Aphasia Neuroplasticity Review

Schofield et al. (2012)

Reference

AuthorsSchofield TM, Penny WD, Stephan KE, Crinion JT, Thompson AJ, Price CJ, Leff AP
TitleChanges in auditory feedback connections determine the severity of speech processing deficits after stroke
ReferenceJ Neurosci 2012; 32: 4260-4270
PMID22442088
DOI10.1523/jneurosci.4670-11.2012

Participants

LanguageUK English
Inclusion criteriaComprehension deficit
Number of individuals with aphasia20 (plus 1 excluded: excessive head motion)
Number of control participants26
Were any of the participants included in any previous studies?Yes (patients recruited from database so may have participated in prior studies from this group, but not stated explicitly)
Is age reported for patients and controls, and matched?Yes (range 35.8-90.3 years)
Is sex reported for patients and controls, and matched?No (males: 16; females: 4; control sex not stated)
Is handedness reported for patients and controls, and matched?No
Is time post stroke onset reported and appropriate to the study design?Yes (mean 3.5 years, range 0.6-8.6 years)
To what extent is the nature of aphasia characterized?Severity only
Language evaluationCAT
Aphasia severity11 patients (plus one excluded) had moderate comprehension impairments, 9 had severe comprehension impairments; this distribution was bimodal
Aphasia typeNot stated
First stroke only?Yes
Stroke typeIschemic only
To what extent is the lesion distribution characterized?Lesion overlay
Lesion extentRange 24.2-403.6 cc
Lesion locationL MCA
Participants notesDemographic data includes excluded patient

Imaging

ModalityfMRI
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?Yes (Siemens Sonata 1.5 Tesla)
Is the timing of stimulus presentation and image acquisition clearly described and appropriate?Yes
Design typeBlock
Total images acquired488
Are the imaging acquisition parameters, including coverage, adequately described and appropriate?Yes (mostly whole brain but convexity or cerebellum excluded in some participants)
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

Conditions

Are the conditions clearly described?Yes
ConditionResponse typeRepetitionsAll groups could do?All individuals could do?
listening to word pairs, speaker gender judgmentButton press18YesUnknown
listening to reversed word pairs, speaker gender judgmentButton press18YesUnknown
restNone40 (?)N/AN/A
Conditions notes

Contrasts

Are the contrasts clearly described?Yes

Contrast 1: listening to word pairs or reversed word pairs, speaker gender judgment vs rest

Language conditionListening to word pairs or reversed word pairs, speaker gender judgment
Control conditionRest
Are the conditions matched for visual demands?No
Are the conditions matched for auditory demands?No
Are the conditions matched for motor demands?No
Are the conditions matched for cognitive/executive demands?No
Is accuracy matched between the language and control tasks for all relevant groups?N/A, tasks not comparable
Is reaction time matched between the language and control tasks for all relevant groups?N/A, tasks not comparable
Behavioral data notes
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?No
Are activations lateralized in the control data?No
Control activation notesControl data in Leff et al. (2008); auditory contrast, not intended to be language contrast
Contrast notes

Contrast 2: listening to word pairs, speaker gender judgment vs listening to reversed word pairs, speaker gender judgment

Language conditionListening to word pairs, speaker gender judgment
Control conditionListening to reversed word pairs, speaker gender judgment
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 notesBehavioral data not separated by condition
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?Somewhat
Are activations lateralized in the control data?Yes
Control activation notesControl data in Leff et al. (2008); L-lateralized activation of posterior STS
Contrast notes

Analyses

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

Voxelwise analysis 1

First level contrastListening to word pairs or reversed word pairs, speaker gender judgment vs rest
Analysis classCross-sectional aphasia vs control
Group(s)Moderate aphasia (n = 11) 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?Unknown, not reported
Is reaction time matched across the second level contrast?Unknown, not reported
Behavioral data notes
Type of analysisVoxelwise
Search volumeWhole brain
Correction for multiple comparisonsNo correction
SoftwareSPM8
Voxelwise p.001
Cluster extentNone
Statistical details
Findings↓ L Heschl's gyrus
Findings notesStructurally, HG was not significantly damaged in this group

Voxelwise analysis 2

First level contrastListening to word pairs or reversed word pairs, speaker gender judgment vs rest
Analysis classCross-sectional aphasia vs control
Group(s)Severe aphasia (n = 9) 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?Unknown, not reported
Is reaction time matched across the second level contrast?Unknown, not reported
Behavioral data notes
Type of analysisVoxelwise
Search volumeWhole brain
Correction for multiple comparisonsMixed** (major limitation)
SoftwareSPM8
Voxelwise pMGB: SVC; elsewhere: .001
Cluster extentNone
Statistical details
Findings↓ L posterior STG
↓ L Heschl's gyrus
↓ L thalamus
Findings notesSpecifically: PT, HG and MGB; structurally, the PT and HG were significantly damaged, but not the MGB

Voxelwise analysis 3

First level contrastListening to word pairs or reversed word pairs, speaker gender judgment vs rest
Analysis classCross-sectional between two groups with aphasia
Group(s)Severe (n = 9) vs moderate (n = 11) aphasia
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?Unknown, not reported
Is reaction time matched across the second level contrast?Unknown, not reported
Behavioral data notes
Type of analysisVoxelwise
Search volumeWhole brain
Correction for multiple comparisonsNo correction
SoftwareSPM8
Voxelwise p.001
Cluster extentNone
Statistical details
Findings↓ L posterior STG
Findings notesSpecifically, PT; structurally, severe patients had more damage in HG and PT

Notes

Excluded analysesIntelligibility contrasts, because findings are unclear: statements of significance in the text do not match Table 5; DCM analyses (which are the main focus of the paper)