Words fail: Lesion‐symptom mapping of errors of omission in post‐stroke aphasia

Abstract

Impaired object naming is a core deficit in post-stroke aphasia, which can manifest as errors of commission - producing an incorrect word or a non-word - or as errors of omission - failing to attempt to name the object. Detailed behavioural, computational, and neurological investigations of errors of commission have played a key role in the development of neurocognitive models of word production. In contrast, the neurocognitive basis of omission errors is radically underspecified despite being a prevalent phenomenon in aphasia and other populations. The prevalence of omission errors makes their neurocognitive basis important for characterizing an individual's deficits and, ideally, for personalizing treatment and evaluating treatment outcomes. This study leveraged established relationships between lesion location and errors of commission to investigate omission errors in picture naming. Omission error rates from the Philadelphia Naming Test for 123 individuals with post-stroke aphasia were analysed using support vector regression lesion-symptom mapping. Omission errors were most strongly associated with left frontal and mid-anterior temporal lobe lesions. Computational model analysis further showed that omission errors were positively associated with impaired semantically driven lexical retrieval rather than phonological retrieval. These results suggest that errors of omission in aphasia predominantly arise from lexical-semantic deficits in word retrieval and selection from a competitor set.

The network underlying human higher-order motor control: Insights from machine learning-based lesion-behaviour mapping in apraxia

“…This method is an extension of support vector machines (Cortes and Vapnik, 1995). SVR is able to model continuous variables and has been successfully implemented in SVR-based lesion symptom mapping (SVR-LSM) to map lesion-behaviour relationships with high resolution on a whole-brain voxel-level (Zhang et al, 2014;Mirman et al, 2015b;Fama et al, 2017;Griffis et al, 2017;Ghaleh et al, 2018;Chen et al, 2018;Sperber et al, in press). Most importantly, SVR-LSM was validated in a set of simulation studies for simple brain networks (Zhang et al, 2014).…”

Morphometric correlates of anomia in patients with small left temporopolar lesions

“…As recently highlighted, ‘the same error can be caused by more than one type of deficit’ (Halai et al ., ). In the case of omissions, different reasons have been enumerated, ranging from insufficient semantic activation of lexical representations to difficulties at the low‐level visual input (see Chen et al ., ; Tochadse et al ., ). Infering the neural correlates of a function by studying dysfunction following brain damage or inactivation, the so‐called lesion‐deficit approach (Genon, Reid, Langner, Amunts, & Eickhoff, ), has proven to be a successful strategy.…”

“…Infering the neural correlates of a function by studying dysfunction following brain damage or inactivation, the so‐called lesion‐deficit approach (Genon, Reid, Langner, Amunts, & Eickhoff, ), has proven to be a successful strategy. In this sense, convergent data from neuropsychological studies with patients with primary progressive aphasia (Mesulam et al ., ; Wilson, Dehollain, Ferrieux, Christensen, & Teichmann, ; Wilson et al ., ); stroke‐related aphasia (Chen et al ., ; Halai et al ., ); anatomo‐electro‐clinical correlations of patterns of ictal aphasia in temporal lobe epilepsy (TLE) using stereoelectroencephalography (Trebuchon et al ., ); and brain (Pobric, Jefferies, & Ralph, ), and intraoperative stimulation studies (Miozzo, Williams, McKhann, & Hamberger, ), have suggested an association of omission errors with anterior temporal lobe (ATL) dysfunction. Nonetheless, other studies have indicated that omission errors can be also related to damage to regions in the posterior temporal cortex (Antonucci, Beeson, Labiner, & Rapcsak, ; Baldo, Arévalo, Patterson, & Dronkers, ; Cloutman et al ., ; Herbet et al ., ; Trebuchon‐Da Fonseca et al ., ).…”

“…Among the most prominent types of error are semantic errors and omissions. While the neural correlates of semantic errors have been extensively studied, the neural basis of omission errors remains relatively unspecified (Chen, Middleton, & Mirman, ; Halai et al ., ; Tochadse, Halai, Lambon Ralph, & Abel, ). As recently highlighted, ‘the same error can be caused by more than one type of deficit’ (Halai et al ., ).…”

Lexical-semantic and executive deficits revealed by computational modelling: a drift diffusion model perspective

“…To sum up, we investigated the contribution of control mechanisms during semantic retrieval and selection in healthy adults and adults with stroke-induced lesions using a word-picture matching task and computational modelling (HDDM). With that, we add to an existing body of literature that combines computational modelling with a lesion mapping approach, which provides a promising avenue towards formalizing brain-behavior relations (Chen, Middleton, & Mirman, 2018;Dell, Martin, & Schwartz, 2007;Hoffman, McClelland, & Lambon Ralph, 2018).…”