Right Hemisphere Damage Research Articles

The disengagement deficit after right-hemisphere damage: Distinct roles of lateral frontal and parietal damage

An influential model of spatial attention postulates three main attention-orienting mechanisms: disengagement, shifting, and engagement. Early research linked disengagement deficits with superior parietal damage, regardless of hemisphere or presence of spatial neglect. Subsequent studies supported the involvement of more ventral parietal regions, especially in the right hemisphere, and linked spatial neglect to deficient disengagement from ipsilateral cues. However, previous lesion studies faced serious limitations, such as small sample sizes and the lack of brain-injured controls without neglect. Additionally, some studies employed symbolic cues or used long cue-target intervals, which may fail to reveal impaired disengagement. We here used a machine-learning approach to conduct lesion-symptom mapping (LSM) on 89 patients with focal cerebral lesions to the left (LH) or right (RH) cerebral hemisphere. A group of 54 healthy participants served as controls. The paradigm used to uncover disengagement deficits employed non-predictive cues presented in the visual periphery and at short cue-target intervals, targeting exogenous attention. The main factors of interest were group (healthy participants, LH, RH), target position (left, right hemifield) and cue validity (valid, invalid). LSM-analyses were performed on two indices: the validity effect, computed as the absolute difference between reaction times (RTs) following invalid compared to valid cues, and the disengagement deficit, determined by the difference between contralesional and ipsilesional validity effects. While LH patients showed general slowing of RTs to contralesional targets, only RH patients exhibited a disengagement deficit from ipsilesional cues. LSM associated the validity effect with a right lateral frontal cluster, which additionally affected subcortical white matter of the right arcuate fasciculus, the corticothalamic pathway, and the superior longitudinal fasciculus. In contrast, the disengagement deficit was related to damage involving the right temporoparietal junction. Thus, our results support the crucial role of right inferior parietal and posterior temporal regions for attentional disengagement, but also emphasize the importance of lateral frontal regions, for the reorienting of attention.

Investigating the Effect of Different Types of Exercise on Upper Limb Functional Recovery in Patients with Right Hemisphere Damage Based on fNIRS.

To investigate the effects of functional occupational therapy (FOT) combined with different types of exercise on upper limb motor function recovery and brain function remodeling in patients with right hemisphere damage (RHD) by analyzing functional near-infrared spectroscopy (fNIRS). Patients (n = 32) with RHD at Beijing Bo'ai Hospital were recruited and randomly allocated to receive either FOT combined with passive motion (N=16) or FOT combined with assisted active movement (N=16). The passive motion group (FOT-PM) received functional occupational therapy for 20 min and passive exercise for 10 min in each session, while the assisted active movement group (FOT-AAM) received functional occupational therapy for 20 min and assisted active exercise for 10 min. Both groups received conventional drug therapy and other rehabilitation therapy. Treatment was performed once a day, 5 times a week for 4 weeks. The recovery of motor function and activities of daily living (ADL) was assessed using Fugl-Meyer Assessment upper extremity (FMA-UE) and modified Barthel index (MBI) before and after treatment, and brain activation of the bilateral motor area was analyzed with fNIRS. The findings suggested that FOT combined with AAM was more effective than FOT combined with PM in improving the motor function of RHD patients' upper limbs and fingers, improving their ability to perform activities of daily living, and facilitating brain function remodeling of the motor area.

Discriminative value of different combinations of tests to detect unilateral neglect in patients with right hemisphere damage.

This study was undertaken to assess the most sensitive combination of tests to detect peripersonal unilateral neglect (UN) after stroke. The present study is a secondary analysis of a previously reported multicentric study of 203 individuals with right hemisphere damage (RHD), mainly subacute stroke, 11 weeks postonset on average, and 307 healthy controls. A battery of seven tests, providing 19 age- and education-adjusted z-scores, were given: the bells test, line bisection, figure copying, clock drawing, overlapping figures test, and reading and writing. Statistical analyses used a logistic regression and a receiver operating characteristic (ROC) curve after adjustment on demographic variables. A combination of four z-scores based on the following three tests provided good discrimination of patients with RHD from matched healthy controls: the starting point and the difference between the number of omissions on left and right sides from the bells test, rightward deviation in bisection of long lines (20 cm), and left-sided omissions in a reading task. The area under the ROC curve was 0.865 (95% confidence interval = 0.83-0.901), with sensitivity = 0.68, specificity = 0.95, accuracy = 0.85, positive predictive value = 0.90, and negative predictive value = 0.82. The most sensitive and parsimonious combination of tests to detect UN after stroke relies on four scores from three simple tests (bells test, line bisection, and reading). Future study is warranted to assess its ability to account for the functional difficulties of UN in daily life in the patient's actual environment.

Evaluation of driving fitness using driving simulators in patients with right-hemisphere damage: an unmatched case-control study

ABSTRACT Background Patients with right hemisphere damage (RHD) may exhibit mild unilateral spatial neglect (USN), which is difficult to detect in general assessments performed during driving rehabilitation. Objectives We compared driving simulator performance, practical driving performance, and neuropsychological test results between patients with RHD who were able and unable to return to driving to predict driving fitness based on driving simulator performance. Methods This unmatched case-control study included 29 patients with RHD who were able (return-to-driving group, n = 16) and unable (non-return-to-driving group, n = 13) to return to driving. Patient demographics, motor function, attention, driving simulator performance (participants’ reaction time and rate to green lamps appearing in any of the three displays and average lane position), and practical driving performance were compared between the groups. Receiver operating characteristic (ROC) analysis was performed to examine the predictive performance of driving fitness in reaction rate and paper-and-pencil tests. Results The non-return-to-driving group had a significantly lower reaction rate than the return-to-driving group (p = 0.027; 95% confidence interval [CI], 0–7; r = 0.407). No significant difference in reaction time or lane position in either the left or right lane during driving simulation was observed. ROC analysis of the reaction rate in the driving simulator task showed sensitivity of 0.692, specificity of 0.812, and area under the curve of 0.738 [95% CI, 0.541–0.935]. Conclusions Decreases in reaction rates during simulated driving assessments are associated with an inability to resume driving in patients with RHD. Such assessments may aid in predicting fitness for driving in these patients.

The continuous performance test aids the diagnosis of post-stroke cognitive impairment in patients with right hemisphere damage.

The purpose of the study was to investigate the time course difference of relative changes in oxygenated hemoglobin (Oxy-Hb) concentration in the prefrontal cortex (PFC) between controls and patients with post-stroke cognitive impairment (PSCI) who had right hemisphere damage (RHD) using the continuous performance test (CPT) and functional near-infrared spectroscopy (fNIRS) technology. The study aimed to evaluate the feasibility of CPT in the diagnosis and evaluation of PSCI with RHD. A total of 16 patients with RHD (RHD group) and 32 normal subjects (control group) were recruited. The Montreal Cognitive Assessment Scale was used to assess post-stroke cognitive impairment. The CPT and fNIRS were employed to investigate task-related changes in Oxy-Hb levels. The RHD group showed significantly lower accuracy and hit rates than the control group; however, the average reaction time was significantly longer in the former. Although the two groups showed no statistically significant difference in terms of left and right PFC integral values, the mean values were greater in the RHD group. The centroid value of the right PFC was significantly higher in the RHD group than in the control group. The time course of Oxy-Hb concentrations in the PFC differed between the two groups. In the RHD group, neural compensation was observed in both prefrontal lobes; however, the rate of compensation was slower on the affected side. The CPT may be helpful in the clinical diagnosis of PSCI with RHD. It may therefore be used to evaluate the effectiveness of cognitive interventions.

Perception of grammatical tone in Akan patients with left and right hemisphere brain damage

ABSTRACT It remains a matter of debate what roles the left and right hemispheres play in processing speech prosody. Brain lesion studies have demonstrated that lexical tone perception among native speakers of tonal languages is more disrupted in left hemisphere damaged (LHD) individuals than right hemisphere damaged (RHD) individuals. This has been taken to suggest that linguistically-relevant prosodic cues are predominantly left-lateralised, whereas non-linguistic stimuli are predominantly right-lateralised. However, this phenomenon has only been examined in lexical tone, leaving grammatical tone perception unexplored. The aim of this study was twofold: Firstly, to examine how individuals with LHD and RHD perceive grammatical tone, and secondly to compare grammatical tone to non-linguistic tone perception. Therefore, native Akan speakers with LHD, RHD and no-brain damage (NBD) controls were tested in two discrimination tasks that examined linguistic and non-linguistic tone perception. The results showed that while both the individuals with LHD and RHD show impairment in grammatical tone perception, there was a trend of a better performance for the RHD group. Nonetheless, for non-linguistic tone perception, individuals with LHD outperformed the RHD individuals, although both had reduced performance compared to the NBD individuals. A further analysis revealed that the reduced perceptual abilities of both the LHD and RHD groups in grammatical tone perception can be attributed to grammatical problems rather than tone per se. We conclude that there is potentially a bilateral involvement of the two hemispheres in grammatical tone processing, with the left being the dominant hemisphere.

Long COVID: The impact on language and cognition

COVID-19 continues to have profound health and economic consequences around the world. Aside from the large number of deaths from this viral infection, there is a growing population of individuals who have not made a good recovery from their COVID illnesses. These children and adults continue to experience COVID symptoms for months and even years after the onset of their illness. One group of symptoms that can be particularly troubling are language and cognitive difficulties. These difficulties can compromise learning and academic attainment and prevent a return to employment in adults. The author has examined the language skills of 110 adults who reported experiencing Long COVID. Among these individuals, 99 adults reported significant cognitive-linguistic difficulties as part of their ongoing COVID symptoms. This article examines these difficulties in detail. It proposes that these cognition-based language difficulties should be included in the class of cognitive-communication disorders. These disorders are typically assessed and treated by speech-language pathologists who manage communication difficulties in clients with traumatic brain injury, right-hemisphere damage, and neurodegeneration.

Reading and listening comprehension in Cantonese-speaking people with right hemisphere versus left hemisphere brain damage

ABSTRACT The problem in language comprehension in people with right hemisphere damage (RHD) is more equivocal than people with left hemisphere damage. This study explores the reading and listening comprehension of Cantonese-speaking individuals with RHD, left hemisphere damage, and neurotypical healthy controls using the Cantonese Computerized Revised Token Test (CRTT-Cantonese) adapted from the English CRTT. Eighteen native Cantonese-speaking individuals with RHD, 32 individuals with left hemisphere damage and aphasia (PWA), and 42 healthy controls participated in this study. All the participants completed the Cantonese Aphasia Battery, Hong Kong Oxford Cognitive Screen, the listening comprehension version of CRTT-Cantonese (CRTT-L-Cantonese), and the reading comprehension version of CRTT-Cantonese (CRTT-R-WF-Cantonese) across different sessions. Linear mixed-effect analysis revealed significant differences among the groups in CRTT-Cantonese tests. However, there were no significant difference between CRTT-L-Cantonese and CRTT-R-WF-Cantonese within the PWA, RHD and healthy control groups. Tukey post-hoc pairwise comparisons showed that PWA scored significantly lower than RHD and healthy control groups (p < 0.0001) in both CRTT-L-Cantonese and CRTT-R-WF-Cantonese, and the RHD group scored significantly lower than healthy control group only on the CRTT-R-WF-Cantonese. The results demonstrate that the CRTT-L-Cantonese and CRTT-R-WF-Cantonese differentiate language comprehension abilities among PWA, RHD and healthy control groups. Although the current findings did not show any diversion between reading and listening comprehension in RHD group, this group showed poorer performance in reading comprehension when compared to healthy controls. The latter findings may support the view that the right hemisphere contributes to reading comprehension in Chinese.

Use of multi-perturbation Shapley analysis in lesion studies of functional networks: The case of upper limb paresis.

Understanding the impact of variation in lesion topography on the expression of functional impairments following stroke is important, as it may pave the way to modeling structure-function relations in statistical terms while pointing to constraints for adaptive remapping and functional recovery. Multi-perturbation Shapley-value analysis (MSA) is a relatively novel game-theoretical approach for multivariate lesion-symptom mapping. In this methodological paper, we provide a comprehensive explanation of MSA. We use synthetic data to assess the method's accuracy and perform parameter optimization. We then demonstrate its application using a cohort of 107 first-event subacute stroke patients, assessed for upper limb (UL) motor impairment (Fugl-Meyer Assessment scale). Under the conditions tested, MSA could correctly detect simulated ground-truth lesion-symptom relationships with a sensitivity of 75% and specificity of ~90%. For real behavioral data, MSA disclosed a strong hemispheric effect in the relative contribution of specific regions-of-interest (ROIs): poststroke UL motor function was mostly contributed by damage to ROIs associated with movement planning (supplementary motor cortex and superior frontal gyrus) following left-hemispheric damage (LHD) and by ROIs associated with movement execution (primary motor and somatosensory cortices and the ventral brainstem) following right-hemispheric damage (RHD). Residual UL motor ability following LHD was found to depend on a wider array of brain structures compared to the residual motor ability of RHD patients. The results demonstrate that MSA can provide a unique insight into the relative importance of different hubs in neural networks, which is difficult to obtain using standard univariate methods.

Pragmatic deficits in patients with schizophrenia and right hemisphere damage: A pilot study.

While pragmatic deficits are well documented in patients with schizophrenia (SCZ) and right hemisphere damage (RHD), there is a paucity of research comparing the pragmatic deficits of these two groups. Do they experience similar cognitive dysfunction or is there a dissociation between the two patient groups? To investigate the nature of pragmatic deficits in these two groups and to gain an understanding of the underlying cognitive mechanisms that might be associated with these deficits to further future investigations. A total of 60 participants (15 patients with SCZ; 15 with RHD; 30 (15 + 15) healthy controls (HC) were administered the Bengali Audio-Visual Test-Battery for Assessment of Pragmatic Skills. Both SCZ and RHD patients were found to have significant pragmatic deficits compared with their matched controls. SCZ patients were found to score significantly better than the RHD group in six out of the 10 pragmatic skills when controlled for age and education. Discriminant function analysis was performed and 86.7% of the cases (HC = 100%, SCZ = 73.3% and RHD = 86.7%) were correctly reclassified into their original categories using the test scores. The study suggests that there is heterogeneity in the nature of the pragmatic breakdown within and across patient groups. Therefore, individualized restorative measures targeting the disrupted cognitive mechanism(s) might help elevate pragmatic competence and enhance the social functioning of patients with pragmatic deficits. What is already known on the subject Pragmatic deficits are common in adults with cognitive impairments of different etiologies. However, few studies have explored pragmatic deficits across clinical populations. Consequently, very little is known about the nature of pragmatic deficits in patients with schizophrenia and right hemisphere damage. What this paper adds to existing knowledge This work offers preliminary data on pragmatic difficulties in patients with schizophrenia and right hemisphere damage. This study overrides the boundaries of traditional classifications and evaluates pragmatic difficulties in these two clinical populations with reference to the underlying cognitive mechanisms, which might be disrupted. What are the potential or actual clinical implications of this work? The study adds a transdiagnostic perspective suggesting that there might be heterogeneity in pragmatic deficits, both within and across patient groups, and stresses the need for individualized therapy.

Effect of right hemispheric damage on structured spoken conversation.

Patients with right hemisphere damage (RHD) occasionally complain of difficulties in conversation. A conversation is a type of communication between the speaker and listener, and several elements are required for a conversation to take place. However, it is unclear which of those elements affect communication in patients with RHD. Therefore, we prospectively enrolled 11 patients with right hemispheric damage due to acute cerebral infarction, within 1 week of onset. To evaluate patients’ conversational abilities, we used a structured conversation task, namely, the “Hallym Conversation and Pragmatics Protocol”. The topics of conversation were “family”, “leisure”, and “other/friends”. The conversation characteristics were classified according to three indices: the “conversational participation index”, “topic manipulation index”, and “conversational breakdown index”. Patients with RHD were compared with 11 age-, sex-, and years of education-matched healthy adults. The most common site of damage in the patients with RHD was the periventricular white matter. There was no significant difference in performance between the two groups according to the conversation participation index and in the discontinuance rate assessed with the conversational breakdown index. However, patients with RHD showed a lower topic maintenance rate and higher topic initiation and topic switching rates, according to the topic manipulation index. Therefore, we explored the characteristics of impaired conversation abilities in patients with RHD by assessing their ability to converse and manage topics during structured conversations, and found difficulties with pragmatics and communication discourse in these patients.

Right-side spatial neglect and white matter disconnection after left-hemisphere strokes.

Spatial neglect usually concerns left-sided events after right-hemisphere damage. Its anatomical correlates are debated, with evidence suggesting an important role for fronto-parietal white matter disconnections in the right hemisphere. Here, we describe the less frequent occurrence of neglect for right-sided events, observed in three right-handed patients after a focal stroke in the left hemisphere. Patients were tested 1 month and 3 months after stroke. They performed a standardized paper-and-pencil neglect battery and underwent brain MRI with both structural and diffusion tensor (DT) sequences, in order to assess both grey matter and white matter tracts metrics. Lesions were manually reconstructed for each patient. Patients presented signs of mild right-sided neglect during visual search and line bisection. One patient also showed pathological performance in everyday life. Structural MRI demonstrated left parietal strokes in two patients, in the region extending from the postcentral gyrus to the temporo-parietal junction. One of these two patients also had had a previous occipital stroke. The remaining patient had a left frontal stroke, affecting the precentral, the postcentral gyri and the basal ganglia. DT MRI tractography showed disconnections in the fronto-parietal regions, concerning principally the superior longitudinal fasciculus (SLF). These results suggest an important role for left SLF disconnection in right-side neglect, which complements analogous evidence for right SLF disconnection in left-side neglect.

Acoustic cues associated with Korean sarcastic utterances produced by right- and left-hemisphere damaged individuals

PurposeSarcasm, prevalent in everyday conversation, refers to the use of words that express negative attitudes toward persons or events. Acoustic cues associated with sarcasm have been reported to vary across studies and the relative importance of particular acoustic parameters for signaling sarcasm has not been fully determined. The hemispheric specialization for the production of acoustic cues has been a matter of controversy. This study investigated the possible prosodic cues associated with Korean sarcastic utterances and the differential effect of left hemisphere damage (LHD) or right hemisphere damage (RHD) on the production of acoustic features of Korean sarcastic utterances. MethodTwenty one native speakers of Korean (7 individuals with LHD, 7 individuals with RHD, and 7 healthy controls (HC)) produced six Korean utterances in two different modes: sarcastic and literal. Utterances validated by sarcasm ratings by native listeners were analyzed acoustically utilizing durational and fundamental frequency (F0) measures. ResultsListeners’ ratings and acoustic analyses indicated that sarcastic utterances in Korean were produced with a combination of multiple acoustic cues. Discriminant function analyses and multiple linear regression showed that LHD and RHD differentially affected the production of acoustic cues associated with sarcasm. ConclusionLHD negatively affects the production of durational cues, while RHD negatively affects the production of F0 cues.

Awareness is in the eye of the observer: Preserved third-person awareness of deficit in anosognosia for hemiplegia

In recent decades, the research traditions of (first-person) embodied cognition and of (third-person) social cognition have approached the study of self-awareness with relative independence. However, neurological disorders of self-awareness offer a unifying perspective to empirically investigate the contribution of embodiment and social cognition to self-awareness. This study focused on a neuropsychological disorder of bodily self-awareness following right-hemisphere damage, namely anosognosia for hemiplegia (AHP). A previous neuropsychological study has shown AHP patients, relative to neurological controls, to have a specific deficit in third-person perspective taking and allocentric stance (the other unrelated to the self) in higher order mentalizing tasks. However, no study has tested if verbal awareness of motor deficits is influenced by perspective-taking and centrism and identified the related anatomical correlates. Accordingly, two novel experiments were conducted with right-hemisphere stroke patients with (n = 17) and without AHP (n = 17) that targeted either their own (egocentric, experiment 1) or another stooge patients (allocentric, experiment 2) motor abilities from a first-or-third person perspective. In both experiments, neurological controls showed no significant difference in perspective-taking, suggesting that social cognition is not a necessary consequence of right-hemisphere damage. More specifically, experiment 1 found AHP patients more aware of their own motor paralysis (egocentric stance) when asked from a third compared to a first-person perspective, using both group level and individual level analysis. In experiment 2, AHP patients were less accurate than controls in making allocentric judgements about the stooge patient, but with only a trend towards significance and with no difference between perspectives. As predicted, deficits in egocentric and allocentric third-person perspective taking were associated with lesions in the middle frontal gyrus, superior temporal and supramarginal gyri, and white matter disconnections were more prominent with deficits in allocentricity. Behavioural and neuroimaging results demonstrate the intersecting relationship between bodily self-awareness and self-and-other-directed metacognition or mentalisation.

Hemispheric Differences in Self-evaluation Errors of Upper Extremity Movement in Patients with Chronic Stroke.

There is growing evidence that the side of brain lesions results in distinct upper extremity deficits in motor control, movement behavior, and emotional and cognitive function poststroke. We investigated self-evaluation errors, which are the differences in scores between patient self-evaluation and clinician evaluations, and compared patients with left hemisphere damage (LHD) and right hemisphere damage (RHD) poststroke. Twenty-eight patients with chronic stroke (LHD = 16) performed the actual amount of the test twice with a one-week interval. We videotaped the participants' movements, and participants with stroke and evaluators graded the quality of movement scores by watching video recordings. Self-evaluation errors were significantly lower in patients with LHD than in those with RHD (t = 2.350, p = .019). Interestingly, this error did not change after the clinician provided the correct score as feedback. Chi-squared analysis revealed that more patients with LHD underestimated their movements (χ2 = 9.049, p = .002), while more patients with RHD overestimated (χ2 = 7.429, p = .006) in the send evaluation. Furthermore, there were no correlations between self-evaluation error and age, cognitive function, physical impairment, ability to control emotions, or onset months poststroke. Patients with stroke and therapists evaluated the same movements differently, and this can be dependent on hemispheric damage. Therapists might need to encourage patients with LHD who underestimate their movement to ensure continuous use of their more-affected arm. Patients with RHD who overestimate their movement might need treatment to overcome impaired self-awareness, such as video recordings, to protect from unexpected dangerous situations.

좌반구 손상과 우반구 손상 뇌졸중 환자의 의문문 유형에 따른 운율 특성 비교*

This study examined the characteristics of linguistic prosody in terms of cerebral lateralization in three groups of 9 healthy speakers and 14 speakers with a history of stroke (7 with left hemisphere damage (LHD), 7 with right hemisphere damage (RHD)). Specifically, prosodic characteristics related to speech rate, duration, pitch, and intensity were examined in three types of interrogative sentences (wh-questions, yes-no questions, alternative questions) with auditory perceptual evaluation. As a result, the statistically significant key variables showed flaws in production of the linguistic prosody in the speakers with LHD. The statistically significant variables were more insufficiently produced for wh-questions than for yes-no and alternative questions. This trend was particularly noticeable in variables related to pitch and speech rate. This result suggests that when Korean speakers process linguistic prosody, such as that of lexico-semantic and syntactic information in interrogative sentences, the left hemisphere seems to be superior to the right hemisphere.

Explicit Training to Improve Affective Prosody Recognition in Adults with Acute Right Hemisphere Stroke.

Difficulty recognizing affective prosody (receptive aprosodia) can occur following right hemisphere damage (RHD). Not all individuals spontaneously recover their ability to recognize affective prosody, warranting behavioral intervention. However, there is a dearth of evidence-based receptive aprosodia treatment research in this clinical population. The purpose of the current study was to investigate an explicit training protocol targeting affective prosody recognition in adults with RHD and receptive aprosodia. Eighteen adults with receptive aprosodia due to acute RHD completed affective prosody recognition before and after a short training session that targeted proposed underlying perceptual and conceptual processes. Behavioral impairment and lesion characteristics were investigated as possible influences on training effectiveness. Affective prosody recognition improved following training, and recognition accuracy was higher for pseudo- vs. real-word sentences. Perceptual deficits were associated with the most posterior infarcts, conceptual deficits were associated with frontal infarcts, and a combination of perceptual-conceptual deficits were related to temporoparietal and subcortical infarcts. Several right hemisphere ventral stream regions and pathways along with frontal and parietal hypoperfusion predicted training effectiveness. Explicit acoustic-prosodic-emotion training improves affective prosody recognition, but it may not be appropriate for everyone. Factors such as linguistic context and lesion location should be considered when planning prosody training.

Motor Deficits in the Ipsilesional Arm of Severely Paretic Stroke Survivors Correlate With Functional Independence in Left, but Not Right Hemisphere Damage.

Chronic stroke survivors with severe contralesional arm paresis face numerous challenges to performing activities of daily living, which largely rely on the use of the less-affected ipsilesional arm. While use of the ipsilesional arm is often encouraged as a compensatory strategy in rehabilitation, substantial evidence indicates that motor control deficits in this arm can be functionally limiting, suggesting a role for remediation of this arm. Previous research has indicated that the nature of ipsilesional motor control deficits vary with hemisphere of damage and with the severity of contralesional paresis. Thus, in order to design rehabilitation that accounts for these deficits in promoting function, it is critical to understand the relative contributions of both ipsilesional and contralesional arm motor deficits to functional independence in stroke survivors with severe contralesional paresis. We now examine motor deficits in each arm of severely paretic chronic stroke survivors with unilateral damage (10 left-, 10 right-hemisphere damaged individuals) to determine whether hemisphere-dependent deficits are correlated with functional independence. Clinical evaluation of contralesional, paretic arm impairment was conducted with the upper extremity portion of the Fugl-Meyer assessment (UEFM). Ipsilesional arm motor performance was evaluated using the Jebsen-Taylor Hand Function Test (JTHFT), grip strength, and ipsilesional high-resolution kinematic analysis during a visually targeted reaching task. Functional independence was measured with the Barthel Index. Functional independence was better correlated with ipsilesional than contralesional arm motor performance in the left hemisphere damage group [JTHFT: [r(10) = −0.73, p = 0.017]; grip strength: [r(10) = 0.64, p = 0.047]], and by contralesional arm impairment in the right hemisphere damage group [UEFM: [r(10) = 0.66, p = 0.040]]. Ipsilesional arm kinematics were correlated with functional independence in the left hemisphere damage group only. Examination of hemisphere-dependent motor correlates of functional independence showed that ipsilesional arm deficits were important in determining functional outcomes in individuals with left hemisphere damage only, suggesting that functional independence in right hemisphere damaged participants was affected by other factors.

Discourse MarkerNa(那) as an Interpersonal-Level Compensatory Strategy in Clinical Interviews

AbstractDiscourse markers (DMs) are characterized by multifunctionality in different contexts. This study addressed the use of the Chinese DM,na(那), as a solution to topical divergence, during clinical interactions with right-hemisphere-damaged (RHD) patients. Drawing on data collected from clinical interviews between psychotherapists and RHD patients, this study examined the functions ofnain response to RHD topical divergence, focusing on the topic and attitudinal aspects. It was found thatnawas mainly employed by psychotherapists to mark a reproffer of interview topics (i. e., an attempt to return to earlier topics), and a display of disalignment and disaffiliation with RHD topical divergence. These functions ofnareflect the psychotherapists’ attempts to overcome communicative problems arising from RHD topical divergence, so as to ensure the achievement of the communicative goal. Thus,nacan be interpreted as a compensatory strategy for dealing with RHD topical divergence on an interpersonal level. These findings not only expand our knowledge about the function spectrum ofna, but also offer insights for RHD patients’ interlocutors to enhance conversational communication with RHD patients via the compensatory strategy.

Working Memory in Unilateral Spatial Neglect: Evidence for Impaired Binding of Object Identity and Object Location.

Working memory (WM) is known to be impaired in patients with stroke experiencing unilateral spatial neglect (USN). Here, we examined in a systematic manner three WM components: memory of object identity, memory of object location, and binding between object identity and location. Moreover, we used two different retention intervals to isolate maintenance from other mnemonic and perceptual processes. Fourteen USN first-event stroke patients with right-hemisphere damage were tested in two different WM experiments using long and short retention intervals and an analog response scale. Patients exhibited more identification errors for items displayed on the contralesional side. Localization errors were also more prominent in the contralesional side, especially after a long retention interval. These localization errors were often a result of swap errors, that is, erroneous localizations of correctly identified contralesional objects in correctly memorized locations of ipsilesional objects. We conclude that a key WM deficit in USN is a lateralized impairment in binding between the identity of an object and its spatial tag.