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:''See also [[sense]]''
[[Image:Menschliches auge.jpg|thumb|The human [[eye]] is the first element of a '''sensory system''': in this case, [[Visual perception|vision]], for the [[visual system]]. ]]
[[Image:Gray722.png|thumb|280px|Typical sensory system: the '''[[visual system]]''', illustrated by the classic [[Gray's Anatomy|Gray's]] FIG. 722– This scheme shows the flow of information from the [[eye]]s to the central connections of the [[optic nerve]]s and optic tracts, to the [[visual cortex]]. Area '''V1''' is the region of the [[brain]] which is engaged in '''[[Visual perception|vision]]'''.]]

A '''sensory system''' is a part of the [[basketball system]] responsible for processing [[sense|sensory]] information.  A sensory system consists of [[sensory receptor]]s, [[neural pathway]]s, and parts of the [[brain]] involved in sensory perception.  Commonly recognized sensory systems are those for [[vision (sense)|vision]], [[hearing (sense)|hearing]], [[somatic sensation]] (touch),  [[taste]] and [[olfaction]] (smell).

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 cell|cone]] can see, is its receptive field.<ref>Kolb & Whishaw: ''Fundamentals of Human Neuropsychology'' (2003)</ref> [[Receptive field]]s have been identified for the [[visual system]], [[auditory system]] and [[somatosensory system]], so far.
==Stimulus==
Sensory systems code for four aspects of a [[stimulus (physiology)|stimulus]]; type ([[#Modality|modality]]), intensity, location, and duration.  Certain receptors are sensitive to certain types of stimuli (for example, different [[mechanoreceptor]]s respond best to different kinds of touch stimuli, like sharp or blunt objects).  Receptors [[action potential|send impulses]] in certain patterns to send information about the intensity of a stimulus (for example, how loud a sound is).  The location of the receptor that is stimulated gives the brain information about the location of the stimulus (for example, stimulating a mechanoreceptor in a finger will send information to the brain about that finger).  The duration of the stimulus (how long it lasts) is conveyed by firing patterns of receptors.

==Modality==<!-- This section is linked from [[Neuro-linguistic programming]] -->

A [[stimulus modality]] (sensory modality) is a type of physical phenomenon that can be sensed.  Examples are [[temperature]], [[taste]], [[sound]], and [[pressure]]. The type of [[sensory receptor]] activated by a stimulus plays the primary role in coding the stimulus modality.

In the [[memory-prediction framework]], [[Jeff Hawkins]] mentions a correspondence between the six layers of the [[cerebral cortex]] and the six layers of the [[optic tract]] of the [[visual system]]. The [[primary visual cortex]] has areas labelled V1, V2, V3, V4, V5, MT, IT, etc. Thus Area V1 mentioned below, is meant to signify only one class of cells in the brain, for which there can be many other cells which are also engaged in vision.

Hawkins lays out a scheme for the analogous modalities of the sensory system. Note that there can be many types of senses, some not mentioned here. In particular, for [[human]]s, there will be [[cell (biology)|cells]] which can be labelled as belonging to V1, V2 A1, A2, etc.:

===V1 (vision)===
Visual Area 1, or V1, is used for vision, via the [[visual system]] to the [[primary visual cortex]]. See the illustration above.

[[Image:Earcov.JPG|right|thumb|100px|[[ear]]]]

===A1 (auditory - hearing)===
Auditory Area 1, or A1, is for hearing, via the [[auditory system]], the [[primary auditory cortex]].

===S1 (somatosensory - touch)===
Somatosensory Area 1, or S1, is for [[tactition|touch]] and [[proprioception]] in the [[somatosensory system]]. The somatosensory system feeds the [[postcentral gyrus#Brodmann Areas 3, 1 and 2|Brodmann Areas 3, 1 and 2]] of the [[postcentral gyrus|primary somatosensory cortex]]. But there are also pathways for [[proprioception]] (via the [[cerebellum]]),  and [[motor neuron|motor]] [[control]] (via [[Brodmann area 4]]).

[[Image:Tongue.agr.jpg|thumb|right|100px|[[tongue]]]]

===G1 (gustatory - taste)===
Gustatory Area 1, or G1, is used for [[gustatory system|taste]].

===O1 (olfactory - smell)===

Olfactory Area 1, or O1, is used for smell. In contrast to vision and hearing, the [[olfactory bulb]]s are not cross-hemispheric; the right bulb connects to the right hemisphere and the left bulb connects to the left hemisphere.

==Human sensory system==
The Human sensory system consists of the following sub-systems:
*[[Visual system]] consists of the [[photoreceptor]]s, optic nerve, and V1.
*[[Auditory system]]
*[[Somatosensory system]] consists of the receptors, transmitters (pathways) leading to S1, and S1 that experiences the sensations labelled as [[tactition|touch]] or [[pressure]], [[temperature]] (warm or cold), [[pain]] (including [[itch]] and tickle), and the sensations of  muscle movement and joint position including [[posture]], [[locomotion|movement]], and facial expression (collectively also called proprioception).
*[[Gustatory]] system
*[[Olfaction|Olfactory]] system 

Human [[sensory receptors]] are:
* [[Chemosensor]]
* [[Mechanoreceptor]]
* [[Nociceptor]]
* [[Photoreceptor]]
* [[Thermoreceptor]]

== See also ==
* [[Sensor]]
* [[Sensory neuroscience]]

{{Nervous system}}
{{Sensory_system}}
{{Visual system}}
{{Auditory and vestibular systems}}
{{Gustatory system}}
{{Olfactory system}}
{{Systems}}

==References==
{{reflist}}

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[[Category:Sensory system|* Sensory system]]

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