-
Continuum (Minneapolis, Minn.) Oct 2019This article reviews the disorders that result from disruption of extrastriate regions of the cerebral cortex responsible for higher visual processing. For each... (Review)
Review
PURPOSE OF REVIEW
This article reviews the disorders that result from disruption of extrastriate regions of the cerebral cortex responsible for higher visual processing. For each disorder, a historical perspective is offered and relevant neuroscientific studies are reviewed.
RECENT FINDINGS
Careful analysis of the consequences of lesions that disrupt visual functions such as facial recognition and written language processing has improved understanding of the role of key regions in these networks. In addition, modern imaging techniques have built upon prior lesion studies to further elucidate the functions of these cortical areas. For example, functional MRI (fMRI) has identified and characterized the response properties of ventral regions that contribute to object recognition and dorsal regions that subserve motion perception and visuospatial attention. Newer network-based functional imaging studies have shed light on the mechanisms behind various causes of spontaneous visual hallucinations.
SUMMARY
Understanding the regions and neural networks responsible for higher-order visual function helps the practicing neurologist to diagnose and manage associated disorders of visual processing and to identify and treat responsible underlying disease.
Topics: Adult; Aged; Female; Humans; Male; Middle Aged; Occipital Lobe; Perceptual Disorders; Vision Disorders; Visual Perception; Young Adult
PubMed: 31584540
DOI: 10.1212/CON.0000000000000774 -
Brain Topography Sep 2023The purpose of this scoping review is to provide updated information on the neural basis and neurophysiological features associated with unilateral spatial neglect (USN)... (Review)
Review
The purpose of this scoping review is to provide updated information on the neural basis and neurophysiological features associated with unilateral spatial neglect (USN) recovery. We applied the Preferred Reporting Systems for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) framework and identified 16 relevant papers from the databases. Critical appraisal was performed by two independent reviewers using a standardized appraisal instrument developed by the PRISMA-ScR. We identified and categorized investigation methods for the neural basis and neurophysiological features of USN recovery after stroke using magnetic resonance imaging (MRI), functional MRI, and electroencephalography (EEG). This review found two brain-level mechanisms underlying USN recovery at the behavioral level. These include the absence of stroke-related damage to the right ventral attention network during the acute phase and compensatory recruitment of analogous areas of the undamaged opposite hemisphere and prefrontal cortex during visual search tasks in the subacute or later phases. However, the relationship between the neural and neurophysiological findings and improvements in USN-related activities of daily living remains unknown. This review adds to the growing body of evidence regarding the neural mechanisms underlying USN recovery.
Topics: Humans; Activities of Daily Living; Brain; Functional Laterality; Perceptual Disorders; Stroke; Stroke Rehabilitation
PubMed: 37410274
DOI: 10.1007/s10548-023-00980-x -
Developmental Medicine and Child... Jul 2020
Topics: Cerebral Palsy; Humans; Movement Disorders; Perceptual Disorders; Somatosensory Disorders
PubMed: 32484581
DOI: 10.1111/dmcn.14542 -
Expert Review of Neurotherapeutics 2023Spatial neglect remains an underdiagnosed and undertreated consequence of stroke that imposes significant disability. A growing appreciation of brain networks involved... (Review)
Review
INTRODUCTION
Spatial neglect remains an underdiagnosed and undertreated consequence of stroke that imposes significant disability. A growing appreciation of brain networks involved in spatial cognition is helping us to develop a mechanistic understanding of different therapies under development.
AREAS COVERED
This review focuses on neuromodulation of brain networks for the treatment of spatial neglect after stroke, using evidence-based approaches including 1) Cognitive strategies that are more likely to impact frontal lobe executive function networks; 2) Visuomotor adaptation, which may depend on the integrity of parietal and parieto- and subcortical-frontal connections and the presence of a particular subtype of neglect labeled Aiming neglect; 3) Non-invasive brain stimulation that may modulate relative levels of activity of the two hemispheres and depend on corpus callosum connectivity; and 4) Pharmacological modulation that may exert its effect primarily via right-lateralized networks more closely involved in arousal.
EXPERT OPINION
Despite promising results from individual studies, significant methodological heterogeneity between trials weakened conclusions drawn from meta-analyses. Improved classification of spatial neglect subtypes will benefit research and clinical care. Understanding the brain network mechanisms of different treatments and different types of spatial neglect will make possible a precision medicine treatment approach.
Topics: Humans; Neuropsychology; Space Perception; Brain; Stroke; Frontal Lobe; Perceptual Disorders
PubMed: 37273197
DOI: 10.1080/14737175.2023.2221788 -
Geriatrie Et Psychologie... Sep 2019Visual perception is humans' preferred way for taking information on the surrounding world. Visual perception is frequently impaired in patients with Alzheimer's... (Review)
Review
Visual perception is humans' preferred way for taking information on the surrounding world. Visual perception is frequently impaired in patients with Alzheimer's disease, lessening patients' quality of life, and making evaluation of other cognitive deficits more complicated. Our review covers the recent literature describing visual perception deficits in patients suffering from Alzheimer's disease by classifying them according to their neuroanatomical correspondence: retina, visual pathway, subcortical structures, occipital visual cortex, occipito-temporal "what" and occipito-parietal "where" pathways. Overall, both low-level and high-level visual perception disorders seem quite common in Alzheimer's disease, including, on a low-level, loss of visual field, decreased acuity and contrast sensitivity, and impaired color vision, and on a high-level, impaired color vision, motion perception, visuospatial deficits, object agnosia, prosopagnosia and impaired recognition of facial emotional expressions. Professionals working with Alzheimer's disease should be aware of visuoperceptual deficits, which could impair the quality of life of the patients, and distort the results of neuropsychological tests using visual material. Moreover, some tests assessing visual perception could be of interest for early diagnosis of the disease.
Topics: Aged; Aged, 80 and over; Alzheimer Disease; Humans; Neuropsychological Tests; Perceptual Disorders; Vision Disorders; Visual Pathways; Visual Perception
PubMed: 31449049
DOI: 10.1684/pnv.2019.0815 -
Hearing Research Sep 2023Congenital amusia is a neuro-developmental disorder of music perception and production, with the observed deficits contrasting with the sophisticated music processing... (Review)
Review
Congenital amusia is a neuro-developmental disorder of music perception and production, with the observed deficits contrasting with the sophisticated music processing reported for the general population. Musical deficits within amusia have been hypothesized to arise from altered pitch processing, with impairments in pitch discrimination and, notably, short-term memory. We here review research investigating its behavioral and neural correlates, in particular the impairments at encoding, retention, and recollection of pitch information, as well as how these impairments extend to the processing of pitch cues in speech and emotion. The impairments have been related to altered brain responses in a distributed fronto-temporal network, which can be observed also at rest. Neuroimaging studies revealed changes in connectivity patterns within this network and beyond, shedding light on the brain dynamics underlying auditory cognition. Interestingly, some studies revealed spared implicit pitch processing in congenital amusia, showing the power of implicit cognition in the music domain. Building on these findings, together with audiovisual integration and other beneficial mechanisms, we outline perspectives for training and rehabilitation and the future directions of this research domain.
Topics: Humans; Auditory Cortex; Auditory Perceptual Disorders; Pitch Discrimination; Memory, Short-Term; Music; Pitch Perception
PubMed: 37572645
DOI: 10.1016/j.heares.2023.108855 -
Neuropsychologia May 2023Acquired prosopagnosia is often associated with other deficits such as dyschromatopsia and topographagnosia, from damage to adjacent perceptual networks. A recent study...
BACKGROUND
Acquired prosopagnosia is often associated with other deficits such as dyschromatopsia and topographagnosia, from damage to adjacent perceptual networks. A recent study showed that some subjects with developmental prosopagnosia also have congenital amusia, but problems with music perception have not been described with the acquired variant.
OBJECTIVE
Our goal was to determine if music perception was also impaired in subjects with acquired prosopagnosia, and if so, its anatomic correlate.
METHOD
We studied eight subjects with acquired prosopagnosia, all of whom had extensive neuropsychological and neuroimaging testing. They performed a battery of tests evaluating pitch and rhythm processing, including the Montréal Battery for the Evaluation of Amusia.
RESULTS
At the group level, subjects with anterior temporal lesions were impaired in pitch perception relative to the control group, but not those with occipitotemporal lesions. Three of eight subjects with acquired prosopagnosia had impaired musical pitch perception while rhythm perception was spared. Two of the three also showed reduced musical memory. These three reported alterations in their emotional experience of music: one reported music anhedonia and aversion, while the remaining two had changes consistent with musicophilia. The lesions of these three subjects affected the right or bilateral temporal poles as well as the right amygdala and insula. None of the three prosopagnosic subjects with lesions limited to the inferior occipitotemporal cortex exhibited impaired pitch perception or musical memory, or reported changes in music appreciation.
CONCLUSION
Together with the results of our previous studies of voice recognition, these findings indicate an anterior ventral syndrome that can include the amnestic variant of prosopagnosia, phonagnosia, and various alterations in music perception, including acquired amusia, reduced musical memory, and subjective reports of altered emotional experience of music.
Topics: Humans; Prosopagnosia; Music; Temporal Lobe; Auditory Perceptual Disorders; Perception; Pitch Perception
PubMed: 36913989
DOI: 10.1016/j.neuropsychologia.2023.108540 -
Neuroscience and Biobehavioral Reviews Jun 2021Lilliputian hallucinations concern hallucinated human, animal or fantasy entities of minute size. Having been famously described by the French psychiatrist Raoul Leroy... (Review)
Review
Lilliputian hallucinations concern hallucinated human, animal or fantasy entities of minute size. Having been famously described by the French psychiatrist Raoul Leroy in 1909, who wrote from personal experience, to date they are mentioned almost routinely in textbooks of psychiatry, albeit with little in-depth knowledge. I therefore systematically reviewed 145 case reports and case series comprising 226 case descriptions, concluding that lilliputian hallucinations are visual (61 %) or multimodal (39 %) in nature. In 97 % of the cases, they are perceived as grounded in the actual environment, thus indicating involvement of higher-level regions of the perceptual network subserving the fusion of sensory and hallucinatory content. Perceptual release and deafferentiation are the most likely underlying mechanisms. Etiology is extremely diverse, with schizophrenia spectrum disorder, alcohol use disorder and loss of vision accounting for 50 % of the cases and neurological disease for 36 %. Recovery was obtained in 62 % of the cases, whereas 18 % of the cases ended in chronicity and 8 % in death. Recommendations are made for clinical practice and future research.
Topics: Hallucinations; Humans; Schizophrenia; Vision Disorders
PubMed: 33676962
DOI: 10.1016/j.neubiorev.2021.03.002 -
Brain and Nerve = Shinkei Kenkyu No... Jun 2024Unilateral spatial neglect (USN) is a symptom of unilateral brain damage resulting in failure to report sensory phenomena in the contra-lesional space. It is associated... (Review)
Review
Unilateral spatial neglect (USN) is a symptom of unilateral brain damage resulting in failure to report sensory phenomena in the contra-lesional space. It is associated with motor impairment as well as sensory deficits. Recent research suggests that USN, may be caused by a disruption in the interhemispheric balance of the visual attention network. Based on this hypothesis, non-invasive brain stimulation (NIBS), such as repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS), is utilized in the rehabilitation of USN patients. Presently, inhibitory stimulation by continuous theta burst stimulation (cTBS) on contra-lesional parietal cortex are believed to be the most promising method. Conversely, compensation by attentional network of the non-lesioned hemisphere plays an important role in the recovery of USN. Recent imaging studies revealed that functional and structural connectivity of attentional networks within a lesioned hemisphere and between lesioned and non-lesioned hemispheres affects spontaneous recovery and effectiveness of rehabilitation approach such as prism adaptation therapy. These findings are useful in elucidating the pathophysiology of USN and predicting functional outcome. Furthermore, we hope that understanding the pathophysiology will enable the development of new rehabilitation strategies and appropriate treatment selection.
Topics: Humans; Perceptual Disorders; Transcranial Magnetic Stimulation; Transcranial Direct Current Stimulation; Attention
PubMed: 38853505
DOI: 10.11477/mf.1416202674 -
BMJ Case Reports Nov 2020
Topics: Aged; Brain; Diffusion Magnetic Resonance Imaging; Female; Functional Laterality; Humans; Ischemic Stroke; Magnetic Resonance Angiography; Middle Cerebral Artery; Perceptual Disorders; Space Perception
PubMed: 33229488
DOI: 10.1136/bcr-2020-239770