Child development and the role of visual experience in the use of spatial and non-spatial features in haptic object perception.

Previous work has suggested a different developmental timeline and role of visual experience for the use of spatial and non-spatial features in haptic object recognition. To investigate this conjecture, we used a haptic ambiguous odd-one-out task in which one object needed to be selected as being different from two other objects. The odd-one-out could be selected based on four characteristics: size, shape (spatial), texture, and weight (non-spatial). We tested sighted children from 4 to 12 years of age; congenitally blind, late blind, and adult participants with low vision; and normally sighted adults. Given the protracted developmental time course for spatial perception, we expected a shift from a preference for non-spatial features toward spatial features during typical development. Due to the dominant influence of vision for spatial perception, we expected congenitally blind adults to show a similar preference for non-spatial features as the youngest children. The results confirmed our first hypothesis; the 4-year-olds demonstrated a lower dominance for spatial features for object classification compared with older children and sighted adults. In contrast, our second hypothesis was not confirmed; congenitally blind adults' preferred categorization criteria were indistinguishable from those of sighted controls. These findings suggest an early development, but late maturation, of spatial processing in haptic object recognition independent of visual experience.

Wernicke's Encephalopathy in Acute and Chronic Kidney Disease: A Systematic Review.

Thiamine (vitamin B1) deficiency is relatively common in patients with kidney disease. Wernicke's encephalopathy (WE) is caused by vitamin B1 deficiency. Our aim was to systematically review the signs and symptoms of WE in patients with kidney disease. We conducted a systematic literature review on WE in kidney disease and recorded clinical and radiographic characteristics, treatment and outcome. In total 323 manuscripts were reviewed, which yielded 46 cases diagnosed with acute and chronic kidney disease and WE published in 37 reports. Prodromal characteristics of WE were loss of appetite, vomiting, weight loss, abdominal pain, and diarrhea. Parenteral thiamine 500 mg 3 times per day often led to full recovery, while Korsakoff's syndrome was found in those receiving low doses. To prevent WE in kidney failure, we suggest administering high doses of parenteral thiamine in patients with kidney disease who present with severe malnutrition and (prodromal) signs of thiamine deficiency.

The era of our lives: The memory of Korsakoff patients for the first Covid-19 pandemic lockdown in the Netherlands.

Memories for worldwide and emotional events (such as 9/11) are more vividly relived and recalled than memories for everyday events. Previous studies have shown that flashbulb memories of a single event enhanced the memory strength in severe amnesia. It is currently unknown whether macro-events that stretch out over longer periods of time (weeks, months) strengthen memory even further. Our aim was therefore to investigate to what extent patients with severe amnesia, due to Korsakoff's syndrome (KS), were able to relive the first Covid-19 lockdown in the Netherlands, and whether experienced emotions enhanced reliving of the participants. We included 22 KS patients and 24 age-, education-, and gender-matched healthy controls. Covid-19 related memories were assessed by measures of autobiographical memory specificity, phenomenological reliving, emotional intensity and semantic-and episodic knowledge about the first lockdown in March 2020 - May 2020 in the Netherlands. Although amnesia patients remembered significantly fewer autobiographical details regarding the Covid-19 lockdown than healthy controls, one fourth of the KS patients recalled specific events. Amnesia patients reported levels of emotional intensity equivalent to those in the control group. Stronger autobiographical reliving was associated with higher emotional intensity. Both amnesia patients and healthy controls had higher recall of episodic than semantic lockdown related information. In conclusion, results demonstrate that information for macro-events can still be memorized and relived, most specifically when emotional valence is high, even by highly amnestic patients.

Smartwatch reminders are as effective as verbal reminders in patients with Korsakoff's syndrome: three case studies.

Korsakoff's syndrome (KS) is a neurocognitive disorder caused by severe malnutrition. KS patients typically show severe impairments in prospective memory (PM), thus, have difficulties with remembering to perform delayed intentions. The current study investigated the possible benefits of a smartwatch aid for PM tasks in patients with KS and compared its efficacy with verbal in-person reminders. Three patients participated in the present study and were asked to complete everyday PM tasks. The results of each patient were analyzed as a single-case study. The results highlight the great potential of using smartwatches as external memory aids in KS patients in everyday life.

Exploring episodic and semantic contributions to past and future thinking performance in Korsakoff's syndrome.

Korsakoff's syndrome (KS) is a neuropsychiatric disorder characterized by severe declarative memory disruption. While episodic memory deficits and confabulation are well documented, it remains unclear to what extent semantic memory is compromised in this syndrome. Moreover, how such impairments relate to the capacity for future-oriented thinking remains unknown. Here, we sought to determine the extent to which episodic and semantic forms of past and future thinking are impacted in KS and the interrelationship between different classes of memory in this syndrome. Twenty patients with KS and 17 matched healthy controls took part in this study. We included well-established indices of past and future thinking capacity, enabling us to compare episodic (event-based) versus semantic (nonpersonal knowledge) across past and future conditions. We also included a novel event generation task to probe implausible event simulation (i.e., spending a day on the moon). Our findings revealed marked impairments in KS across all forms of past and future thinking, as well as the generation of episodic details on the implausible event simulation task. Correlation analyses revealed significant associations between implausible event construction and episodic and semantic future thinking in KS; however, no significant associations were found between future thinking performance and confabulation. This study is the first, to our knowledge, to reveal striking impairments in the capacity for past and future thinking across episodic and semantic domains in KS. Our findings resonate with current theoretical perspectives in which the lines between episodic and semantic memory systems are viewed as increasingly blurred.

Behavioural effects of light intervention in people with Korsakoff Syndrome: A pilot study.

Korsakoff Syndrome (KS) is commonly associated with behavioural symptoms such as agitation, apathy, and disinhibition. People with KS often reside in long-term care facilities, which reduces their exposure to natural light. Little is known regarding positive effects of light intervention in KS. Our objective was to evaluate the influence of a dawn simulation therapy on behavioural symptoms in KS. 38 patients residing in a 24-hour care facility were exposed for 6 weeks to a dawn simulation system in their bedrooms, which gradually increased from 0 lux to 290 lux. Behavioural symptoms were measured over 9 weeks. Weeks 1-3 consisted of the baseline phase and weeks 3-9 consisted of the light intervention phase. Our study showed that total severity of neuropsychiatric symptoms was less prominent during light intervention. More specifically, a decrease on the apathy, disinhibition, behaviour at night and appetite and eating behaviour subscales was found during the light intervention phase compared to the baseline phase. Additionally, a significant effect was found on decreasing emotional distress for caregivers. Results suggest that light intervention therapy has a positive effect on reducing behavioural symptoms in KS as well as the levels of stress experienced by the patients' caregivers.

Unraveling Apathy in Korsakoff Syndrome Patients Receiving Long-Term Care With and Without Cerebrovascular Comorbidity.

BACKGROUND: Korsakoff syndrome (KS) is a severe neuropsychiatric disorder caused by acute deficiency of vitamin B1 and concomitant alcoholism. Patients with KS are particularly vulnerable for cerebrovascular comorbidity. KS is characterized by cognitive and neuropsychiatric symptoms, one of which is apathy. Apathy is a pathological lack of goal-directed behaviors, goal-directed cognitions, and goal-directed emotions. Cerebrovascular accidents are known to carry a risk for developing apathy. Apathy has a dramatic effect on the autonomy and daily lives of patients suffering from this condition. METHODS: We assessed general apathy and related subconstructs in fifteen patients with KS, fifteen patients with KS and cerebrovascular comorbidity who reside in a 24-hour care facility, and fifteen healthy controls. RESULTS: Compared with healthy controls, both KS patient groups showed higher levels of apathy as rated by a close informant. We found no difference between both KS patient groups and the healthy control group on the self-report section of the Pleasant Activities List, suggesting that motivation is still intact in KS patients. It is important to note a discrepancy was found between self-reporting and proxy reporting on this list. KS patients with cerebrovascular comorbidity showed more severe emotional blunting compared to both KS patients without cerebrovascular comorbidity and healthy controls. The competency to consent was lower in patients compared with healthy controls, but no difference was found between KS patients with cerebrovascular comorbidity and those without. CONCLUSIONS: Our results suggest that KS patients show increased levels of general apathy compared with healthy controls. Patients show a diminished competency to consent and increased emotional blunting, while motivation is not compromised. Cerebrovascular comorbidity in KS forms a high risk for emotional blunting. The results of this study suggest that apathy is a severe problem in KS. More attention in both the literature and clinical practice would benefit this complex patient population.

More mental rotation time does not imply more mental effort: Pupillary diameters do not change with angular distance.

The ability to mentally rotate objects in space is a fundamental cognitive capacity. Previous studies showed that the time to rotate the image of a figure to match another increases progressively with angular disparity. It remains unclear whether this increase in response time with angular disparity could reflect increased processing operations or more cognitive effort instead of a sustained use of a 'rotate' mechanism without a change in workload. We collected response times as well as pupillary responses that index cognitive workload and activity in the brainstem's locus coeruleus, from a sample of 38 young adults performing a chronometric mental rotations task. The results showed the expected increase in response times but no increase in pupil diameters between 60, 120, and 180 degrees of rotation, suggesting no significant changes in arousal levels when rotating figures near and far. This indicates that during mental rotation the load on cognitive resources remains constant irrespective of angular distance.

Lifelogging as a rehabilitation tool in patients with amnesia: A narrative literature review on the effect of lifelogging on memory loss.

Visual lifelogging is the procedure that enables individuals to visually record daily life activities by means of small wearable cameras, which can be worn around the neck or on the clothing. Lifelogging devices automatically take pictures or videos after pre-set time intervals or after dynamic input changes. Although some studies have shown effectivity of reviewing lifelogging images in brain-damaged individuals with forms of amnesia as a rehabilitation tool, systematic endeavours to overview this literature is yet missing. The aim of this narrative literature review was to review all the available case-studies, experimental studies and group studies in brain-damaged individuals applying lifelogging devices in a clinical context. The included studies showed efficacy for both subjective and objective measures of memory. In mild to severe amnesia, reviewing images recorded by the lifelogging device was beneficial to subjective and objective measures of memory. Lifelogging is demonstrated to have a great potential in helping people who are suffering from memory loss. It can offer an excellent alternative to currently more frequently used memory rehabilitation techniques and can be applied more in clinical settings.

Wernicke Encephalopathy in schizophrenia: a systematic review.

INTRODUCTION: In schizophrenia, patients can experience delusions or hallucinations regarding their food or health status, leading to diminished intake. Fasting or not eating a balanced diet can cause neurological complications after severe vitamin B1 malnourishment. The precise signs and symptoms of Wernicke's Encephalopathy (WE) in schizophrenia are not clear. Our aim, therefore, was to conduct a systematic review of the characteristics of WE in patients with schizophrenia. METHODS: We conducted our search from inception using Mesh terms schizophrenia, Wernicke Encephalopathy, Korsakoff's syndrome. We searched Pubmed, ISI Web of Science, and Scopus. We defined WE as mental, oculomotor, and motoric alterations and thiamine deficiency; schizophrenia was defined as psychosis, hallucinations and/or delusions; adequate WE treatment as >500 mg/day intramuscular or intravenous. Our search yielded 15 WE cases. RESULTS: WE is characterised by a triad of mental status change, ocular signs and ataxia. In alcohol use disorder, this triad is present in 16% of the cases, but 12 out of the 15 published schizophrenia cases presented themselves with a full triad. Importantly, as an additional characteristic, patients often lost weight within a short period of time. CONCLUSIONS: The development of a full triad and additional symptomatology suggests a late recognition of signs and symptoms of WE in schizophrenia. Prophylactic thiamine checks and treatment in patients with schizophrenia are relevant, and if WE is suspected adequate parenteral thiamine supplementation is necessary.Key pointsOnly few cases of schizophrenia-related WE have been published in the literature, though challenges in diagnosing and recognising WE suggest that the vast majority of cases go undetected.Acute thiamine deficiency leads to Wernicke's Encephalopathy.Patients diagnosed with schizophrenia are at risk to develop Wernicke's Encephalopathy.Timely treatment with high doses of thiamine can adequately treat Wericke's Encephalopathy.

Episodic future thinking together with observational learning benefits prospective memory in high-functioning Korsakoff's syndrome patients.

OBJECTIVE: Patients with Korsakoff's syndrome (KS) have difficulty carrying out tasks which rely on prospective memory (PM). Since remembering to carry out an action in the future is crucial for living independently, it is of primary interest to develop strategies that improve PM performance in KS patients. DESIGN: The study employed a computer categorization task as an ongoing activity into which a PM task was embedded. We included episodic future thinking (EFT) and observational learning (Experiment 2) to boost PM. METHODS: Experiment 1 evaluated the efficacy of EFT following written PM task instructions in ten KS patients. Due to floor-level PM performance in Experiment 1, Experiment 2 included an instructional video demonstrating the PM intention. In Experiment 2, twenty-six KS patients performed both conditions (EFT and no-EFT) at least 1 week apart, while twelve controls with alcohol use disorder without KS performed the no-EFT condition. In Experiment 2, the PM instructions were also shown through video (observational learning component). Mild cognitive impairment was assessed in a short test battery. RESULTS: Experiment 1 showed overall floor performance in both conditions. Experiment 2 showed that KS patients performed PM tasks less accurately than the control group in the no-EFT condition. In Experiment 2, where the observational learning component was included, EFT improved PM performance in KS patients. This effect was driven by a sub-group of high-functioning KS patients. CONCLUSIONS: This study showed the value of an observational learning component together with EFT in improving PM performance, in relatively high-functioning KS patients. PRACTITIONER POINTS: KS patients performed the PM task less accurately than non-KS controls with alcohol use disorder, confirming PM impairment in this patient population. Controls with alcohol use disorder performed the PM task at ceiling level. Showing an instructional video demonstrating the PM intention improved PM performance and later recall of PM task instructions in KS patients. Episodic future thinking strategy improved PM performance in KS patients with relatively intact cognitive functioning.

How to separate coordinate and categorical spatial relation components in integrated spatial representations: A new methodology for analysing sketch maps.

Spatial relations between landmarks can be represented by means of categories and coordinates. In the present research, this paradigm was applied to sketch maps based on information acquired in goal-directed behaviour of exploration of a university campus area. The first aim was to investigate whether categorical and coordinate information can be considered conceptually independent in sketch maps. The second aim was to assess which kind of distance measure served better to represent coordinate information in the present case study, and finally to assess the factorial structure of coordinate and categorical data. Analytic methodology as well as statistical analysis were found to confirm that separating coordinate and categorical components was formally as well as empirically appropriate. A series of confirmatory factor analyses showed the best fit for the model with two correlated components, as well as an acceptable reliability of measures emerged. The two components were moderately correlated. Moreover, the adoption of Manhattan distance seemed to be the most effective method to represent coordinate spatial relations in spatial sketch maps of areas acquired through navigation.

Smartwatch aids time-based prospective memory in Korsakoff syndrome: a case study.

Prospective memory (PM) is the ability to remember to carry out an intention in the future. PM is particularly impaired in Korsakoff syndrome (KS). We investigated the benefit of a smartwatch and smartphone compared to no aid in supporting time accuracy and PM task performance in KS. Time accuracy was improved with a smartwatch compared to the other conditions. Furthermore, the smartwatch and phone conditions were more effective than no aid in assisting memory for task content. Together these results suggest that using an external memory aid is beneficial for successful PM in KS.

Visuospatial declarative learning despite profound verbal declarative amnesia in Korsakoff's syndrome.

Korsakoff's syndrome (KS) is a neuropsychiatric disorder characterised by severe amnesia. Although the presence of impairments in memory has long been acknowledged, there is a lack of knowledge about the precise characteristics of declarative memory capacities in order to implement memory rehabilitation. In this study, we investigated the extent to which patients diagnosed with KS have preserved declarative memory capacities in working memory, long-term memory encoding or long-term memory recall operations, and whether these capacities are most preserved for verbal or visuospatial content. The results of this study demonstrate that patients with KS have compromised declarative memory functioning on all memory indices. Performance was lowest for the encoding operation compared to the working memory and delayed recall operation. With respect to the content, visuospatial memory was relatively better preserved than verbal memory. All memory operations functioned suboptimally, although the most pronounced disturbance was found in verbal memory encoding. Based on the preserved declarative memory capacities in patients, visuospatial memory can form a more promising target for compensatory memory rehabilitation than verbal memory. It is therefore relevant to increase the number of spatial cues in memory rehabilitation for KS patients.

Cognitive and affective theory of mind in Korsakoff's syndrome.

OBJECTIVE: Korsakoff's syndrome (KS) is a chronic neuropsychiatric disorder characterised by severe anterograde amnesia and executive deficits. Theory of Mind (ToM) is the capacity to represent others' mental states such as their knowledge, thoughts, feelings, beliefs, and intentions in order to explain and predict their behaviour. Surprisingly this topic has received hardly any attention in research on KS, although the severity of behavioural problems in KS suggest possible ToM difficulties. The aim of the present study was therefore to assess whether cognitive and affective ToM are impaired in patients with KS. METHODS: We examined 21 KS patients and 21 age- and gender-matched healthy controls on three standardised tests that assess cognitive and affective ToM, including the subtests of the mini-Social Cognition and Emotional Assessment battery and a specialised version of the Sally-Anne Test. RESULTS: KS patients showed largely impaired cognitive and affective ToM compared to healthy controls, as reflected in large effect sizes on both cognitive and affective ToM tests. Executive deficits explained problems in emotion recognition, but not other ToM aspects. CONCLUSION: KS patients have large impairments in both cognitive and affective aspects of social cognition. Their ability to recognise emotions, take the perspective of others, and understand socially awkward situations is vastly compromised. The impairments in ToM functioning are to a large degree functionally discrepant from executive disorders that are commonly present in KS. This study therefore highlights the importance to properly index ToM functioning in neuropsychological assessments for individuals with a possible KS diagnosis.

Forgetting the new locations of one's keys: spatial-memory interference in Korsakoff's amnesia.

The present study focused on interference in a group of patients with amnesia due to Korsakoff's syndrome (KS) within the domain of spatial memory. An object-location memory task was used in which participants first learned an array of objects on a computer screen, followed by a reconstruction of the object positions. Next a trial was given in which the same objects were presented only now in different locations. Participants had to place the objects a second time but at the new locations. This was repeated for seven pairs of baseline/interference trials. Both Korsakoff patients and matched controls did worse on the interference trials than on the baseline trials, indicating that it is difficult to relearn new spatial locations for objects that previously were remembered in other locations. When computing relative interference effects (that is the percentage change from baseline in the interference trials), Korsakoff patients were less affected than controls. It is discussed in how far interference depends on the strength of the original memories, which are markedly lower in KS patients.

Social and emotional loneliness in Korsakoff's syndrome.

INTRODUCTION: Loneliness is the subjective negative evaluation of social participation and isolation. Emotional loneliness reflects the absence of close relationships, and social loneliness the absence of a social network. Although loneliness is a growing problem in modern society, studies about loneliness in patients with Korsakoff's syndrome (KS) in need of chronic care are currently missing. METHODS: Sixty-three KS patients in long-term care and their primary caregivers reported loneliness of the patients on the De Jong Gierveld Loneliness Scale. RESULTS: A majority of KS patients reliably reported to feel lonely on both a social and emotional level of loneliness. The caregiving professionals rated loneliness of the patients even higher. Patients that had stayed in the clinic for a longer time tended to report less social loneliness, while caregivers reported less emotional loneliness in those patients. The KS-specific neuropsychiatric symptom of confabulations and a lack of social visits had a negative impact on social loneliness as perceived by the caregivers. CONCLUSION: Loneliness is a large problem in patients with KS that live in a long term care facility. Social loneliness can be positively influenced by creating possibilities to interact with other people, although the severity of the neuropsychiatric aspects of KS could compromise the presence of those interactions.

Preventing Wernicke's encephalopathy in anorexia nervosa: A systematic review.

Anorexia nervosa (AN) is a common eating disorder that affects 2.9 million people worldwide. Not eating a balanced diet or fasting can cause neurological complications after severe vitamin B1 malnourishment, although the precise signs and symptoms of Wernicke's encephalopathy (WE) are not clear. Our aim was to review the signs and symptoms of WE in patients with AN. We searched MEDLINE, EMBASE, Scopus, and PiCarta on all case descriptions of WE following AN. All case descriptions of WE in AN, irrespective of language, were included. Twelve WE cases were reviewed, suggesting that WE following AN is still a relatively rare neuropsychiatric disorder. WE is characterized by a triad of: mental status change, ocular signs, and ataxia. In alcoholism, this triad is present in 16% of cases, but eight out of 12 AN cases presented themselves with a full triad of symptomatology. Importantly, patients often had a more complex triad than has been previously described, involving vertigo, diplopia, and the consequences of refeeding syndrome. The development of a full triad and additional symptomatology suggests a late recognition of signs and symptoms of WE in AN. A complicating factor is the overlap between symptoms of thiamine deficiency and the symptoms of WE. Specifically, patients who show rapid weight loss are vulnerable for the development of WE. Eating disorders, such as AN, can lead to WE. Prophylactic thiamine checks and treatment in patients with AN are relevant, and in case of suspicion of WE, adequate parenteral thiamine supplementation is necessary.

The Box Task: A tool to design experiments for assessing visuospatial working memory.

The present paper describes the Box Task, a paradigm for the computerized assessment of visuospatial working memory. In this task, hidden objects have to be searched by opening closed boxes that are shown at different locations on the computer screen. The set size (i.e., number of boxes that must be searched) can be varied and different error scores can be computed that measure specific working memory processes (i.e., the number of within-search and between-search errors). The Box Task also has a developer's mode in which new stimulus displays can be designed for use in tailored experiments. The Box Task comes with a standard set of stimulus displays (including practice trials, as well as stimulus displays with 4, 6, and 8 boxes). The raw data can be analyzed easily and the results of individual participants can be aggregated into one spreadsheet for further statistical analyses.

Microstructure of Strategic White Matter Tracts and Cognition in Memory Clinic Patients with Vascular Brain Injury.

BACKGROUND: White matter injury is an important factor for cognitive impairment in memory clinic patients. We determined the added value of diffusion tensor imaging (DTI) of strategic white matter tracts in explaining variance in cognition in memory clinic patients with vascular brain injury. METHODS: We included 159 patients. Conventional MRI markers (white matter hyperintensity volume, lacunes, nonlacunar infarcts, brain atrophy, and microbleeds), and fractional anisotropy and mean diffusivity (MD) of the whole brain white matter and of 18 white matter tracts were related to cognition using linear regression and Bayesian network analysis. RESULTS: On top of all conventional MRI markers combined, MD of the whole brain white matter explained an additional 3.4% (p = 0.014), 7.8% (p < 0.001), and 1.2% (p = 0.119) variance in executive functioning, speed, and memory, respectively. The Bayesian analyses of regional DTI measures identified strategic tracts for executive functioning (right superior longitudinal fasciculus), speed (left corticospinal tract), and memory (left uncinate fasciculus). MD within these tracts explained an additional 3.4% (p = 0.012), 3.8% (p = 0.007), and 2.1% (p = 0.041) variance in executive functioning, speed, and memory, respectively, on top of all conventional MRI and global DTI markers combined. CONCLUSION: In memory clinic patients with vascular brain injury, DTI of strategic white matter tracts has a significant added value in explaining variance in cognitive functioning.