Your 8 Senses
The greatest “general knowledge” of this century – that you have 5 senses, is wrong. What? Yes, that’s right – wrong. You actually have 8 senses. 8, completely different, very necessary senses. If you think I’m crazy, I’ll post sources at the end of this article. I promise you, if you hear me out, you may get it. First you may be wondering: Okay, fine, there’s 8 senses, but why haven’t I heard of them? Well, the trouble with the other 3 senses is that they only come up when there’s a problem. Most people day to day have no (or little) trouble with these senses.
The 8 senses start off simply. We have the 5 you all know (and hopefully, if you’re lucky, love). I won’t tell you what these do – chances are, you already know…
To see disorders related to the senses, click on the name:
The sense of smell, known as the olfactory system, allows us to perceive specific, important factors about our environments. Evolutionarily, smell has aided humans in detecting which foods could and could not be safely eaten, whether an area’s air was healthful to breath, and even helped to determined social interactions. Certain types of brain damage, unfortunately, can damage or destroy our sense of smell.
Taste, known scientifically as “gustation,” is the ability of the brain to sense the flavor of items entering the mouth, through their interaction with taste buds, largely located on the tongue. Disorders affecting the sense of taste can cause people to taste flavors that are not present in their mouths (phantom taste perception), lose the ability to taste sweet, sour, bitter, salty and savory flavors (hypogeusia), and lose the ability to taste at all (ageusia).
The sense of touch (tactile sense), is perceived largely through the skin. This system allows us to comprehend the texture of objects, as well as the pressure and traction exerted on our bodies by the world around us. Individuals suffering from tactile sensitivity (as well as SPD and other sensory disorders) may have a hypersensitive, or hyposensitivity, to touch that others would not consider bothersome.
For many people, sight is the primary means of taking in the world around them. This complex system of light entering the eye, and being processed within the brain, allows us to perceive our position in space, and the features of our environment. When things go wrong with this system, whether within the eye itself (glaucoma, retinal tear) or within the brain (optic nerve disorders, multiple sclerosis), vision can be disrupted. Some disorders may involve a strange interpretation of visuals, such as what happens with Sensory Over-Responsivity (a subset of SPD). When this happens, a person may view visuals as a threat, or nuisance when a normal person would simply interpret the stimuli.
What we hear determines a lot of how we interpret our surroundings. Particularly important in the hunter gathering times, hearing allows for basic survival. When hearing goes wrong, such as persons that are deaf, it is easy to see how life can be altered. Many disorders encompass the auditory system. Some involve the ear itself, and others have to do with the processing of sound in the brain.
The vestibular system contributes to balance and orientation in space. It is the leading system informing us about movement and position of head relative to gravity. Our movements include two positions rotations and linear directionality. Thus, the vestibular system has two related components: the semicircular canal system, (related to detecting rotation) and the otoliths, (related to detecting linear acceleration/deceleration). The vestibular system sends signals primarily to the neural parts of the brain that control our eye movements, and that keep us upright. (SPD Star)
The proprioceptive system (sometimes abbreviated as “prop” by therapists when they talk about it) senses the position, location, orientation, and movement of the body muscles and joints. Proprioception provides us with the sense of the relative position of neighboring parts of the body and effort used to move body parts. Proprioception is activated by input to a proprioceptor in the periphery of the body. The proprioceptive sense combines sensory information from neurons in the inner ear (detecting motion and orientation) and stretch receptors in the muscles and the joint-supporting ligaments for stance. (SPD Star)
The eighth, often neglected, but frequently problematic sensory system in SPD is the Interoceptive System. Interoception refers to sensations related to the physiological / physical condition of the body. Interoceptors are internal sensors that provide a sense of what our internal organs are feeling. Hunger and thirst are examples of interoception. Interoception detects responses that guide regulation, including hunger, heart rate, respiration and elimination. The Interoceptive stimulation is detected through nerve endings lining the respiratory and digestive mucous membranes. Interoception works the vestibular and proprioceptive senses to determine how an individual perceives their own body. Well-modulated interoception helps the individual detect proprioceptive and vestibular sensation normally. For example, if a person feels his/her heart pounding, while it is not comfortable, trauma from the stimulation is not likely; nor will the stimulation be craved. The same is true for hunger and thirst, as well as the feeling of the need to urinate or have a bowel movement.