Trainability of affordance judgments in right and left hemisphere stroke patients.

Whenever we are confronted with action opportunities in everyday life, e.g., when passing an opening, we rely on our ability to precisely estimate our own bodily capabilities in relation to the environmental conditions. So-called affordance judgments can be affected after brain damage. Previous studies with healthy adults showed that such judgments appeared to be trainable within one session. In the current study, we examined whether stroke patients with either right brain damage (n = 30) or left brain damage (n = 30) may similarly profit from training in an aperture task. Further, the role of neuropsychological deficits in trainability was investigated. In the administered task, stroke patients decided whether their hand would fit into a presented opening with varying horizontal width (Aperture Task). During one training session, patients were asked to try to fit their hand into the opening and received feedback on their decisions. We analyzed accuracy and the detection theory parameters perceptual sensitivity and judgment tendency. Both patients with right brain damage and patients with left brain damage showed improved performance during training as well as post training. High variability with differential profiles of trainability was revealed in these patients. Patients with impaired performance in a visuo-spatial or motor-cognitive task appeared to profit considerably from the target-driven action phase with feedback, but the performance increase in judgments did not last when the action was withdrawn. Future studies applying lesion analysis with a larger sample may shed further light on the dissociation in the trainability of affordance judgments observed in patients with versus without visuo-spatial or motor-cognitive deficits.

Attention deficits and depressive symptoms improve differentially after rehabilitation of post-COVID condition - A prospective cohort study.

BACKGROUND: Depressive and cognitive symptoms like fatigue, loss of energy or sleep disorders characterise the post-COVID condition. Post-COVID psychosomatic rehabilitation should focus on both symptom groups. The current prospective cohort study addresses the change in these symptoms in the context of a psychosomatic rehabilitation. METHOD: N = 80 patients with post-COVID symptoms underwent psychological testing on admission and discharge: PHQ-9 questionnaire for depression, TAP - test battery for the attention test with the sub-tests working memory, sustained attention, divided attention and alertness. Sample characteristics, including health-related and work-related parameters, the general symptom load and the course of symptoms during the five weeks of rehabilitation were evaluated. RESULTS: On admission, the PHQ-9 indicated the presence of depressive symptoms in post-COVID patients (PHQ-9 = 15.15 ± 5.11). Over the course of rehabilitation, the depressive symptoms decreased to a sub-clinical level (PHQ-9 = 8.80 ± 4.61), suggesting a strong effect of post-COVID inpatient rehabilitation (Cohen's d = 1.57). At the same time, post-COVID patients showed clinically relevant impairments in attention and working memory that persisted throughout the rehabilitation period despite multimodal post-COVID treatment. CONCLUSION: Over the course of post-COVID rehabilitation, depressive symptoms appear to be significantly reduced. With regard to cognitive impairment, a comparable effect within the short period of 5 weeks is not evident. Our results suggest the need for specific treatment of persistent neuropsychological deficits following post-COVID rehabilitation.

Short-term intervention complemented by wearable technology improves Trichotillomania - A naturalistic single-case report.

There is a growing interest in using wearable technology for the treatment of body-focused repetitive behaviors (BFRBs), such as Trichotillomania. Yet, to our knowledge, few studies address the applicability and use of wearable technology as a therapeutic element in more naturalistic situations. Here we would like to introduce its potential use combined with a Habit-Reversal Training in a single-case experimental design. In practice, individuals with BFRBs frequently show complex constellations of psychiatric disorders. Accordingly, the here presented participant was diagnosed with Trichotillomania as well as comorbid ADHD and examination phobia. The participant was offered to wear an unobtrusive and user-friendly vibration device that sent an alarm when her critical hairpulling behaviors occurred. The complementing Habit-Reversal Training included an Awareness Training supported by the vibration alarm of the wearable device. It further included a Competing Response Training by learning benign behaviors that could replace the hairpulling behavior. The frequency of hairpulling episodes was assessed using daily self-reports and by using the monitoring function of the wearable device. The intervention procedure was implemented into the participant's everyday life and evaluated over the course of 214 days. The results indicated a significant reduction in the daily episodes of hair pulling. Our preliminary findings suggest that the here applied intervention has the potential to effectively treat Trichotillomania in individuals with comorbid disorders in psychotherapeutic outpatient care. Certainly, group-studies will need to further validate the approach's effectiveness.

Does aging amplify the rule-based efficiency effect in action selection?

When it comes to the selection of adequate movements, people may apply varying strategies. Explicit if-then rules, compared to implicit prospective action planning, can facilitate action selection in young healthy adults. But aging alters cognitive processes. It is unknown whether older adults may similarly, profit from a rule-based approach to action selection. To investigate the potential effects of aging, the Rule/Plan Motor Cognition (RPMC) paradigm was applied to three different age groups between 31 and 90 years of age. Participants selected grips either instructed by a rule or by prospective planning. As a function of age, we found a general increase in a strategy-specific advantage as quantified by the difference in reaction time between plan- and rule-based action selection. However, in older age groups, these differences went in both directions: some participants initiated rule-based action selection faster, while for others, plan-based action selection seemed more efficient. The decomposition of reaction times into speed of the decision process, action encoding, and response caution components suggests that rule-based action selection may reduce action encoding demands in all age groups. There appears a tendency for the younger and middle age groups to have a speed advantage in the rule task when it comes to information accumulation for action selection. Thus, one influential factor determining the robustness of the rule-based efficiency effect across the lifespan may be presented by the reduced speed of information uptake. Future studies need to further specify the role of these parameters for efficient action selection.

Diagnosing homo digitalis: towards a standardized assessment for digital tool competencies.

Introduction: In the 21st century, digital devices have become integral to our daily lives. Still, practical assessments designed to evaluate an individual's digital tool competencies are absent. The present study introduces the "Digital Tools Test" ("DIGI"), specifically designed for the evaluation of one's proficiency in handling common applications and functions of smartphones and tablets. The DIGI assessment has been primarily tailored for prospective use among older adults and neurological patients with the latter frequently suffering from so-called apraxia, which potentially also affects the handling of digital tools. Similar to traditional tool use tests that assess tool-selection and tool-action processes, the DIGI assessment evaluates an individual's ability to select an appropriate application for a given task (e.g., creating a new contact), their capacity to navigate within the chosen application and their competence in executing precise and accurate movements, such as swiping. Methods: We tested the implementation of the DIGI in a group of 16 healthy adults aged 18 to 28 years and 16 healthy adults aged 60 to 74 years. All participants were able to withstand the assessment and reported good acceptance. Results: The results revealed a significant performance disparity, with older adults displaying notably lower proficiency in the DIGI. The DIGI performance of older adults exhibited a correlation with their ability to employ a set of novel mechanical tools, but not with their ability to handle a set of familiar common tools. There was no such correlation for the younger group. Conclusion: In conclusion, this study introduces an innovative assessment tool aimed at evaluating common digital tool competencies. Our preliminary results demonstrate good acceptance and reveal expected group differences. For current cohorts of older adults, the results seem to indicate that the ability to use novel tools may aid digital tool use. In the next step, the psychometric properties of the DIGI assessment should be evaluated in larger and more diverse samples. The advancement of digital tool competency assessments and rehabilitation strategies is essential when we aim at facilitating societal inclusion and participation for individuals in affected populations.

Selective effects of psychosocial stress on plan based movement selection.

Efficient movement selection is crucial in everyday activities. Whether this function is governed by our stress system is so far unknown. In the current study, data from thirty-six young male adults were analyzed. They performed rule- and plan-based movement selection tasks before (session 1) and after (session 2) a psychosocial stressor, or after a control condition without additional social stressor. Results showed that the rule-based efficiency advantage which was observed prior to the psychosocial stressor was significantly reduced afterwards in the whole sample, as well as in the stress group. Regression analyses revealed that this effect was due to a modulation of the plan-based approach. Especially variations-both increase and decrease-in the parasympathetic activity (reflected by the heart rate variability measure RMSSD) appeared to be disadvantageous for plan-based movement selection improvement. In contrast, performance in the rule-based movement selection tasks appeared to be rather invariant to external influences. The current results suggest that autonomic nervous system activity might modulate motor-cognitive performance. This modulatory capability might be selective for plan-based approaches, hence the applied strategy to movement selection could be decisive when it comes to the vulnerability of motor-cognitive processes towards psychosocial stress.

100 years after Liepmann-Lesion correlates of diminished selection and application of familiar versus novel tools.

100 years ago, Liepmann highlighted the role of left ventro-dorsal lesions for impairments in conceptual (rather ventral) and motor (more dorsal) related aspects of apraxia. Many studies thereafter attributed to an extended left fronto-temporo-parietal network. Yet, to date there are only few studies that looked at apraxic performance in the selection and application of familiar versus novel tools. In the current study we applied modern voxel-based lesion-symptom mapping (VLSM) to analyze neural correlates of impaired selection and application of familiar versus novel tools. 58 left (LBD) and 51 right brain damaged (RBD) stroke patients participated in the Novel Tools Test (NTT) and the Familiar Tools Test (FTT) of the Diagnostic Instrument for Limb Apraxia (DILA-S). We further assessed performance in control tasks, namely semantic knowledge (BOSU), visuo-spatial working memory (Corsi Block Tapping) and meaningless imitation of gestures (IML). Impaired tool use was most pronounced after LBD. Our VLSM results in the LBD group suggested that selection- versus application-related aspects of praxis and semantics of familiar versus novel tool use can be behaviorally and neuro-anatomically differentiated. For impairments in familiar tool tasks, the major focus of lesion maps was rather ventral while deficiencies in novel tool tasks went along with rather dorsal lesions. Affected selection processes were linked to rather anterior lesions, while impacted application processes went along with rather posterior lesion maps. In our study, particular tool selection processes were rather specific for familiar versus novel tools. Foci for lesion overlaps of experimental and control tasks were noticed ventrally for semantic knowledge and FTT, in fronto-parietal regions for working memory and NTT, and ventro-dorsally for imitation of meaningless gestures and the application of NTT and FTT. We visualized our current interpretation within a neuroanatomical model for apraxia of tool use.

Improvement of Apraxia With Augmented Reality: Influencing Pantomime of Tool Use via Holographic Cues.

Background: Defective pantomime of tool use is a hall mark of limb apraxia. Contextual information has been demonstrated to improve tool use performance. Further, knowledge about the potential impact of technological aids such as augmented reality for patients with limb apraxia is still scarce. Objective: Since augmented reality offers a new way to provide contextual information, we applied it to pantomime of tool use. We hypothesize that the disturbed movement execution can be mitigated by holographic stimulation. If visual stimuli facilitate the access to the appropriate motor program in patients with apraxia, their performance should improve with increased saliency, i.e., should be better when supported by dynamic and holographic cues vs. static and screen-based cues. Methods: Twenty one stroke patients and 23 healthy control subjects were randomized to mime the use of five objects, presented in two Environments (Screen vs. Head Mounted Display, HMD) and two Modes (Static vs. Dynamic) resulting in four conditions (ScreenStat, ScreenDyn, HMDStat, HMDDyn), followed by a real tool demonstration. Pantomiming was analyzed by a scoring system using video recordings. Additionally, the sense of presence was assessed using a questionnaire. Results: Healthy control participants performed close to ceiling and significantly better than patients. Patients achieved significantly higher scores with holographic or dynamic cues. Remarkably, when their performance was supported by animated holographic cues (e.g., striking hammer), it did not differ significantly from real tool demonstration. As the sense of presence increases with animated holograms, so does the pantomiming. Conclusion: Patients' performance improved with visual stimuli of increasing saliency. Future assistive technology could be implemented upon this knowledge and thus, positively impact the rehabilitation process and a patient's autonomy.

Manual praxis and language-production networks, and their links to handedness.

While Liepmann was one of the first researchers to consider a relationship between skilled manual actions (praxis) and language for tasks performed "freely from memory", his primary focus was on the relations between the organization of praxis and left-hemisphere dominance. Subsequent attempts to apply his apraxia model to all cases he studied - including his first patient, a "non-pure right-hander" treated as an exception - left the praxis-handedness issue unresolved. Modern neuropsychological and recent neuroimaging evidence either showed closer associations of praxis and language, than between handedness and any of these two functions, or focused on their dissociations. Yet, present-day developments in neuroimaging and statistics allow us to overcome the limitations of the earlier work on praxis-language-handedness links, and to better quantify their interrelationships. Using functional magnetic resonance imaging (fMRI), we studied tool use pantomimes and subvocal word generation in 125 participants, including righthanders (NRH = 52), ambidextrous individuals (mixedhanders; NMH = 31), and lefthanders (NLH = 42). Laterality indices were calculated both in two critical cytoarchitectonic maps, and 180 multi-modal parcellations of the human cerebral cortex, using voxel count and signal intensity, and the most relevant regions of interest and their networks were further analyzed. We found that atypical organization of praxis was present in all handedness groups (RH = 25.0%, MH = 22.6%; LH = 45.2%), and was about two and a half times as common as atypical organization of language (RH = 3.8%; MH = 6.5%; LH = 26.2%), contingent on ROI selection/LI-calculation method. Despite strong associations of praxis and language, regardless of handedness and typicality, dissociations of atypically represented praxis from typical left-lateralized language were common (~20% of cases), whereas the inverse dissociations of atypically represented language from typical left-lateralized praxis were very rare (in ~2.5% of all cases). The consequences of the existence of such different phenotypes for theoretical accounts of manual praxis, and its links to language and handedness are modeled and discussed.

Association of Fatigue Severity With Maladaptive Coping in Multiple Sclerosis: A Data-Driven Psychodynamic Perspective.

Fatigue in persons with multiple sclerosis (PwMS) is severely disabling. However, the underlying mechanisms remain incompletely understood. Recent research suggests a link to early childhood adversities and psychological trait variables. In line with these studies, this paper took a psychodynamic perspective on MS-fatigue. It was hypothesized that fatigue could represent a manifestation of maladaptive coping with intense emotions. The schema therapeutic mode model served as a theoretical and empirically validated framework, linking psychodynamic theory and empirical research methods. The study was based on a data set of N = 571 PwMS that has also served as the basis for another publication. Data was collected online. The Schema Mode Inventory was used to quantify regulatory strategies to cope with emotionally stressful experiences. In addition, depressive symptoms (Beck's Depression Inventory - FastScreen), physical disability (Patient Determined Disease Steps), alexithymia (Toronto Alexithymia Scale-26), adverse childhood experiences (Childhood Trauma Questionnaire), and self-reported fatigue (Fatigue Scale for Motor and Cognitive Functions) were assessed. Latent profile analysis revealed three distinct groups of PwMS, based on their coping mode profiles: (1) PwMS with low maladaptive coping, (2) PwMS with avoidant/submissive coping styles, and (3) PwMS with avoidant/overcompensatory coping styles. Multivariate comparisons showed no significant difference in physical disability across the three groups. However, heightened levels of self-reported fatigue and depression symptoms occurred in PwMS with maladaptive coping styles. A path model uncovered that self-reported fatigue was robustly related to physical disability (ß = 0.33) and detached/avoidant coping (Detached Protector; ß = 0.34). There was no specific relation between any of the maladaptive coping modes and depression symptoms. Detached/avoidant coping was in turn predicted by childhood emotional abuse and neglect. The results indicate that childhood adversity and detached/avoidant coping styles may be associated with variability in MS-fatigue severity: PwMS that resort to detached/avoidant coping in response to negative emotions also tend to report heightened levels of fatigue, although they do not differ in their perceived disability from PwMS with low levels of fatigue and maladaptive coping. A link between MS-fatigue and the psychodynamic traumatic conversion model is discussed. The implications of these findings for therapeutic interventions require further study.

Exploring Adherence to First-Line and Second-Line Immunotherapies in Multiple Sclerosis: An Interview Study.

BACKGROUND: Treatment adherence is fundamental in multiple sclerosis (MS) management. Adherence rates vary significantly between studies, ranging from 30% to almost 90%, depending on assessment method and medication type. This study aimed to identify patient-related categories associated with treatment modification or discontinuation in people with MS receiving either first- or second-line treatment. METHODS: Semistructured interviews were performed with 23 people with MS: 11 receiving first-line treatment and 12 receiving second-line treatment. Medication history, experiences with previous medications, decision-making processes regarding immunotherapy, adherence behavior, and reasons for adherence/nonadherence were explored using open-ended questions. Qualitative content analysis was performed using a combined deductive-inductive approach in building a coding frame. Differences in coding frequencies were compared between the two groups and analyzed quantitatively. Cohen's kappas of 0.76 for people with MS receiving first-line treatment and 0.64 for the second-line sample were achieved between the two coders. RESULTS: One key reason for nonadherence reported by first-line-treated people with MS was burdensome side effects, and for adherence was belief in medication effectiveness. In people with MS receiving second-line treatment, lack of perceived medication effectiveness was a key category related to changes in or discontinuation of immunotherapy. Reasons for adherence were positive illness beliefs/perceptions and belief in highly active disease. Intentional nonadherence was a major issue for first-line treatment and less relevant for second-line treatment. CONCLUSIONS: These results indicate specific differences in factors mitigating adherence in people with MS receiving first- and second-line treatment.

Fatigue in Multiple Sclerosis Is Associated With Childhood Adversities.

Fatigue is a common and disabling symptom in patients with Multiple Sclerosis (PwMS). Its pathogenesis, however, is still not fully understood. Potential psychological roots, in particular, have received little attention to date. The present study examined the association of childhood adversities, specific trait characteristics, and MS disease characteristics with fatigue symptoms utilizing path analysis. Five hundred and seventy-one PwMS participated in an online survey. Standardized psychometric tools were applied. The Childhood Trauma Questionnaire (CTQ) served to assess childhood adversities. Trait variables were alexithymia (Toronto Alexithymia Scale; TAS-26) and early maladaptive schemas (Young Schema Questionnaire; YSQ). Current pathology comprised depression (Beck's Depression Inventory FastScreen; BDI-FS) and anxiety symptoms (State-Trait Anxiety Inventory; STAI-state), as well as physical disability (Patient determined Disease Steps; PDDS). The Fatigue Scale for Motor and Cognitive Functions (FSMC) was the primary outcome variable measuring fatigue. PwMS displayed high levels of fatigue and depression (mean FSMC score: 72; mean BDI-II score: 18). The final path model revealed that CTQ emotional neglect and emotional abuse remained as the only significant childhood adversity variables associated with fatigue. There were differential associations for the trait variables and current pathology: TAS-26, the YSQ domain impaired autonomy and performance, as well as all current pathology measures had direct effects on fatigue symptoms, accounting for 28.2% of the FSMC variance. Bayesian estimation also revealed indirect effects from the two CTQ subscales on FSMC. The final model fitted the data well, also after a cross-validation check and after replacing the FSMC with the Chalder Fatigue Questionnaire (CFQ). This study suggests an association psychological factors on fatigue in Multiple Sclerosis. Childhood adversities, as well as specific trait characteristics, seem to be associated with current pathology and fatigue symptoms. The article discusses potential implications and limitations.

Medication beliefs in first-line and second-line treated multiple sclerosis patients.

BACKGROUND: Immune treatments of multiple sclerosis (MS) can be classified in first-line and second-line approaches. While in both treatment efficacy is often not easy to assess in the short-term, treatment and illness beliefs may differ in first-line and second-line treated patients. The current study aimed to assess differential beliefs about medicine and illness perception between these groups based on the hypothesis that they are closely connected to adherence behaviour. METHODS: An online survey through the website of the German MS Society was performed investigating beliefs about immune treatments as well as the patients' illness perceptions with validated questionnaires. Demographic factors, disability and self-reported adherence rates were studied as moderator variables. RESULTS: In total, 630 patients participated. Data of 433 first-line treated and 192 second-line treated patients with MS (PwMS) were analysed. Necessity beliefs and also concerns beliefs were significantly higher in second-line treated PwMS (MANCOVA p =.001 and p =.006) and generally in patients with higher disability, while illness perception did not differ between groups. Self-assessed adherence rates were around 70% for oral treatments and injectables irrespective of first-line or second-line. Nonadherence was below 5% for infusion treatments. However, most patients reported only single omissions. CONCLUSION: The current study reveals differential behavioural attitudes between first-line versus second-line-treated PwMS. However, follow-up studies are needed to further unravel the relationship between behavioural attitudes and treatment adherence.

Is This Within Reach? Left but Not Right Brain Damage Affects Affordance Judgment Tendencies.

The ability to judge accurately whether or not an action can be accomplished successfully is critical for selecting appropriate response options that enable adaptive behaviors. Such affordance judgments are thought to rely on the perceived fit between environmental properties and knowledge of one's current physical capabilities. Little, however, is currently known about the ability of individuals to judge their own affordances following a stroke, or about the underlying neural mechanisms involved. To address these issues, we employed a signal detection approach to investigate the impact of left or right hemisphere injuries on judgments of whether a visual object was located within reach while remaining still (i.e., reachability). Regarding perceptual sensitivity and accuracy in judging reachability, there were no significant group differences between healthy controls (N = 29), right brain damaged (RBD, N = 17) and left brain damaged stroke patients (LBD, N = 17). However, while healthy controls and RBD patients demonstrated a negative response criterion and thus overestimated their reach capability, LBD patients' average response criterion converged to zero, indicating no judgment tendency. Critically, the LBD group's judgment tendency pattern is consistent with previous findings in this same sample on an affordance judgment task that required estimating whether the hand can fit through apertures (Randerath et al., 2018). Lesion analysis suggests that this loss of judgment tendency may be associated with damage to the left insula, the left parietal and middle temporal lobe. Based on these results, we propose that damage to the left ventro-dorsal stream disrupts the retrieval and processing of a stable criterion, leading to stronger reliance on intact on-line body-perceptive processes computed within the preserved bilateral dorsal network.

[Formula: see text] Limb apraxia profiles in different clinical samples.

Objective: Limb apraxia is a motor cognitive disorder that has been mainly studied in patients with dementia or left hemisphere stroke (LHS). However, limb apraxia has also been reported in patients with right hemisphere stroke (RHS), multiple sclerosis (MS) or traumatic brain injury (TBI). This study's aim was to report detailed praxis performance profiles in samples suffering from these different neurological disorders by use of the Diagnostic Instrument for Limb Apraxia (DILA-S).Method: 44 LHS patients, 36 RHS patients, 27 patients with dementia, 26 MS and 44 TBI patients participated. The diagnostics included the imitation of meaningless and meaningful hand gestures, pantomime of tool-use, single real tool-use as well as a multistep naturalistic action task (preparing breakfast).Results: Apraxia occurred in all tested samples but to a varying degree and with dissimilar profiles. LHS patients demonstrated most severe deficits in pantomime, but they were also vulnerable to deficits in real tool-use. Dementia patients showed high incidence rates of apraxia in almost all subscales of the DILA-S. RHS patients demonstrated difficulties in imitation and pantomime of tool-use, but they did not show severe difficulties with real tool-use. TBI patients appeared challenged by multistep naturalistic actions. The tested MS sample did not show clinically relevant symptoms in the DILA-S.Conclusion: Different types of patients display varying limb apraxic symptoms detectable by the DILA-S. In these limb apraxia susceptible populations, testing should be warranted as standard. Prospectively, individual error profiles may be helpful for shaping motor cognitive training.

A combined therapy for limb apraxia and related anosognosia.

Left hemisphere stroke frequently leads to limb apraxia, a disorder that has been reported to impact independence in daily life and rehabilitation success. Nonetheless, there is a shortcoming in research and availability of applicable trainings. Further, to date, anosognosia for limb apraxia has largely been neglected. Therefore, we developed a Naturalistic Action Therapy that trains object selection and application with an errorless learning approach and which includes supported self-evaluation. The current study presents the results of two stroke patients participating in the training. The procedure entailed two baseline and one post-training sessions including standardized limb apraxia and anosognosia assessments as well as 18 naturalistic action tasks. The training consisted of 15 sessions during which 4-6 of the 18 naturalistic action tasks (e.g., pour water into a glass, make a phone call) were trained. Both patients showed improvement in trained and untrained tasks as well as in standardized apraxia and anosognosia assessments. Training effects appeared strongest for the trained items. The procedure is documented in detail and easy to administer and thus may have the potential to be applied by relatives. The results of this pilot-study are promising and suggest that the approach is suitable for further evaluation.

Does it still fit? - Adapting affordance judgments to altered body properties in young and older adults.

Actor-related affordance judgments are decisions about potential actions that arise from environmental as well as bodily and cognitive conditions. The system can be challenged by sudden changes to otherwise rather stable actor references e.g. due to accidental bodily injuries or due to brain damage and resulting motor and cognitive constraints. The current study investigated adaptation to suddenly artificially altered body properties and its reversibility in healthy young versus older adults. Participants were asked to judge whether they would be able to fit their hand through a given horizontal opening (Aperture Task). Body alterations were induced by equipping participants with one hand splint for 24 hours that enlarged the hand in width and height. Participants were tested before and directly after putting the splint on as well as after a habituation period of 24 hours. To assess reversibility, participants were tested again directly after removing the splint and one day later. Judgment accuracy values and detection theory measures were reported. Both, young and older adults judged more conservatively when body properties were altered compared to initial judgments for normal body properties. Especially older adults showed major difficulties in such quick adaptation. Older adults' judgment accuracy as well as perceptual sensitivity were significantly lowered when body properties were suddenly altered. Importantly, lowered judgment performance occurred for both, the splinted as well as the non-splinted hand in older adults. Only after 24 hours of habituation, older adults tended to regain initial performance levels showing adaptive behavior to the altered condition. Removing the hand splint for one day was sufficient to reverse these adaptive effects. Our study results suggest that aging slows down adaptation to sudden bodily alterations affecting actor-related affordance judgments. We propose that these altered processes may go along with uncertainty and a heightened concern about potential consequences of misjudgments. Clearly, future studies are needed to further elucidate the underlying processes of adaptation in affordance judgments. These may reveal major implications for the aging society and its associated problems with an increased risk of falling or stroke related bodily constraints.

Correction: Does it fit?-Trainability of affordance judgments in young and older adults.

[This corrects the article DOI: 10.1371/journal.pone.0212709.].

In search of distinct MS-related fatigue subtypes: results from a multi-cohort analysis in 1.403 MS patients.

Fatigue is among the most disabling symptoms in patients with multiple sclerosis (PwMS). The common distinction between cognitive and motor fatigue is typically incorporated in self-rating instruments, such as the Chalder Fatigue Questionnaire (CFQ), the Fatigue Scale for Motor and Cognitive Functions (FSMC) or the Modified Fatigue Impact Scale (MFIS). The present study investigated the factor structure of the CFQ, the FSMC and the MFIS utilizing exploratory (EFA) and confirmatory factor analysis (CFA) as well as exploratory structural equation modeling (ESEM). Data of 1.403 PwMS were analyzed, utilizing four samples. The first sample (N = 605) was assessed online and split into two stratified halves to perform EFA, CFA, and ESEM on the CFQ and FSMC. The second sample (N = 293) was another online sample. It served to calculate CFA and ESEM on the CFQ and FSMC. The third sample was gathered in a clinical setting (N = 196) and analyzed by applying CFA and ESEM to the FSMC. The fourth sample (N = 309) was assessed in a clinical setting and allowed to run a CFA and ESEM on the MFIS. Proposed factor structures of all questionnaires were largely confirmed in EFA. However, none of the calculated CFAs and ESEMs could verify the proposed factor structures of the three measures, even with oblique rotation techniques. The findings might have implications for future research into the pathophysiological basis of MS-related fatigue and could affect the suitability of such measures as outcomes for treatment trials, presumably targeting specific sub-components of fatigue.

Does it fit? - Trainability of affordance judgments in young and older adults.

Will I fit into the overcrowded subway? Advanced aging can change our abilities associated with accurately judging the fit between perceived environmental properties and our own actual physical capabilities (affordance judgments). Two experimental studies examined the effects of aging and trainability in affordance judgments. Participants were asked to decide whether their hand fits into a given opening (Aperture Task). We used a detection theory approach to evaluate different judgment characteristics. Study 1 demonstrated that older (N = 39) compared to younger adults (N = 39) produced rather conservative judgments, but did not differ in perceptual sensitivity. Distributions of Hit and False-Alarm rates, as well as risk-perception statements (DOSPERT questionnaire), indicated a heightened concern about potential consequences of misjudgments in older adults. In Study 2, 20 younger and 22 older adults were trained by actually trying to fit their hand into each presented opening. Training included acoustic, haptic and visual feedback. Compared to pre-training, both groups demonstrated significant increases in accuracy when assessed post-training and after a one-week follow-up. While younger adults improved in perceptual sensitivity in post-training as well as in follow-up, the older group adjusted their tendency towards less conservative judgments in both following sessions. Our results are consistent with affordance models that propose a complex and dynamic interplay of different neural processes involved in this skill. Future studies are needed to further elucidate that interplay and the trainability of affordance judgments.