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Scientific Reports Jul 2021Developmental prosopagnosia (DP) is a selective neurodevelopmental condition defined by lifelong impairments in face recognition. Despite much research, the extent to...
Developmental prosopagnosia (DP) is a selective neurodevelopmental condition defined by lifelong impairments in face recognition. Despite much research, the extent to which DP is associated with broader visual deficits beyond face processing is unclear. Here we investigate whether DP is accompanied by deficits in colour perception. We tested a large sample of 92 DP individuals and 92 sex/age-matched controls using the well-validated Ishihara and Farnsworth-Munsell 100-Hue tests to assess red-green colour deficiencies and hue discrimination abilities. Group-level analyses show comparable performance between DP and control individuals across both tests, and single-case analyses indicate that the prevalence of colour deficits is low and comparable to that in the general population. Our study clarifies that DP is not linked to colour perception deficits and constrains theories of DP that seek to account for a larger range of visual deficits beyond face recognition.
Topics: Adult; Color Perception; Discrimination, Psychological; Electroencephalography; Facial Recognition; Female; Humans; Male; Middle Aged; Pattern Recognition, Visual; Photic Stimulation; Prosopagnosia; Visual Perception; Young Adult
PubMed: 34215772
DOI: 10.1038/s41598-021-92840-6 -
OTJR : Occupation, Participation and... Apr 2018Unilateral neglect (neglect) and anosognosia often co-occur post stroke. It is unknown whether anosognosia of neglect varies for different types of daily activities. The...
Unilateral neglect (neglect) and anosognosia often co-occur post stroke. It is unknown whether anosognosia of neglect varies for different types of daily activities. The objective is to examine the frequency of anosognosia of neglect for items on the Catherine Bergego Scale (CBS) and to determine the level of agreement between participant/assessor item ratings and total scores. Secondary analysis of data was carried out. We conducted descriptive analyses and interrater reliability analyses (Cohen's kappa) to determine the level of agreement between assessor and participant item ratings. A paired t test was conducted to compare assessor and participant total scores. The frequency of anosognosia among items varied (29.2%-83.3%) and Kappa statistics ranged from -0.07 (no agreement) to 0.23 (fair agreement) for item ratings. There was a significant difference- t(36) = 3.02, p ≤ .01)-between assessor ( M = 8.0, SD = 5.2) and participant-rated ( M = 5.3, SD = 4.5) total CBS scores. Anosognosia is prevalent among those with neglect. Findings highlight the importance of assessing for anosognosia.
Topics: Aged; Agnosia; Cross-Sectional Studies; Female; Humans; Male; Middle Aged; Neuropsychological Tests; Observer Variation; Perceptual Disorders; Prevalence; Psychometrics; Reproducibility of Results; Stroke
PubMed: 29251546
DOI: 10.1177/1539449217747586 -
Neurology India 2021Reflected image processing is a unique brain function and its abnormalities result in problems of localizing, recognizing the images, and utilizing this information in...
BACKGROUND
Reflected image processing is a unique brain function and its abnormalities result in problems of localizing, recognizing the images, and utilizing this information in everyday life.
OBJECTIVES
The aim of this study was to characterize clinical and neuropsychological profiles and to identify the probable neural substrate for this phenomenon in major cognitive disorder.
MATERIALS AND METHODS
We conducted a prospective study from February 2015 to May 2017 in patients with Major Cognitive Disorder (MCD, DSM-5 criteria). All patients were tested for problems in reflected image processing using the detailed protocol after ethical approval of the institute and consent. They also underwent a detailed neuropsychological evaluation, biochemical tests and neuroimaging (structural, diffusion, and resting-state functional MRI) as per established protocol.
RESULTS
Of the 18 patients, 11 had mirror agnosia (MA), 5 had mirror image agnosia (MIA) and 2 had both. MRI of MA patients showed parietal atrophy and whereas diffuse pattern of atrophy was seen with MIA. In the MA group, the left superior longitudinal fasciculus showed significantly greater fractional anisotropy and the left angular gyrus showed increased functional connectivity with left anterior cingulate, left dorsolateral prefrontal and bilateral posterior cingulate regions.
CONCLUSION
Mirror image processing defects were not related to the type of MCD, severity or pattern of neuropsychological dysfunction. There are structural and functional alterations in localized regions as well as both hemispheres. Therefore, it is more likely to be a network disorder, irrespective of the MCD type or severity.
Topics: Agnosia; Humans; Magnetic Resonance Imaging; Neuropsychological Tests; Prospective Studies; White Matter
PubMed: 34507415
DOI: 10.4103/0028-3886.325339 -
Neuropsychologia Jun 2024Facial identity recognition (FIR) is arguably the ultimate form of recognition for the adult human brain. Even if the term prosopagnosia is reserved for exceptionally... (Review)
Review
Facial identity recognition (FIR) is arguably the ultimate form of recognition for the adult human brain. Even if the term prosopagnosia is reserved for exceptionally rare brain-damaged cases with a category-specific abrupt loss of FIR at adulthood, subjective and objective impairments or difficulties of FIR are common in the neuropsychological population. Here we provide a critical overview of the evaluation of FIR both for clinicians and researchers in neuropsychology. FIR impairments occur following many causes that should be identified objectively by both general and specific, behavioral and neural examinations. We refute the commonly used dissociation between perceptual and memory deficits/tests for FIR, since even a task involving the discrimination of unfamiliar face images presented side-by-side relies on cortical memories of faces in the right-lateralized ventral occipito-temporal cortex. Another frequently encountered confusion is between specific deficits of the FIR function and a more general impairment of semantic memory (of people), the latter being most often encountered following anterior temporal lobe damage. Many computerized tests aimed at evaluating FIR have appeared over the last two decades, as reviewed here. However, despite undeniable strengths, they often suffer from ecological limitations, difficulties of instruction, as well as a lack of consideration for processing speed and qualitative information. Taking into account these issues, a recently developed behavioral test with natural images manipulating face familiarity, stimulus inversion, and correct response times as a key variable appears promising. The measurement of electroencephalographic (EEG) activity in the frequency domain from fast periodic visual stimulation also appears as a particularly promising tool to complete and enhance the neuropsychological assessment of FIR.
Topics: Humans; Facial Recognition; Neuropsychological Tests; Prosopagnosia; Recognition, Psychology; Electroencephalography
PubMed: 38522782
DOI: 10.1016/j.neuropsychologia.2024.108865 -
Neuropsychologia May 2018The cognitive organisation of nonverbal auditory knowledge remains poorly defined. Deficits of environmental sound as well as word and visual object knowledge are...
The cognitive organisation of nonverbal auditory knowledge remains poorly defined. Deficits of environmental sound as well as word and visual object knowledge are well-recognised in semantic dementia. However, it is unclear how auditory cognition breaks down in this disorder and how this relates to deficits in other knowledge modalities. We had the opportunity to study a patient with a typical syndrome of semantic dementia who had extensive premorbid knowledge of birds, allowing us to assess the impact of the disease on the processing of auditory in relation to visual and verbal attributes of this specific knowledge category. We designed a novel neuropsychological test to probe knowledge of particular avian characteristics (size, behaviour [migratory or nonmigratory], habitat [whether or not primarily water-dwelling]) in the nonverbal auditory, visual and verbal modalities, based on a uniform two-alternative-forced-choice procedure. The patient's performance was compared to healthy older individuals of similar birding experience. We further compared his performance on this test of bird knowledge with his knowledge of familiar human voices and faces. Relative to healthy birder controls, the patient showed marked deficits of bird call and bird name knowledge but relatively preserved knowledge of avian visual attributes and retained knowledge of human voices and faces. In both the auditory and visual modalities, his knowledge of the avian characteristics of size and behaviour was intact whereas his knowledge of the associated characteristic of habitat was deficient. This case provides further evidence that nonverbal auditory knowledge has a fractionated organisation that can be differentially targeted in semantic dementia.
Topics: Acoustic Stimulation; Aged; Agnosia; Animals; Auditory Perception; Birds; Female; Humans; Knowledge; Male; Middle Aged; Photic Stimulation; Recognition, Psychology; Semantics; Sound
PubMed: 29572063
DOI: 10.1016/j.neuropsychologia.2018.03.024 -
Journal of Neurology, Neurosurgery, and... Feb 2002From a series of glimpses, we perceive a seamless and richly detailed visual world. Cerebral damage, however, can destroy this illusion. In the case of Bálint's... (Review)
Review
OBJECTIVES
From a series of glimpses, we perceive a seamless and richly detailed visual world. Cerebral damage, however, can destroy this illusion. In the case of Bálint's syndrome, the visual world is perceived erratically, as a series of single objects. The goal of this review is to explore a range of psychological and anatomical explanations for this striking visual disorder and to propose new directions for interpreting the findings in Bálint's syndrome and related cerebral disorders of visual processing.
METHODS
Bálint's syndrome is reviewed in the light of current concepts and methodologies of vision research.
RESULTS
The syndrome affects visual perception (causing simultanagnosia/visual disorientation) and visual control of eye and hand movement (causing ocular apraxia and optic ataxia). Although it has been generally construed as a biparietal syndrome causing an inability to see more than one object at a time, other lesions and mechanisms are also possible. Key syndrome components are dissociable and comprise a range of disturbances that overlap the hemineglect syndrome. Inouye's observations in similar cases, beginning in 1900, antedated Bálint's initial report. Because Bálint's syndrome is not common and is difficult to assess with standard clinical tools, the literature is dominated by case reports and confounded by case selection bias, non-uniform application of operational definitions, inadequate study of basic vision, poor lesion localisation, and failure to distinguish between deficits in the acute and chronic phases of recovery.
CONCLUSIONS
Studies of Bálint's syndrome have provided unique evidence on neural substrates for attention, perception, and visuomotor control. Future studies should address possible underlying psychoanatomical mechanisms at "bottom up" and "top down" levels, and should specifically consider visual working memory and attention (including object based attention) as well as systems for identification of object structure and depth from binocular stereopsis, kinetic depth, motion parallax, eye movement signals, and other cues.
Topics: Agnosia; Attention; Brain Mapping; Cerebrovascular Disorders; Dominance, Cerebral; Humans; Occipital Lobe; Perceptual Disorders; Psychomotor Disorders; Visual Cortex; Visual Perception
PubMed: 11796765
DOI: 10.1136/jnnp.72.2.162 -
F1000Research 2019Prosopagnosia is an impairment in the ability to recognize faces and can be acquired after a brain lesion or occur as a developmental variant. Studies of prosopagnosia... (Review)
Review
Prosopagnosia is an impairment in the ability to recognize faces and can be acquired after a brain lesion or occur as a developmental variant. Studies of prosopagnosia make important contributions to our understanding of face processing and object recognition in the human visual system. We review four areas of advances in the study of this condition in recent years. First are issues surrounding the diagnosis of prosopagnosia, including the development and evaluation of newer tests and proposals for diagnostic criteria, especially for the developmental variant. Second are studies of the structural basis of prosopagnosia, including the application of more advanced neuroimaging techniques in studies of the developmental variant. Third are issues concerning the face specificity of the defect in prosopagnosia, namely whether other object processing is affected to some degree and in particular the status of visual word processing in light of recent predictions from the "many-to-many hypothesis". Finally, there have been recent rehabilitative trials of perceptual learning applied to larger groups of prosopagnosic subjects that show that face impairments are not immutable in this condition.
Topics: Facial Recognition; Humans; Learning; Neuroimaging; Prosopagnosia
PubMed: 31231507
DOI: 10.12688/f1000research.18492.1 -
Journal of Neurology, Neurosurgery, and... Apr 1986Visual agnosia is impaired visual recognition not explained by defective visual acuity, visual fields, attention, or general mental ability. Two nonapraxic patients with...
Visual agnosia is impaired visual recognition not explained by defective visual acuity, visual fields, attention, or general mental ability. Two nonapraxic patients with lesions in the left occipital lobe could imitate pantomimes they could not recognise. Although both patients had a hemianopia, sparing of gesture imitation shows that no visual defect accounts for their inability to recognise pantomimes. Both patients were amnestic and alexic but had no general impairment of cognitive ability to account for a pantomime-recognition disorder. These patients seem to have agnosia for pantomime. From the computed tomograms from these patients, we propose that inferior visual association cortex is critical for gesture comprehension, whereas superior portions of these structures are critical for imitating or performing pantomime to an object presented visually.
Topics: Aged; Agnosia; Brain Mapping; Cerebral Hemorrhage; Gestures; Humans; Kinesics; Male; Occipital Lobe; Tomography, X-Ray Computed; Visual Cortex; Visual Perception
PubMed: 3701356
DOI: 10.1136/jnnp.49.4.451 -
Psychiatria Danubina Jun 2010Neuropsychology includes both the psychiatric manifestations of neurological illness (primary brain-based disorders) and neurobiology of "idiopathic" psychiatric... (Review)
Review
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.
Topics: Agnosia; Aphasia; Awareness; Cerebral Infarction; Delirium; Denial, Psychological; Depressive Disorder; Dominance, Cerebral; Hemianopsia; Hemiplegia; Humans; Neurocognitive Disorders; Perceptual Disorders
PubMed: 20562762
DOI: No ID Found -
Annals of Physical and Rehabilitation... Jun 2017This review article summarizes neuropsychological descriptions of abnormal body representations in brain-damaged patients and recent neuroscientific investigations of... (Review)
Review
This review article summarizes neuropsychological descriptions of abnormal body representations in brain-damaged patients and recent neuroscientific investigations of their sensorimotor underpinnings in healthy participants. The first part of the article describes unilateral disorders of the bodily self, such as asomatognosia, feelings of amputation, supernumerary phantom limbs and somatoparaphrenia, as well as descriptions of non-lateralized disorders of the bodily self, including Alice in Wonderland syndrome and autoscopic hallucinations. Because the sensorimotor mechanisms of these disorders are unclear, we focus on clinical descriptions and insist on the importance of reporting clinical cases to better understand the full range of bodily disorders encountered in neurological diseases. The second part of the article presents the advantages of merging neuroscientific approaches of the bodily self with immersive virtual reality, robotics and neuroprosthetics to foster the understanding of the multisensory, motor and neural mechanisms of bodily representations.
Topics: Agnosia; Alice in Wonderland Syndrome; Body Image; Brain Injuries; Delusions; Depersonalization; Hallucinations; Humans; Phantom Limb; Robotics; Virtual Reality
PubMed: 27318928
DOI: 10.1016/j.rehab.2016.04.007