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Data and analysis scripts associated with Voits et al.,(2023) Hippocampal adaptations in Mild Cognitive Impairment patients are modulated by bilingual language experiences. Submitted to Bilingualism: Language and Cognition

This project details the development of remove language comprehension assessment for post-stroke aphasia. Modifiable assessment templates are provided.

Recent evidence has shown that speaking more than one language impacts bilinguals’ cognitive processes and brain architecture. Current literature suggests that bilingualism has a significant and well-pronounced effect in older age - cognitive abilities are better preserved (Bialystok et al.,2012), and brain structures maintain their integrity for longer (Luk et al.,2011). It has even been suggested that bilingual individuals experience clinical symptoms of dementia at least 4 years later than monolinguals (Alladi et al.,2013). Bilinguals also exhibit better cognitive functioning at higher levels of dementia-related brain atrophy than monolinguals, which suggests a higher 'cognitive reserve' in bilingual patients (Schweizer et al.,2011) and has been attributed to protection of executive control circuits (Gold,2015). However, these claims remain controversial (Zahodne et al.,2014), the literature does not provide a direct brain- behaviour link, nor is there any longitudinal evidence linking bilingualism to the progression of dementia. Further investigating these claims is crucial, as bilingualism may emerge as a one long-term strategy against the impact of dementia. With this project we propose a cross-sectional and longitudinal study that will test monolingual and bilingual groups of patients with an early diagnosis of dementia. This study will help us determine the effects of additional language learning and use on brain structure and behaviour, as well as how the two are linked and interact. Testing will take place at the Centre for Integrative Neuroscience and Neurodynamics, University of Reading, in collaboration with the Berkshire Memory and Cognition Centre (Berkshire Healthcare NHS Foundation Trust). It will include behavioural tests tapping on cognitive skills that are affected by dementia (memory, executive control), as well as structural MRI scans to assess the structure of the ageing brain.

Recent evidence has shown that speaking more than one language impacts bilinguals’ cognitive processes and brain architecture. Current literature suggests that bilingualism has a significant and well-pronounced effect in older age - cognitive abilities are better preserved (Bialystok et al.,2012), and brain structures maintain their integrity for longer (Luk et al.,2011). It has even been suggested that bilingual individuals experience clinical symptoms of dementia at least 4 years later than monolinguals (Alladi et al.,2013). Bilinguals also exhibit better cognitive functioning at higher levels of dementia-related brain atrophy than monolinguals, which suggests a higher 'cognitive reserve' in bilingual patients (Schweizer et al.,2011) and has been attributed to protection of executive control circuits (Gold,2015). However, these claims remain controversial (Zahodne et al.,2014), the literature does not provide a direct brain- behaviour link, nor is there any longitudinal evidence linking bilingualism to the progression of dementia. Further investigating these claims is crucial, as bilingualism may emerge as a one long-term strategy against the impact of dementia. With this project we propose a cross-sectional and longitudinal study that will test monolingual and bilingual groups of patients with an early diagnosis of dementia. This study will help us determine the effects of additional language learning and use on brain structure and behaviour, as well as how the two are linked and interact. Testing will take place at the Centre for Integrative Neuroscience and Neurodynamics, University of Reading, in collaboration with the Berkshire Memory and Cognition Centre (Berkshire Healthcare NHS Foundation Trust). It will include behavioural tests tapping on cognitive skills that are affected by dementia (memory, executive control), as well as structural MRI scans to assess the structure of the ageing brain.

Long-term management of more than one language has been argued to contribute to changes in brain and cognition. This has been particularly well documented in older age, where bilingualism has been linked to protective effects against neurocognitive decline. Since memory difficulties are key aspects of this decline, herein we examine potential effects of bilingualism on the hippocampus, a brain structure related to memory that is particularly vulnerable to cognitive ageing. Hippocampal volume has been shown to increase as a result of second language learning and use in younger adults. However, it is unknown if this is maintained throughout the lifespan. We examine hippocampal volume and episodic memory performance in a participant sample consisting of healthy older individuals with a wide range of experiences in exposure and using a second language. Results reveal greater hippocampal volume calibrated to degree of quantified dual language use. Our results mirror those of immersive active bilingualism in younger populations, suggesting that long-term active bilingualism leads to neuroprotective effects in the hippocampus. We discuss this in the context of literature proposing bilingualism-induced brain reserve in the older age.

Jargon aphasia is a language disorder characterised by phonological and nonword error.\ud Errors are thought to arise when target segments are insufficiently activated, allowing non-target or recently used phonology to intrude. Words which are more frequent and familiar reside with greater degrees of activation and therefore should be less susceptible to error. The current study tested this hypothesis in a group of ten people with Jargon aphasia using single word repetition and reading aloud. Each task had two lexicality conditions, one high and one low lexical availability word set. Measures of nonword quantity, phonological accuracy and perseveration were used in group and case series analyses. Results demonstrated that fewer nonwords were produced when lexical availability was greater. However, lexicality effects on phonological accuracy and perseveration were only observed in repetition in a sub-group of moderately impaired individuals, demonstrating that lexical information does not consistently influence phonological processing in Jargon aphasia.

Supplemental material, Aud_Phon_Sem_Factors_Recovery_Wernickeas_Aphasia_SupplementaryMaterials_19-6-19 for Auditory, Phonological, and Semantic Factors in the Recovery From Wernicke’s Aphasia Poststroke: Predictive Value and Implications for Rehabilitation by Holly Robson, Timothy D. Griffiths, Manon Grube and Anna M. Woollams in Neurorehabilitation and Neural Repair

Images are often used in cueing therapy and other kinds of rehabilitation activities for people with an acquired brain injury. This paper presents a small-scale pilot study, which explores the appropriateness of different styles of illustration applied to visual resources used in combination with assistive technologies for people with aphasia. The study is part of a larger multidisciplinary project exploring how assistive technologies can be used to facilitate maximal engagement with rehabilitation and to facilitate communication and reengagement with hobbies and leisure activities. The study explored participants’ preferences and impressions of the materials with a view to informing design choices made for resources developed for the larger project.\ud Three participants with aphasia participated in a focus group in which they were shown examples of materials developed as resources for cueing therapy and lifestyle activities. Four sets of illustrations varying in visual complexity – from icons with no context to illustrations with developed backgrounds – were shown at two sizes (A3 and A4). Participants shared their impressions of ease of use and their preferences for different levels of visual complexity in the illustrations, as well as changes in format and layout (combinations of six, nine and 12 images per board).\ud Based on previous research and existing guidelines for good practice, we had anticipated that participants would find the contextualised examples more meaningful. However, our findings highlighted that participants preferred simple, icon-style illustrations rather than those with contextual detail. Participants’ comments suggested that familiarity with this style of illustration – based on their everyday engagement with mobile interfaces – was a likely explanation for this.

Comprehension deficits are common in stroke aphasia, including in cases with (i) semantic aphasia, characterized by poor executive control of semantic processing across verbal and non-verbal modalities; and (ii) Wernicke's aphasia, associated with poor auditory-verbal comprehension and repetition, plus fluent speech with jargon. However, the varieties of these comprehension problems, and their underlying causes, are not well understood. Both patient groups exhibit some type of semantic 'access' deficit, as opposed to the 'storage' deficits observed in semantic dementia. Nevertheless, existing descriptions suggest that these patients might have different varieties of 'access' impairment-related to difficulty resolving competition (in semantic aphasia) versus initial activation of concepts from sensory inputs (in Wernicke's aphasia). We used a case series design to compare patients with Wernicke's aphasia and those with semantic aphasia on Warrington's paradigmatic assessment of semantic 'access' deficits. In these verbal and non-verbal matching tasks, a small set of semantically-related items are repeatedly presented over several cycles so that the target on one trial becomes a distractor on another (building up interference and eliciting semantic 'blocking' effects). Patients with Wernicke's aphasia and semantic aphasia were distinguished according to lesion location in the temporal cortex, but in each group, some individuals had additional prefrontal damage. Both of these aspects of lesion variability-one that mapped onto classical 'syndromes' and one that did not-predicted aspects of the semantic 'access' deficit. Both semantic aphasia and Wernicke's aphasia cases showed multimodal semantic impairment, although as expected, the Wernicke's aphasia group showed greater deficits on auditory-verbal than picture judgements. Distribution of damage in the temporal lobe was crucial for predicting the initially 'beneficial' effects of stimulus repetition: cases with Wernicke's aphasia showed initial improvement with repetition of words and pictures, while in semantic aphasia, semantic access was initially good but declined in the face of competition from previous targets. Prefrontal damage predicted the 'harmful' effects of repetition: the ability to reselect both word and picture targets in the face of mounting competition was linked to left prefrontal damage in both groups. Therefore, patients with semantic aphasia and Wernicke's aphasia have partially distinct impairment of semantic 'access' but, across these syndromes, prefrontal lesions produce declining comprehension with repetition in both verbal and non-verbal tasks.

Comprehension deficits are common in both Wernicke’s aphasia and semantic aphasia. Thompson et al. compare these groups of patients on a task in which related items are repeatedly presented, increasing semantic competition across repetitions. Both groups show semantic impairment, but only individuals with prefrontal damage show harmful effects of repetition., Comprehension deficits are common in stroke aphasia, including in cases with (i) semantic aphasia, characterized by poor executive control of semantic processing across verbal and non-verbal modalities; and (ii) Wernicke’s aphasia, associated with poor auditory–verbal comprehension and repetition, plus fluent speech with jargon. However, the varieties of these comprehension problems, and their underlying causes, are not well understood. Both patient groups exhibit some type of semantic ‘access’ deficit, as opposed to the ‘storage’ deficits observed in semantic dementia. Nevertheless, existing descriptions suggest that these patients might have different varieties of ‘access’ impairment—related to difficulty resolving competition (in semantic aphasia) versus initial activation of concepts from sensory inputs (in Wernicke’s aphasia). We used a case series design to compare patients with Wernicke’s aphasia and those with semantic aphasia on Warrington’s paradigmatic assessment of semantic ‘access’ deficits. In these verbal and non-verbal matching tasks, a small set of semantically-related items are repeatedly presented over several cycles so that the target on one trial becomes a distractor on another (building up interference and eliciting semantic ‘blocking’ effects). Patients with Wernicke’s aphasia and semantic aphasia were distinguished according to lesion location in the temporal cortex, but in each group, some individuals had additional prefrontal damage. Both of these aspects of lesion variability—one that mapped onto classical ‘syndromes’ and one that did not—predicted aspects of the semantic ‘access’ deficit. Both semantic aphasia and Wernicke’s aphasia cases showed multimodal semantic impairment, although as expected, the Wernicke’s aphasia group showed greater deficits on auditory-verbal than picture judgements. Distribution of damage in the temporal lobe was crucial for predicting the initially ‘beneficial’ effects of stimulus repetition: cases with Wernicke’s aphasia showed initial improvement with repetition of words and pictures, while in semantic aphasia, semantic access was initially good but declined in the face of competition from previous targets. Prefrontal damage predicted the ‘harmful’ effects of repetition: the ability to reselect both word and picture targets in the face of mounting competition was linked to left prefrontal damage in both groups. Therefore, patients with semantic aphasia and Wernicke’s aphasia have partially distinct impairment of semantic ‘access’ but, across these syndromes, prefrontal lesions produce declining comprehension with repetition in both verbal and non-verbal tasks.