearly described and appropriate? | Yes |
| Design type | Block |
| Total images acquired | 165 |
| Are the imaging acquisition parameters, including coverage, adequately described and appropriate? | Yes (whole brain) |
| Is preprocessing and intrasubject coregistration adequately described and appropriate? | Yes |
| Is first level model fitting adequately described and appropriate? | Yes |
| Is intersubject normalization adequately described and appropriate? | Yes |
| Imaging notes | — |
| Are the conditions clearly described? | Yes |
| Condition | Response type | Repetitions | All groups could do? | All individuals could do? |
|---|---|---|---|---|
| semantic decision | Button press | 5 | No | No |
| tone decision | Button press | 6 | Unknown | Unknown |
| Conditions notes | Group performance below chance; several patients at 0 which is difficult to understand in a 2AFC task |
| Are the contrasts clearly described? | Yes |
| Language condition | Semantic decision |
| Control condition | Tone decision |
| Are the conditions matched for visual demands? | Yes |
| Are the conditions matched for auditory demands? | Yes |
| Are the conditions matched for motor demands? | Yes |
| Are the conditions matched for cognitive/executive demands? | Yes |
| Is accuracy matched between the language and control tasks for all relevant groups? | Unknown, not reported |
| Is reaction time matched between the language and control tasks for all relevant groups? | Unknown, not reported |
| Behavioral data notes | Tone decision accuracy not reported |
| Are control data reported in this paper or another that is referenced? | Yes |
| Does the contrast selectively activate plausible relevant language regions in the control group? | Yes |
| Are activations lateralized in the control data? | Yes |
| Control activation notes | Temporal activation is mid MTG and AG rather than pSTS |
| Contrast notes | — |
| Are the analyses clearly described? | Yes |
| First level contrast | Semantic decision vs tone decision |
| Analysis class | Cross-sectional correlation with language or other measure |
| Group(s) | Aphasia |
| Covariate | Semantic decision accuracy |
| Is the second level contrast valid in terms of the group(s), time point(s), and measures involved? | Yes |
| Is accuracy matched across the second level contrast? | Accuracy is covariate |
| Is reaction time matched across the second level contrast? | Unknown, not reported |
| Behavioral data notes | — |
| Type of analysis | Regions of interest (ROI) |
| ROI type | Other |
| How many ROIs are there? | 3 |
| What are the ROI(s)? | (1) L AG and bilateral midline components of the canonical semantic network, along with reduced activity in R frontal, temporal and parietal regions; (2) bilateral IFG pars orbitalis; (3) L IFG and DLPFC along with bilateral midline regions |
| How are the ROI(s) defined? | ROIs are mixing coefficients of functional networks arising from mCCA + jICA that were differently represented in the patient and control groups |
| Correction for multiple comparisons | Familywise error (FWE) |
| Statistical details | — |
| Findings | ↑ L IFG ↑ L dorsolateral prefrontal cortex ↑ L SMA/medial prefrontal ↑ L angular gyrus ↑ L precuneus ↑ L posterior cingulate ↑ R IFG pars orbitalis ↑ R SMA/medial prefrontal ↑ R precuneus ↑ R posterior cingulate ↓ L insula ↓ R IFG pars opercularis ↓ R IFG pars triangularis ↓ R insula ↓ R dorsal precentral ↓ R supramarginal gyrus ↓ R posterior STG ↓ R mid temporal |
| Findings notes | All 3 networks were significantly correlated; analysis of networks so involvement of each individual region cannot be assured |
| First level contrast | Semantic decision vs tone decision |
| Analysis class | Cross-sectional correlation with language or other measure |
| Group(s) | Aphasia |
| Covariate | Average of semantic and phonemic fluency |
| Is the second level contrast valid in terms of the group(s), time point(s), and measures involved? | Yes |
| Is accuracy matched across the second level contrast? | Unknown, not reported |
| Is reaction time matched across the second level contrast? | Unknown, not reported |
| Behavioral data notes | — |
| Type of analysis | Regions of interest (ROI) |
| ROI type | Other |
| How many ROIs are there? | 3 |
| What are the ROI(s)? | (1) L AG and bilateral midline components of the canonical semantic network, along with reduced activity in R frontal, temporal and parietal regions; (2) bilateral IFG pars orbitalis; (3) L IFG and DLPFC along with bilateral midline regions |
| How are the ROI(s) defined? | ROIs are mixing coefficients of functional networks arising from mCCA + jICA that were differently represented in the patient and control groups |
| Correction for multiple comparisons | Familywise error (FWE) |
| Statistical details | — |
| Findings | ↑ L IFG ↑ L dorsolateral prefrontal cortex ↑ L SMA/medial prefrontal ↑ L angular gyrus ↑ L precuneus ↑ L posterior cingulate ↑ R SMA/medial prefrontal ↑ R precuneus ↑ R posterior cingulate ↓ L insula ↓ R IFG pars opercularis ↓ R IFG pars triangularis ↓ R insula ↓ R dorsal precentral ↓ R supramarginal gyrus ↓ R posterior STG ↓ R mid temporal |
| Findings notes | Networks 1 and 3 were significantly correlated; analysis of networks so involvement of each individual region cannot be assured |
| First level contrast | Semantic decision vs tone decision |
| Analysis class | Cross-sectional correlation with language or other measure |
| Group(s) | Aphasia |
| Covariate | BNT |
| Is the second level contrast valid in terms of the group(s), time point(s), and measures involved? | Yes |
| Is accuracy matched across the second level contrast? | Unknown, not reported |
| Is reaction time matched across the second level contrast? | Unknown, not reported |
| Behavioral data notes | — |
| Type of analysis | Regions of interest (ROI) |
| ROI type | Other |
| How many ROIs are there? | 3 |
| What are the ROI(s)? | (1) L AG and bilateral midline components of the canonical semantic network, along with reduced activity in R frontal, temporal and parietal regions; (2) bilateral IFG pars orbitalis; (3) L IFG and DLPFC along with bilateral midline regions |
| How are the ROI(s) defined? | ROIs are mixing coefficients of functional networks arising from mCCA + jICA that were differently represented in the patient and control groups |
| Correction for multiple comparisons | Familywise error (FWE) |
| Statistical details | — |
| Findings | ↑ L IFG ↑ L dorsolateral prefrontal cortex ↑ L SMA/medial prefrontal ↑ L angular gyrus ↑ L precuneus ↑ L posterior cingulate ↑ R SMA/medial prefrontal ↑ R precuneus ↑ R posterior cingulate ↓ L insula ↓ R IFG pars opercularis ↓ R IFG pars triangularis ↓ R insula ↓ R dorsal precentral ↓ R supramarginal gyrus ↓ R posterior STG ↓ R mid temporal |
| Findings notes | Networks 1 and 3 were significantly correlated; analysis of networks so involvement of each individual region cannot be assured |
| First level contrast | Semantic decision vs tone decision |
| Analysis class | Cross-sectional aphasia vs control |
| Group(s) | Aphasia vs control |
| Covariate | — |
| Is the second level contrast valid in terms of the group(s), time point(s), and measures involved? | Yes |
| Is accuracy matched across the second level contrast? | No, different |
| Is reaction time matched across the second level contrast? | Unknown, not reported |
| Behavioral data notes | Semantic decision accuracy not matched, but tone decision accuracy not reported |
| Type of analysis | Complex |
| Statistical details | Multimodal canonical correlation analysis (mCCA) and joint ICA were used to identify 3 joint ICs (structural/functional) that were differently represented in the patient and control groups. Although there was no correction for multiple comparisons when the functional maps were thresholded, the maps for the three networks each appeared to relate to coherent parts of the semantic network. |
| Findings | Other |
| Findings notes | The first joint IC comprised preservation of tissue in L posterior temporo-parietal region, activity in the L AG and bilateral midline components of the canonical semantic network, and reduced activity in R frontal, temporal and parietal regions. The second joint IC comprised preservation of tissue in the the L basal ganglia/insula region, and activity predominantly in the IFG pars orbitalis bilaterally. The third joint IC comprised preservation of the L IFG and activity in the L IFG and DLPFC along with bilateral midline regions. The first joint IC was considered to provide more robust evidence for structure-function relationships than the other two, because it was the only one where individual structural and functional mixing coefficients remained correlated even when lesion volume was included as a covariate. |
| Excluded analyses | (1) group analyses that were described in a previous paper (Griffis et al., 2017, Hum Brain Mapp); (2) ancillary analysis using different numbers of components per modality; (3) ancillary analysis using lesion masks instead of brain tissue maps; (4) ancillary analysis using multivariate lesion-symptom mapping, because these analyses yielded similar results to the main analysis |
