Body Senses

5 Key excerpts on "Body Senses"

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  eBook - ePub

  The Science of Story

  The Brain Behind Creative Nonfiction

  • Sean Prentiss, Nicole Walker(Authors)
  • 2020(Publication Date)
  • Bloomsbury Academic

    (Publisher)

  7 When the Body Reads: Writing Sensory Perception for Reader Embodiment Nancer Ballard

  “There’s a common fallacy that we have only five senses,” notes scientist and craniosacral therapist Andrew Cook. In fact, we have somewhere between twenty-two and thirty distinct types of sensory perception including: sight, hearing, smell, taste, touch, balance, muscle strength, temperature, hunger, pain, fatigue, itch, satiation, the carbon dioxide/oxygen ratio (feeling of suffocation), pressure, gravity, thirst, circadian rhythms, the gag reflex, proprioception (relative body and limb position sensed by muscles and joints), kinesthesia (sense of motion), direction, acceleration and deacceleration, force, and vibration. Some scientists also include a sense of effort (the perceived force needed to lift, move, or manipulate an object), a sense of agency (the sense that tells us that when we lift a tea cup it is our own arm that is doing the lifting), rhythm/oscillation, electromagnetic vibration, and the passage of time. In a less-scientific way we also use the words “sense of . . .” to describe perception-emotion-behavior routines, as in having a “sense of humor” or a “sense of obligation.” Some of our senses, such as smell and sight, respond to external stimuli; others, like muscle strength and thirst, are generated internally. Still others, such as balance, vibration, and temperature, can be initiated by internal or external stimuli.

  Our sensory perceptions often involve multiple parts of the body working in concert. We “hear” through our skulls as well as our ears. The semicircular canals needed for balance are located in our inner ears, but our ears get help from our eyes, and we make constant micro-adjustments in muscle tension throughout our bodies. Many people can distinguish a dozen distinct types of pain including throb, ache, pierce, crush, grind, and “pins and needles.” Others are sensitive to electromagnetic radiation, the “peri-space” envelope that surrounds our body proper, or subtle vibrations that allow them to “see” behind their backs. Humans also use their individual senses in diverse ways. For example, our eyes recognize friends, locate objects we intend to manipulate, orient us in time and space, and detect fleeting movement that could signal danger and automatically activates a fight or flight response.

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  Principles Of Biopsychology

  • Simon Greene(Author)
  • 2013(Publication Date)
  • Psychology Press

    (Publisher)

  10 Sensory Systems

  I

  n Chapter 2 , I mentioned briefly the role of sensory receptors in converting stimuli from the outside world into action potentials in the axons of sensory neurons. The range of receptors we possess defines what sort of world we live in, as we can only respond to and be aware of stimuli that our receptors can convert into action potentials.

  We can reverse the argument and consider what types of sensations humans can deal with; then, by definition, we must have sensory receptors adapted for those stimuli. One group are the somatic senses of the skin and body, including touch, pressure, vibration, tickling, temperature (warm and cold), and pain. Then there is proprioception, the awareness of the position of our limbs and body in space. Smell (olfaction) and taste (gustation) have similarities as they both involve chemical stimuli, while our most sophisticated and complex senses are sight (vision) and hearing (audition).

  Each of these systems has the same components. Sensory stimuli are converted (transduced) by specialised receptors into action potentials in sensory axons heading into the central nervous system (afferent pathways). After traversing several synapses they arrive (usually) in cortical receiving areas for high level analysis, where sensation (simple awareness of a stimulus) becomes perception (awareness of complex stimulus properties). Of course there is great variation in the nature of the receptors, the distribution of the pathways, and in the precise cortical areas involved.

  Much of the detailed work on sensory systems is beyond the scope of this book. I will briefly review the somatic senses, proprioception, smell and taste, and then deal with pain perception in more detail. Most of the chapter will concern hearing as this, along with vision, is the system on which we rely most.

  Somatic Senses

  If you imagine the range of stimuli you can feel on your skin, then you are imagining the range of our somatic senses. Some seem to be related—light touch, pressure, tickling etc—and some seem very different—pain, heat and cold. Those related to touch involve mechanical pressure on the skin. This produces movement of the skin surface, and this is picked up by sensory receptors beneath the surface. Changes in skin temperature are also sensed by specialised receptors. The perception of pain can be produced by all sorts of stimuli, as it depends in part on stimulus intensity rather than type; pinching, jabs with a sharp instrument, extreme heat or cold, can all lead to a feeling of pain along with the sensation of being hit or of being hot or cold.

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  The Senses in Self, Society, and Culture

  A Sociology of the Senses

  • Phillip Vannini, Dennis Waskul, Simon Gottschalk(Authors)
  • 2013(Publication Date)
  • Routledge

    (Publisher)

  Of course, we are not under the illusion that any perspective can be broad enough to accommodate everyone, regardless of interest or philosophical orientation. However, in beginning our conceptual exercise by positing the senses and sensations as the key form of humans’ active construction of the world, we hope to appeal to as broad a spectrum as possible. We find the metaphor of work especially useful to understand the senses, so it is to the treatment of somatic work that we now turn. OUR THEORETICAL APPROACH: SOMATIC WORK [S]ensory experiences are produced, enacted and perceived in combination with each other, intertwined with emotion, meaning and memory. (Hsu 2008:440) The basic premise of this book can be stated as follows: humans sense as well as make sense. This process of sense-making entails minded and embodied social and cultural practices that cannot be explained or reduced to physiological processes alone. The senses “are fundamental to personhood” and they concern “bodily engagement with the world,” thus creating a structure “both offering and constraining possibilities for the human subject” (Edwards, Gosden, and Phillips 2006:23). They mediate between meaning and materiality—“sensory experience is socially made and mediated” (Hsu 2008:433)—and they “mediate the relationship between self and society, mind and body, idea and object” (Bull, Gilroy, Howes, and Kahn 2006:5). The senses are skills (Ingold 2000) that we actively employ in interpreting and evaluating the world. To see, for example, entails more than opening our eyes to allow light passively to bounce off our retinas. We must actively perceive that which is seen and thus make sense of somatic experience (see Howes 2003; Rodaway 1994). In this way, sensing and sense-making are necessarily conjoined, codetermined, and mutually emergent in active and reflexive practices in which we are both the subject and object of the sensations we perceive or, for that matter, fail to recognize

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  Sensation and Perception

  • Hugh J. Foley, Mary Bates(Authors)
  • 2019(Publication Date)
  • Routledge

    (Publisher)

  Chapter 12 The Skin Senses

  • The Skin
    • Receptors in the Skin
    • From the Skin to the Brain
  • Touch
    • Afferent Systems for Touch
    • Passive Touch
    • Active Touch
    • Interactions between Touch and Other Senses
  • Temperature
    • Afferent Systems for Temperature
    • Thresholds for Temperature
    • Adapting to Temperature
  • Pain
    • Afferent Systems for Pain and Gate-Control Theory
    • ● IN-DEPTH: Phantom Limbs and Pain
    • Measuring Pain
    • Adapting to Pain
    • Controlling Pain
  • Kinesthetic and Vestibular Senses
    • Kinesthetic Sense
    • Vestibular Sense

  In elementary school, your teacher might have told you about the five senses: vision, hearing, touch, smell, and taste. Aristotle used this classification system more than 2300 years ago, and it is probably still the most common one. However, it’s clear that we rely on more than five senses. In this chapter, we’ll explore a set of senses embedded in our bodies, collectively called the somatosensory system (from the Latin and Greek soma meaning “body”).

  The somatosensory system has three separate systems that interact with one another (Pinel, 2006 ). We’ll ignore one system, which monitors your body’s internal states. We’ll focus primarily on another system, which interprets the impact of the outside world on your body. This system provides you with touch, temperature perception, and pain perception. Finally, we’ll consider the system that informs you about whether you are standing upright or tilted and where your body parts are in relation to each other. That somatosensory system is augmented by information from the vestibular system of the inner ear, which we first mentioned in Chapter 9 .

  The Skin

  Your skin represents the largest sensory system you own, with a surface area of about 2 square yards in adults (Weisenberger, 2001

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  Getting your head around the brain

  • Amanda Ellison(Author)
  • 2012(Publication Date)
  • Bloomsbury Academic

    (Publisher)

  The five senses, vision, audition (hearing), somatosensation (pain and touch), taste and olfaction (smell) all have sensory organs and similar pathways to the brain where the sensory experience is interpreted. Thus, what most people lump together as “sensation” is actually a two-step process. There is the translation of a sensory stimulus into an electrical signal (action potentials) via a sensory organ of which we have – the eyes, ears, skin (and other tissues), tongue and nose – but there is also the brain’s processing of these signals which is called perception. As individuals, our perception of the same sensory stimulus can vary widely from somebody else’s. Take touch for example. A grasp of one person’s arm may be felt as merely a firm touch to them but another person may scream in pain. So, touch and consequently pain thresholds vary across humans as do our visual, auditory, somatosensory, taste and olfactory thresholds. Scientists who investigate this absolute performance are called psychophysicists. Again, sensation is the registration of a physical stimulus from the environment by the sensory organs whereas perception is the interpretation of the sensations by the brain. Our version of reality is, in effect,our perception of the sensory world, but without the activity of either the sensory organ or the brain, our senses are useless. We will be discussing vision and hearing in later chapters, but for now let us first discuss somatosensation and then the chemical senses of taste and smell.

  Somatosensation comprises three sensory systems in the body: hapsis or touch, noiciception, which is pain and temperature, and proprioception, which is body awareness. The main sensory organ for hapsis and nociception is the skin with the muscles containing the sensory organs for proprioception (see Figure 3.1 ). There are five types of sensory receptors contained in the skin that respond to haptic or fine touch and pressure stimuli. These are the Meissner’s corpuscle for touch, the Pacinian corpuscle for fluttering sensations, the Ruffini corpuscle for vibration, Merkel’s receptor for steady skin indentation and the hair receptors, which are also for steady skin vibrations as well as fluttering sensations. Pressure on any of these receptors causes mechanical opening of ion channels and generation of action potentials in the dendrites of the sensory neurons that are attached to them.

  These receptors can be either fast adapting or slow adapting. Fast adaptation is important for the detection of on/off signals and doesn’t give you much information during the stimulus particularly if it is there for a long time. A really good example of this is when you wear glasses or shades. When you pop them on, you feel their presence on your nose and over your ears, but after that, you don’t really notice them. How many times have you walked in to find your granny looking for her specs when they were on her face all along? The Meissner, Pacinian and Ruffini corpuscles are all fast adapting. In contrast, the hair cells and the Merkel receptor are slow adapting and so it takes longer for these receptors to become immune to the stimulus, although given the glasses example, it does happen. Because they are slow adapting, they also take some time to catch up to the fact that the stimulus has been removed and so you may actually feel the indentation when the stimulus is gone. Try this: press the cap of your pen into your arm, not so that the stimulus is painful, just so that you can feel it. The Meissner, Pacinian and Ruffini corpuscles feel the onset of the cap but rapidly adapt; they don’t constantly produce action potentials. The hair cells and Merkel receptors continue to produce action potentials and this is how you know the stimulus is still there. Indeed, when you remove the cap after 20 seconds or so, it takes a second or two for the sensation of the cap to go away as these receptors are slow adapting, but the other fast-adapting corpuscles have already told you the cap has been lifted. This works even without visual input, so get one of your mates to press the pen into your arm while your eyes are closed. My advice? Pick a gentle one, friend that is ... when did you know the pen was lifted and when did the sensation go away?

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