The Auditory Agnosias: a Short Review of Neurofunctional Evidence

PURPOSE OF REVIEW

To investigate the neurofunctional correlates of pure auditory agnosia and its varieties (global, verbal, and nonverbal), based on 116 anatomoclinical reports published between 1893 and 2022, with emphasis on hemispheric lateralization, intrahemispheric lesion site, underlying cognitive impairments.

RECENT FINDINGS

Pure auditory agnosia is rare, and observations accumulate slowly. Recent patient reports and neuroimaging studies on neurotypical subjects offer insights into the putative mechanisms underlying auditory agnosia, while challenging traditional accounts. Global auditory agnosia frequently results from bilateral temporal damage. Verbal auditory agnosia strictly correlates with language-dominant hemisphere lesions. Damage involves the auditory pathways, but the critical lesion site is unclear. Both the auditory cortex and associative areas are reasonable candidates, but cases resulting from brainstem damage are on record. The hemispheric correlates of nonverbal auditory input disorders are less clear. They correlate with unilateral damage to either hemisphere, but evidence is scarce. Based on published cases, pure auditory agnosias are neurologically and functionally heterogeneous. Phenotypes are influenced by co-occurring cognitive impairments. Future studies should start from these facts and integrate patient data and studies in neurotypical individuals.

A - 180 Anosognosia across the Spectrum of Alzheimer's Pathology and Validation of a New Measure

OBJECTIVE

Two studies were performed to validate a brief, new method for assessing informant-patient discrepancies to quantify cognitive insight, and to compare it to an empirically supported model - the Cognitive Awareness Model (CAM).

METHOD

Study 1 included 31 (52% male; Mage = 69.42) patients from an outpatient neuropsychological assessment clinic. Seven patients were diagnosed with probable Alzheimer's dementia (PAD), 15 mild cognitive impairment (MCI), and 9 no diagnosis (i.e., healthy controls; HC). The Cognitive Coding Form (CCF) was compared with several measures to assess convergent and discriminant validity. Study 2 entailed archival data extraction of 240 patients (80 HC, 80 MCI, and 80 PAD; 53.3% female; Mage = 72.8) to examine the ability of the CCF to predict various cognitive domains, including executive functioning (Trail-Making Test Form B).

RESULTS

In study 1, the 8-item CCF demonstrated good convergent and discriminant validity with established measures. Study 2 identified that both patient-reported cognitive concerns and, to a greater degree, CCF informant-patient discrepancy scores, can distinguish HCs from those with MCI and PAD. Further, a regression indicated that depression (Geriatric Depression Scale; 5.5%; β = -0.38, p < 0.001) and TMT-B (13%; β = -0.43, p < 0.001), together accounted for 18.5% of the variance in insight (R2 = 0.19, F(2,219) = 26.10, p < 0.001), supporting the CAM.

CONCLUSIONS

In addition to establishing an efficient measure of insight with high clinical utility (the CCF), these studies inform the literature on the role of insight in predicting performance in those with Alzheimer's pathology.

Can a failure in the error-monitoring system explain unawareness of memory deficits in Alzheimer's disease?

Unawareness of memory deficits is an early manifestation in patients with Alzheimer's disease (AD), which often delays diagnosis. This intriguing behavior constitutes a form of anosognosia, whose neural mechanisms remain largely unknown. We hypothesized that anosognosia may depend on a critical synaptic failure in the error-monitoring system, which would prevent AD patients from being aware of their own memory impairment. To investigate, we measured event-related potentials (ERPs) evoked by erroneous responses during a word memory recognition task in two groups of amyloid positive individuals with only subjective memory complaints at study entry: those who progressed to AD within the five-year study period (PROG group), and those who remained cognitively normal (CTRL group). A significant reduction in the amplitude of the positivity error (Pe), an ERP related to error awareness, was observed in the PROG group at the time of AD diagnosis (vs study entry) in intra-group analysis, as well as when compared with the CTRL group in inter-group analysis, based on the last EEG acquisition for all subjects. Importantly, at the time of AD diagnosis, the PROG group exhibited clinical signs of anosognosia, overestimating their cognitive abilities, as evidenced by the discrepancy scores obtained from caregiver/informant vs participant reports on the cognitive subscale of the Healthy Aging Brain Care Monitor. To our knowledge, this is the first study to reveal the emergence of a failure in the error-monitoring system during a word memory recognition task at the early stages of AD. This finding, along with the decline of awareness for cognitive impairment observed in the PROG group, strongly suggests that a synaptic dysfunction in the error-monitoring system may be the critical neural mechanism at the origin of unawareness of deficits in AD.

Detecting Anosognosia from the Prodromal Stage of Alzheimer's Disease

BACKGROUND

Though not originally developed for this purpose, the Healthy Aging Brain Care Monitor (HABC-M) seems a valuable instrument for assessing anosognosia in Alzheimer's disease (AD).

OBJECTIVES

Our study aimed at 1) investigating the validity of the HABC-M (31 items), and its cognitive, psychological, and functional subscales, in discriminating AD patients from controls; 2) exploring whether the HABC-M discrepancy scores between the self-reports of patients/controls in these different domains and the respective ratings provided by their caregivers/informants correlate with an online measure of self-awareness; 3) determining whether the caregiver burden level, also derived from the HABC-M, could add additional support for detecting anosognosia.

METHODS

The HABC-M was administered to 30 AD patients and 30 healthy controls, and to their caregivers/informants. A measure of online awareness was established from subjects' estimation of their performances in a computerized experiment.

RESULTS

The HABC-M discrepancy scores distinguished AD patients from controls. The cognitive subscale discriminated the two groups from the prodromal AD stage, with an AUC of 0.88 [95% CI: 0.78;0.97]. Adding the caregiver burden level raised it to 0.94 [0.86;0.99]. Significant correlations between the HABC-M and online discrepancy scores were observed in the patients group, providing convergent validity of these methods.

CONCLUSIONS

The cognitive HABC-M (six items) can detect anosognosia across the AD spectrum. The caregiver burden (four items) may corroborate the suspicion of anosognosia. The short-hybrid scale, built from these 10 items instead of the usual 31, showed the highest sensitivity for detecting anosognosia from the prodromal AD stage, which may further help with timely diagnosis.

Benson's Disease or Posterior Cortical Atrophy, Revisited

BACKGROUND

D. Frank Benson and colleagues first described the clinical and neuropathological features of posterior cortical atrophy (PCA) from patients in the UCLA Neurobehavior Program.

OBJECTIVE

We reviewed the Program's subsequent clinical experience with PCA, and its potential for clarifying this relatively rare syndrome in comparison to the accumulated literature on PCA.

METHODS

Using the original criteria derived from this clinic, 65 patients with neuroimaging-supported PCA were diagnosed between 1995 and 2020.

RESULTS

On presentation, most had visual localization complaints and related visuospatial symptoms, but nearly half had memory complaints followed by symptoms of depression. Neurobehavioral testing showed predominant difficulty with visuospatial constructions, Gerstmann's syndrome, and Balint's syndrome, but also impaired memory and naming. On retrospective application of the current Consensus Criteria for PCA, 59 (91%) met PCA criteria with a modification allowing for "significantly greater visuospatial over memory and naming deficits." There were 37 deaths (56.9%) with the median overall survival of 10.3 years (95% CI: 9.6-13.6 years), consistent with a slow neurodegenerative disorder in most patients.

CONCLUSION

Together, these findings recommend modifying the PCA criteria for "relatively spared" memory, language, and behavior to include secondary memory and naming difficulty and depression, with increased emphasis on the presence of Gerstmann's and Balint's syndromes.

Trajectory of Unawareness of Memory Decline in Individuals With Autosomal Dominant Alzheimer Disease

IMPORTANCE

Recent studies have suggested that unawareness, or anosognosia, of memory decline is present in predementia stages of Alzheimer disease (AD) and may serve as an early symptomatic indicator of AD.

OBJECTIVE

To investigate the evolution of anosognosia of memory decline in individuals who carry the PSEN1 E280A variant for autosomal dominant AD compared with family members who do not carry the variant.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study investigated a total of 2379 members of a Colombian kindred with autosomal dominant AD who were part of the Alzheimer's Prevention Initiative Registry. Assessments were completed at the University of Antioquia, Colombia, with data collected between January 1, 2000, and July 31, 2019.

MAIN OUTCOMES AND MEASURES

Awareness of memory function was operationalized using the discrepancy between self-report and study partner report on a memory complaint scale. Linear mixed effects models were used to assess memory self-awareness over age separately in variant carriers and noncarriers.

RESULTS

This study included 396 variant carriers (mean [SD] age, 32.7 [11.9] years; 200 [50.5%] female), of whom 59 (14.9%) were cognitively impaired, and 1983 cognitively unimpaired noncarriers (mean [SD] age, 33.5 [12.5] years; 1129 [56.9%] female). The variant carriers demonstrated increased awareness until the mean (SD) age of 35.0 (2.0) years and had anosognosia at approximately 43 years of age, approximately 6 years before their estimated median age of dementia onset (49 years; 95% CI, 49-51 years). Cognitively unimpaired noncarriers reported more complaints than their study partners aged 20 and 60 years (10.1 points, P < .001). On the awareness index, a decrease with age (mean [SE] estimate, -0.04 [0.02] discrepant-points per years; t = -2.2; P = .03) in the noncarriers and in the variant carriers (mean [SE] estimate, -0.21 [0.04] discrepant-points per years; t = -5.1; P < .001) was observed.

CONCLUSIONS AND RELEVANCE

In this cohort study, increased participant complaints were observed in both groups, suggesting that increased awareness of memory function was common and nonspecific to AD in this cohort. In variant carriers, awareness of memory function decreased in the predementia stages, reaching anosognosia close to the age of mild cognitive impairment onset, providing support for the usefulness of awareness of memory decline.

Evolution of anosognosia in alzheimer's disease and its relationship to amyloid

OBJECTIVE

Unawareness, or anosognosia, of memory deficits is a challenging manifestation of Alzheimer's disease (AD) that adversely affects a patient's safety and decision-making. However, there is a lack of consensus regarding the presence, as well as the evolution, of altered awareness of memory function across the preclinical and prodromal stages of AD. Here, we aimed to characterize change in awareness of memory abilities and its relationship to beta-amyloid (Aβ) burden in a large cohort (N = 1,070) of individuals across the disease spectrum.

METHODS

Memory awareness was longitudinally assessed (average number of visits = 4.3) and operationalized using the discrepancy between mean participant and partner report on the Everyday Cognition scale (memory domain). Aβ deposition was measured at baseline using [18F]florbetapir positron emission tomographic imaging.

RESULTS

Aβ predicted longitudinal changes in memory awareness, such that awareness decreased faster in participants with increased Aβ burden. Aβ and clinical group interacted to predict change in memory awareness, demonstrating the strongest effect in dementia participants, but could also be found in the cognitively normal (CN) participants. In a subset of CN participants who progressed to mild cognitive impairment (MCI), heightened memory awareness was observed up to 1.6 years before MCI diagnosis, with memory awareness declining until the time of progression to MCI (-0.08 discrepant-points/yr). In a subset of MCI participants who progressed to dementia, awareness was low initially and continued to decline (-0.23 discrepant-points/yr), reaching anosognosia 3.2 years before dementia onset.

INTERPRETATION

Aβ burden is associated with a progressive decrease in self-awareness of memory deficits, reaching anosognosia approximately 3 years before dementia diagnosis. ANN NEUROL 2020;87:267-280.

Avian agnosia: A window into auditory semantics

The functional and neural organisation of auditory knowledge is relatively poorly understood. The breakdown of conceptual knowledge in semantic dementia has revealed that pre-morbid expertise influences the extent to which knowledge is differentiated. Whether this principle applies to a similar extent in the auditory domain is not yet known. Previous reports of patients with impaired auditory vs. intact visual expert knowledge suggest that expertise may have differential effects upon the organisation of auditory and visual knowledge. An equally plausible alternative, however, is that auditory knowledge is simply more vulnerable to deterioration. Thus, expertise effects in the auditory domain may not yet have been observed because knowledge of auditory expert vs. non-expert knowledge has yet to be compared. We had the opportunity to address this issue by studying SA, a patient with semantic dementia and extensive pre-morbid knowledge of birds. We undertook a systematic investigation of SA's auditory vs. visual knowledge from matched expert vs. non-expert categories. Relative to a group of 10 age, education and IQ matched bird experts, SA showed impaired auditory vs. intact visual avian knowledge, despite intact basic auditory perceptual abilities. This was explained by independent effects of modality and expertise. Thus, he was also disproportionately impaired for auditory vs. visual knowledge of items from non-expert categories. In both auditory and visual modalities, his performance was relatively more impaired on tests of non-expert vs. expert knowledge. These findings suggest that, while auditory knowledge may be more vulnerable to deterioration, expertise modulates visual and auditory knowledge to a similar extent.

Profiles of visuospatial memory dysfunction in opioid-exposed and dependent populations

BACKGROUND

Chronic opioid exposure is common world-wide, but behavioural performance remains under-investigated. This study aimed to investigate visuospatial memory performance in opioid-exposed and dependent clinical populations and its associations with measures of intelligence and cognitive impulsivity.

METHODS

We recruited 109 participants: (i) patients with a history of opioid dependence due to chronic heroin use (n = 24), (ii) heroin users stabilised on methadone maintenance treatment (n = 29), (iii) participants with a history of chronic pain and prescribed tramadol and codeine (n = 28) and (iv) healthy controls (n = 28). The neuropsychological tasks from the Cambridge Neuropsychological Test Automated Battery included the Delayed Matching to Sample (DMS), Pattern Recognition Memory, Spatial Recognition Memory, Paired Associate Learning, Spatial Span Task, Spatial Working Memory and Cambridge Gambling Task. Pre-morbid general intelligence was assessed using the National Adult Reading Test.

RESULTS

As hypothesised, this study identified the differential effects of chronic heroin and methadone exposures on neuropsychological measures of visuospatial memory (p &lt; 0.01) that were independent of injecting behaviour and dependence status. The study also identified an improvement in DMS performance (specifically at longer delays) when the methadone group was compared with the heroin group and also when the heroin group was stabilised onto methadone. Results identified differential effects of chronic heroin and methadone exposures on various neuropsychological measures of visuospatial memory independently from addiction severity measures, such as injecting behaviour and dependence status.

The Impact of Awareness of and Concern About Memory Performance on the Prediction of Progression From Mild Cognitive Impairment to Alzheimer Disease Dementia

OBJECTIVE

To investigate the relationship of awareness of and concern about memory performance to progression from mild cognitive impairment (MCI) to Alzheimer disease (AD) dementia.

METHODS

Participants (n = 33) had a diagnosis of MCI at baseline and a diagnosis of MCI or AD dementia at follow-up. Participants were categorized as "Stable-MCI" if they retained an MCI diagnosis at follow-up (mean follow-up = 18.0 months) or "Progressor-MCI" if they were diagnosed with AD dementia at follow-up (mean follow-up = 21.6 months). Awareness was measured using the residual from regressing a participant's objective memory score onto their subjective complaint score (i.e., residual<0 indicates overestimation of performance). Concern was assessed using a questionnaire examining the degree of concern when forgetting. Logistic regression was used to determine whether the presence of these syndromes could predict future diagnosis of AD dementia, and repeated measures analysis of covariance tests were used to examine longitudinal patterns of these syndromes.

RESULTS

Baseline anosognosia was apparent in the Progressor-MCI group, whereas participants in the Stable-MCI group demonstrated relative awareness of their memory performance. Baseline awareness scores successfully predicted whether an individual would progress to AD-dementia. Neither group showed change in awareness of performance over time. Neither group showed differences in concern about memory performance at baseline or change in concern about performance over time.

CONCLUSION

These data suggest that anosognosia may appear prior to the onset of AD dementia, while anosodiaphoria likely does not appear until later in the AD continuum. Additionally, neither group showed significant changes in awareness or concern over time, suggesting that change in these variables may happen over longer periods.

Involvement of the Cingulate Cortex in Anosognosia: A Multimodal Neuroimaging Study in Alzheimer's Disease Patients

BACKGROUND

Anosognosia is a frequent symptom of Alzheimer's disease (AD), but its neural substrates remain in question.

OBJECTIVE

In this study, we combined neuroimaging with a neuropsychological evaluation to assess neural substrates of anosognosia.

METHODS

We prospectively recruited 30 patients with probable early-stage AD and matched healthy controls. Participants underwent MRI, FDG-PET, and a neuropsychological evaluation that includes an assessment of anosognosia. In the AD group, correlations between the anosognosia score, neuroimaging modalities, and neuropsychological performance were performed.

RESULTS

Atrophy and hypometabolism were correlated with the anosognosia score in the left dorsal anterior cingulate cortex. The anosognosia score was also correlated with atrophy of the cerebellar vermis, the left postcentral gyrus, and the right fusiform gyrus. No relation was found between anosognosia and the neuropsychological assessment.

DISCUSSION

Structural and metabolic alteration in the dorsal anterior cingulate cortex seems to be associated with a diminution of awareness in patients with early-stage AD.

[Auditory agnosia associated with bilateral putaminal hemorrhage: A case report of clinical course of recovery]

A 45-year-old right-handed man with a past history (10 years) of putaminal hemorrage presented with auditory agnosia associated with left putaminal hemorrhage. It was suspected that the auditory agnosia was due to bilateral damage in the acoustic radiations. Generalized auditory agnosia, verbal and non-verbal (music and environmental), was diagnosed by neuropsychological examinations. It improved 4 months after the onset. However, the clinical assessment of attention remained poor. The cognition for speech sounds improved slowly, but once it started to improve, the progress of improvement was rapid. Subsequently, the cognition for music sounds also improved, while the recovery of the cognition for environmental sounds remained delayed. There was a dissociation in recovery between these cognitions. He was able to return to work a year after the onset. We also reviewed the literature for cases with auditory agnosia and discuss their course of recovery in this report.

The struggle for schizophrenia treatment: A case study

Individual of legal age with schizophrenia presenting anosognosia was abandoned, as a result of a court decision. Close family members were not allowed to provide medical follow-up, treatment, protection regarding his vulnerability, and preserve the dignity of their loved one. The issue was the court's prioritization of the autonomy of the individual over his mental health status. The purpose of this case study was to identify the pitfalls of a court case seeking medical follow-up and treatment for a family member with schizophrenia and anosognosia. The method was qualitative and the design was descriptive and instrumental, linking the law to the life experience resulting from the procedures for its implementation. This study examined the difference between clinical and medical-legal evaluation of the examinee. The application of the Therapeutic Jurisprudence principles to the high number of schizophrenia cases with anosognosia, the abandonment of the mentally ill, and family crisis call healthcare providers and the Judiciary for an improvement action of the process of guardianship.

Incomplete Figure Perception and Invisible Masking

The Gollin test (measuring recognition thresholds for fragmented line drawings of everyday objects and animals) has traditionally been regarded as a test of incomplete figure perception or ‘closure’, though there is a debate about how such closure is achieved. Here, figural incompleteness is considered to be the result of masking, such that absence of contour elements of a fragmented figure is the result of the influence of an ‘invisible’ mask. It is as though the figure is partly obscured by a mask having parameters identical to those of the background. This mask is ‘invisible’ only consciously, but for the early stages of visual processing it is real and has properties of multiplicative noise. Incomplete Gollin figures were modeled as the figure covered by the mask with randomly distributed transparent and opaque patches. We adjusted the statistical characteristics of the contour image and empty noise patches and processed those using spatial and spatial-frequency measures. Across 73 figures, despite inter-subject variability, mean recognition threshold was always approximately 15% of total contour in naive observers. Recognition worsened with increasing spectral similarity between the figure and the ‘invisible’ mask. Near threshold, the spectrum of the fragmented image was equally similar to that of the ‘invisible’ mask and complete image. The correlation between spectral parameters of figures at threshold and complete figures was greatest for figures that were most easily recognised. Across test sessions, thresholds reduced when either figure or mask parameters were familiar. We argue that recognition thresholds for Gollin stimuli in part reflect the extraction of signal from noise.

Efficacy of self-perception after traumatic brain injury

BACKGROUND

Anosognosia is a lack of awareness of personal deficits that is commonly observed in people with a traumatic brain injury (TBI).

OBJECTIVE

The purpose of this paper is to examine whether self-appraisal of executive functioning differs for students with and without TBI.

METHODS

Students who had survived a TBI and those who had never had a TBI filled out the Behavior Rating Inventory of Executive Functioning from three different perspectives. Each participant was paired with an observer who was familiar with the person's behavior. Self-appraisal ratings, observer ratings of the participant, and reflective appraisal of how the participant thought the observer would rate them were compared.

RESULTS

For the students without TBI, reflective appraisal was significantly correlated with self-appraisal but observer appraisal was not. For students with TBI, neither reflected appraisal nor observer appraisal correlated with self-appraisal. Both TBI and non-TBI participants overestimated their problems on measures of Inhibition, Shifting, Emotional Control, Initiation, and Planning/Organizing. TBI participants underestimated their problems on measures of Working Memory, Organization, and Task Monitoring relative to the non-TBI group.

CONCLUSIONS

Students with TBI do not accurately perceive how others perceive their behavior.

Mentalizing the body: spatial and social cognition in anosognosia for hemiplegia

Following right-hemisphere damage, a specific disorder of motor awareness can occur called anosognosia for hemiplegia, i.e. the denial of motor deficits contralateral to a brain lesion. The study of anosognosia can offer unique insights into the neurocognitive basis of awareness. Typically, however, awareness is assessed as a first person judgement and the ability of patients to think about their bodies in more 'objective' (third person) terms is not directly assessed. This may be important as right-hemisphere spatial abilities may underlie our ability to take third person perspectives. This possibility was assessed for the first time in the present study. We investigated third person perspective taking using both visuospatial and verbal tasks in right-hemisphere stroke patients with anosognosia (n = 15) and without anosognosia (n = 15), as well as neurologically healthy control subjects (n = 15). The anosognosic group performed worse than both control groups when having to perform the tasks from a third versus a first person perspective. Individual analysis further revealed a classical dissociation between most anosognosic patients and control subjects in mental (but not visuospatial) third person perspective taking abilities. Finally, the severity of unawareness in anosognosia patients was correlated to greater impairments in such third person, mental perspective taking abilities (but not visuospatial perspective taking). In voxel-based lesion mapping we also identified the lesion sites linked with such deficits, including some brain areas previously associated with inhibition, perspective taking and mentalizing, such as the inferior and middle frontal gyri, as well as the supramarginal and superior temporal gyri. These results suggest that neurocognitive deficits in mental perspective taking may contribute to anosognosia and provide novel insights regarding the relation between self-awareness and social cognition.

[Geriatric psychiatric home counseling for people with dementia and anosognosia : Results of a model project]

BACKGROUND

Lack of awareness of an illness (anosognosia) is a common symptom in dementia and has a significant impact on the course of the disease. It is associated with dysfunctional interaction with caregivers. Due to unawareness patients are not able to accept diagnostic procedures or medical treatment and refuse any kind of support. Thus, they are not integrated into psychosocial networks and medical support. This has a significant impact on patient-centered care in a domestic environment. In this article a model project with home visits to patients with dementia and anosognosia is described.

METHOD

A total of 55 home visits were carried out. The aim of this project was the integration into the existing healthcare services in order to safeguard the domestic environment. These visits focused on advice and information for the patients and their caregivers initiating the visits. Sociodemographic data of the patient cohort and the satisfaction of the caregiving relatives and general practitioners are presented.

RESULTS

Subjects with dementia were found to be in advanced stages of the disease, caring situations were complex and required assistance. Caregivers showed a substantial burden in accordance with previous reports.

CONCLUSION

New strategies are required to cope with anosognosia in patients with dementia and their caregivers. Even single home visits seem to be sufficient to initiate support for subjects with dementia and their relatives.

[Clinical utility and psychometric properties of Prefrontal Symptoms Inventory (PSI) in acquired brain injury and degenerative dementias]

INTRODUCTION

The cognitive, emotional and behavioural alterations secondary to acquired brain injury and degenerative dementias can be quantitatively and quantitatively appraised by administering self-reports that ask both patients and reliable informants about the difficulties patients have in their everyday life.

SUBJECTS AND METHODS

The Prefrontal Symptoms Inventory (PSI) and the Modified Memory Failures in Everyday Life Questionnaire (MFE-30) were administered to 174 paired participants: 87 patients with brain damage or degenerative dementias and their 87 reliable informants. In addition to the psychometric goodness of the tests, the study also explored the clinical usefulness of applying these questionnaires to patients and their informants in order to obtain a rate of discrepancy in the scores as a measure of anosognosia.

RESULTS

The results show how applying the PSI-20 (20 items) or the PSI (46 items), whether administered together with the MFE-30 (30 items) or not, is a very useful procedure for assessing the symptoms in individuals with acquired brain injury or degenerative dementias, since it yields a great deal of information about patients' difficulties in their daily life.

CONCLUSIONS

We recommend that, in addition to the compulsory neuropsychological assessment, questionnaires or inventories of symptoms like those proposed here should be carried out, due to the fact that they offer a number of advantages from the clinical point of view, as well as being efficacious and effective in economic terms.

Visuo-constructional functions in patients with mild cognitive impairment, Alzheimer's disease, and Parkinson's disease

BACKGROUND

Several recently proposed criteria for assessing cognitive disorder require measuring the cognitive domain of visuo-constructional function. The aims of the present study were to develop a new test (Vienna Visuo-constructional Test-VVT) measuring visuo-constructional functions and to determine the reliability and validity of the VVT in patients with mild cognitive impairment (MCI), Parkinson's disease (PD), and Alzheimer's disease (AD). We further examined age and sex effects and the psychometric quality of the VVT.

METHODS

The study included 76 healthy controls and 103 patients who were referred to the Department of Neurology, Medical University of Vienna for neurocognitive assessment. An administering and scoring system for the VVT was developed.

RESULTS

Internal consistency (Cronbach's alpha) was found to range from 0.82 for the healthy control group to 0.93 for the total patient group. There was no sex effect, but age had a negative effect on VVT performance. The VVT successfully differentiated healthy controls from MCI patients, AD patients, and PD patients, respectively.

CONCLUSION

The VVT shows satisfactory validity and reliability and can be administered easily in clinical practice. It constitutes a new measure that can successfully be used to identify visuo-constructional problems in patients with cognitive dysfunction.

Visuo-spatial ability in individuals with Down syndrome: is it really a strength?

Down syndrome (DS) is associated with extreme difficulty in verbal skills and relatively better visuo-spatial skills. Indeed, visuo-spatial ability is often considered a strength in DS. However, it is not clear whether this strength is only relative to the poor verbal skills, or, more impressively, relative to cognitive ability in general. To answer this question, we conducted an extensive literature review of studies on visuo-spatial abilities in people with Down syndrome from January 1987 to May 2013. Based on a general taxonomy of spatial abilities patterned after Lohman, Pellegrino, Alderton, and Regian (1987) and Carroll (1993) and existing studies of DS, we included five different domains of spatial abilities - visuo-spatial memory, visuo-spatial construction, mental rotation, closure, and wayfinding. We evaluated a total of 49 studies including 127 different comparisons. Most comparisons involved a group with DS vs. a group with typical development matched on mental age and compared on a task measuring one of the five visuo-spatial abilities. Although further research is needed for firm conclusions on some visuo-spatial abilities, there was no evidence that visuo-spatial ability is a strength in DS relative to general cognitive ability. Rather, the review suggests an uneven profile of visuo-spatial abilities in DS in which some abilities are commensurate with general cognitive ability level, and others are below.

[Awareness disorders in Alzheimer's disease and in mild cognitive impairment]

INTRODUCTION

Awareness disorders in Alzheimer's disease still remains unclear despite much research regarding this phenomenon. Papers report various and contrasted results with varying frequency from one study to another. Hence, the interest in awareness in Alzheimer's disease remains limited. Nevertheless, this symptom is closely associated with caregivers' burden and increases the patient's dependency, since the patient is unable to avoid dangers, requiring some care services or institutionalization The purpose of this current review is to recall the main neuro-anatomical and theoretical basis of awareness disorders, and to highlight the recent findings in Alzheimer's disease and in its pre-clinical stages.

METHOD

With this in mind, we have conducted a non-exhaustive search using the pubmed online database to collect the most important reviews and the most recent findings regarding awareness disorders in Mild Cognitive Impairment (MCI) and/or in Alzheimer's disease.

LITERATURE FINDINGS

In Alzheimer's disease, the links between awareness disorders and other variables, such as severity of dementia or depression, change from one study to the other and do not permit one to understand whether unawareness is an intrinsic or extrinsic reaction to the pathological process itself. Recent results suggest executive, cognitive and behavioral correlates more than psychopathological correlates, although the latter cannot be excluded. In Mild Cognitive Impairment, studies show varied results. Some studies report that patients suffering from Mild Cognitive Impairment can be compared to healthy control subjects and both groups have better awareness than patients with Alzheimer's disease. However, other studies show contrary results and awareness disorders might be a predictor of conversion from Mild Cognitive Impairment to dementia, as with apathy, in which the ability to cope with difficulties represents one of the main features.

DISCUSSION

These controversial results are due to the heterogeneity of Alzheimer patients and in particular of MCI patients, but also to various conceptions of awareness disorders in Alzheimer's disease; none of them, however, taking into account all its diversity and complexity. Thus, neurological approaches underline neuropsychological dysfunctions linked to right frontal and/or hemispheric damage but are based on brain injury or strokes, which are events that differ greatly from a neurodegenerative disease involving progressive cognitive, emotional and social disturbances. Psychiatric approaches have taken into account the various aspects of insight, which before were often forbidden and reduced to a categorical point of view, and so could contribute to a better understanding of awareness disorders in Alzheimer's disease. However, these aspects have been conceptualized for psychiatric patients, suffering from positive symptoms, where compliance in treatment is the central key. Insight in neurological diseases is more focused on negative symptoms and generally concerns a basic perception of impairments in mainly cognitive domains. Moreover, modeling has often opposed neurological and psychological mechanisms, so awareness disorders are out of scope of a primary and secondary symptomatology. Although some authors have proposed to take into account these two mechanisms (unawareness and denial), clinical practice has shown that it was impossible to distinguish them both. Finally, some social cognitive approaches are able to demonstrate that there is no correlation between severity of dementia and awareness disorders. Nevertheless, the Self-concept, underlying this point of view, does not permit distinguishing neuropsychological from psycho-social factors. Moreover, only one evaluation tool based on Self-modeling in Alzheimer's disease exists, and to conceptualize Self in a specific pathology does not permit the comparison of this pathology to others or to healthy control subjects. So, the authors present the multidimensional model proposed by Clare et al., and some perspectives to stimulate future research, and perform potential meta-analyses.

[Relationship between memory disorders and self-consciousness in Alzheimer's disease]

Episodic memory deficits are almost always the first cognitive impairment in Alzheimer disease (AD). AD is also characterized by a loss of self-awareness. The aim of this article is to give an interpretation of AD patients' episodic impairments through the study of the relationship between memory and the self. Using the Remember/Know paradigm associated with the self-reference effect and emotional valence, we showed that this relationship may be impaired in AD. On the one hand, this could explain AD patients' difficulty accessing autonoetic consciousness, that is to say mentally bring back events of the past. On the other hand, the difficulty to precisely relieve previous events may be in turn at the root of AD patients' loss of self-awareness, namely anosognosia. Thus, based on the previous studies in the field of self-referential processing and on our findings, we proposed that the combination of an emotion analysis and a cognitive approach of AD patients' episodic memory impairments is an interesting way to better understand the complete functioning of AD patients.

Anosognosia: patients' distress and self-awareness of deficits in Alzheimer's disease

We aimed to study how patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD) suffer from awareness of their deficits. Self-awareness was assessed using the Anosognosia Questionnaire for Dementia in 12 pairs of MCI outpatients and caregivers, 23 with mild AD, and 18 with moderate AD. The discrepancy between patient's and caregiver's evaluation (anosognosia) became greater as AD progressed. The predictors of patients' distress, shown by multiple linear regression analyses, were awareness of decline in intellectual or social functioning; self-awareness of deficits in remembering appointments in MCI; in remembering appointments, writing, mental calculation, and understanding the newspaper in mild AD; and in mental calculation and doing clerical work in moderate AD. Caregivers assumed the predictors of patients' distress differently: awareness of deterioration of memory in MCI and mild AD, and basic activities of daily living in moderate AD. Understanding patients' disability from patients' perspective is required for successful care.

Alzheimer's disease can spare local metacognition despite global anosognosia: revisiting the confidence-accuracy relationship in episodic memory

Alzheimer's disease (AD) can impair metacognition in addition to more basic cognitive functions like memory. However, while global metacognitive inaccuracies are well documented (i.e., low deficit awareness, or anosognosia), the evidence is mixed regarding the effects of AD on local or task-based metacognitive judgments. Here we investigated local metacognition with respect to the confidence-accuracy relationship in episodic memory (i.e., metamemory). AD and control participants studied pictures of common objects and their verbal labels, and then took forced-choice picture recollection tests using the verbal labels as retrieval cues. We found that item-based confidence judgments discriminated between accurate and inaccurate recollection responses in both groups, implicating relatively spared metamemory in AD. By contrast, there was evidence for global metacognitive deficiencies, as AD participants underestimated the severity of their everyday problems compared to an informant's assessment. Within the AD group, individual differences in global metacognition were related to recollection accuracy, and global metacognition for everyday memory problems was related to task-based metacognitive accuracy. These findings suggest that AD can spare the confidence-accuracy relationship in recollection tasks, and that global and local metacognition measures tap overlapping neuropsychological processes.

Agnosias: recognition disorders in patients with brain tumors

Two main varieties of recognition disorders are distinguished in neuropsychology: agnosias and semantic disorders. The term agnosias is generally used to denote recognition defects limited to a single perceptual modality (which is itself apparently intact), whereas the term semantic disorders is used to denote recognition defects involving all the sensory modalities in a roughly similar manner. Brain tumors can be one of the aetiologies underlying agnosias and semantic disorders. However, due to the heterogeneity and the rarity of recognition disorders, their investigation can be useful only to suggest or exclude the oncological nature of a brain lesion, but not to systematically monitor the clinical outcome in tumor patients. Furthermore, the relevance of recognition disorders as a hint toward a diagnosis of brain tumor varies according to the type of agnosia and of semantic disorder and the localization of the underlying brain pathology. The hypothesis that a variety of agnosia (or of semantic disorder) may be due to a neoplastic lesion can, therefore, be advanced if it is consistent with our knowledge about the usual localization and the growing patterns of different types of brain tumors.

[Integrating patients with dementia and anosognosia into community care by a psychogeriatric consultation service]

OBJECTIVE

Patients with dementia and anosognosia were to be integrated into a dementia-network.

METHODS

Home visits were performed during a period of two years. Socio-demographic variables, degree of severity of dementia and recommended measures were documented and evaluated.

RESULTS

Treatment by a general practitioner was reestablished in many cases.

CONCLUSIONS

Home visits with psychogeriatric competence facilitate the integration into individual dementia-specific medical support.

[The questionnaire "alcohol anosognosia" is a new tool for assessment of anosognosia in patients with alcohol dependence]

The aim of this study was to develop and validate a patient-rated questionnaire for the complex express-assessment of alcohol anosognosia. The questionnaire was tested in 106 inpatients diagnosed with alcohol dependence (ICD-10, item F10.2). The age of the study participants (M+/-SD) was 42.1+/-8.8 years, duration of alcohol dependence 11.3+/-7.0 years. The questionnaire consisted of 7 subscales: Not being in the know, Non-recognition of disease symptoms, Non-recognition of disease in whole, Non-recognition of disease consequences, Emotional rejection of disease, Disagreement with treatment, Non-acceptance of temperance. Psychometric characteristics (external-criterion validity, test-retest validity, internal consistency) were studied and the standardization of the questionnaire was performed. Mean empiric values of subscales were determined. The questionnaire allows to get the complex assessment of anosognosia level by separate components and to present the profile of alcohol anosognosia as well.

Neuropsychology of acute stroke

Neuropsychology includes both the psychiatric manifestations of neurological illness (primary brain-based disorders) and neurobiology of "idiopathic" psychiatric disorders. Neurological primary brain disorders provoke broad spectrum of brain pathophysiology that cause deficit sin human behaviour, and the magnitude of neurobehavioral-related problems is a world wide health concern. Speech disorders of aphasic type, unilateral neglect, anosognosia (deficit disorders), delirium and mood disorders (productive disorders) in urgent neurology, first of all in acute phase of stroke are more frequent disorders then it verified in routine exam, not only in the developed and large neurological departments. Aphasia is common consequence of left hemispheric lesion and most common neuropsychological consequence of stroke, with prevalence of one third of all stroke patients in acute phase although exist reports on greater frequency. Unilateral neglect is a disorder that mostly effects the patient after the lesion of the right hemisphere, mostly caused by a cerebrovascular insult (infarct or haemorrhage affecting a large area - up to two thirds of the right hemisphere), and in general the left-side neglect is the most widespread neuropsychological deficit after the lesion of the right cerebral hemisphere. Reports on the incidence of visual neglect vary and they range from 13 to 85%. Anosognosia is on the second place as neuropsychological syndrome of stroke in right hemisphere, characterized by the denial of the motor, visual or cognitive deficit. This syndrome, defined as denial of hemiparesis or hemianopsia, is a common disorder verified in 17-28% of all patents with acute brain stoke. There are different reports on frequency of delirium in acute stroke, from 24 to 48%, and it is more frequent in hemorrhagic then ischemic stoke. Post stroke depression (PSD) is one of the more frequent consequences on the stroke, and the prevalence of PSD has ranged from 5 to 63% of patients in several cross-sectional studies, peaking three to six months after a stroke.

Self-estimation of performance time versus actual performance time in older adults with suspected mild cognitive impairment: a clinical perspective

BACKGROUND

Estimation of the passage of time has received marginal attention in contemporaneous psychiatric assessment and diagnosis. There is disagreement regarding the ability of older adults with dementia, particularly of the Alzheimers type, to estimate time passage, and there is lack of data concerning the ability of older adults in the early stages of cognitive impairment to estimate the passage of time.

OBJECTIVE

We investigated the hypothesis that individuals with mild dementia perform worse compared to those with no cognitive impairment, and that those with mild cognitive impairment (MCI) assume an intermediate position in terms of their ability to accurately estimate time passage. Another objective was to study demographic and clinical (cognitive, functional, psychiatric) predictors of self-estimation of performance time versus actual performance time.

METHOD

In the context of a comprehensive psychogeriatric evaluation, three performance time measures were established: actual performance time, subjective estimation of performance time, and accuracy of estimation of performance time.

RESULTS

102 consecutive persons with suspected MCI were assessed. Final cognitive diagnoses were: dementia 49 (48%), MCI 36 (35%), no cognitive impairment (NCI) 17 (17%). Whereas there were significant group differences (dementia, MCI, NCI) on all cognitive measures and on functional impairment, there were no significant group differences on the three time measures. With the exception of age, estimation of performance time was not associated with any of the other demographic and clinical variables.

CONCLUSION

Self-estimation of performance time versus actual performance time was not found impaired either in the dementia group or in the MCI group when compared to participants without cognitive impairment.

["I'm not crazy!" Studies of agnosia in Alzheimer's disease]

Anosognosia corresponds to a lack of awareness about the own clinical disease of a patient. Anosognosia is frequent in Alzheimer's disease (AD). Researchers explore several hypotheses, psychological (deny) or cognitive (an association of memory and executive impairment), and recently models describing the dynamics of self representation provided convincing interpretations. Self models are modular. They comprise a central executive organising information processing according to subject's objectives. The central executive takes into account personal beliefs and social schemata and it uses autobiographical memory. The analysis of information by the self system leads to decision taking that relies on two principles, self continuity and adaptation. Neuroimaging studies showed that self reflection activates specific brain regions, comprising the ventromedial prefrontal cortex, the medial parietal and posterior cingulate cortex and the inferior parietal lobule. Other studies demonstrated that the same regions are particularly affected by AD. Experimental data currently allows making relationships between regional brain involvement, diverse difficulties in self representation and different forms of anosognosia for clinical status in AD patients.

[Unawareness in brain disorders: a complex and multifaceted phenomenon]

Unawareness of the diseases or its consequences can be a protective mechanism against a traumatic event. However, it can also result in dangerous behaviors and hamper the care management. Still not well understood, unawareness is a very complex and multidimensional construct involving neurological, neuropsychological, psychopathological and psychosocial dimensions. Sometimes considered to be a categorical phenomenon, unawareness is actually partial and dimensional. Nevertheless, no or only weak correlation are found between the results of various methods used to its assessment. We propose that the usual opposition between neurological (anosognosia) and psychopathological (denial) conceptions should be replaced by an integrative approach of the various dimensions involved in unawareness to allow a better adaptation of the care management.

Verbal intelligence in Neglect: the role of anosognosia for hemiplegia

AIM

General intelligence of patients with neglect has been poorly investigated and data at present are contrasting. Moreover it is not yet defined whether the presence of anosognosia for hemiplegia is associated with intellectual impairment in patients with neglect.

METHODS

In this prospective study the authors evaluated the verbal intelligence quotient in neglect patients. This study was carried out on 33 patients with left hemiparesis: 11 patients had neglect (group N), 11 had neglect + anosognosia (group N+A) and 11 had neither neglect nor anosognosia (control group).

RESULTS

Patients of group neglect + anosognosia had significantly lower verbal IQ (VIQ) and mini-mental state examination (MMSE) scores than those of neglect (respectively: P=0.004 and P=0.000) and control groups (respectively: P=0.041 and P=0.000). No significant differences were detected between neglect and control groups for VIQ and MMSE. In N+A group VIQ score was lower than 90 in 81.8% and MMSE score was lower than 24 in 100% of patients. Moreover, 18.2% of N+A patients had VIQ score lower than 80 and 45.4% had MMSE score lower than 18/30. Also 9.1% of neglect group had VIQ score lower than 90 and 36.4% MMSE scores less than 24/30, but none of these patients had VIQ and MMSE scores respectively lower than 80 and 18/30. Similar data were present in control group.

CONCLUSIONS

This study focuses on mental impairment in neglect + anosognosia patients and indicates that A for hemiplegia is a condition that more often occurs when severe mental impairment is present.

Recovery from unilateral neglect after right-hemisphere stroke

PURPOSE

To show the recovery process for different forms of unilateral neglect (UN)--including personal neglect and neglect of far space--in relationship to impairment, disability, cognition and mood.

METHOD

Patients were tested at 2-4 weeks, at 6 months and at 1 year. We used the Behaviour Inattention Test and a test for personal neglect. We also used the NIH Stroke Scale, the Functional Independence Measure (FIM), the Mini-Mental State Evaluation and the Geriatric Depression Scale.

RESULTS

Peripersonal neglect diminishes within 6 months, but complete recovery occurred in only 13%. The prognosis for personal neglect and neglect of far space is better, with a recovery ratio at 6 months of 52% and 46%, respective. The correlations between UN and FIM are high. A few patients deteriorate in the absence of recurrent stroke.

CONCLUSIONS

For clinical purposes, it is practical to postpone UN evaluation until a couple of weeks after a stroke. Many of the patients who then have UN are likely to retain their UN, although many will improve. Patients with UN should receive special attention in the rehabilitation phase, as well as at discharge. One explanation of the worsening of UN seen in some patients, may be continuing cerebral atherosclerosis.

The relationship between naming difficulty and FAS performance following traumatic brain injury

PRIMARY OBJECTIVE

To investigate the relationship between naming difficulty (ND) and FAS performance in traumatic brain injury (TBI).

METHODS AND PROCEDURE

Sixty-three patients with a TBI were divided into two groups based on the presence of a ND and were compared with a control group on FAS performance.

RESULTS

Whilst the group with a TBI performed more poorly than the control group on the FAS task, there was no difference between those participants who featured a ND and those who did not. The TBIs produced fewer words than the control group in the first time slice of the task, but there was no difference between the group with a ND and the non-ND group on this measure.

CONCLUSION

The results indicate that the effect of word finding deficits is not the principal cause of the diminution of phonemic verbal fluency performance in TBI, which is probably more likely due to compromise in speed of information processing associated with the injury.

Pleasurable emotional response to music: a case of neurodegenerative generalized auditory agnosia

Recent functional neuroimaging studies implicate the network of mesolimbic structures known to be active in reward processing as the neural substrate of pleasure associated with listening to music. Psychoacoustic and lesion studies suggest that there is a widely distributed cortical network involved in processing discreet musical variables. Here we present the case of a young man with auditory agnosia as the consequence of cortical neurodegeneration who continues to experience pleasure when exposed to music. In a series of musical tasks, the subject was unable to accurately identify any of the perceptual components of music beyond simple pitch discrimination, including musical variables known to impact the perception of affect. The subject subsequently misidentified the musical character of personally familiar tunes presented experimentally, but continued to report that the activity of 'listening' to specific musical genres was an emotionally rewarding experience. The implications of this case for the evolving understanding of music perception, music misperception, music memory, and music-associated emotion are discussed.

Reality monitoring in anosognosia for hemiplegia

Anosognosia for hemiplegia (AHP) is a lack of awareness about paralysis following stroke. Recent explanations use a 'forward model' of movement to suggest that AHP patients fail to register discrepancies between internally- and externally-generated sensory information. We predicted that this failure would impair the ability to recall from memory whether information is internally- or externally-generated (i.e., reality monitor). Two experiments examined this prediction. Experiment 1 demonstrated that AHP patients exhibit a reality monitoring deficit for non-motor information (i.e., perceived vs. imagined drawings), whilst hemiplegic controls without anosognosia (nonAHP) perform like age-matched healthy volunteers (HVs). Experiment 2 explored if this deficit occurs when AHP patients discriminate performed, imagined, or observed movement. Results showed impaired reality monitoring for movements in AHP and nonAHP patients relative to HVs. Findings suggest that reality monitoring processes not directly related to movement, together with a failure to reality monitor movements, contribute to the pathogenesis of AHP.

Prefrontal cortex function in nonpsychotic siblings of individuals with schizophrenia

BACKGROUND

Cognitive dysfunction is a hallmark feature of schizophrenia. In recent years, it has been proposed that impairments in attention, working memory and executive function may all reflect an underlying deficit in context processing. In individuals with schizophrenia, deficits in context processing have been associated with functional impairments of the dorsolateral prefrontal cortex (DLPFC).

METHODS

We used a variation of the continuous performance task, the AX-CPT, to test the hypothesis that genetic high-risk individuals (full siblings of individuals with schizophrenia) have deficits in context processing and abnormal activation of the DLPFC as compared to community controls.

RESULTS

Siblings of individuals with schizophrenia made significantly more B-X errors on the AX-CPT, indicative of a deficit in context processing. They also showed task-related hyper-activation in a number of brain regions, including the DLPFC.

CONCLUSIONS

Inefficient hyper-activation of the DLPFC may underlie deficits in context processing and contribute to the genetic vulnerability for developing schizophrenia.

A comparison of unawareness in frontotemporal dementia and Alzheimer's disease

BACKGROUND

Loss of insight is a core diagnostic feature of frontotemporal dementia (FTD) and anosognosia is frequently reported in Alzheimer's disease (AD).

AIM

To compare unawareness (anosognosia) for different symptoms, measured with a discrepancy score between patient's and caregiver's assessment, in AD and FTD.

METHOD

In a prospective, multi-centre study, 123 patients with probable AD, selected according to the NINCDS-ADRDA procedure, were matched for age, sex, education, disease duration and dementia severity to patients with FTD (n = 41), selected according to international consensus criteria. A research complaint questionnaire was used to obtained patient's and caregiver's assessment concerning neuropsychological and behavioural symptoms. Data were compared in each group and between groups. Unawareness (measured by discrepancy scores) was compared between patients with AD and FTD.

RESULTS

The caregivers generally assessed symptoms more severely than did patients, but both patient groups reported changes in affect (depressive mood or irritability) as their caregivers did. Unawareness was greater in patients with FTD than in patients with AD for language and executive difficulties, and for changes in behaviour and daily activities.

CONCLUSION

The main finding is that unawareness was observed in both patients with FTD and patients with AD for most clinical domains. However, qualitative and quantitative differences showed that lack of awareness was greater in patients with FTD.

Insight and danger in Alzheimer's disease

To determine the frequency, and demographic and clinical correlates of dangerous behaviours in Alzheimer's disease (AD). We assessed a consecutive series of 278 patients with AD and 45 age-comparable healthy controls with a comprehensive psychiatric and neuropsychological evaluation. Caregivers rated the frequency of patients' exposure to dangerous situations or commission of dangerous behaviours. The frequency of dangerous behaviours was 16% in the AD group and 2% in the healthy control group. The presence of anosognosia was associated with a threefold increase in the risk of dangerous behaviours, but there was no significant association between dangerous behaviours and patients' age, years of education, diagnosis of major or minor depression and presence of suicide ideation. Sixteen per cent of a consecutive series of patients with AD had dangerous behaviours during the month preceding the clinical evaluation. Anosognosia was the main clinical correlate of dangerous behaviours in this population.

Social Mind Representation: Where Does It Fail in Frontotemporal Dementia?

We aimed at investigating social disability and its cerebral correlates in frontotemporal dementia (FTD). To do so, we contrasted answers of patients with early-stage FTD and of their relatives on personality trait judgment and on behavior prediction in social and emotional situations. Such contrasts were compared to control contrasts calculated with answers of matched controls tested with their relatives. In addition, brain metabolism was measured in patients with positron emission tomography and the [18F]fluorodeoxyglucose method. Patients turned out to be as accurate as controls in describing their relative's personality, but they failed to predict their relative's behavior in social and emotional circumstances. Concerning the self, patients were impaired both in current personality assessment and in prediction of their own behavior. Those two self-evaluation measures did not correlate. Only patients' anosognosia for social behavioral disability was found to be related to decreased metabolic activity in the left temporal pole. Such results suggest that anosognosia for social disability in FTD originates in impaired processing of emotional autobiographical information, leading to a self-representation that does not match current behavior. Moreover, we propose that perspective-taking disability participates in anosognosia, preventing patients from correcting their inaccurate self-representation based on their relative's perspective.

Ventral extra-striate cortical areas are required for optimal orientation averaging

We examined the ability of a previously well-studied patient with visual agnosia to compute the average orientation of elements in visual displays. In a structural MRI study, we show that the lesion is likely to involve a variety of ventral extra-striate areas, including V2, V3 and V4; however, the lesion does not extend dorsally. Subsequently we show that some ability to compute average orientation is spared, though there are limitations on the ability to scale the averaging process as a function of the numbers of elements. The results suggest that some aspects of orientation averaging can be accomplished in spared regions of V1 but flexible averaging requires ventral extra-striate cortex.

[Neuropsychological approach to visual attention]

Visual experience depends critically on visual attention, which selects a particular aspect of a visual display. Recent clinical, neuroimaging, and animal studies revealed that visual attention was divided into active and passive or top-down and bottom-up attention. Although these dichotomies are clear-cut in definition, visual attention could be modulated by many factors. Detailed observation of brain-injured patients provides with evidence for dynamic and fine control of visual attention. We observed patients with dorsal simultanagnosia and that with callosal disconnection syndrome. Patients with dorsal simultanagnosia demonstrated that extent of visual attention was dynamically changed depending on the level of visual processing. Despite the ability to read a kanji character and to describe its components correctly, a patient could not notice a component that he had just written and could not assemble individual components to make up a correct kanji character. He could point to an overlapping area of two figures. But once he started to color the overlapping area, he missed the margin of the area and colored much larger area. Another patient with dorsal simultanagnosia missed borderlines between columns of a newspaper and read letters continuously across columns. In contrast, he could point to lines between figures or meaningless patterns easily. These findings indicated that visual attention was directed automatically to meaningful characters. A patients with callosal disconnection syndrome demonstrated left unilateral spatial neglect only when he used his right hand to draw figures. Right hand movement, controlled by the left hemisphere, elicited visual attention to the right hemispace, resulting in the left unilateral spatial neglect. Thus visual attention is not simply top-down or bottom up, but is implicitly affected by the visual recognition as well as motor component of the task.

[Parallel processing of motion vision]

Several neuropsychological studies have reported dissociation between motion vision and object vision. One patient with motion blindness had a bilateral MT/V5 lesion and could see objects, but could not see the motion of the objects (Zihl et al, 1983). By contrast, some blindsight patients with primary visual cortex lesions cannot see objects but can see their movement (e.g. Riddoch, 1917). These results imply that movement vision and form vision rely on independent mechanisms. However one patient with motion blindness had controversial symptoms concerning motion vision. She could not perceive the movement of objects, although she could walk without colliding with obstacles and could catch incoming objects. It has also been reported that patients with a bilateral parietal lesion had well-preserved primary motion vision, but had problems walking and catching a ball (Vaina, 1998). Therefore, motion for vision and motion for action might have independent mechanisms. Such dissociation has also been noted in patients with Bálint syndrome. Some patients behave like a blind person but can walk and catch a ball, while other patients bump into obstacles while walking. These results indicate that the neural bases of motion vision are distinct from those of form vision and that there are subdivisions of motion vision.

[Neuropsychological approach to visual attention]

Visual experience depends critically on visual attention, which selects a particular aspect of a visual display. Recent clinical, neuroimaging, and animal studies revealed that visual attention was divided into active and passive or top-down and bottom-up attention. Although these dichotomies are clear-cut in definition, visual attention could be modulated by many factors. Detailed observation of brain-injured patients provides with evidence for dynamic and fine control of visual attention. We observed patients with dorsal simultanagnosia and that with callosal disconnection syndrome. Patients with dorsal simultanagnosia demonstrated that extent of visual attention was dynamically changed depending on the level of visual processing. Despite the ability to read a kanji character and to describe its components correctly, a patient could not notice a component that he had just written and could not assemble individual components to make up a correct kanji character. He could point to an overlapping area of two figures. But once he started to color the overlapping area, he missed the margin of the area and colored much larger area. Another patient with dorsal simultanagnosia missed borderlines between columns of a newspaper and read letters continuously across columns. In contrast, he could point to lines between figures or meaningless patterns easily. These findings indicated that visual attention was directed automatically to meaningful characters. A patients with callosal disconnection syndrome demonstrated left unilateral spatial neglect only when he used his right hand to draw figures. Right hand movement, controlled by the left hemisphere, elicited visual attention to the right hemispace, resulting in the left unilateral spatial neglect. Thus visual attention is not simply top-down or bottom up, but is implicitly affected by the visual recognition as well as motor component of the task.