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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 h ... [...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 and causing it to be 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 7,688 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. Overall, around 90% of people are right-handed. Handedness is often defined by one's writing hand. It is fairly common for people to prefer to do a particular task with a particular hand. Cross-dominance, Mixed-handed people change hand preference depending on the task. Not to be confused with handedness, ambidexterity describes having equal ability in both hands. Those who learn it still tend to favor their originally dominant hand. Natural ambidexterity (equal preference of either hand) d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motor Neuron
A motor neuron (or motoneuron), also known as 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 superimpo ... [...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 series of nerves that connect the CNS to the rest of the body (known as the peripheral nervous system, or PNS). Breaking down and identifying specific parts of the nervous system has been crucial for figuring out how it operates. 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 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limbic System
The limbic system, also known as the paleomammalian cortex, is a set of brain structures located on both sides of the thalamus, immediately beneath the medial temporal lobe of the cerebrum primarily in the forebrain.Schacter, Daniel L. 2012. ''Psychology''.sec. 3.20 Its various components support a variety of functions including emotion, behavior, long-term memory, and olfaction. The limbic system is involved in lower order emotional processing of input from sensory systems and consists of the amygdala, mammillary bodies, stria medullaris, central gray and dorsal and ventral nuclei of Gudden. This processed information is often relayed to a collection of structures from the telencephalon, diencephalon, and mesencephalon, including the prefrontal cortex, cingulate gyrus, limbic thalamus, hippocampus including the parahippocampal gyrus and subiculum, nucleus accumbens (limbic striatum), anterior hypothalamus, ventral tegmental area, midbrain raphe nuclei, habenular commi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type I And Type II Errors
Type I error, or a false positive, is the erroneous rejection of a true null hypothesis in statistical hypothesis testing. A type II error, or a false negative, is the erroneous failure in bringing about appropriate rejection of a false null hypothesis. Type I errors can be thought of as errors of commission, in which the status quo is erroneously rejected in favour of new, misleading information. Type II errors can be thought of as errors of omission, in which a misleading status quo is allowed to remain due to failures in identifying it as such. For example, if the assumption that people are ''innocent until proven guilty'' were taken as a null hypothesis, then proving an innocent person as guilty would constitute a Type I error, while failing to prove a guilty person as guilty would constitute a Type II error. If the null hypothesis were inverted, such that people were by default presumed to be ''guilty until proven innocent'', then proving a guilty person's innocence would ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parametric Test
Parametric statistics is a branch of statistics which leverages models based on a fixed (finite) set of parameters. Conversely nonparametric statistics does not assume explicit (finite-parametric) mathematical forms for distributions when modeling data. However, it may make some assumptions about that distribution, such as continuity or symmetry, or even an explicit mathematical shape but have a model for a distributional parameter that is not itself finite-parametric. 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 o ... [...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 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 Carolus Oldfield and has been used in various scientific studies as well as popular literature. According to Google Scholar it has been cited tens of thousands of times. Within the very substantial literature on handedness it is used far more than any rival, such as FLANDERS, or the Annett Hand Preference Questionnaire, which is not good at eliciting either-hand responses. Nevertheless, profound dissatisfaction with the Inventory has been expressed and statistical analysis of the Inventory has shown that the two-handed items broom an ... [...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 (social science), identity, what they are thinking and feeling, anticipate their actions, Emotion recognition, 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 s ... [...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 ... [...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 are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Putamen
The putamen (; from Latin, meaning "nutshell") is a subcortical nucleus (neuroanatomy), nucleus with a rounded structure, in the basal ganglia nuclear group. It is located at the base of the forebrain and above the midbrain. The putamen and caudate nucleus together form the dorsal striatum. 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 such as in preparation and execution; and to influence various types of learning. It employs GABA, acetylcholine, and enkephalin to perform its functions. The putamen also plays a role in neurodegenerative diseases, 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". Most MRI research was focused broadly on th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinal Cord
The spinal cord is a long, thin, tubular structure made up of nervous tissue that extends from the medulla oblongata in the lower brainstem to the lumbar region of the vertebral column (backbone) of vertebrate animals. The center of the spinal cord is hollow and contains a structure called the central canal, which contains cerebrospinal fluid. The spinal cord is also covered by meninges and enclosed by the neural arches. Together, the brain and spinal cord make up the central nervous system. In humans, the spinal cord is a continuation of the brainstem and anatomically begins at the occipital bone, passing out of 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 tapers to become the cauda equina. 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 diam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
