Aphasia Neuroplasticity Review

Mohr et al. (2014)

Reference

AuthorsMohr B, Difrancesco S, Harrington K, Evans S, Pulvermüller F
TitleChanges of right-hemispheric activation after constraint-induced, intensive language action therapy in chronic aphasia: fMRI evidence from auditory semantic processing
ReferenceFront Hum Neurosci 2014; 8: 919
PMID25452721
DOI10.3389/fnhum.2014.00919

Participants

LanguageUK English
Inclusion criteriaMCA; mild-moderate non-fluent aphasia; no severe comprehension deficit
Number of individuals with aphasia6 (plus 6 excluded: 4 for health risks; 2 for technical problems and data loss)
Number of control participants0
Were any of the participants included in any previous studies?No
Is age reported for patients and controls, and matched?Yes (range 41-76 years)
Is sex reported for patients and controls, and matched?Yes (males: 5; females: 1)
Is handedness reported for patients and controls, and matched?Yes (right: 6; left: 0)
Is time post stroke onset reported and appropriate to the study design?Yes (range 17-234 months (including excluded patients))
To what extent is the nature of aphasia characterized?Severity only
Language evaluationBDAE, TT
Aphasia severityMild-moderate; T1: TT range 15-49 errors (including 2 excluded patients)
Aphasia typeNot stated
First stroke only?Yes
Stroke typeMixed etiologies
To what extent is the lesion distribution characterized?Lesion overlay
Lesion extentNot stated
Lesion locationL MCA
Participants notesPatient numbers in tables 1 and 2 appear not to correspond with patient numbers later in the paper

Imaging

ModalityfMRI
Is the study cross-sectional or longitudinal?Longitudinal—chronic treatment
If longitudinal, at what time point(s) were imaging data acquired?T1: pre-treatment/chronic; T2: post-treatment, ~2 weeks later
If longitudinal, was there any intervention between the time points?CIAT, 3-4 hours/day, 5 days/week, 2 weeks
Is the scanner described?Yes (Siemens Trio 3 Tesla)
Is the timing of stimulus presentation and image acquisition clearly described and appropriate?Yes
Design typeEvent-related
Total images acquired76
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?No (lesion impact not addressed)
Imaging notessparse sampling

Conditions

Are the conditions clearly described?Yes
ConditionResponse typeRepetitionsAll groups could do?All individuals could do?
listening to high ambiguity sentencesNone19N/AN/A
listening to low ambiguity sentencesNone19N/AN/A
listening to signal-correlated noiseNone19N/AN/A
restNone19N/AN/A
Conditions notes

Contrasts

Are the contrasts clearly described?Yes

Contrast 1: listening to sentences (high and low ambiguity) vs listening to signal-correlated noise

Language conditionListening to sentences (high and low ambiguity)
Control conditionListening to signal-correlated noise
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?N/A, no behavioral measure
Is reaction time matched between the language and control tasks for all relevant groups?N/A, no timeable task
Behavioral data notes
Are control data reported in this paper or another that is referenced?No
Does the contrast selectively activate plausible relevant language regions in the control group?Unknown
Are activations lateralized in the control data?Unknown
Control activation notesSome control data in Rodd et al. (2005), but half of the participants were performing a probe judgment task, unlike in the present study
Contrast notes

Contrast 2: listening to high ambiguity sentences vs listening to low ambiguity sentences

Language conditionListening to high ambiguity sentences
Control conditionListening to low ambiguity sentences
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?N/A, no behavioral measure
Is reaction time matched between the language and control tasks for all relevant groups?N/A, no timeable task
Behavioral data notes
Are control data reported in this paper or another that is referenced?No
Does the contrast selectively activate plausible relevant language regions in the control group?Unknown
Are activations lateralized in the control data?Unknown
Control activation notesSome control data in Rodd et al. (2005), but half of the participants were performing a probe judgment task, unlike in the present study
Contrast notes

Analyses

Are the analyses clearly described?No* (moderate limitation) (see specific limitation(s) below)

Voxelwise analysis 1

First level contrastListening to sentences (high and low ambiguity) vs listening to signal-correlated noise
Analysis classLongitudinal change in aphasia
Group(s)Aphasia T2 vs T1
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?N/A, no behavioral measure
Is reaction time matched across the second level contrast?N/A, no timeable task
Behavioral data notes
Type of analysisVoxelwise
Search volumeWhole brain
Correction for multiple comparisonsNo direct comparison
SoftwareSPM8
Voxelwise p
Cluster extent
Statistical detailsQualitative generalization across individuals on pp. 8-9
FindingsNone
Findings notes

ROI analysis 1

First level contrastListening to high ambiguity sentences vs listening to low ambiguity sentences
Analysis classLongitudinal change in aphasia
Group(s)Aphasia T2 vs T1
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?N/A, no behavioral measure
Is reaction time matched across the second level contrast?N/A, no timeable task
Behavioral data notes
Type of analysisRegions of interest (ROI)
ROI typeFunctional
How many ROIs are there?4
What are the ROI(s)?(1) L IFG; (2) R IFG; (3) L ITG; (4) R ITG; the temporal ROIs are described as STG but they seem to be in the ITG
How are the ROI(s) defined?Defined based on control data from Rodd et al. (2005) but the coordinates do not match so it is not clear exactly how they were defined
Correction for multiple comparisonsNo correction
Statistical detailsANOVA of timepoint by hemisphere by site, with a significant interaction of timepoint by hemisphere
Findings↑ R IFG
↑ R posterior inferior temporal gyrus/fusiform gyrus
Findings notesAll signal changes were negative (i.e. less activation for ambiguous sentences), making interpretation challenging

Notes

Excluded analysesNoise vs rest (not language); individual patient analyses