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Neuroanatomy Of Handedness
An estimated 90% of the world's human population consider themselves to be right-handed. The human brain's control of motor function is a mirror image in terms of connectivity; the left hemisphere controls the right hand and vice versa. This theoretically means that the hemisphere contralateral to the dominant hand tends to be more dominant than the ipsilateral hemisphere, however this is not always the case and there are numerous other factors which contribute in complex ways to physical hand preference. Language and speech areas Language areas are represented unilaterally in the human brain. In around 95% of right-handers, these brain areas are often located on the left hemisphere, however the proportion reduces in left handers down to around 70%. Therefore 7 in every 100 individuals is right-hemisphered for language and left-hand dominant. It is unclear as to whether or not left-hemisphered left handers suffer any language or writing deficits because of this. Broca's area has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Handedness
In human biology, handedness is an individual's preferential use of one hand, known as the dominant hand, due to it being stronger, faster or more Fine motor skill, dextrous. The other hand, comparatively often the weaker, less dextrous or simply less subjectively preferred, is called the non-dominant hand. In a study from 1975 on 7688 children in US grades 1-6, Left handers comprised 9.6% of the sample, with 10.5% of male children and 8.7% of female children being left-handed. Handedness is often defined by one's writing hand, as it is fairly common for people to prefer to do some tasks with each hand. There are examples of true ambidexterity (equal preference of either hand), but it is rare—most people prefer using one hand for most purposes. Most of the current research suggests that left-handedness has an epigenetic marker—a combination of genetics, biology and the environment. Because the vast majority of the population is right-handed, many devices are designed for u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebral Cortex
The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. The cerebral cortex mostly consists of the six-layered neocortex, with just 10% consisting of allocortex. It is separated into two cortices, by the longitudinal fissure that divides the cerebrum into the left and right cerebral hemispheres. The two hemispheres are joined beneath the cortex by the corpus callosum. The cerebral cortex is the largest site of neural integration in the central nervous system. It plays a key role in attention, perception, awareness, thought, memory, language, and consciousness. The cerebral cortex is part of the brain responsible for cognition. In most mammals, apart from small mammals that have small brains, the cerebral cortex is folded, providing a greater surface area in the confined volume of the cranium. Apart from minimising brain and cranial volume, cortical folding is crucial for the brain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuroanatomy
Neuroanatomy is the study of the structure and organization of the nervous system. In contrast to animals with radial symmetry, whose nervous system consists of a distributed network of cells, animals with bilateral symmetry have segregated, defined nervous systems. Their neuroanatomy is therefore better understood. In vertebrates, the nervous system is segregated into the internal structure of the brain and spinal cord (together called the central nervous system, or CNS) and the routes of the nerves that connect to the rest of the body (known as the peripheral nervous system, or PNS). The delineation of distinct structures and regions of the nervous system has been critical in investigating how it works. For example, much of what neuroscientists have learned comes from observing how damage or "lesions" to specific brain areas affects behavior or other neural functions. For information about the composition of non-human animal nervous systems, see nervous system. For information ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type I And Type II Errors
In statistical hypothesis testing, a type I error is the mistaken rejection of an actually true null hypothesis (also known as a "false positive" finding or conclusion; example: "an innocent person is convicted"), while a type II error is the failure to reject a null hypothesis that is actually false (also known as a "false negative" finding or conclusion; example: "a guilty person is not convicted"). Much of statistical theory revolves around the minimization of one or both of these errors, though the complete elimination of either is a statistical impossibility if the outcome is not determined by a known, observable causal process. By selecting a low threshold (cut-off) value and modifying the alpha (α) level, the quality of the hypothesis test can be increased. The knowledge of type I errors and type II errors is widely used in medical science, biometrics and computer science. Intuitively, type I errors can be thought of as errors of ''commission'', i.e. the researcher unluck ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parametric Test
Parametric statistics is a branch of statistics which assumes that sample data comes from a population that can be adequately modeled by a probability distribution that has a fixed set of parameters. Conversely a non-parametric model does not assume an explicit (finite-parametric) mathematical form for the distribution when modeling the data. However, it may make some assumptions about that distribution, such as continuity or symmetry. Most well-known statistical methods are parametric. Regarding nonparametric (and semiparametric) models, Sir David Cox has said, "These typically involve fewer assumptions of structure and distributional form but usually contain strong assumptions about independencies". Example The normal family of distributions all have the same general shape and are ''parameterized'' by mean and standard deviation. That means that if the mean and standard deviation are known and if the distribution is normal, the probability of any future observation lying in a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edinburgh Handedness Inventory
The Edinburgh Handedness Inventory is a measurement scale used to assess the dominance of a person's right or Left-handedness, left hand in everyday activities, sometimes referred to as laterality. The inventory can be used by an observer assessing the person, or by a person self-reporting hand use. The latter method tends to be less reliable due to a person over-attributing tasks to the dominant hand. The Edinburgh Handedness Inventory was published in 1971 by Richard Charles Oldfield and has been used in various scientific studies as well as popular literature. See also * Ambidexterity * Cross-dominance * Dextrocardia * Footedness * Handedness * Laterality * Ocular dominance * Situs inversus References External links An online example of the tool authored by Mark Cohen hosted ahttp://www.brainmapping.org Motor skills Upper limb anatomy Handedness Chirality {{anatomy-stub ... [...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] |
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] |
Fusiform Face Area
The fusiform face area (FFA, meaning spindle-shaped face area) is a part of the human visual system (while also activated in people blind from birth) that is specialized for facial recognition. It is located in the inferior temporal cortex (IT), in the fusiform gyrus (Brodmann area 37). Structure The FFA is located in the ventral stream on the ventral surface of the temporal lobe on the lateral side of the fusiform gyrus. It is lateral to the parahippocampal place area. It displays some lateralization, usually being larger in the right hemisphere. The FFA was discovered and continues to be investigated in humans using positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) studies. Usually, a participant views images of faces, objects, places, bodies, scrambled faces, scrambled objects, scrambled places, and scrambled bodies. This is called a functional localizer. Comparing the neural response between faces and scrambled faces will reveal areas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Putamen
The putamen (; from Latin, meaning "nutshell") is a round structure located at the base of the forebrain (telencephalon). The putamen and caudate nucleus together form the dorsal striatum. It is also one of the structures that compose the basal nuclei. Through various pathways, the putamen is connected to the substantia nigra, the globus pallidus, the claustrum, and the thalamus, in addition to many regions of the cerebral cortex. A primary function of the putamen is to regulate movements at various stages (e.g. preparation and execution) and influence various types of learning. It employs GABA, acetylcholine, and enkephalin to perform its functions. The putamen also plays a role in degenerative neurological disorders, such as Parkinson's disease. History The word "putamen" is from Latin, referring to that which "falls off in pruning", from "putare", meaning "to prune, to think, or to consider". Until recently, most MRI research focused broadly on the basal ganglia as a who ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinal Cord
The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the spinal cord, which contains cerebrospinal fluid. The brain and spinal cord together make up the central nervous system (CNS). In humans, the spinal cord begins at the occipital bone, passing through the foramen magnum and then enters the spinal canal at the beginning of the cervical vertebrae. The spinal cord extends down to between the first and second lumbar vertebrae, where it ends. The enclosing bony vertebral column protects the relatively shorter spinal cord. It is around long in adult men and around long in adult women. The diameter of the spinal cord ranges from in the cervical and lumbar regions to in the thoracic area. The spinal cord functions primarily in the transmission of nerve signals from the motor cortex to the body, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motor Neuron
A motor neuron (or motoneuron or efferent neuron) is a neuron whose cell body is located in the motor cortex, brainstem or the spinal cord, and whose axon (fiber) projects to the spinal cord or outside of the spinal cord to directly or indirectly control effector organs, mainly muscles and glands. There are two types of motor neuron – upper motor neurons and lower motor neurons. Axons from upper motor neurons synapse onto interneurons in the spinal cord and occasionally directly onto lower motor neurons. The axons from the lower motor neurons are efferent nerve fibers that carry signals from the spinal cord to the effectors. Types of lower motor neurons are alpha motor neurons, beta motor neurons, and gamma motor neurons. A single motor neuron may innervate many muscle fibres and a muscle fibre can undergo many action potentials in the time taken for a single muscle twitch. Innervation takes place at a neuromuscular junction and twitches can become superimposed as a resu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
