Effort-based decision making and motivational deficits in stroke patients.

Motivational deficits in patients recovering from stroke are common and can reduce active participation in rehabilitation and thereby impede functional recovery. We investigated whether stroke patients with clinically reduced drive, initiation, and endurance during functional rehabilitative training (n = 30) display systematic alterations in effort-based decision making compared to age, sex, and severity-matched stroke patients (n = 30) whose drive appeared unaffected. Notably, the two groups did not differ in self-reported ratings of apathy and depression. However, on an effort-based decision-making task, stroke patients with clinically apparent drive impairment showed intact willingness to accept effort for reward, but were more likely to fail to execute the required effort compared to patients without apparent drive impairments. In other words, the decision behavioural assessment revealed that stroke patients that displayed reduced drive, initiation, and endurance during inpatient neurorehabilitation failed to persist in goal-directed effort production, even over very short periods. These findings indicate that reduced drive during rehabilitative therapy in post-stroke patients is not due to a diminished motivation to invest physical effort, but instead is related to a reduced persistence with effortful behaviour.

Altered social decision making in patients with chronic pain.

BACKGROUND: Chronic pain affects up to 20% of the population, impairs quality of life and reduces social participation. Previous research reported that pain-related perceived injustice covaries with these negative consequences. The current study probed whether chronic pain patients responded more strongly to disadvantageous social inequity than healthy individuals. METHODS: We administered the Ultimatum Game, a neuroeconomic social exchange game, where a sum of money is split between two players to a large sample of patients with chronic pain disorder with somatic and psychological factors (n = 102) and healthy controls (n = 101). Anonymised, and in truth experimentally controlled, co-players proposed a split, and our participants either accepted or rejected these offers. RESULTS: Chronic pain patients were hypersensitive to disadvantageous inequity and punished their co-players for proposed unequal splits more often than healthy controls. Furthermore, this systematic shift in social decision making was independent of patients' performance on tests of executive functions and risk-sensitive (non-social) decision making . CONCLUSIONS: Our findings indicate that chronic pain is associated with anomalies in social decision making (compared to healthy controls) and hypersensitivity to social inequity that is likely to negatively impact social partaking and thereby the quality of life.

Neurorehabilitation of the upper extremity - immersive virtual reality vs. electromechanically assisted training. A comparative study.

Background: Severe paresis of the contralesional upper extremity is one of the most common and debilitating post-stroke impairments. The need for cost-effective high-intensity training is driving the development of new technologies, which can complement and extent conventional therapies. Apart from established methods using electromechanical devices, immersive virtual reality (iVR) systems hold promise to provide cost-efficient high-intensity arm training. Objective: We investigated whether iVR-based arm training yields at least equivalent effects on upper extremity function as compared to an electromechanically assisted training in stroke patients with severe arm paresis. Methods: 52 stroke patients with severe arm paresis received a total of ten daily group therapy sessions over a period of three weeks, which consisted of 20 min of conventional therapy and 20 min of either electromechanically assisted (ARMEOSpring®) or iVR-based (CUREO®) arm training. Changes in upper extremity function was assessed using the Action Research Arm Test (ARAT) and user acceptance was measured with the User Experience Questionnaire (UEQ). Results: iVR-based training was not inferior to electromechanically assisted training. We found that 84% of patients treated with iVR and 50% of patients treated with electromechanically assisted arm training showed a clinically relevant improvement of upper extremity function. This difference could neither be attributed to differences between the groups regarding age, gender, duration after stroke, affected body side or ARAT scores at baseline, nor to differences in the total amount of therapy provided. Conclusion: The present study results show that iVR-based arm training seems to be a promising addition to conventional therapy. Potential mechanisms by which iVR unfolds its effects are discussed.

Evident lower blood levels of multiple nutritional compounds and highly prevalent malnutrition in sub-acute stroke patients with or without dysphagia.

Introduction: Malnutrition is prevalent after stroke, particularly if post-stroke oropharyngeal dysphagia (OD) reduces nutritional intake. To further understand stroke-related malnutrition, a thorough nutritional assessment was performed in ischemic stroke patients with or without OD during sub-acute inpatient rehabilitation. Methods: In this exploratory, observational, cross-sectional, multi-center study in Germany (NTR6802), ischemic stroke patients with (N = 36) or without (N = 49) OD were age- and sex-matched to healthy reference subjects. Presence of (risk of) malnutrition (MNA-SF), blood concentration of stroke-relevant nutritional compounds and metabolites, nutritional intake, quality of life (EQ-5D-5L), and activities of daily living (Barthel index) were assessed. Results: More than half of the stroke patients displayed (risk of) malnutrition, with higher prevalence in patient with OD vs. without OD. Fasted blood concentrations of vitamins B1, B2, B6, A, D, and E, selenium, choline, coenzyme Q10, albumin, pre-albumin, transferrin, docosahexaenoic acid, and eicosapentaenoic acid were all lower in stroke patients compared to their matched healthy reference subjects, irrespective of OD status. Reported energy, macronutrient, and water intake were lower in stroke patients vs. healthy reference subjects. As expected, quality of life and activities of daily living scores were lower in stroke vs. healthy reference subjects, with OD scoring worse than non-OD patients. Discussion: This study shows that malnutrition is highly prevalent in sub-acute stroke patients during rehabilitation. Even though patients with OD were more likely to be malnourished, blood levels of specific nutritional compounds were similarly lower in stroke patients with or without OD compared to healthy reference subjects. Furthermore, subgroup analysis showed similarly lower blood levels of specific nutritional compounds in patients that are normal nourished vs. patients with (risk of) malnutrition. This might imply disease-specific changes in blood levels on top of overall protein-energy malnutrition. The results of the current study underline that it is important to screen for nutritional impairments in every stroke patient, either with or without OD.

Lesion Evidence for a Causal Role of the Insula in Aversion to Social Inequity.

Humans resist unequal distributions of goods in their social interactions, even if it requires foregoing personal gains. Functional neuroimaging studies implicate the insula in this aversion to social inequity and in fairness-related decisions, but a causal contribution has not yet been established. We compared the responses of 30 patients with lesions to the insula on a multiple-trial version of the one-shot Ultimatum Game, a neuroeconomic social exchange paradigm where a sum of money is split between two players, to those of 30 matched patients with brain injuries sparing the insula. Insula lesion patients accepted offers of an unequal disadvantageous split significantly more often than comparison lesion patients. Computational modeling confirmed that this difference in choice behavior was due to decreased aversion to disadvantageous inequity following insula damage, rather than due to increased decision noise or non-consideration of inequity. Our results provide novel evidence that the insula is causally involved in aversion to inequity and in value-based choices in the context of social interactions.

Not giving up: Testosterone promotes persistence against a stronger opponent.

Recent research suggests that when we lack a sense of control, we are prone to motivational failures and early quitting in competitions. Testosterone, on the other hand, is thought to boost competitiveness. Here we investigate the interaction between these factors, testing the testosterone's potential to enhance persistence in a competition against a stronger opponent, depending on experimentally manipulated perceived control. Healthy participants were administered a single dose of testosterone or placebo. They first underwent a task designed to either induce low or high perceived control and then entered a costly competition against a progressively stronger opponent that they could quit at any time. In the placebo group, men with low perceived control quitted twice as early as those with high perceived control. Testosterone countered this effect, making individuals with low control persist in the competition for as long as those with high perceived control, and did so also despite raising participants' explicit awareness of the opponents' advantage. This psychoendocrinological effect was not modulated by basal cortisol levels, CAG repeat polymorphism of the androgen receptor gene, or trait dominance. Our results provide the first causal evidence that testosterone promotes competitive persistence in humans and demonstrate that this effect depends on the psychological state elicited prior to the competition, broadening our understanding of the complex relationships between testosterone and social behaviors.

A decision-neuroscientific intervention to improve cognitive recovery after stroke.

Functional recovery after stroke is dose-dependent on the amount of rehabilitative training. However, rehabilitative training is subject to motivational hurdles. Decision neuroscience formalizes drivers and dampers of behaviour and provides strategies for tipping motivational trade-offs and behaviour change. Here, we used one such strategy, upfront voluntary choice restriction ('precommitment'), and tested if it can increase the amount of self-directed rehabilitative training in severely impaired stroke patients. In this randomized controlled study, stroke patients with working memory deficits (n = 83) were prescribed daily self-directed gamified cognitive training as an add-on to standard therapy during post-acute inpatient neurorehabilitation. Patients allocated to the precommitment intervention could choose to restrict competing options to self-directed training, specifically the possibility to meet visitors. This upfront choice restriction was opted for by all patients in the intervention group and highly effective. Patients in the precommitment group performed the prescribed self-directed gamified cognitive training twice as often as control group patients who were not offered precommitment [on 50% versus 21% of days, Pcorr = 0.004, d = 0.87, 95% confidence interval (CI95%) = 0.31 to 1.42], and, as a consequence, reached a 3-fold higher total training dose (90.21 versus 33.60 min, Pcorr = 0.004, d = 0.83, CI95% = 0.27 to 1.38). Moreover, add-on self-directed cognitive training was associated with stronger improvements in visuospatial and verbal working memory performance (Pcorr = 0.002, d = 0.72 and Pcorr = 0.036, d = 0.62). Our neuroscientific decision add-on intervention strongly increased the amount of effective cognitive training performed by severely impaired stroke patients. These results warrant a full clinical trial to link decision-based neuroscientific interventions directly with clinical outcome.

Illusion of control affects ERP amplitude reductions for auditory outcomes of self-generated actions.

The reduction of neural responses to self-generated stimuli compared to external stimuli is thought to result from the matching of motor-based sensory predictions and sensory reafferences and to serve the identification of changes in the environment as caused by oneself. The amplitude of the auditory event-related potential (ERP) component N1 seems to closely reflect this matching process, while the later positive component (P2/ P3a) has been associated with judgments of agency, which are also sensitive to contextual top-down information. In this study, we examined the effect of perceived control over sound production on the processing of self-generated and external stimuli, as reflected in these components. We used a new version of a classic two-button choice task to induce different degrees of the illusion of control (IoC) and recorded ERPs for the processing of self-generated and external sounds in a subsequent task. N1 amplitudes were reduced for self-generated compared to external sounds, but not significantly affected by IoC. P2/3a amplitudes were affected by IoC: We found reduced P2/3a amplitudes after a high compared to a low IoC induction training, but only for self-generated, not for external sounds. These findings suggest that prior contextual belief information induced by an IoC affects later processing as reflected in the P2/P3a, possibly for the formation of agency judgments, while early processing reflecting motor-based predictions is not affected.

Frequency and nature of pain in patients undergoing neurorehabilitation.

OBJECTIVE: This prospective study investigated the extent to which patients undergoing neurorehabilitation reported pain, how this pain developed during inpatient stay and whether patients were treated accordingly (using pain medication). METHODS: The extent of pain, performance in daily activities, with a focus on possible impairment from pain, and pain medication were assessed at the beginning and the end of neurorehabilitation treatment. Overall 584 patients, with various neurological diagnoses, such as stroke, intracerebral hemorrhage, polyneuropathy, etc. were classified into four groups based on whether they reported having "no pain," "mild pain," "moderate pain," or "severe pain." All patients received conventional neurorehabilitation therapy in the Mauritius Hospital, Germany. RESULTS: A total of 149 patients had clinically relevant pain at the beginning of their inpatient stay, at a group level this did not change significantly during the treatment period. At the end of inpatient stay, a slight increase was noted in patients reporting pain. Overall 164 patients suffered from moderate or severe pain, operationalized of pain scores >3 on the visual analog scale. A total of 145 patients who had pain at the end of inpatient stay, did not receive pain medication. There was a weak negative association between pain at baseline and activities of daily living at the end of the treatment period, such that, patients with higher pain levels tended to showed lower Barthel Index scores at the end. CONCLUSION: In our study, about one-third of patients suffered from clinically relevant pain during neurorehabilitation treatment and most of them did not receive any pain medication.

[Acute care interventions in inpatient neurorehabilitation]. / Krankenhausmedizinische Interventionen in der neurologischen Anschlussrehabilitation.

Treatment in hospitals differs from treatment in rehabilitation centers from a legal perspective because German law mandates that in hospitals physicians and other qualified personnel must be on duty at all times. This is not required for inpatient rehabilitation centers. Since this Act was passed more than 30 years ago, more acute medical interventions are now carried out and the number of older people in the population has increased. As a result patients are nowadays older, more multimorbid and therefore have a greater risk for medical complications. This is especially true for postacute neurological care. For this reason, the original legal framework for neurological rehabilitation treatment has become questionable. Therefore, we prospectively tested how often patients in inpatient neurorehabilitation suffer from complications that require immediate attention by qualified personnel. In 759 patients observed over a period of 6 months we found 602 complications requiring immediate interventions by physicians (e.g. falls, urinary tract infections, other forms of fever, diarrhea associated with Clostridium difficile, pneumonia, respiratory insufficiency, sepsis, epileptic seizures and arrhythmia). On average at least three acute care interventions occurred per day at the facility examined. We conclude that neurological inpatient rehabilitation has outgrown its legal foundations and now incorporates hospital care.

Inducing illusory control ensures persistence when rewards fade and when others outperform us.

Persisting even when the rewards of continued effort are fading is essential for achieving long-term goals, skills, and good health, alike. Yet, we often quit when things get hard. Here, we tested whether augmenting the feeling of control through external measures increases persistence under such discouraging circumstances. In two laboratory experiments, we first induced illusory control by manipulating the base-rate of positive outcomes and then tested the effect of this elevation of participants' perceived control upon their persistence under diminishing returns and in a competition against a stronger opponent. Induced illusory control significantly enhanced people's persistence in both of these motivationally challenging situations. Our findings demonstrate that motivation is dependent upon perceived, rather than objective, control, and reveal that this can be leveraged to counteract quitting behavior when things get hard, for instance in rehabilitation, physical activity interventions, or other training settings.

Conquering the inner couch potato: precommitment is an effective strategy to enhance motivation for effortful actions.

Letting effort-free gratification derail us from effort-requiring goals is one reason why we fail to realize health-relevant intentions like 'exercise regularly'. We tested the effectiveness of the self-control strategy precommitment in such effort-related conflicts, using a novel laboratory choice paradigm, where participants could precommit to an effort-requiring large reward by pre-eliminating an effort-free small reward from their choice set. Our participants used precommitment frequently and effectively, such that they reached effort-requiring large rewards more often. Using computational modelling and Bayesian model comparisons, we assessed whether participants employed precommitment to avoid anticipated willpower failures (i.e. as a self-regulatory measure) or to maximize their motivation to choose the effort-requiring option (i.e. as a self-motivational measure). Observed choices and precommitment decisions were consistent with the motivation maximization hypothesis, but not the willpower hypothesis. Our findings show that offering precommitment is effective in helping individuals optimize their motivation and choice behaviour and thereby achieve effort-requiring goals, and strongly encourage application of precommitment schemes in exercise and rehabilitation interventions. This article is part of the theme issue 'Risk taking and impulsive behaviour: fundamental discoveries, theoretical perspectives and clinical implications'.

[Integrated neurorehabilitation improves efficacy of treatment]. / Integrierte Neurorehabilitation verbessert Versorgungseffizienz.

Neurorehabilitation comprises medical and functional treatment. If patients in the post-hospital phase need acute medical interventions but these cannot be provided by the rehabilitation center, patients must be referred to suitable acute care hospitals; however, such referrals incur additional costs, are fraught with medical risks and delay further rehabilitation. We evaluated how integrating non-neurological medical specialties and a hospital unit into a neurorehabilitation center affects the rate of acute hospital referrals. The special situation in North-Rhine Westfalia, which was the last state in Germany to grant restricted hospital certification to neurorehabilitation centers, enabled a longitudinal assessment over 10 years. We analyzed the referral rate at one of the first hospitals in the state, which in addition to rehabilitation treatment (according to § 40 of the Social Security Code V, SGB V) now also provide hospital treatment (according to § 39 SGB V) and have reorganized in preparation for integrated treatment structures. In the center investigated (St. Mauritius Therapy Hospital Meerbusch) the average patient age increased between 2007 and 2017 from 69 years to 72 years and the proportion of severely ill patients on admission by 70%. Starting in 2012 integrated structures were established in a stepwise fashion with the inclusion of specialists in intensive care, cardiology and neurosurgery, extension of the diagnostic and interventional spectrum and establishment of a 24/7 emergency team with back-up from a new intensive care and mechanical ventilation unit. As a result referrals to hospitals dropped by more than 50% in all categories of disease severity despite the increase in age and morbidity. In view of the savings in costs of hospital treatment, reduced risks due to transfer and less interruption of rehabilitation, it is concluded that the efficacy of patient treatment is improved by discipline and sector integrated neurorehabilitation compared to isolated structures.

Second look Holter ECG in neurorehabilitation.

BACKGROUND: Many stroke survivors suffer recurrent stroke because paroxysmal atrial fibrillation (AF) was missed and no preventive anticoagulation initiated. This prospective cohort study determined the added diagnostic yield of second-look 24-h electrocardiographic recording (ECG) in a population at high risk for AF: patients who suffered a stroke of such severity that they require inpatient neurorehabilitation. METHODS: We enrolled 508 patients with ischemic stroke admitted to post-acute inpatient neurorehabilitation and determined whether AF was detected during acute care at the referring hospital. Second-look baseline and 24-h Holter ECG were then conducted during neurorehabilitation. Primary outcome was number of newly detected AF with duration of > 30 s; secondary outcomes were number of newly detected absolute arrhythmia of 10-30 s and < 10 s duration. For comparison, we further enrolled 100 patients with hemorrhagic stroke without history of AF (age = 72 + 11 years, 51% female). RESULTS: In 206 of the 508 ischemic stroke patients, AF had been detected during acute phase work-up (age = 78 + 10 years, 55% female). For the remaining 302 ischemic stroke patients, no AF was detected during acute phase work-up (age = 74 + 9 years; 47% female). Second-look 24-h ECG showed previously missed AF of > 30 s in 20 of these patients, i.e. 6.6% of the sample, and shorter absolute arrhythmia in 50 patients (i.e. 16.5%). CONCLUSIONS: Second-look 24-Hour ECG performed during post-acute inpatient neurorehabilitation has a high diagnostic yield and should become a standard component of recurrent stroke prevention.

Psychophysiological arousal and inter- and intraindividual differences in risk-sensitive decision making.

The current study assessed peripheral responses during decision making under explicit risk, and tested whether intraindividual variability in choice behavior can be explained by fluctuations in peripheral arousal. Electrodermal activity (EDA) and heart rate (HR) were monitored in healthy volunteers (N = 68) during the Roulette Betting Task. In this task, participants were presented with risky gambles to bet on, with the chances of winning varying across trials. Hierarchical Bayesian analyses demonstrated that EDA and HR acceleration responses during the decision phase were sensitive to the chances of winning. Interindividual differences in this peripheral reactivity during risky decision making were related to trait sensitivity to punishment and trait sensitivity to reward. Moreover, trial-by-trial variation in EDA and HR acceleration responses predicted a small portion of intraindividual variability in betting choices. Our results show that psychophysiological responses are sensitive to explicit risk and can help explain intraindividual heterogeneity in choice behavior.

Old benefit as much as young patients with stroke from high-intensity neurorehabilitation: cohort analysis.

BACKGROUND AND OBJECTIVE: In current clinical practice, old patients with stroke are less frequently admitted to neurorehabilitation units following acute care than younger patients based on an assumption that old age negatively impacts the benefit obtained from high-intensity neurorehabilitation. Our objective was to test this assumption empirically in a large sample of patients with stroke. METHODS: Functional recovery during 4 weeks of inpatient neurorehabilitation was assessed with the Barthel Index (BI) in 422 middle-aged (<65 years), 1399 old (65-80 years) and 473 very old (>80 years) patients with stroke. Overall functional recovery, recovery patterns and the relationship between therapy intensity and recovery were statistically compared between the three age groups. RESULTS: Overall functional recovery was statistically equivalent in middle-aged, old and very old patients (average improvement in BI total score: middle-aged: 15 points; old: 15 points; very old: 14 points). A novel item-wise logistic regression analysis (see Pedersen, Severinsen & Nielsen, 2014, Neurorehabil Neural Repair) revealed that this was true for 9 of the 10 everyday functions assessed by the BI. Furthermore, functional recovery was predicted by the amount of therapy (R=0.14; p=0.0001), and age did not moderate this relationship between therapy intensity and recovery (p=0.70). CONCLUSIONS: Old and even very old patients with stroke benefit from specialised inpatient neurorehabilitation and high amounts of therapy in the same degree as younger patients. Contrary to current clinical practice, old age should not be a criterion against admission to a neurorehabilitation unit following acute stroke treatment.

'Put Your Money Where Your Mouth Is!': Effects of Streaks on Confidence and Betting in a Binary Choice Task.

Human choice under uncertainty is influenced by erroneous beliefs about randomness. In simple binary choice tasks, such as red/black predictions in roulette, long outcome runs (e.g. red, red, red) typically increase the tendency to predict the other outcome (i.e. black), an effect labeled the "gambler's fallacy." In these settings, participants may also attend to streaks in their predictive performance. Winning and losing streaks are thought to affect decision confidence, although prior work indicates conflicting directions. Over three laboratory experiments involving red/black predictions in a sequential roulette task, we sought to identify the effects of outcome runs and winning/losing streaks upon color predictions, decision confidence and betting behavior. Experiments 1 (n = 40) and 3 (n = 40) obtained trial-by-trial confidence ratings, with a win/no win payoff and a no loss/loss payoff, respectively. Experiment 2 (n = 39) obtained a trial-by-trial bet amount on an equivalent scale. In each experiment, the gambler's fallacy was observed on choice behavior after color runs and, in experiment 2, on betting behavior after color runs. Feedback streaks exerted no reliable influence on confidence ratings, in either payoff condition. Betting behavior, on the other hand, increased as a function of losing streaks. The increase in betting on losing streaks is interpreted as a manifestation of loss chasing; these data help clarify the psychological mechanisms underlying loss chasing and caution against the use of betting measures ("post-decision wagering") as a straightforward index of decision confidence. © 2014 The Authors. Journal of Behavioral Decision Making published by John Wiley & Sons Ltd.