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Abstract We administered a discrepancy-based measure of anosognosia for hemiplegia (AHP) to a group of 42 right-brain-damaged (RBD) and left-brain-damaged (LBD) stroke patients with varying levels of functional motor ability. In addition to the expected (anosognosic) pattern of overestimation of motor function in some RBD patients, we found an equal and opposite underestimation in some others, both RBD and LBD. We also found that around a quarter of self-estimation error could be predicted directly from actual ability, such that patients with poorer motor function tended to overestimate, and vice versa. This pattern suggests that some misestimation is attributable simply to statistical regression. However, even after adjusting for this regression effect, levels of overestimation were significantly greater in RBD patients, while LBD patients were more likely to underestimate their motor ability. Highlights • Extreme over- and underestimation of post-stroke motor ability was observed. • One quarter of the variation in misestimation was attributable to actual ability. • Right-brain-damaged patients both over- and underestimated. • The only extreme misestimation in left-brain-damaged patients was underestimation. • Underestimation was associated with lower moods. [ABSTRACT FROM AUTHOR]

While loss of insight of cognitive deficits, anosognosia, is a common symptom in Alzheimer's disease dementia, there is a lack of consensus regarding the presence of altered awareness of memory function in the preclinical and prodromal stages of the disease. Paradoxically, very early in the Alzheimer's disease process, individuals may experience heightened awareness of memory changes before any objective cognitive deficits can be detected, here referred to as hypernosognosia . In contrast, awareness of memory dysfunction shown by individuals with mild cognitive impairment (MCI) is very variable, ranging from marked concern to severe lack of insight. This study aims at improving our mechanistic understanding of how alterations in memory self-awareness are related to pathological changes in clinically normal (CN) adults and MCI patients. 297 CN and MCI patients underwent PiB-PET (Positron Emission Tomography using Pittsburgh Compound B) in vivo amyloid imaging. Amyloid burden was estimated from Alzheimer's disease vulnerable regions, including the frontal, lateral parietal and lateral temporal, and retrosplenial cortex. Memory self-awareness was assessed using discrepancy scores between subjective and objective measures of memory function. A set of univariate analysis of variance were performed to assess the relationship between self-awareness of memory and amyloid pathology. Whereas CN individuals harboring amyloid pathology demonstrated hypernosognosia, MCI patients with increased amyloid pathology demonstrated anosognosia. In contrast, MCI patients with low amounts of amyloid were observed to have normal insight into their memory functions. Altered self-awareness of memory tracks with amyloid pathology. The findings of variability of awareness may have important implications for the reliability of self-report of dysfunction across the spectrum of preclinical and prodromal Alzheimer's disease. [ABSTRACT FROM AUTHOR]

Anosognosic patients show a lack of awareness for their hemiplegia coupled with a distorted sense of agency for the actions performed by the plegic limbs. Since anosognosia is often associated with right brain damage, this hemisphere seems to play a dominant role in monitoring awareness for motor actions. Therefore, we would expect that anosognosic patients show distorted awareness and sense of agency also for actions performed with the unimpaired limb. To test this hypothesis, we induced illusory actions that could be congruent or incongruent with a preceding verbal command. A group of 16 right brain-damaged patients performed this task and then rated i) their ability to anticipate the actions, ii) their sense of agency and iii) their sense of ownership for each limb. Measures of awareness, neglect and motor impairment were also considered for the patient group. Following incongruent actions with the unimpaired limb, less aware patients showed a relatively mild distortion in all three aspects. In addition, we also found a crucial relationship between motor impairment (for the plegic limb) and sense of agency for both plegic and healthy limbs. Although the distortion linked to both limbs supports the initial hypothesis that the right hemisphere is responsible for monitoring awareness for action for the whole body, our data also suggest that the observed distortion may be linked to a motor compensatory phenomenon, not necessarily related to awareness processes. • Right-hemisphere networks play a dominant role on ownership, awareness and agency. • Motor deficits modulate of sense of agency but not ownership. • Motor compensatory processes may conflate with sense of agency. • Distortions of agency may be latent for ipsilateral actions also in aware patients. • Studies on awareness and agency for actions should consider impact of hemiplegia. [ABSTRACT FROM AUTHOR]

Brain-damaged patients with anosognosia for hemiplegia deny their motor deficit and believe they can still move the paralyzed limb. Previous studies suggest that anosognosia can arise from intact motor intentionality and planning for the plegic hand. However, few studies focused on the relationship between this spared intentionality and perception. To further investigate this topic, we used an apparent motion paradigm, where a stimulus generated an ambiguous motion and participants were simply asked to judge its direction (right or left). We confirmed that, when healthy participants are asked to press a key either with their right or left hand, triggering the apparent motion, they show a perceptual bias toward the direction of the moving hand. Both bimanual and unimanual modalities (i.e. key pressing with-both-hands or with-one-hand, respectively) of the same apparent motion paradigm were administered to two groups of healthy participants. Interestingly, only in the bimanual modality, participants showed a significant perceptual bias. Hemiplegic patients with and without anosognosia, were requested to perform the bimanual task. Patients without anosognosia, fully aware of their left motor deficit, only programed right hand movements, behaving similarly to healthy controls performing the unimanual task. On the contrary, in patients with anosognosia, an effective motor intentionality for the left (plegic) hand influenced visual perception, giving rise to similar perceptual bias as that found in healthy controls actually performing bimanual movements. These findings suggest that having a specific motor representation can lead to different outcomes in the perception of the outside world. [ABSTRACT FROM AUTHOR]

Unawareness of memory loss is a challenging characteristic of Alzheimer’s disease (AD) and other age-related neurodegenerative conditions at their earliest stages, adversely affecting important outcomes such as patient decision making and safety. The basis of this metacognitive disturbance has been elusive; however it is almost certainly determined in part by compromise to brain regions critical for self-assessment. The subjectivity of traditional measurements of self-awareness in dementia has likely limited the rigor with which its neuroanatomic correlates can be established. Here we objectively measure memory awareness (metamemory) using a Feeling of Knowing (FOK) task in a group of cognitively diverse older adults, including 14 with mild AD and 20 cognitively healthy older adults. Performance on the metamemory task was examined in relation to the structural integrity of 14 bilateral neuroanatomic regions hypothesized to support self-awareness. Less accurate metamemory was associated only with reduced right insular volume ( r =.41, p =.019). Implications of the current findings for models of metacognitive aging are discussed, with attention to the role of the insula in the conscious detection of errors. [ABSTRACT FROM AUTHOR]

Spatial neglect has been related to both cortical (predominantly at the temporal–parietal junction) and subcortical (predominantly of the superior longitudinal fasciculus) lesions. The objectives of this observational study were to specify the anatomical relationships of behavioral neglect in activities of daily living (N-ADLs), and the anatomical and psychometric relationships of N-ADLs on one hand and components of neglect (peripersonal neglect and personal neglect) and anosognosia on the other. Forty five patients were analyzed for behavioral difficulties in daily living (on the Catherine Bergego scale) and the main components of neglect (using conventional clinical assessments) during the first months post right hemisphere stroke. Voxel-based lesion-symptom mapping was used to identify brain areas within which lesions explained the severity of bias in each assessment (non-parametric permutation test; p <0.01, one tailed). N-ADLs was associated with lesions centered on the posterior part of the superior temporal gyrus and extending to the temporo-parietal junction, temporo-occipital junction and subcortical white matter (including the superior longitudinal fasciculus). Peripersonal neglect resulted from extended cortical lesions centered on the superior temporal gyrus and the inferior parietal gyrus, with subcortical extension. Personal neglect resulted predominantly from lesions centered on the somatosensory cortex and at a lesser degree on the superior temporal sulcus. Anosognosia resulted from lesions of the posterior inferior temporal gyrus and superior temporal gyrus. In anatomic terms, N-ADLs was strongly related to peripersonal neglect, and those relationships were also shown by the psychometric analysis. In conclusions, superior temporal gyrus and superior longitudinal fasciculus lesions have a pivotal role in N-ADLs. N-ADLs is principally related (anatomically and psychometrically) to peripersonal neglect, and at a lesser degree to anosognosia and personal neglect. [ABSTRACT FROM AUTHOR]

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

Abstract: Clinical experience and prior studies suggest that Huntington disease (HD) patients have low insight into their motor disturbances and poor real-time awareness (concurrent awareness) of chorea. This has been attributed to sensory deficits but, until now, concurrent awareness of choreic movements has not been compared to the degree of insight that presymptomatic carriers of the HD gene and healthy control subjects have into non-pathological involuntary movements. To further investigate loss of insight into motor dysfunction in HD patients, we administered a video-recorded interview and 4experimental tasks to 68 subjects from the TRACK-HD cohort, including 28 high-functioning patients in early stages of HD, 28 premanifest mutation carriers and 12 controls. All underwent full neurological and neuropsychological evaluations and 3T MRI examinations. Subjects were asked to assess the presence, body location, frequency, practical consequences and probable causes of motor impairments, as well as the presence and body location of involuntary movements during 4experimental tasks. The accuracy of their judgments, assessed by comparison with objective criteria, was used as a measure of their insight into motor disturbances and of their concurrent awareness of involuntary movements. Insight was poor in early HD patients: motor symptoms were nearly always underestimated. In contrast, concurrent awareness of involuntary movements, although also poor, was essentially indistinguishable across the 3groups of subjects: non-pathological involuntary movements were as difficult to perceive by controls and premanifest carriers as was chorea for early HD patients. GLM analysis suggested that both concurrent awareness and perception of practical consequences of movement disorder had a positive effect on intellectual insight, and that mental flexibility is involved in concurrent awareness. Our results suggest that low insight into motor dysfunction in early HD, although marginally modulated by cognitive factors, is mainly non-pathological, and parallels a general tendency, shared by healthy subjects, to neglect self-generated involuntary movements in real time. This tendency, combined with the paucity of functional consequences of incipient chorea, could explain the difficulty of its discovery by the patients. [Copyright &y& Elsevier]

Abstract: 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. [Copyright &y& Elsevier]

Abstract: Lack of awareness about performance in tasks is a common feature of Alzheimer''s disease. Nevertheless, clinical anecdotes have suggested that patients may show emotional or behavioural responses to the experience of failure despite reporting limited awareness, an aspect which has been little explored experimentally. The current study investigated emotional reactions to success or failure in tasks despite unawareness of performance in Alzheimer''s disease. For this purpose, novel computerised tasks which expose participants to systematic success or failure were used in a group of Alzheimer''s disease patients (n=23) and age-matched controls (n=21). Two experiments, the first with reaction time tasks and the second with memory tasks, were carried out, and in each experiment two parallel tasks were used, one in a success condition and one in a failure condition. Awareness of performance was measured comparing participant estimations of performance with actual performance. Emotional reactivity was assessed with a self-report questionnaire and rating of filmed facial expressions. In both experiments the results indicated that, relative to controls, Alzheimer''s disease patients exhibited impaired awareness of performance, but comparable differential reactivity to failure relative to success tasks, both in terms of self-report and facial expressions. This suggests that affective valence of failure experience is processed despite unawareness of task performance, which might indicate implicit processing of information in neural pathways bypassing awareness. [Copyright &y& Elsevier]

Abstract: This is the case report of RB, a 68-year-old retired woman who, following an extensive right sided ischaemic stroke, showed hemiplegia, anosognosia and allochiria, but no somato-sensory deficits and no visuospatial neglect. A high resolution 3D MRI structural scan of her brain was acquired to define the structural damage in detail. Morphometric analyses of grey and white matter data revealed a large lesion which involved most of her right parietal, temporal, and mesial frontal cortex, with partial sparing of the right dorsolateral prefrontal cortex and part of the posterior corpus callosum. Detailed examination showed that RB attributed sensory stimuli, both on the left and on the right, to the opposite side of her body. This mirror reversed representation of her body caused misattribution of items even in the absence of stimulation, as for instance when the patient spontaneously reported pain in her right knee while pointing to her left knee. RB''s neuropsychological profile showed normal or borderline performance on most cognitive tasks. Language comprehension was intact and she could tell left from right without difficulty in all instances except for those referable to her soma. To our knowledge this is the first description of severe allochiria for body representation in the absence of neglect. The evidence from this case supports the developing concept that the body representation is not simply a systematic registration of proprioceptive inputs, but that the brain has a more sophisticated high level representation of one''s body map which is updated on the basis of multimodal information. [Copyright &y& Elsevier]

Abstract: It is tentatively estimated that 25% of people with early Alzheimer''s disease (AD) show impaired awareness of disease-related changes in their own cognition. Research examining both normative self-awareness and altered awareness resulting from brain disease or injury points to the central role of the medial prefrontal cortex (MPFC) in generating accurate self-appraisals. The current project builds on this work – examining changes in MPFC functional connectivity that correspond to impaired self-appraisal accuracy early in the AD time course. Our behavioral focus was self-appraisal accuracy for everyday memory function, and this was measured using the Memory Function Scale of the Memory Awareness Rating Scale – an instrument psychometrically validated for this purpose. Using regression analysis of data from people with healthy memory (n =12) and people with impaired memory due to amnestic mild cognitive impairment or early AD (n =12), we tested the hypothesis that altered MPFC functional connectivity – particularly with other cortical midline structures and dorsolateral prefrontal cortex – explains variation in memory self-appraisal accuracy. We spatially constrained (i.e., explicitly masked) our regression analyses to those regions that work in conjunction with the MPFC to evoke self-appraisals in a normative group. This empirically derived explicit mask was generated from the result of a psychophysiological interaction analysis of fMRI self-appraisal task data in a separate, large group of cognitively healthy individuals. Results of our primary analysis (i.e., the regression of memory self-appraisal accuracy on MPFC functional connectivity) were generally consistent with our hypothesis: people who were less accurate in making memory self-appraisals showed attenuated functional connectivity between the MPFC seed region and proximal areas within the MPFC (including subgenual anterior cingulate cortex), bilateral dorsolateral prefrontal cortex, bilateral caudate, and left posterior hippocampus. Contrary to our expectations, MPFC functional connectivity with the posterior cingulate was not significantly related to accuracy of memory self-appraisals. Results reported here corroborate findings of variable memory self-appraisal accuracy during the earliest emergence of AD symptoms and reveal alterations in MPFC functional connectivity that correspond to impaired memory self-appraisal. [Copyright &y& Elsevier]

Abstract: This survey takes into account the unconscious aspects of emotions and the critical role played in them by the right hemisphere, considering different acceptations of the term ‘unconscious’. In a preliminary step, the nature of emotions, their componential and hierarchical organization and the relationships between emotions and hemispheric specialization are shortly discussed, then different aspects of emotions are surveyed: first are reviewed studies dealing with the unconscious processing of emotional information, taking separately into account various lines of research. All these studies suggest that unconscious processing of emotional information is mainly subsumed by a right hemisphere subcortical route, through which emotional stimuli quickly reach the amygdala. We afterwards inquire if a right hemisphere dominance can also be observed in automatic emotional action schemata and if ‘non-removed preverbal implicit memories’ also have a preferential link with the right hemisphere. Finally, we try to evaluate if the right hemisphere may also play a critical role in dynamic unconscious phenomena, such as anosognosia/denial of hemiplegia in patients with unilateral brain lesions. In the last part of the review, the reasons that could subsume the right hemisphere dominance for unconscious emotions are shortly discussed. [Copyright &y& Elsevier]

Abstract: We assessed the ability of two groups of patients with mild Alzheimer''s disease (AD) and two groups of older adults to monitor the likely accuracy of recognition judgments and source identification judgments about who spoke something earlier. Alzheimer''s patients showed worse performance on both memory judgments and were less able to monitor with confidence ratings the likely accuracy of both kinds of memory judgments, as compared to a group of older adults who experienced the identical study and test conditions. Critically, however, when memory performance was made comparable between the AD patients and the older adults (e.g., by giving AD patients extra exposures to the study materials), AD patients were still greatly impaired at monitoring the likely accuracy of their recognition and source judgments. This result indicates that the monitoring impairment in AD patients is actually worse than their memory impairment, as otherwise there would have been no differences between the two groups in monitoring performance when there were no differences in accuracy. We discuss the brain correlates of this memory-monitoring deficit and also propose a Remembrance–Evaluation model of memory-monitoring. [Copyright &y& Elsevier]

Abstract: The current study adds to the growing empirical research into the mechanisms underlying unawareness of paralysis following stroke (anosognosia for hemiplegia or AHP) by investigating action awareness for the non-paralysed limb in a single AHP patient. Visual feedback representing patient GG''s goal-directed reaching movements was either modified by a computer or left unperturbed. Unlike healthy and brain-damaged controls, GG was unable to detect computer-generated visual perturbations as large as 20°. GG also failed to report awareness of the large on-line corrective movements that he made when compensating (often unsuccessfully) for the visual perturbations. These results suggest that the motor comparators implicated in AHP are functioning, but not at optimum levels. Moreover, because the current findings reveal a deficit in awareness for reaches with the unimpaired limb, it is suggestive of common right hemisphere networks for motor awareness in both limbs and that AHP may be a global deficit in motor awareness as opposed to a specific lack of awareness for a particular motor deficit. [Copyright &y& Elsevier]

Abstract: It is still a matter of debate whether constructive apraxia (CA) should be considered a form of apraxia or, rather, the motor expression of a more pervasive impairment in visuo-spatial processing. Constructive disorders were linked to visuo-spatial disorders and to deficits in appreciating spatial relations among component sub-parts or problems in reproducing three-dimensionality. We screened a large population of brain-damaged patients for CA. Only patients with constructive disorders and no signs of neglect and/or aphasia were selected. Five apractic subjects were tested with both visuo-spatial and verbal tasks requiring constructive abilities. The former ones were tests such as design copying, while the latter were experimental tasks built to transpose into the linguistic domain the constructive process as phrasing by arranging paper scraps into a sentence. A first result showed a constructive impairment in both the visuo-spatial and the linguistic domain; this finding challenges the idea that CA is confined to the visuo-spatial domain. A second result showed a systematic association between CA and unawareness for constructive disorders. Third, lack of awareness was always associated with a lesion in the right dorsolateral prefrontal cortex, a region deemed as involved in managing a conflict between intentions and sensory feed-back. Anosognosia for constructive disorders and the potential role of the right prefrontal cortex in generating the impairment, are discussed in the light of current models of action control. The core of CA could be the inability to detect any inconsistency between intended and executed action rather than a deficit in reproducing spatial relationship. [Copyright &y& Elsevier]

Abstract: If asked directly, anosognosic patients deny or seriously underestimate their motor difficulties. However explicit denial of hemiplegia does not necessarily imply a lack of insight of the deficit. In this study we explored explicit and implicit awareness for upper limb motor impairment in a group of 30 right-brain damaged patients. Explicit awareness was assessed using a questionnaire (the VATAm) in which patients are asked to rate their motor abilities, whereas implicit awareness was assessed by means of a newly developed test (BMT – bimanual task). This test requires the performance of a series of bimanual tasks that can be better performed using two hands, but could also be performed using one hand only. With the BMT, patients’ performance rather than their verbal reports is evaluated and scored as an index of awareness. Paretic patients with anosognosia tend to approach these tasks as if they could use both hands. Our findings showed that explicit and implicit awareness for motor deficits can be dissociated, and they may be differently affected by feedback suggesting that different underlying mechanisms may account for the multi-factorial phenomenon of anosognosia. [Copyright &y& Elsevier]

Abstract: Cerebral achromatopsia is a rare disorder of colour vision caused by bilateral damage to the occipito-temporal cortex. Patients with cerebral achromatopsia are commonly said to suffer due to their disturbed colour sense. Here, we report the case of a patient with cerebral achromatopsia who was initially unaware of his deficit, although three experiments with eye movement recordings demonstrated his severe inability to use colour information in everyday tasks. During two months, the evolution of his colour vision deficit was followed with repeated standardized colour vision tests and eye movement recordings. While his performance continuously improved, he became more and more aware of the deficit. Only after colour vision had almost normalized, his subjective colour sensation was inconspicuous again. The simultaneous occurrence of achromatopsia and the corresponding anosognosia and their parallel recovery suggest that both deficits were due to dysfunction of the same brain region. Consequently, the subjective experience of colour loss in achromatopsia may depend on the residual function of the damaged colour centre. [Copyright &y& Elsevier]

Abstract: We report a patient with severe anosognosia for hemiplegia, who recovered instantly and permanently when viewing herself in a video replay. We believe the observed dramatic reinstatement of the patient''s awareness related to her self-observation ‘from the outside’ (3rd person perspective) and ‘off-line’ (at a time later than the actual attempt to execute a movement); her anosognosia had been unaltered when she observed her plegic arm in her ipsilateral visual field (self-observation from a 1st-person perspective and ‘on-line’). To our knowledge, the role of self-observation in videos or mirrors has not being assessed in AHP to date. Our study provides preliminary evidence that, when right hemisphere damage impairs the ability to update one''s body representation, judgements relying on 3rd-person and off-line self-observation may be spared in some patients and may facilitate 1st person awareness. [Copyright &y& Elsevier]

Abstract: Anosognosia for hemiplegia (AHP) is characterised by poor insight or underestimation of hemiplegia after brain injury. Recent explanations of AHP have used an established ‘forward model’, which proposes that normal motor awareness involves comparing the predicted and actual sensory consequences of movements. These accounts propose that AHP patients may be able to form representations of their intended movements (i.e., motor representations), but fail to register discrepancy between intended and actual movements. A prediction arising from this proposal is that AHP patients are able to generate motor representations involving their hemiplegic limb(s). Our study provides the first direct examination of this prediction in patients with AHP. We used an existing ‘grip selection task’, which investigates motor representations by comparing how patients would grasp an object and how they actually grasp the same object. Eight right hemisphere stroke patients with AHP, 10 control patients (non-AHP), and 22 age-matched healthy volunteers (HVs) completed the task. Results showed that HVs outperformed both AHP and non-AHP patients in their motor representations for the hemiplegic limb; however, the performance of AHP and non-AHP patients did not differ significantly. Motor representations for the intact limb were lower than normal in AHP patients, whereas performance in non-AHP patients was midway between the AHP and HV groups. Findings suggested that the ability to form motor representations lie on a continuum, but that impaired motor representations for the paralysed limb cannot account for AHP. Distorted motor representations, in combination with other deficits, might contribute to the pathogenesis of AHP. [Copyright &y& Elsevier]

Abstract: In the present paper, we shall review clinical evidence and theoretical models related to anosognosia for sensorimotor impairments that may help in understanding the normal processing underlying conscious self-awareness. The dissociations between anosognosia for hemiplegia and anosognosia for hemianaesthesia are considered to give important clinical evidence supporting the hypothesis that awareness of sensory and motor deficits depends on the functioning of discrete self-monitoring processes. We shall also present clinical and anatomical data on four single case reports of patients selectively affected by anosognosia for hemianaesthesia. The differences in the anatomical localization of lesions causing anosognosia for hemiplegia and anosognosia for hemianaesthesia are taken as evidence that cerebral circuits subserving these monitoring processes are located in separate brain areas, which may be involved both in the execution of primary functions and the emergence of awareness related to the monitoring of the same functions. The implications of these findings for the structure of conscious processes shall be also discussed. [Copyright &y& Elsevier]

Abstract: Agnew and Morris [Agnew, S. K. & Morris, R. G. (1998). The heterogeneity of anosognosia for memory impairment in Alzheimer''s disease: A review of the literature and a proposed model. Aging and Mental Health, 2, 9–15] model of awareness for memory functioning has attempted to account for the variance of anosognosia exhibited within the Alzheimer''s disease (AD) population. There has been tentative evidence to suggest that the mnemonic anosognosia sub-type, proposed by this model, is common within the early stages of AD. However, this study is the first directly to test the model. Eighteen older adults with early AD and 18 healthy older adults were recruited. Awareness of memory functioning was monitored using patient-performance measures of “task specific” awareness; a measure of global memory awareness; and a patient-informant measure. The stability of participants’ awareness was measured across three word recall lists and after a 20-min delay. Results suggested that, whilst the participants with early AD were less aware of their memory ability than the healthy older adults, they were able to improve their awareness following exposure to a memory task. Furthermore, the improvements in awareness were largely retained after the delay period. These findings are discussed in relation to Agnew and Morris [Agnew, S. K. & Morris, R. G. (1998). The heterogeneity of anosognosia for memory impairment in Alzheimer''s disease: A review of the literature and a proposed model. Aging and Mental Health, 2, 9–15] model of mnemonic anosognosia and to current thinking about autobiographical memory. [Copyright &y& Elsevier]

Persisting anosognosia after acute lesions is relatively rare, and no case studies to date have reported functional scanning investigation of this disorder. This is a case report of an 85-year-old right-handed Scottish woman, EN, who showed persistent anosognosia for hemiplegia following a haemorrhagic stroke. Extensive damage in the right hemisphere caused left upper and lower limb flaccid hemiplegia and severe left-sided neglect. Lack of awareness for her deficits was still present 2 years after the stroke, when neurological, neuropsychological, and SPECT examinations were performed. Testing revealed severe left unilateral neglect and poor performance on verbal fluency tasks. EN had age normal memory performance, and her object recognition and praxic abilities were preserved. She showed no global reasoning or language problems apart from her abnormal beliefs. EN believed that she was able to walk and carry out several activities, in a context of other disorders of belief. SPECT scan showed marked hypoperfusion in the right parietotemporal cortex and this extended to the associative cortex in the right frontal regions.The persistence of anosognosia in this patient cannot be explained by memory impairments or global cognitive decline. A possible account might be that alteration in awareness was maintained by contingent right frontal and/or parietal dysfunction causing a suspension or change in the ability to monitor and check the ‘real’ and especially to assess the veracity of mental contents. [Copyright &y& Elsevier]

Unawareness of motor disorders (anosognosia) has often been reported after brain lesions, and it has been considered a temporary condition common in the acute and post-acute phases. The presence of anosognosia in a chronic phase (i.e. lasting more than few weeks) is a rare occurrence, thought to be the result of reasoning deficits which prevent patients from performing an adequate check of reality. Although this assumption is widely shared amongst researchers, only a few studies have actually addressed this issue. We report on the case of a patient (NS) who was still showing anosognosia for hemiplegia 1 year after a traumatic brain–head injury, while his reasoning abilities were well preserved. By means of a series of tests and experiments, we evaluated the main theoretical approaches. NS’s long-lasting anosognosia is discussed in terms of a combination of clinical manifestations, whereby personal neglect and motor–sensory information play a key role in preventing awareness, whereas memory difficulties in updating pre-existing personal schema may be crucial in maintaining NS’s anosognosic status. [Copyright &y& Elsevier]

Systematic individual neuroanatomical (MRI) and neuropsychological investigations were conducted for nine patients with unilateral neglect persisting at least 3 months after a cerebral vascular accident. The pattern of referrals, together with subsequent investigation, demonstrates that persisting neglect is rare in both right- and left-hemispheric lesioned patients. But while persisting neglect following a left-hemispheric lesion is even rarer than following a right-hemispheric lesion, it does occur.The neuroanatomical results indicate that persisting neglect may be associated with a different pattern of damage from acute neglect. In the nine patients investigated, persisting neglect reflected extensive lesions that involved three or more cortical lobes or subcortical regions. The results support previous findings that parietal lesions are common but not essential for persisting neglect. In the seven of nine neglect patients with parietal lesions, the rostral inferior parietal lobe and the parietal–frontal junction were involved. Of note was the finding that the brain regions most commonly implicated were the basal ganglia and the superior dorsolateral prefrontal cortex (including the frontal eye field).All of the patients with persisting neglect had a range of neuropsychological deficits, including extinction, personal neglect, and anosognosia for one or more aspects of their neglect. Although it was not possible to demonstrate a double dissociation with this pattern of results, the findings indicate that extinction and anosognosia are dissociable into function-specific forms. Most of the neglect patients also had sustained attention deficits, visual memory problems, and visuospatial constructional difficulties. [Copyright &y& Elsevier]

Anosognosia, or lack of self-awareness, is often present following neurological injury and can result in poor functional outcomes. The specific phenomenon of intellectual awareness, the knowledge that a function is impaired in oneself, has not been widely studied in post-stroke aphasia. We aim to identify behavioral and neural correlates of intellectual awareness by comparing stroke survivors' self-reports of anomia to objective naming performance and examining lesion sites. Fifty-three participants with chronic aphasia without severe comprehension deficits rated their naming ability and completed a battery of behavioral tests. We calculated the reliability and accuracy of participant self-ratings, then examined the relationship of poor intellectual awareness to speech, language, and cognitive measures. We used support vector regression lesion-symptom mapping (SVR-LSM) to determine lesion locations associated with impaired and preserved intellectual awareness. Reliability and accuracy of self-ratings varied across the participants. Poor intellectual awareness was associated with reduced performance on tasks that rely on semantics. Our SVR-LSM results demonstrated that anterior inferior frontal lesions were associated with poor awareness, while mid-superior temporal lesions were associated with preserved awareness. An anterior-posterior gradient was evident in the unthresholded lesion-symptom maps. While many people with chronic aphasia and relatively intact comprehension can accurately and reliably report the severity of their anomia, others overestimate, underestimate, or inconsistently estimate their naming abilities. Clinicians should consider this when administering self-rating scales, particularly when semantic deficits or anterior inferior frontal lesions are present. Administering self-ratings on multiple days may be useful to check the reliability of patient perceptions. • Some people with aphasia are aware of their naming abilities, while others are not. • People with reduced awareness also demonstrated semantic deficits. • Frontal lesions, particularly of pars orbitalis, related to reduced awareness. • Intellectual awareness did not correlate with emergent awareness. • The results inform current neurocognitive theories of awareness. [ABSTRACT FROM AUTHOR]

Being aware of one's own ability to interact socially is crucial to everyday life. After a brain injury, patients may lose their capacity to understand others' intentions and beliefs, that is, the Theory of Mind (ToM). To date, the debate on the association between ToM and other cognitive deficits (in particular executive functions and behavioural disorders) remains open and data regarding awareness of ToM deficits are meagre. By means of an ad-hoc neuropsychological battery of tests, we report on a patient who suffers from ToM deficits and is not aware of these disorders, although aware of his other symptoms. The study is accompanied by a review of the literature (PRISMA guidelines) demonstrating that ToM deficits are independent of executive functions. Furthermore, an advanced lesion analysis including tractography was executed. The results indicate that: i) ToM deficits can be specific and independent of other cognitive symptoms; ii) unawareness may be specific for ToM impairment and not involve other disorders and iii) the medial structures of the limbic, monitoring and attentional systems may be involved in anosognosia for ToM impairment. • Anosognosia after TBI can be selective for Theory of Mind deficits. • Theory of Mind deficits are not secondary to executive functions impairment. • The limbic, monitoring and attentional systems play a role in anosognosia. [ABSTRACT FROM AUTHOR]