Sensation Perception The senses provide our brains with information about the outside world and about our own internal world Even single celled organisms have ways to detect facts about their environments and they typically have the ability to use this information either to find nutrients or avoid danger for more complex organisms certainly for humans many sources of information about the external and internal world are necessary to allow us to survive and thrive The systems we have throughout our bodies that allow us to detect information and transform energy intro neural impulses are called senses or sensory systems Detection of food or danger is generally not enough to permit an organism to respond effectively for survival Organisms generally use both genetically and transmitted knowledge and knowledge derived from experience to organize and interpret incoming sensory information This process of organization and interpretation is what we refer to as perception In this unit we discuss the strengths and limitations of these capacities focusing both sensation awareness resulting from the stimulation of a sense organ and perception the organization and interpretation of sensations Sensation and perception work seamlessly together to allow us to experience the world though our eyes ears nose tongue and skin but also to combine what we are currently learning from the environment with what we already know about it to make judgments and to choose appropriate behaviors We begin with a focus on the six senses of seeing hearing smelling touching tasting and monitoring the body s positions also called proprioception We will see that sensation is sometimes relatively direct in the sense that the wide variety of stimuli around us inform and guide our behaviors quickly and accurately but nevertheless is always the result of at least some interpretation We do not directly experience stimuli but rather we experience those stimuli as they are created by our senses Each sense accomplishes the basic process of transduction the conversion of stimuli detected by receptor cells to electrical impulses that are then transported to the brain in different but relaxed ways Each of your sense organs is a specialized system for detecting energy in the external environment and initiating neural messages action potentials to send information to the brain about the strength and other characteristics of the detected stimulus Each of the senses has a specific place in the brain where information from that particular sense is processed Very often the information from these sensespecific brain areas is then sent to other parts of the brain for further analysis and integration with information with other senses The result is your experience of a rich and constantly changing multisensory world full of sights sounds smells tastes and texture The brain s processing of sensory experience allows us to process and organize our experience of the outside world The perceptual system does more than pass on information to the brain Perception involves interpretation and even distortion of the sensory input Perceptual illusions discussed at the end of the unit allow scientists to explore the various ways that the brain goes beyond the information that it receives System Seeing Hearing Smelling Tasting Touching Proprioception System Seeing Hearing Smelling Tasting Touching Proprioception Sensation You detect motion off to the left out of the corner of eye A loud noise from behind startles you as you are about to cross the street A sharp strong odor gives you an unpleasant feeling on your noise A smooth sweet cold feeling on your tongue focuses your attention A tickling feeling on your leg makes you look down quickly Suddenly you feel like your feet are sliding out from under you and your body is pitching forward Perception That s my friend Cathy waving at me That car horn is coming from that Toyota that almost hit me Sensation You detect motion off to the left out of the corner of eye A loud noise from behind startles you as you are about to cross the street A sharp strong odor gives you an unpleasant feeling on your noise A smooth sweet cold feeling on your tongue focuses your attention A tickling feeling on your leg makes you look down quickly Suddenly you feel like your feet are sliding out from under you and your body is pitching forward Perception That s my friend Cathy waving at me That car horn is coming from that Toyota that almost hit me That smells like the spaghetti sauce on the stove is burning This triple chocolate truffle ice cream is even better than chocolate cherry ice cream It feels like a spider or an ant is crawling up my leg Im going to fall on my rear on the ice again if I don t hold onto my friend Jared That smells like the spaghetti sauce on the stove is burning This triple chocolate truffle ice cream is even better than chocolate cherry ice cream It feels like a spider or an ant is crawling up my leg Im going to fall on my rear on the ice again if I don t hold onto my friend Jared Did I get this Sensation and Perception Stimulation of the cells in the back of the eye by light energy photons is an example of sensation You are alone in your house at night and her a loud noise You check to see if someone is trying to break into the house Your response of checking for an intruder is based directly on you perception All of the senses are specialized to pick up information coming from the outside world False Which way of the two processes sensation or perception is more likely to be influenced by our beliefs and expectations Perception Transduction Creating Sensory Messages What senses are they Vision audition smell olfaction taste gustation touch balance What is transduction Transduction is the process of turning energy detected around us into nerve impulses A nerve impulse is called and action potential so the result of transduction is always an action along a nerve going to the brain All action potentials are the same At the neural level there is no difference between an action potential coming from the eye or the ear or any other sensory system What makes sensory experiences different from one another is based on which brain are interprets the incoming message Transduction Energy Initiates Action Potential Each of our senses is specialized to detect a certain kind of energy and then to send a message to the brain in the form of action potentials in nerves that run from the sense receptor to specific