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Inferior Longitudinal Fasciculus
The inferior longitudinal fasciculus (ILF) is traditionally considered one of the major occipitotemporal association tracts. It is the white matter backbone of the ventral visual stream. It connects the ventral surface of the anterior temporal lobe and the extrastriate cortex of the occipital lobe, running along the lateral and inferior wall of the lateral ventricle. The existence of this fasciculus and its anatomical description have been the subject of several mutually conflicting studies. Some authors denied its existence because of the unclear results obtained in non-human brains. Using diffusion tensor imaging (DTI), several authors have confirmed the presence of this constant longitudinal pathway in humans. Some other studies of the ILFLatini, F., Mårtensson, J., Larsson, E.-M., Fredrikson, M., Åhs, F., Hjortberg, M., et al. (2017). Segmentation of the inferior longitudinal fasciculus in the human brain: A white matter dissection and diffusion tensor tractography study. Br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebral Hemisphere
The vertebrate cerebrum (brain) is formed by two cerebral hemispheres that are separated by a groove, the longitudinal fissure. The brain can thus be described as being divided into left and right cerebral hemispheres. Each of these hemispheres has an outer layer of grey matter, the cerebral cortex, that is supported by an inner layer of white matter. In eutherian (placental) mammals, the hemispheres are linked by the corpus callosum, a very large bundle of nerve fibers. Smaller commissures, including the anterior commissure, the posterior commissure and the fornix, also join the hemispheres and these are also present in other vertebrates. These commissures transfer information between the two hemispheres to coordinate localized functions. There are three known poles of the cerebral hemispheres: the ''occipital pole'', the ''frontal pole'', and the ''temporal pole''. The central sulcus is a prominent fissure which separates the parietal lobe from the frontal lobe and the prim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fusiform Gyrus
The fusiform gyrus, also known as the ''lateral occipitotemporal gyrus'','' ''is part of the temporal lobe and occipital lobe in Brodmann area 37. The fusiform gyrus is located between the lingual gyrus and parahippocampal gyrus above, and the inferior temporal gyrus below. Though the functionality of the fusiform gyrus is not fully understood, it has been linked with various neural pathways related to recognition. Additionally, it has been linked to various neurological phenomena such as synesthesia, dyslexia, and prosopagnosia. Anatomy Anatomically, the fusiform gyrus is the largest macro-anatomical structure within the ventral temporal cortex, which mainly includes structures involved in high-level vision. The term fusiform gyrus (lit. "spindle-shaped convolution") refers to the fact that the shape of the gyrus is wider at its centre than at its ends. This term is based on the description of the gyrus by Emil Huschke in 1854. (see also section on history). The fusiform gyrus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autism Spectrum Disorder
The autism spectrum, often referred to as just autism or in the context of a professional diagnosis autism spectrum disorder (ASD) or autism spectrum condition (ASC), is a neurodevelopmental disorder, neurodevelopmental condition (or conditions) characterized by difficulties in Social relation, social interaction, verbal and nonverbal communication, and the presence of repetitive behavior and restricted interests. Other common signs include unusual responses to Multisensory integration, sensory stimuli. Autism is generally understood as a ''spectrum disorder'', which means that it can manifest differently in each person: any given autistic individual is likely to show some, but not all, of the characteristics associated with it, and the person may exhibit them to varying degrees. Some autistic people remain nonverbal autism, nonspeaking over the course of their lifespan, while others have relatively unimpaired spoken language. There is large variation in the level of support peop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prosopagnosia
Prosopagnosia (from Greek ''prósōpon'', meaning "face", and ''agnōsía'', meaning "non-knowledge"), also called face blindness, ("illChoisser had even begun tpopularizea name for the condition: face blindness.") is a cognitive disorder of face perception in which the ability to recognize familiar faces, including one's own face (self-recognition), is impaired, while other aspects of visual processing (e.g., object discrimination) and intellectual functioning (e.g., decision-making) remain intact. The term originally referred to a condition following acute brain damage (acquired prosopagnosia), but a congenital or developmental form of the disorder also exists, with a prevalence of 2.5%. The brain area usually associated with prosopagnosia is the fusiform gyrus, which activates specifically in response to faces. The functionality of the fusiform gyrus allows most people to recognize faces in more detail than they do similarly complex inanimate objects. For those with prosopagno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visual Agnosia
Visual agnosia is an impairment in recognition of visually presented objects. It is not due to a deficit in vision (acuity, visual field, and scanning), language, memory, or intellect. While cortical blindness results from lesions to primary visual cortex, visual agnosia is often due to damage to more anterior cortex such as the posterior occipital and/or temporal lobe(s) in the brain. /sup> There are two types of visual agnosia: apperceptive agnosia and associative agnosia. Recognition of visual objects occurs at two primary levels. At an apperceptive level, the features of the visual information from the retina are put together to form a perceptual representation of an object. At an associative level, the meaning of an object is attached to the perceptual representation and the object is identified. If a person is unable to recognize objects because they cannot perceive correct forms of the objects, although their knowledge of the objects is intact (i.e. they do not have anomia), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Face Perception
Facial perception is an individual's understanding and interpretation of the face. Here, perception implies the presence of consciousness and hence excludes automated facial recognition systems. Although facial recognition is found in other species, this article focuses on facial perception in humans. The perception of facial features is an important part of social cognition. Information gathered from the face helps people understand each other's identity, what they are thinking and feeling, anticipate their actions, recognize their emotions, build connections, and communicate through body language. Developing facial recognition is a necessary building block for complex societal constructs. Being able to perceive identity, mood, age, sex, and race lets people mold the way we interact with one another, and understand our immediate surroundings. Though facial perception is mainly considered to stem from visual intake, studies have shown that even people born blind can learn face ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visual Object Recognition (animal Test)
Visual object recognition refers to the ability to identify the objects in view based on visual input. One important signature of visual object recognition is "object invariance", or the ability to identify objects across changes in the detailed context in which objects are viewed, including changes in illumination, object pose, and background context. Basic stages of object recognition Neuropsychological evidence affirms that there are four specific stages identified in the process of object recognition. These stages are: :Stage 1 Processing of basic object components, such as color, depth, and form. :Stage 2 These basic components are then grouped on the basis of similarity, providing information on distinct edges to the visual form. Subsequently, figure-ground segregation is able to take place. :Stage 3 The visual representation is matched with structural descriptions in memory. :Stage 4 Semantic attributes are applied to the visual representation, providing meaning, and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Two-streams Hypothesis
The two-streams hypothesis is a model of the neural processing of vision as well as hearing. The hypothesis, given its initial characterisation in a paper by David Milner and Melvyn A. Goodale in 1992, argues that humans possess two distinct visual systems. Recently there seems to be evidence of two distinct auditory systems as well. As visual information exits the occipital lobe, and as sound leaves the phonological network, it follows two main pathways, or "streams". The ventral stream (also known as the "what pathway") leads to the temporal lobe, which is involved with object and visual identification and recognition. The dorsal stream (or, "where pathway") leads to the parietal lobe, which is involved with processing the object's spatial location relative to the viewer and with speech repetition. History Several researchers had proposed similar ideas previously. The authors themselves credit the inspiration of work on blindsight by Weiskrantz, and previous neuroscientific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lingual Gyrus
The lingual gyrus, also known as the ''medial'' occipitotemporal gyrus, is a brain structure that is linked to processing vision, especially related to letters. It is thought to also play a role in analysis of logical conditions (i.e., logical order of events) and encoding visual memories. It is named after its shape, which is somewhat similar to a tongue. Contrary to the name, the region has little to do with speech. It is believed that a hypermetabolism of the lingual gyrus is associated with visual snow. Location The lingual gyrus of the occipital lobe lies between the calcarine sulcus and the posterior part of the collateral sulcus; behind, it reaches the occipital pole; in front, it is continued on to the tentorial surface of the temporal lobe, and joins the parahippocampal gyrus. Function Role in vision This region is believed to play an important role in vision and dreaming. Visual memory dysfunction and visuo-limbic disconnection have been shown in cases where the lingu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tractography
In neuroscience Neuroscience is the scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions and disorders. It is a multidisciplinary science that combines physiology, anatomy, molecular biology, development ..., tractography is a 3D modeling technique used to visually represent nerve tracts using data collected by diffusion MRI. It uses special techniques of magnetic resonance imaging (MRI) and computer-based diffusion MRI. The results are presented in two- and three-dimensional images called tractograms. In addition to the long tracts that connect the brain to the rest of the body, there are complicated neural circuits formed by short connections among different Cerebral cortex, cortical and subcortical regions. The existence of these tracts and circuits has been revealed by histochemistry and biology, biological techniques on post-mortem specimens. Nerve tracts are not identifiable by direct exam, computed tomography, CT ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Association Tract
Association fibers are axons that connect cerebral cortex, cortical areas within the same cerebral hemisphere. In human neuroanatomy, axons (nerve fibers) within the brain, can be categorized on the basis of their course and connections as association fibers, projection fibers, and commissural fibers. The association fibers unite different parts of the same cerebral hemisphere, and are of two kinds: (1) short association fibers that connect adjacent gyri; (2) long association fibers that make connections between more distant parts. Short association fibers Many of the short association fibers (also called arcuate or "U"-fibers) lie immediately beneath the gray substance of the cortex of the hemispheres, and connect together adjacent Gyrus, gyri. Some pass from one wall of the sulcus to the other. Long association fibers The long association fibers connect the more widely separated gyri and are grouped into bundles. They include the following: Diffusion tensor imaging is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Matter Dissection
White matter dissection refers to a special anatomical technique able to reveal the subcortical organization of white matter fibers in the human or animal cadaver brain. The first studies of cerebral white matter (WM) were described by Galen and by the subsequent efforts of Vesalius Andreas Vesalius (Latinized from Andries van Wezel) () was a 16th-century anatomist, physician, and author of one of the most influential books on human anatomy, ''De Humani Corporis Fabrica Libri Septem'' (''On the fabric of the human body'' '' ... on human cadaver specimens.Clarke E, O’Malley CD. 1968. The Human Brain and Spinal Cord, A Historical Study Illustrated By Writings from Antiquity To The Twentieth Century. Berkeley and Los Angeles: University of California Press. The interest for the deep anatomy of the brain pushed anatomist during centuries to create and develop different techniques for specimen preparation and dissection in order to better reveal the complex white matter architect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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