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Senses

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A sensory system is a part of the nervous system responsible for processing sensory information. A sensory system consists of sensory receptors, neural pathways, and parts of the brain involved in sensory perception.

Commonly recognized sensory systems are those for vision, auditory (hearing), somatic sensation (touch), gustatory (taste), olfaction (smell) and vestibular (balance/movement). In short, senses are transducers from the physical world to the realm of the mind where we interpret the information, creating our perception of the world around us.[1]

The receptive field is the specific part of the world to which a receptor organ and receptor cells respond. For instance, the part of the world an eye can see, is its receptive field; the light that each rod or cone can see, is its receptive field.[2] Receptive fields have been identified for the visual system, auditory system and somatosensory system, so far. Sensory system. Stimulus.

Senses and receptors

Sensory cortex. Modality. Proprioception. The cerebellum is largely responsible for coordinating the unconscious aspects of proprioception.

Proprioception

Proprioception (/ˌproʊpri.ɵˈsɛpʃən/ PRO-pree-o-SEP-shən), from Latin proprius, meaning "one's own", "individual" and perception, is the sense of the relative position of neighbouring parts of the body and strength of effort being employed in movement.[1] It is provided by proprioceptors in skeletal striated muscles and in joints. It is distinguished from exteroception, by which one perceives the outside world, and interoception, by which one perceives pain, hunger, etc., and the movement of internal organs. The brain integrates information from proprioception and from the vestibular system into its overall sense of body position, movement, and acceleration.

The word kinesthesia or kinæsthesia (kinesthetic sense) has been used inconsistently to refer either to proprioception alone or to the brain's integration of proprioceptive and vestibular inputs. Multisensory integration. Multisensory integration, also known as multimodal integration, is the study of how information from the different sensory modalities, such as sight, sound, touch, smell, self-motion and taste, may be integrated by the nervous system.[1] A coherent representation of objects combining modalities enables us to have meaningful perceptual experiences.

Multisensory integration

Indeed, multisensory integration is central to adaptive behavior because it allows us to perceive a world of coherent perceptual entities.[2] Multisensory integration also deals with how different sensory modalities interact with one another and alter each other’s processing. General introduction[edit] Multi-modal perception is a scientific term that describes how humans form coherent, valid, and robust perception by processing sensory stimuli from various modalities. Neural adaptation. Weight training[edit] Studies have shown that there is neural adaptation after as little as one weight training session.

Neural adaptation

Strength gains are experienced by subjects without any increased muscle size. Muscle surface recordings using electromyographic (SEMG) techniques have found that early strength gains throughout training are associated with increased amplitude in SEMG activity. These findings along with various other theories explain increases in strength without increases in muscle mass. Other theories for increases in strength relating to neural adaptation include: agonist-antagonist muscle decreased co-activation, motor unit synchronization, and motor unit increased firing rates.[2] Neural adaptations contribute to changes in V-waves and Hoffmann's reflex. Visual[edit] Sensory neuroscience.

Sensory neuroscience is a subfield of neuroscience which explores the anatomy and physiology of neurons that are part of sensory systems such as vision, hearing, and olfaction.

Sensory neuroscience

Neurons in sensory regions of the brain respond to stimuli by firing one or more nerve impulses (action potentials) following stimulus presentation. How is information about the outside world encoded by the rate, timing, and pattern of action potentials? This so-called neural code is currently poorly understood and sensory neuroscience plays an important role in the attempt to decipher it. Looking at early sensory processing is advantageous since brain regions that are "higher up" (e.g. those involved in memory or emotion) contain neurons which encode more abstract representations. However, the hope is that there are unifying principles which govern how the brain encodes and processes information.

Typical experiments[edit] Single neuron experiments[edit] Special senses. The distinction between special and general senses is used to classify nerve fibres running to and from the central nervous system - information from special senses is carried in special somatic afferents and special visceral afferents.

Special senses

In contrast, the other sense, touch, is a somatic sense which does not have a specialized organ but comes from all over the body, most noticeably the skin but also the internal organs (viscera). Touch includes mechanoreception (pressure, vibration and proprioception), pain (nociception) and heat (thermoception), and such information is carried in general somatic afferents and general visceral afferents.[1] References[edit] Jump up ^ Drake et al. (2010), Gray's Anatomy for Students, 2nd Ed., Churchill Livingstone.

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