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Frontiers in Bioscience (Elite Edition) Jun 2014Understanding the human neuro-anatomy of face recognition is a long-standing goal of Cognitive Neuroscience. Studies of patients with face recognition impairment... (Review)
Review
Understanding the human neuro-anatomy of face recognition is a long-standing goal of Cognitive Neuroscience. Studies of patients with face recognition impairment following brain damage (i.e., acquired prosopagnosia) have revealed the specificity of face recognition, the importance and nature of holistic/configural perception of individual faces, and the distribution of this function in the ventral occipito-temporal (VOT) cortex, with a right hemispheric dominance. Yet, neuroimaging studies in this field have essentially focused on a single face-selective area of the VOT and underestimated the right hemisphere superiority. Findings in these studies have also been taken as supporting a hierarchical view of face perception, according to which a face is decomposed into parts in early face-selective areas, these parts being subsequently integrated into a whole representation in higher-order areas. This review takes a historical and current perspective on the study of acquired prosopagnosia and neuroimaging that challenges this latter view. It argues for a combination of these methods, an approach suggesting a coarse-to-fine emergence of the holistic face percept in a non-hierarchical network of cortical face-selective areas.
Topics: Cues; Face; Humans; Magnetic Resonance Imaging; Models, Neurological; Models, Psychological; Neuroimaging; Prosopagnosia; Recognition, Psychology; Visual Perception
PubMed: 24896206
DOI: 10.2741/E706 -
Consciousness and Cognition May 2015Despite the coherence and seeming directness of our bodily experience, our perception of the world, including that of our own body, may constitute an inference based on... (Review)
Review
Despite the coherence and seeming directness of our bodily experience, our perception of the world, including that of our own body, may constitute an inference based on ambiguous sensory data and prior expectations. In this article, I apply a 'psychologised' version of the recently proposed free energy framework to the understanding of certain disorders of neurological unawareness in order to examine how inferential processes may determine our body perception. I specifically consider three facets of body perception in such disorders: namely, the 'external body' as inferred on the basis of exteroceptive signals and related predictions; the 'internal body' as inferred on the basis of proprioceptive and interoceptive signals and related predictions; and lastly the 'impersonalised body' as inferred on the basis of signals from social and third-person perspectives on the body and related predictions. Several conclusions will be drawn from these considerations: (a) there is a deep interdependency of prior beliefs and sensory data; as the brain uses sensory data to update its virtual model of the world, lack or imprecision of sensory prediction errors may lead to aberrant inferences influenced disproportionally by outdated, premorbid predictions; (b) interoception and interoceptive salience have a unique role in our inferences about body awareness and (c) social, 'objectified' prior beliefs about the body may have a silent but potent role in our bodily self-awareness. Finally, the article emphasizes that our learned, virtual model of the body is depended on the nature and thus integrity of the very body that allowed the model to be formed in the first place.
Topics: Agnosia; Hemiplegia; Humans; Theory of Mind
PubMed: 25459651
DOI: 10.1016/j.concog.2014.09.018 -
The Tohoku Journal of Experimental... Aug 1990Visual information processing are realized by the posterior association cortex spreading in front of the striate and parastriate areas from which two major visual... (Review)
Review
Visual information processing are realized by the posterior association cortex spreading in front of the striate and parastriate areas from which two major visual association pathways arise. The dorsal or the occipito-parietal pathway which transmits the inputs from the peripheral as well as the central visual field to the parietal association cortex is responsible for the visuospatial analysis of the visual informations. The occipito-temporal or the ventral pathway originates only from the foveal vision area, and sends the visual inputs to the inferior temporal lobe which engages in visual pattern or whole gestalt recognition of the visual informations. In addition to this dichotomous disposition of the dorsal and the ventral visual association pathways in each cerebral hemisphere, there is another type of functional specialization which is hierarchical rather than dichotomous. In the left cerebral hemisphere, the collateral pathways arise from both dorsal and ventral main streams and engage in the process of reading, or the verbal mode of visual information processing.
Topics: Agnosia; Agraphia; Association; Brain Damage, Chronic; Corpus Callosum; Culture; Discrimination, Psychological; Dyslexia, Acquired; Functional Laterality; Humans; Japan; Language; Memory; Parietal Lobe; Pattern Recognition, Visual; Reading; Semantics; Temporal Lobe; Visual Pathways; Visual Perception
PubMed: 2082505
DOI: 10.1620/tjem.161.supplement_61 -
Epilepsia Aug 2009This article reviews the history of sign language (SL) and the rationale for its use in children with profound auditory agnosia due to Landau-Kleffner syndrome (LKS),... (Comparative Study)
Comparative Study Review
This article reviews the history of sign language (SL) and the rationale for its use in children with profound auditory agnosia due to Landau-Kleffner syndrome (LKS), illustrated by studies of children and adults followed for many years and rare cases from the literature. The reasons that SL was successful and brought some children out of isolation while it could not be implemented in others are discussed. The nowadays earlier recognition and treatment of LKS and better awareness of the crucial need to maintain communication have certainly improved the outcome of affected children. Alternatives to oral language, even for less severe cases, are increasingly accepted. SL can be learned at different ages with a clear benefit, but the ambivalence of the patients and their families with the world and culture of the deaf may sometimes explain its refusal or limited acceptance. There are no data to support the fear that SL learning may delay or prevent oral language recovery in children with LKS. On the contrary, SL may even facilitate this recovery by stimulating functionally connected core language networks and by helping speech therapy and auditory training.
Topics: Adolescent; Adult; Agnosia; Child; Female; Humans; Landau-Kleffner Syndrome; Language Development; Male; Manual Communication; Sign Language
PubMed: 19682058
DOI: 10.1111/j.1528-1167.2009.02226.x -
European Neurology 2020Anosognosia and hemineglect are among the most startling neurological phenomena identified during the 20th century. Though both are associated with right hemisphere...
Anosognosia and hemineglect are among the most startling neurological phenomena identified during the 20th century. Though both are associated with right hemisphere cerebral dysfunction, notably stroke, each disorder had its own distinct literature. Anosognosia, as coined by Babinski in 1914, describes patients who seem to have no idea of their paralysis, despite general cognitive preservation. Certain patients seem more than unaware, with apparent resistance to awareness. More extreme, and qualitatively distinct, is denial of hemiplegia. Various interpretations of pathogenesis are still deliberated. As accounts of its captivating manifestations grew, anosognosia was established as a prominent symbol of neurological and psychic disturbance accompanying (right-hemisphere) stroke. Although reports of specific neglect-related symptomatology appeared earlier, not until nearly 2 decades after anosognosia's inaugural definition was neglect formally defined by Brain, paving a path spanning some years, to depict a class of disorder with heterogeneous variants. Disordered awareness of body and extrapersonal space with right parietal lesions, and other symptom variations, were gathered under the canopy of neglect. Viewed as a disorder of corporeal awareness, explanatory interpretations involve mechanisms of extinction and perceptual processing, disturbance of spatial attention, and others. Odd alterations involving apparent concern, attitudes, or belief characterize many right hemisphere conditions. Anosognosia and neglect are re-examined, from the perspective of unawareness, the nature of belief, and its baffling distortions. Conceptual parallels between these 2 distinct disorders emerge, as the major role of the right hemisphere in mental representation of self is highlighted by its most fascinating syndromes of altered awareness.
Topics: Agnosia; History, 19th Century; History, 20th Century; Humans; Neurology; Perceptual Disorders
PubMed: 32927461
DOI: 10.1159/000510397 -
Medicina 2021Proposapnosia is a type of visual agnosia characterized by the inability to recognize people's faces. There are basically two variants, apperceptive and associative. The...
Proposapnosia is a type of visual agnosia characterized by the inability to recognize people's faces. There are basically two variants, apperceptive and associative. The "Tortoni effect" is a phenomenon described by Bekinschtein et al a few years ago in waiters from Buenos Aires, who used this tool to remember the orders of each member of a table. We present a case of prosopagnosia associated with bilateral temporo-occipital injury secondary to head trauma, initially manifested by the lack of face recognition with the use of an associative strategy similar to that described in the "Tortoni effect" as compensation, in a 62-year-old female who suffered a severe head injury. A few months after this event, the patient had difficulty in recognizing familiar people, a fact evidenced by her relatives when at a restaurant table, they changed their seats, remained silent momentarily, and right after the patient kept naming them by their previous location. The magnetic resonance imaging of the brain revealed blunt sequelae lesions in the bilateral temporo-occipital region. Acquired prosopagnosia due to focal lesions in the temporo-occipital region, generally bilateral and right, and less frequently left, is a rare condition. The strategy used in the "Tortoni effect" was one of the initial manifestations of the condition in our patient. Carrying out an ecological neuropsychological test that considers this strategy could be useful in the screening and early detection of this entity.
Topics: Brain; Female; Humans; Magnetic Resonance Imaging; Middle Aged; Neuropsychological Tests; Prosopagnosia
PubMed: 34633963
DOI: No ID Found -
Environmental Health Perspectives 2013The etiology and natural history of Parkinson's disease (PD) are not well understood. Some non-motor symptoms such as hyposmia, rapid eye movement sleep behavior... (Review)
Review
BACKGROUND
The etiology and natural history of Parkinson's disease (PD) are not well understood. Some non-motor symptoms such as hyposmia, rapid eye movement sleep behavior disorder, and constipation may develop during the prodromal stage of PD and precede PD diagnosis by years.
OBJECTIVES
We examined the promise and pitfalls of research on premotor symptoms of PD and developed priorities and strategies to understand their clinical and etiological implications.
METHODS
This review was based on a workshop, Parkinson's Disease Premotor Symptom Symposium, held 7-8 June 2012 at the National Institute of Environmental Health Sciences in Research Triangle Park, North Carolina.
DISCUSSION
Research on premotor symptoms of PD may offer an excellent opportunity to characterize high-risk populations and to better understand PD etiology. Such research may lead to evaluation of novel etiological hypotheses such as the possibility that environmental toxicants or viruses may initiate PD pathogenesis in the gastrointestinal tract or olfactory bulb. At present, our understanding of premotor symptoms of PD is in its infancy and faces many obstacles. These symptoms are often not specific to PD and have low positive predictive value for early PD diagnosis. Further, the pathological bases and biological mechanisms of these premotor symptoms and their relevance to PD pathogenesis are poorly understood.
CONCLUSION
This is an emerging research area with important data gaps to be filled. Future research is needed to understand the prevalence of multiple premotor symptoms and their etiological relevance to PD. Animal experiments and mechanistic studies will further understanding of the biology of these premotor symptoms and test novel etiological hypothesis.
Topics: Agnosia; Constipation; Disease Progression; Humans; Parkinson Disease; Prodromal Symptoms; REM Sleep Behavior Disorder; Research
PubMed: 23933572
DOI: 10.1289/ehp.1306967 -
Research in Developmental Disabilities Jul 2014Down syndrome (DS) is associated with extreme difficulty in verbal skills and relatively better visuo-spatial skills. Indeed, visuo-spatial ability is often considered a... (Review)
Review
Down syndrome (DS) is associated with extreme difficulty in verbal skills and relatively better visuo-spatial skills. Indeed, visuo-spatial ability is often considered a strength in DS. However, it is not clear whether this strength is only relative to the poor verbal skills, or, more impressively, relative to cognitive ability in general. To answer this question, we conducted an extensive literature review of studies on visuo-spatial abilities in people with Down syndrome from January 1987 to May 2013. Based on a general taxonomy of spatial abilities patterned after Lohman, Pellegrino, Alderton, and Regian (1987) and Carroll (1993) and existing studies of DS, we included five different domains of spatial abilities - visuo-spatial memory, visuo-spatial construction, mental rotation, closure, and wayfinding. We evaluated a total of 49 studies including 127 different comparisons. Most comparisons involved a group with DS vs. a group with typical development matched on mental age and compared on a task measuring one of the five visuo-spatial abilities. Although further research is needed for firm conclusions on some visuo-spatial abilities, there was no evidence that visuo-spatial ability is a strength in DS relative to general cognitive ability. Rather, the review suggests an uneven profile of visuo-spatial abilities in DS in which some abilities are commensurate with general cognitive ability level, and others are below.
Topics: Agnosia; Aptitude; Down Syndrome; Female; Humans; Male; Memory, Short-Term; Mental Recall; Neuropsychological Tests; Orientation; Pattern Recognition, Visual; Perceptual Closure; Problem Solving; Psychometrics; Reference Values; Serial Learning; Spatial Navigation; Visual Perception
PubMed: 24755229
DOI: 10.1016/j.ridd.2014.04.002 -
Cognitive Neuropsychology 2012Developmental prosopagnosia (DP) is defined by severe face recognition problems resulting from a failure to develop the necessary visual mechanisms for processing faces.... (Review)
Review
Developmental prosopagnosia (DP) is defined by severe face recognition problems resulting from a failure to develop the necessary visual mechanisms for processing faces. While there is a growing literature on DP in adults, little has been done to study this disorder in children. The profound impact of abnormal face perception on social functioning and the general lack of awareness of childhood DP can result in severe social and psychological consequences for children. This review discusses possible aetiologies of DP and summarizes the few cases of childhood DP that have been reported. It also outlines key objectives for the growth of this emerging research area and special considerations for studying DP in children. With clear goals and concerted efforts, the study of DP in childhood will be an exciting avenue for enhancing our understanding of normal and abnormal face perception for all age groups.
Topics: Child; Child, Preschool; Female; Humans; Male; Pattern Recognition, Visual; Prosopagnosia; Recognition, Psychology; Research; Visual Perception
PubMed: 23140142
DOI: 10.1080/02643294.2012.722547 -
American Journal of Alzheimer's Disease... Aug 2016Clinicians often have difficulty distinguishing between various forms of dementia to achieve a correct diagnosis. Little research has been done to examine whether... (Review)
Review
Clinicians often have difficulty distinguishing between various forms of dementia to achieve a correct diagnosis. Little research has been done to examine whether awareness of one's cognitive deficits, or metacognitive monitoring, might differ between dementia diagnoses, thereby providing an additional means of differentiating between dementia subtypes. We review articles examining metacognitive comparisons between two of the most common dementia subtypes: Alzheimer's disease and frontotemporal dementia. Greater monitoring deficits were apparent in frontotemporal dementia than in Alzheimer's disease, and participants with frontotemporal dementia were less likely to utilize task experience to update and improve the accuracy of subsequent monitoring judgments. Results provide evidence for the utility of metacognitive measures as a means of distinguishing between Alzheimer's disease and frontotemporal dementia.
Topics: Agnosia; Alzheimer Disease; Awareness; Cognition Disorders; Frontotemporal Dementia; Humans
PubMed: 26705377
DOI: 10.1177/1533317515618899