Phonological and semantic processing during comprehension in Wernicke’s aphasia: a N400 and Phonological Mapping Negativity study

Comprehension impairments in Wernicke’s aphasia are thought to result from a combination of impaired phonological and semantic processes. However, the relationship between these cognitive processes and language comprehension has only been inferred through offline neuropsychological tasks. This study used ERPs to investigate phonological and semantic processing during online single word comprehension. EEG was recorded in a group of Wernicke’s aphasia n=8 and control participants n=10 while performing a word-picture verification task. The N400 and Phonological Mapping Negativity/ Phonological Mismatch Negativity (PMN) event-related potential components were investigated as an index of semantic and phonological processing, respectively. Individuals with Wernicke’s aphasia displayed reduced and inconsistent N400 and PMN effects in comparison to control participants. Reduced N400 effects in the WA group were simulated in the control group by artificially degrading speech perception. Correlation analyses in the Wernicke’s aphasia group found that PMN but not N400 amplitude was associated with behavioural word-picture verification performance. The results confirm impairments at both phonological and semantic stages of comprehension in Wernicke’s aphasia. However, reduced N400 responses in Wernicke’s aphasia are at least partially attributable to earlier phonological processing impairments. The results provide further support for the traditional model of Wernicke’s aphasia which claims a causative link between phonological processing and language comprehension impairments

Varieties of semantic ‘access’ deficit in Wernicke’s aphasia and semantic aphasia

Comprehension deficits are common in stroke aphasia, including in cases with (i) semantic aphasia (SA), characterised by poor executive control of semantic processing across verbal and nonverbal modalities, and (ii) Wernicke’s aphasia (WA), 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 these patients might have different varieties of ‘access’ impairment – related to difficulty resolving competition (in SA) vs. initial activation of concepts from sensory inputs (in WA). We used a case-series design to compare WA and SA patients 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). WA and SA patients 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 SA and WA cases showed multimodal semantic impairment, although as expected the WA 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: WA cases showed initial improvement with repetition of words and pictures, while in SA, 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 re-select both word and picture targets in the face of mounting competition was linked to left prefrontal damage in both groups. Therefore, SA and WA patients 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

Exploring illustration styles for materials used in visual resources for people with aphasia

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. 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). 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

Sources of phoneme errors in repetition: perseverative, neologistic and lesion patterns in jargon aphasia

This study examined patterns of neologistic and perseverative errors during word repetition in fluent Jargon aphasia. The principal hypotheses accounting for Jargon production indicate that poor activation of a target stimulus leads to weakly activated target phoneme segments, which are outcompeted at the phonological encoding level. Voxel-lesion symptom mapping studies of word repetition errors suggest a breakdown in the translation from auditory-phonological analysis to motor activation. Behavioural analyses of repetition data were used to analyse the target relatedness (Phonological Overlap Index: POI) of neologistic errors and patterns of perseveration in 25 individuals with Jargon aphasia. Lesion-symptom analyses explored the relationship between neurological damage and jargon repetition in a group of 38 aphasia participants. Behavioural results showed that neologisms produced by 23 jargon individuals contained greater degrees of target lexico-phonological information than predicted by chance and that neologistic and perseverative production were closely associated. A significant relationship between jargon production and lesions to temporoparietal regions was identified. Region of interest regression analyses suggested that damage the posterior superior temporal gyrus and superior temporal sulcus in combination was best predictive of a Jargon aphasia profile. Taken together these results suggest that poor phonological encoding secondary to impairment in sensory-motor integration alongside impairments in self-monitoring result in jargon repetition. Insights for clinical management and future directions are discussed

Auditory, phonological and semantic factors in the recovery from Wernicke’s aphasia post stroke: predictive value and implications for rehabilitation

Background: Understanding the factors that influence language recovery in aphasia is important for improving prognosis and treatment. Chronic comprehension impairments Wernicke’s-type aphasia (WA) are associated with impairments in auditory and phonological processing, compounded by semantic and executive difficulties. This study investigated whether the recovery of auditory, phonological, semantic or executive factors underpins the recovery from WA comprehension impairments by charting changes in the neuropsychological profiles from the sub-acute to the chronic phase. Method: This study used a prospective, longitudinal, observational design. Twelve WA participants with superior temporal lobe lesions were recruited before 2 months post stroke onset (MPO). Language comprehension was measured alongside a neuropsychological profile of auditory, phonological and semantic processing alongside phonological short-term memory and nonverbal reasoning at three post stroke time points: 2.5, 5 and 9MPO. Results: Language comprehension displayed a strong and consistent recovery between 2.5 and 9MPO. Improvements were also seen for slow auditory temporal processing, phonological short-term memory, and semantic processing, but not for rapid auditory temporal, spectrotemporal and phonological processing. Despite their lack of improvement, rapid auditory temporal processing at 2.5MPO and phonological processing at 5MPO predicated comprehension outcomes at 9MPO. Conclusions: These results indicate that recovery of language comprehension in WA can be predicted from fixed auditory processing in the subacute stage. This suggests that speech comprehension recovery in WA results from reorganisation of the remaining language comprehension network to enable the residual speech signal to be processed more efficiently, rather than partial recovery of underlying auditory, phonological or semantic processing abilities

A new era of wide-field submillimetre imaging: on-sky performance of SCUBA-2

SCUBA-2 is the largest submillimetre wide-field bolometric camera ever built. This 43 square arc-minute field-of-view instrument operates at two wavelengths (850 and 450 microns) and has been installed on the James Clerk Maxwell Telescope on Mauna Kea, Hawaii. SCUBA-2 has been successfully commissioned and operational for general science since October 2011. This paper presents an overview of the on-sky performance of the instrument during and since commissioning in mid-2011. The on-sky noise characteristics and NEPs of the 450 and 850 micron arrays, with average yields of approximately 3400 bolometers at each wavelength, will be shown. The observing modes of the instrument and the on-sky calibration techniques are described. The culmination of these efforts has resulted in a scientifically powerful mapping camera with sensitivities that allow a square degree of sky to be mapped to 10 mJy/beam rms at 850 micron in 2 hours and 60 mJy/beam rms at 450 micron in 5 hours in the best weather.Comment: 18 pages, 15 figures.SPIE Conference series 8452, Millimetre, Submillimetre and Far-infrared Detectors and Instrumentation for Astronomy VI 201

Walking the Streets Without Fear: Investigating a Specific Offence of Public Sexual Harassment

The events of 2021 sparked a socio-political awakening among our population. Public protests and social media campaigns intensified against the backdrop of recurring high-profile cases of violence against women such as the murders of Sarah Everard, Ashling Murphy and Sabina Nessa. As awareness, and fear, of sexual harassment in public places rises among women and girls in the United Kingdom, it must be investigated whether the law is being fully utilised to protect the female population. This article seeks to understand how we can employ the criminal law to respond to this problem. Through investigating what public sexual harassment is, why it possesses characteristics of criminality and how it engages with existing legal framework. This article argues that the English and Welsh criminal law systems should introduce a specific offence that outlaws public sexual harassment (PSH). At the time of writing, women can, legally, be subjected to public displays of unwanted sexual attention. Where behaviours can be shoehorned under an existing offence, complexities in the framework mean the law struggles to ever be enforced effectively. As such, this discourse will explore the opportunities that a specific office of public sexual harassment would create to address the shortcomings of current law and how such an offence could operate to provide the legal protection desired by so many in our society. It argues that by doing so, favourable social responses can be generated which will deter engagement with the conduct and decrease its prevalence by changing social perceptions of the act itself

Designing remote synchronous auditory comprehension assessment for severely impaired individuals with aphasia

Background The use of telepractice in aphasia research and therapy is increasing in frequency. Teleassessment in aphasia has been demonstrated to be reliable. However, neuropsychological and clinical language comprehension assessments are not always readily translatable to an online environment and people with severe language comprehension or cognitive impairments have sometimes been considered to be unsuitable for teleassessment. Aim This project aimed to produce a battery of language comprehension teleassessments at the single word, sentence and discourse level suitable for individuals with moderate‐severe language comprehension impairments. Methods Assessment development prioritised response consistency and clinical flexibility during testing. Teleassessments were delivered in PowerPoint over Zoom using screen sharing and remote control functions. The assessments were evaluated in 14 people with aphasia and 9 neurotypical control participants. Modifiable assessment templates are available here: https://osf.io/r6wfm/. Main Contributions People with aphasia were able to engage in language comprehension teleassessment with limited carer support. Only one assessment could not be completed for technical reasons. Statistical analysis revealed above chance performance in 141/151 completed assessments. Conclusions People with aphasia, including people with moderate‐severe comprehension impairments, are able to engage with teleassessment. Successful teleassessment can be supported by retaining clinical flexibility and maintaining consistent task demands. WHAT THIS PAPER ADDS What is already known on the subject Teleassessment for aphasia is reliable but assessment of auditory comprehension is difficult to adapt to the online environment. There has been limited evaluation of the ability of people with severe aphasia to engage in auditory comprehension teleassessment. What this paper adds to existing knowledge Auditory comprehension assessment can be adapted for videoconferencing administration while maintaining clinical flexibility to support people with severe aphasia. What are the potential or actual clinical implications of this work? Teleassessment is time and cost effective and can be designed to support inclusion of severely impaired individuals

Executive control in frontal lesion aphasia: Does verbal load matter?

Executive control impairments in aphasia resulting from frontal lesions are expected, given that integrity of frontal regions is critical to executive control task performance. Yet the consistency of executive control impairments in aphasia is poorly understood. This is due to previous studies using only a brief set of measures or failing to account for the high language processing demands of many executive control tasks. This study investigated performance across a series of specific and broad executive control task, whilst comparing differences between low or high verbal task versions. Ten participants with aphasia secondary to left inferior frontal lesions and fifteen age matched controls completed a battery of verbal and low verbal executive control tasks tapping into the three core domains of inhibiting, switching, and updating of working memory. For both controls and participants with aphasia, there was no consistent influence of verbal load on either reaction time or accuracy performance. When compared to controls, participants with aphasia demonstrate a general slowing of responses across all reaction time tasks, and are less accurate on switching and updating tasks. These findings do suggest that language processing is not essential for executive control task performance, given that verbal load does not matter. Furthermore, tasks which involve holding multiple sources of information in mind, such as during switching or updating, are particularly vulnerable in aphasia

When does lexical availability influence phonology? Evidence from jargon reading and repetition

Jargon aphasia is a language disorder characterised by phonological and nonword error. 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