Taste, Smell, Touch

Agenda 1. Finish Vision (5) 2. Notes: Other Senses (20) 3. Taste Experiment, do you need smell or sight? (15 minutes) 4. Touch Localization (10 minutes) 5. Brain Books, Twitter analysis

Taste or Gustation taste cells are chemical sensitive receptors 1. TASTE BUDS - located on the tongue, throat, and soft palate 2. stimulus must be dissolved before it can be tasted

Taste Traditionally, taste sensations consisted of SWEET, SALTY, SOUR, and BITTER tastes. Recently, receptors for a fifth taste have been discovered called “UMAMI”. OBJECTIVE 19| Describe the sense of taste, and explain the principle of sensory interaction. Sweet Sour Salty Bitter Umami (Fresh Chicken)

bitter sour sour salt salt sweet

Other influences on taste: 1. SMELL 2. TOUCH 3. TEMPERATURE When one sense affects another sense, sensory interaction takes place. So, the taste of strawberry interacts with its smell and its texture on the tongue to produce flavor.

What did you notice? Discuss with your partner what you noticed? Did you guess the correct flavor? How does sensory interaction effect taste?

Smell or olfaction Olfactory epithelium are where receptors for smell are located 1. located in your upper nasal cavity 2. cells in this membrane are stimulated by GASES dissolved in the fluid covering the membrane 3. stimulus must first be dissolved before it can be smelled

Smell Like taste, smell is a chemical sense. Odorants enter the nasal cavity to stimulate 5 million receptors to sense smell. Unlike taste, there are many different forms of smell. OBJECTIVE 20| Describe the sense of smell and explain why specific odors so easily trigger memories.

Age, Gender, and Smell Ability to identify smell peaks during early adulthood, but steadily declines after that. Women are better at detecting odors than men.

Smell and Memories The brain region for smell (in red) is closely connected with the brain regions involved with memory (LIMBIC SYSTEM, specifically the HIPPOCAMPUS). That is why strong memories are made through the sense of smell.

Touch Skin senses The sense of touch is a mix of four sensations: COLD, WARMTH, PRESSURE, and PAIN. Body’s most sensitive area is the HEAD region in the area of the NOSE-UPPER LIP. WOMEN are more sensitive than MEN.

Skin Senses Only PRESSURE has identifiable receptors. All other skin sensations are VARIATIONS of pressure, warmth, cold and pain. Pressure Vibration Vibration Burning hot Cold, warmth and pain

Pain PAIN THRESHOLD is the level of stimulation at which pain is first perceived. Pain tells the body that something has gone wrong. Usually pain results from damage to the SKIN and other TISSUES. A rare disease exists in which the afflicted person feels NO PAIN. OBJECTIVE 18| State the purpose of pain, and describe the biopsychosocial perspective on pain.

Ashley Blocker (right) feels neither pain nor extreme hot or cold.

Gate-Control Theory Melzak and Wall (1965, 1983) proposed that our SPINAL CORD contains neurological “GATES” that either BLOCK pain or ALLOW it to be sensed. One way to treat chronic pain is to stimulate it through massage by electrical stimulation or acupuncture. Rubbing causes competitive stimulation to pain thus reduces its effect.

Pain Control Pain can be controlled by a number of therapies including: Drugs, surgery, acupuncture, exercise, hypnosis, and even thought distraction. Burn victims can be distracted by allowing them to engage in illusory virtual reality. Their brain scans show differences in pain perceptions.

Body Position and Movement The sense of our body parts’ position and movement is called kinesthesis. The vestibular sense monitors the head (and body’s) position. OBJECTIVE 21| Distinguish between kinesthesis and vestibular sense.

Experiment Extend your arms straight out to the sides. With your eyes closed, quickly bring your index fingers together. Now do the same things lowly. Was one easier than the other?

Light waves Rods & cones in retina optic auditory Sound waves Taste Sense Stimulus Receptor Nerves Part of Brain Sensation/ Perception   Vision _________ nerve Brightness, color, notion, patterns, figures, faces Hearing ____________ nerve Noise, tones, language, music Taste Glossopharyngeal nerve Tastes (sweet, sour, salty, bitter, umami) Smell _____________ nerve Odors (flowery, musky, foods, etc) Skin senses ___________ nerves from skin, facial nerve Touch, warmth, cold, pain, comfort contact Light waves Rods & cones in retina optic Thalamus, visual cortex of occipital lobe auditory Thalamus, Auditory cortex of temporal lobe Sound waves Hair cells on the basilar membrane Medulla, thalamus, somato- sensory cortex in parietal lobe chemicals Taste buds Hair cells on the olfactory epithelium chemicals Olfactory bulb olfactory Nerve endings in skin Thalamus, Somato- sensory cortex External contact Sensory

Olfactory bulb Thalamus, Somato- sensory cortex Vision Hearing Taste Sense Stimulus Receptor Nerves Part of Brain Sensation/ Perception   Vision _________ nerve Brightness, color, notion, patterns, figures, faces Hearing ____________ nerve Noise, tones, language, music Taste Glossopharyngeal nerve Tastes (sweet, sour, salty, bitter, umami) Smell _____________ nerve Odors (flowery, musky, foods, etc) Skin senses ___________ nerves from skin, facial nerve Touch, warmth, cold, pain, comfort contact Olfactory bulb Thalamus, Somato- sensory cortex