Combined linguistic-executive therapy of word processing in aphasia
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1
University of Manchester, Neuroscience and Aphasia Research Unit, United Kingdom
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2
RWTH Aachen, Department of Neurology, Germany
INTRODUCTION
Functional magnetic resonance imaging (fMRI) studies in healthy participants successfully applied picture/word interference paradigms to localise stages of word processing (Abel et al., 2009). The interference task distracts picture naming by nearly simultaneous presentation of words, which facilitate naming responses when phonologically related or semantically associated, but hinder responses when semantically competing due to a categorical relation. The latter, in particular, impose high demands on executive control as revealed by fMRI, while all three activate language-related brain networks. We for the first time applied this complex paradigm in diagnostic and therapeutic settings for patients with aphasia (PWA) on the group level. We aimed at investigating the neural and behavioural impact on brain and behaviour exerted by (i) each distractor type to diagnose functional and impaired processing components, (ii) a novel treatment method targeting word access (Abel et al., 2015) combined with language control by means of interfered naming.
METHODS
19 PWA with a mean age of 50 years (range 21-74) and 26 months post-onset (4-63) were included in a diagnostic fMRI study comprising a pure naming test, a picture/word matching test for evaluation of distractor comprehension, and the fMRI interference paradigm with 5 distractor conditions (phonological, associative-semantic, categorical-semantic, unrelated word, unrelated noise) in a 3T Philips scanner. 11 PWA completed the 4-weeks fMRI therapy study and the repeated post-therapy measurement. fMRI activations were thresholded at MC-corrected p<.001, 10 voxels, corresponding to FWE p<.05. During therapy, picture naming was distracted by interfering words which were primed by the preceding comprehension task, and directly assisted by increasing semantic and phonological cues.
RESULTS
Using interfered naming and comprehension performance as covariates, we found differential pre-therapy activation dependent on distractor types. Comparing pre- to post-therapy measurements, brain activations predominantly decreased. Both pure and interfered naming as well as distractor comprehension improved significantly (naming/comprehension score, Wilcoxon signed ranks test, one-tailed, naming p<.001 each, comprehension p=.012), and therapy gains were positively correlated with initial distractor comprehension (rs=.699 and .711, p<.01, one-tailed) – but not with language comprehension in general (Aachen Aphasia Test; p>.10) –, and with an indicator of rather preserved lexical semantics (semantic weight in the Foygel & Dell (2000) model, p<05). The pure naming gain affected trained items and generalised to untrained items to a similar extent (Wilcoxon, p<.001 each; difference of differences: Mann-Whitney-U, p>.10). While gains did not generally correlate with initial naming performance or the tendency for automated speech (incl. distractor repetition), two single cases suggest presupposition of minimal performance levels. However, the therapy method has the potential to reduce automatisms in pure and interfered naming (Wilcoxon, p=.008 and p=.003).
CONCLUSIONS
The interference paradigm is a useful means for novel aphasia diagnosis and therapy. The therapy approach revealed to be highly effective, with the degree of automatism reduction and generalisation being surprisingly high, presumably due to amelioration of executive processing beyond linguistic processing.
Acknowledgements
This research was supported by the German Research Foundation (DFG).
References
Abel, S., Dressel, K., Bitzer, R., Kümmerer, D., Mader, I., Weiller, C. et al. (2009). The separation of processing stages in a lexical interference fMRI-paradigm. NeuroImage, 44, 1113-1124.
Abel, S., Weiller, C., Huber, W., Willmes, K., & Specht, K. (2015). Therapy-induced brain reorganisation patterns in aphasia. Brain, 138, 1097-1112.
Foygel, D. & Dell, G. S. (2000). Models of impaired lexical access in speech production. Journal of Memory and Language, 43, 182-216.
Keywords:
Naming deficits,
naming,
therapy,
fMRI,
interference paradigm,
Comprehension,
Speech and language therapy,
Stroke,
Neurorehabilitation
Conference:
54th Annual Academy of Aphasia Meeting, Llandudno, United Kingdom, 16 Oct - 18 Oct, 2016.
Presentation Type:
Poster Sessions
Topic:
Academy of Aphasia
Citation:
Abel
S and
Willmes
K
(2016). Combined linguistic-executive therapy of word processing in aphasia.
Front. Psychol.
Conference Abstract:
54th Annual Academy of Aphasia Meeting.
doi: 10.3389/conf.fpsyg.2016.68.00029
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Received:
22 Apr 2016;
Published Online:
15 Aug 2016.
*
Correspondence:
Dr. Stefanie Abel, University of Manchester, Neuroscience and Aphasia Research Unit, Manchester, United Kingdom, sbruehl@ukaachen.de