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Brain Structure & Function Dec 2022Personal neglect is a disorder in the perception and representation of the body that causes the patients to behave as if the contralesional side of their body does not...
Personal neglect is a disorder in the perception and representation of the body that causes the patients to behave as if the contralesional side of their body does not exist. This clinical condition has not been adequately investigated in the past as it has been considered a symptom of unilateral spatial neglect, which has mainly been studied with reference to extrapersonal space. Only a few studies with small samples have investigated the neuroanatomical correlates of personal neglect, and these have mainly focused on discrete cortical lesions and modular accounts, as well as being based on the hypothesis that this disorder is associated with somatosensory and spatial deficits. In the present study, we tested the novel hypothesis that personal neglect may be associated not only with discrete cortical and subcortical lesions, but also with disconnections of white matter tracts. We performed an advanced lesion analyses in a large sample of 104 right hemisphere damaged patients, 72 of whom were suffering from personal neglect. Results from the analyses of the grey and white matter were controlled for co-occurrent clinical variables such as extrapersonal neglect, anosognosia for hemiplegia and motor deficits, along with other lesion-related variables such as lesion size and the interval from the lesion onset to neuroimaging recordings. Our results reveal that personal neglect is associated with lesions in a medial network which involves the temporal cortex (Heschl's gyrus), the ventro-lateral nuclei of the thalamus and the fornix. This suggests that personal neglect involves a convergence between sensorimotor processes, spatial representation and the processing of self-referred information (episodic memory).
Topics: Humans; Perceptual Disorders; Neuropsychological Tests
PubMed: 35670845
DOI: 10.1007/s00429-022-02511-z -
Schizophrenia Bulletin Jul 2011This theme section on vision science and schizophrenia research demonstrates that our understanding of the disorder could be significantly accelerated by a greater...
This theme section on vision science and schizophrenia research demonstrates that our understanding of the disorder could be significantly accelerated by a greater adoption of the methods of vision science. In this introduction, we briefly describe what vision science is, how it has advanced our understanding of schizophrenia, and what challenges and opportunities lay ahead regarding schizophrenia research. We then summarize the articles that follow. These include reviews of abnormal form perception (perceptual organization and backward masking) and motion processing, and an article on reduced size contrast illusions experienced by hearing but not deaf persons with schizophrenia. These articles reveal that the methods of basic vision research can provide insights into a number of aspects of the disorder, including pathophysiology, development, cognition, social cognition, and phenomenology. Importantly, studies of visual processing in schizophrenia make it clear that there are impairments in the functioning of basic neural mechanisms (e.g., center-surround modulation, contextual modulation of feedforward processing, reentrant processing) that are found throughout the cortex and that are operative in multiple forms of cognitive dysfunction in the illness. Such evidence allows for an updated view of schizophrenia as a condition involving generalized failures in neural network formation and maintenance, as opposed to a primary failure in a higher level factor (e.g., cognitive control) that accounts for all other types of perceptual and cognitive dysfunction. Finally, studies of vision in schizophrenia can identify sensitive probes of neural functioning that can be used as biomarkers of treatment response.
Topics: Brain Mapping; Cerebral Cortex; Cognition Disorders; Forecasting; Humans; Nerve Net; Neurotransmitter Agents; Perceptual Disorders; Research; Schizophrenia; Schizophrenic Psychology; Visual Perception
PubMed: 21700588
DOI: 10.1093/schbul/sbr053 -
Ear and Hearing 2018
Topics: Audiology; Auditory Perceptual Disorders; History, 20th Century; History, 21st Century; Humans; Language Development Disorders; Language Disorders; Learning Disabilities
PubMed: 29664753
DOI: 10.1097/AUD.0000000000000582 -
Journal of Neurology, Neurosurgery, and... Jan 2004The syndrome of hemispatial neglect is characterised by reduced awareness of stimuli on one side of space, even though there may be no sensory loss. Although it is... (Review)
Review
The syndrome of hemispatial neglect is characterised by reduced awareness of stimuli on one side of space, even though there may be no sensory loss. Although it is extremely common, it has proven to be a challenging condition to understand, and to treat. New insights from detailed behavioural and anatomical studies in patients, as well as functional imaging in healthy individuals, have begun to reveal some of the component deficits underlying the disorder. This review focuses on important clinical issues in neglect, including bedside diagnostic tests and emerging therapeutic and rehabilitation methods, involving both behavioural and drug treatments.
Topics: Brain; Diagnosis, Differential; Humans; Perceptual Disorders; Point-of-Care Systems
PubMed: 14707298
DOI: No ID Found -
Developmental Medicine and Child... Jul 2020
Topics: Cerebral Palsy; Humans; Movement Disorders; Perceptual Disorders; Somatosensory Disorders
PubMed: 32484581
DOI: 10.1111/dmcn.14542 -
Cortex; a Journal Devoted To the Study... Dec 2021Synesthesia occurs more commonly in individuals fulfilling criteria for an autism spectrum diagnosis than in the general population. It is associated with autistic...
Synesthesia occurs more commonly in individuals fulfilling criteria for an autism spectrum diagnosis than in the general population. It is associated with autistic traits and autism-related perceptual processing characteristics, including a more detail-focused attentional style and altered sensory sensitivity. In addition, these characteristics correlate with the degree of grapheme-color synesthesia (consistency of grapheme-color associations) in non-synesthetes. We investigated a predominantly non-synesthetic twin sample, including individuals fulfilling criteria for an autism spectrum diagnosis or other neurodevelopmental disorders (n = 65, 14-34 years, 60% female). We modelled linear relationships between the degree of grapheme-color synesthesia and autistic traits, sensory sensitivity, and visual perception, both within-twin pairs (22 pairs) where all factors shared by twins are implicitly controlled (including 50-100% genetics), and across the entire cohort. We found that the degree of grapheme-color synesthesia was associated with autistic traits within the domain of Attention to Details and with sensory hyper-, but not hypo-sensitivity. These associations were stronger within-twin pairs than across the sample. Further, twins with a higher degree of grapheme-color synesthesia were better than their co-twins at identifying fragmented images (Fragmented Pictures Test). This is the first twin study on the association between synesthesia and autism-related perceptual features and traits. The results suggest that investigating these associations within-twin pairs, implicitly adjusting for potential confounding factors shared by twins, is more sensitive than doing so in non-related individuals. Consistent with previous findings, the results suggest an association between the degree of grapheme-color synesthesia and autism-related perceptual features, while utilizing a different measure for sensory sensitivity. The novel finding of enhanced fragmented picture integration in twins with a higher degree of grapheme-color synesthesia challenges the view of a generally more detail-focused attentional style in synesthesia and might be related to enhanced memory or mental imagery in more synesthetic individuals.
Topics: Adolescent; Adult; Autistic Disorder; Color Perception; Female; Humans; Male; Perceptual Disorders; Synesthesia; Visual Perception; Young Adult
PubMed: 34763130
DOI: 10.1016/j.cortex.2021.09.016 -
Annals of Physical and Rehabilitation... Jun 2017Hemispatial neglect is a common disabling condition following brain damage to the right hemisphere. Generally, it involves behavioral bias directed ipsilaterally to the... (Review)
Review
Hemispatial neglect is a common disabling condition following brain damage to the right hemisphere. Generally, it involves behavioral bias directed ipsilaterally to the damaged hemisphere and loss of spatial awareness for the contralesional side. In this syndrome, several clinical subtypes were identified. The objective of this article is to provide a nosological analysis of the recent data from the literature on the different subtypes of neglect (visual, auditory, somatosensory, motor, egocentric, allocentric and representational neglect), associated ipsilesional and contralesional productive manifestations and their anatomical lesion correlates. These different anatomical-clinical subtypes can be associated or dissociated. They reflect the heterogeneity of this unilateral neglect syndrome that cannot be approached or interpreted in a single manner. We propose that these subtypes result from different underlying deficits: exogenous attentional deficit (visual, auditory neglect); representational deficit (personal neglect, representational neglect, hyperschematia); shift of the egocentric reference frame (egocentric neglect); attentional deficit between objects and within objects (allocentric neglect), endogenous attentional deficit (representational neglect) and transsaccadic working memory or spatial remapping deficit (ipsilesional productive manifestations). Taking into account the different facets of the unilateral neglect syndrome should promote the development of more targeted cognitive rehabilitation protocols.
Topics: Auditory Perceptual Disorders; Brain Diseases; Functional Laterality; Humans; Perceptual Disorders; Psychomotor Disorders; Space Perception; Visual Perception
PubMed: 27103056
DOI: 10.1016/j.rehab.2016.03.003 -
Schizophrenia Research Jan 2014The aim of this review is to describe the potential relationship between multisensory disintegration and self-disorders in schizophrenia spectrum disorders. Sensory... (Review)
Review
The aim of this review is to describe the potential relationship between multisensory disintegration and self-disorders in schizophrenia spectrum disorders. Sensory processing impairments affecting multisensory integration have been demonstrated in schizophrenia. From a developmental perspective multisensory integration is considered to be crucial for normal self-experience. An impairment of multisensory integration is called 'perceptual incoherence'. We theorize that perceptual incoherence may evoke incoherent self-experiences including depersonalization, ambivalence, diminished sense of agency, and 'loosening of associations' between thoughts, feelings and actions that lie within the framework of 'self-disorders' as described by Sass and Parnas (2003). We postulate that subconscious attempts to restore perceptual coherence may induce hallucinations and delusions. Increased insight into mechanisms underlying 'self-disorders' may enhance our understanding of schizophrenia, improve recognition of early psychosis, and extend the range of therapeutic possibilities.
Topics: Humans; Perceptual Disorders; Schizophrenia; Schizophrenic Psychology; Sensation Disorders
PubMed: 23973319
DOI: 10.1016/j.schres.2013.07.027 -
Annals of Physical and Rehabilitation... Jun 2017Conventional paper-and-pencil tests of unilateral neglect are of limited ecological validity. To address this issue, a number of assessment procedures have been proposed... (Review)
Review
Conventional paper-and-pencil tests of unilateral neglect are of limited ecological validity. To address this issue, a number of assessment procedures have been proposed to provide clinicians and researchers with more ecologically valid assessments of unilateral neglect, which may be useful to plan rehabilitation and to measure the generalization of the effects of rehabilitation to daily life. We present here an overview of the different assessment measures available in the literature. The most widely used scales are the Behavioural Inattention Test (BIT), the semi-structured scales for assessment of personal and extra-personal neglect, the Subjective Neglect Questionnaire, the Baking Tray Task, the wheelchair obstacle course, the ADL-based neglect battery, and the Catherine Bergego Scale (CBS). The CBS is probably, to date, the most widely used behavioural assessment instrument for unilateral neglect. It has been found to be reliable, valid, and sensitive to change during rehabilitation. It also enables the assessment of awareness of the consequences of unilateral neglect in daily life skills.
Topics: Humans; Neuropsychological Tests; Perceptual Disorders; Surveys and Questionnaires; Symptom Assessment; Task Performance and Analysis
PubMed: 26830087
DOI: 10.1016/j.rehab.2015.12.005 -
Neuroscience and Biobehavioral Reviews Feb 2013Superior perception, peaks of ability, and savant skills are often observed in the autistic phenotype. The enhanced perceptual functioning model (Mottron et al., 2006a)... (Review)
Review
Superior perception, peaks of ability, and savant skills are often observed in the autistic phenotype. The enhanced perceptual functioning model (Mottron et al., 2006a) emphasizes the increased role and autonomy of perceptual information processing in autistic cognition. Autistic abilities also involve enhanced pattern detection, which may develop through veridical mapping across isomorphic perceptual and non-perceptual structures (Mottron et al., 2009). In this paper, we elaborate veridical mapping as a specific mechanism which can explain the higher incidence of savant abilities, as well as other related phenomena, in autism. We contend that savant abilities such as hyperlexia, but also absolute pitch and synaesthesia, involve similar neurocognitive components, share the same structure and developmental course, and represent related ways by which the perceptual brain deals with objective structures under different conditions. Plausibly, these apparently different phenomena develop through a veridical mapping mechanism whereby perceptual information is coupled with homological data drawn from within or across isomorphic structures. The atypical neural connectivity characteristic of autism is consistent with a developmental predisposition to veridical mapping and the resulting high prevalence of savant abilities, absolute pitch, and synaesthesia in autism.
Topics: Aptitude; Autistic Disorder; Brain; Cognition; Humans; Language Disorders; Models, Psychological; Pattern Recognition, Physiological; Perception; Perceptual Disorders; Pitch Discrimination; Synesthesia
PubMed: 23219745
DOI: 10.1016/j.neubiorev.2012.11.016