Aphasia Neuroplasticity Review

Papoutsi et al. (2011)

Reference

AuthorsPapoutsi M, Stamatakis EA, Griffiths J, Marslen-Wilson WD, Tyler LK
TitleIs left fronto-temporal connectivity essential for syntax? Effective connectivity, tractography and performance in left-hemisphere damaged patients
ReferenceNeuroImage 2011; 58: 656-664
PMID21722742
DOI10.1016/j.neuroimage.2011.06.036

Participants

LanguageUK English
Inclusion criteria
Number of individuals with aphasia14
Number of control participants15
Were any of the participants included in any previous studies?Yes (reanalysis of same dataset from Tyler et al. (2011))
Is age reported for patients and controls, and matched?Yes (mean 56 ± 12 years, range 35-77 years)
Is sex reported for patients and controls, and matched?Yes (males: 11; females: 3)
Is handedness reported for patients and controls, and matched?Yes (right: 14; left: 0)
Is time post stroke onset reported and appropriate to the study design?Yes (mean 8 ± 9 years, range 2-40 years)
To what extent is the nature of aphasia characterized?Not at all
Language evaluationSentence-picture matching, grammaticality judgment, lexical decision, phonological discrimination, semantic categorization, sentence repetition, word repetition
Aphasia severityNot stated
Aphasia typeNot stated
First stroke only?Not stated
Stroke typeNot stated
To what extent is the lesion distribution characterized?Lesion overlay
Lesion extentNot stated
Lesion locationL MCA
Participants notes1 patient had post-surgical haematoma rather than stroke (per Tyler et al., 2011)

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 Trio 3 Tesla)
Is the timing of stimulus presentation and image acquisition clearly described and appropriate?No (length of stimuli not described)
Design typeEvent-related
Total images acquired1059
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?No (lacks explanation of event durations)
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 unambiguous sentences ("unambiguous")None42N/AN/A
listening to ambiguous sentences with dominant resolution ("dominant")None42N/AN/A
listening to ambiguous sentences with subordinate resolution ("subordinate")None42N/AN/A
listening to filler sentencesNone126N/AN/A
listening to "musical rain"None42N/AN/A
restNoneimplicit baselineN/AN/A
Conditions notes

Contrasts

Are the contrasts clearly described?Yes

Contrast 1: listening to ambiguous sentences with subordinate resolution ("subordinate") vs listening to ambiguous sentences with dominant resolution ("dominant")

Language conditionListening to ambiguous sentences with subordinate resolution ("subordinate")
Control conditionListening to ambiguous sentences with dominant resolution ("dominant")
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?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 notesControl data in Tyler et al. (2011); L frontal and temporal
Contrast notes

Analyses

Are the analyses clearly described?Yes

Voxelwise analysis 1

First level contrastListening to ambiguous sentences with subordinate resolution ("subordinate") vs listening to ambiguous sentences with dominant resolution ("dominant")
Analysis classCross-sectional correlation with language or other measure
Group(s)Aphasia
CovariateDifference in percent of unacceptable judgments between subordinate and dominant sentences (dominance effect)
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 comparisonsClusterwise correction with with GRFT and lenient voxelwise p
SoftwareSPM8
Voxelwise p.01
Cluster extentBased on GRFT
Statistical details
Findings↑ L insula
↑ L posterior STG/STS/MTG
↑ L mid temporal
Findings notes

Complex analysis 1

First level contrastListening to ambiguous sentences with subordinate resolution ("subordinate") vs listening to ambiguous sentences with dominant resolution ("dominant")
Analysis classCross-sectional correlation with language or other measure
Group(s)Aphasia
CovariateModulation of L IFG connectivity by dominance effect
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 analysisComplex
Statistical detailsA PPI analysis was carried out with the L IFG as the seed region. Correlations were computed between voxelwise modulation of connectivity with this region, and a behavioral measure of syntactic processing, which was the dominance effect: the difference in percent of unacceptable judgments between subordinate and dominant sentences. The resultant SPM was thresholded at voxelwise p < .01 (CDT), then corrected for multiple corrections based on cluster extent and GRFT using SPM8.
FindingsOther
Findings notesPatients with better syntactic performance had more connectivity from the L IFG seed region to L pMTG and adjacent areas (including the insula); pMTG also significant at voxelwise p < .001 in Figure 2B, corrected for multiple comparisons with GRFT

Complex analysis 2

First level contrastListening to ambiguous sentences with subordinate resolution ("subordinate") vs listening to ambiguous sentences with dominant resolution ("dominant")
Analysis classCross-sectional correlation with language or other measure
Group(s)Aphasia
CovariateModulation of L pMTG connectivity by dominance effect
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 analysisComplex
Statistical detailsA similar PPI analysis was carried out with the L pMTG as the seed region. Thresholding was the same as in the previous analysis.
FindingsNone
Findings notes

Notes

Excluded analyses