The Brain and the Senses

1. The Brain and the Senses Psychology

2. The Power of the Brain • Human brain has 10 billion neurons (30,000 can fit in the head of a pin) • Each neuron has 1000-10,000 connections with other neurons; up to 10 trillion possible • Messages between them travel in one thousandth of a second • Average brain weighs 3-4 lbs. and consumes 20% of the body’s oxygen supply and 20% of the blood flow • Almost fully developed by age 11, except for the frontal lobe which develops through your early 20’s

3. Brain Facts • Brain produces 25 watts of power while you’re awake; enough to illuminate a light bulb • At age 35, humans start losing 7000 brain cells a day • Alcohol and drugs also kill brain cells and weakens connections between neurons • Stress over long periods will weaken the brain’s ability to learn and remember • Same part of the brain interprets physical and emotional pain • Your brain is more active at night than during the day

4. Brain Facts • People who ride on roller coasters have a higher chance of having a blood clot in the brain. • An adult bottle-nosed dolphin’s brain is about the size of a human adult’s brain. • A living brain is so soft you could cut it with a butter knife. • There is no sense of pain within the brain itself. This allows neurosurgeons to probe areas of the brain while the patient is awake.

5. How do your senses effect your behavior? • What do you do when you smell something good or bad? • When you taste something good? • When you touch something hot or cold? • When you see something beautiful? Something scary? Something funny? • http://www.youtube.com/watch?v=CeQnwnAVLeQ&safe=active • http://www.youtube.com/watch?v=SGR2BKvEUwk&safe=active • http://www.youtube.com/watch?v=XYz3sl0LEA4&safe=active • Have you ever listened to something that gave you chills or brought you to tears? • http://www.youtube.com/watch?v=86lczf7Bou8&safe=active • http://www.youtube.com/watch?v=e8-sMJZTYf0&safe=active • http://www.youtube.com/watch?v=CS9OO0S5w2k&safe=active • http://www.youtube.com/watch?v=d-diB65scQU&safe=active

6. Our senses are the way we perceive the world • What we perceive depends on the relay of information between the major sensory systems and the central nervous system (CNS) • Information is processed by our senses, interpreted, and acted upon • Senses should work together in an integrated and coordinated way = sensory integration • Allows for smooth development of complex motor skills, learning and proper behavior

7. The Seven Senses • Five main senses: sight, taste, touch, hearing, smell • Exteroception • Less detectable: • Vestibular system: Related to sense of balance, spatial orientation and movement • Proprioception: Sense of orientation of limbs and effort necessary for motion • Interoception: Detection of pain, hunger, heat, time, bladder, etc.

8. Senses developed in utero (vestibular first) • Vulnerable and subject to damage through stress or illness during pregnancy or infancy • Issues associated with learning disabilities, coordination problems, and behavioral/emotional difficulties • Sensory Integration Disorder: causes depression, social anxiety, etc.

9. Visual Perception • Lens focuses on an image, transmits to light-sensitive membrane at the back called retina • Retina: part of the brain that translates patterns of light into neuronal signals, causes neural impulses

10. Sight • http://www.youtube.com/watch?v=PmHHVaYbNmY&feature=related • The McGurk Effect • http://www.youtube.com/watch?v=G-lN8vWm3m0

11. Auditory Perception • Vibrations detected by ear drum; simplifies air pressure waves into a single of amplitude • Inner ear detects distribution of vibrations with hair cells in basilar membrane • Converts vibrations into pattern of nerve-firings on the auditory nerve which transmits sounds to brainstem

12. Hearing • Music has strong effects on emotion and is associated with memories • Voice recognition begins in the womb • http://www.youtube.com/watch?v=rRepnhXq33s&safe=active

13. Olfaction: Sense of Smell • Humans can distinguish over 10,000 different odor molecules • When you inhale, the air hits millions of cilia (little hairs) containing olfactory receptor neurons • The shape of the inhaled molecules is identified and turned into electrical signals sent to the brain

14. The Power of Smells • Scent can effect purchasing decisions, perception of a person or place, your generosity, and political leanings • Example: Clean smells tend to make people more honest and fair in their interactions as well as generous • Properly themed smells for a product or place create a positive image and memory • Animals use pheromones to select mates • http://www.youtube.com/watch?v=W48DoLdR8gA

15. Tactition: Touch • Somatosensory system reacts to stimuli using different receptors on the skin, bones, organs, muscles, joints and cardiovascular system • Integration of senses/receptors including those for pain, temperature, bodily orientation, etc. • Information passes via sensory nerves through the spinal cord to the parietal lobe and cerebral cortex

17. Touch and Behavior • Feeling “warmth” in the sense of closeness is closely tied to actual heat: talking with someone over a warm cup of coffee increases sense of closeness and caring • Sitting in a soft chair makes you more relaxed and “soft” in negotiations, like at a car dealership • Holding a wooden block vs. a soft blanket effects your perception of a social interaction • Physical sensory comfort level effects mood, emotions and behavior

18. Gustation: Taste • Substance reacts chemically with receptors in the 10,000 taste buds on the human tongue, cheeks, and throat • Taste works together with senses of smell, temperature, texture and pain to determine flavors • Sweet, sour, bitter, salty and savory determined by interactions with molecules and ions • Taste senses what is harmful and beneficial (aversive or appetitive)

19. Taste • Three categories of tasters: supertasters (25%), medium tasters(50%), and non-tasters (25%), depending on density of taste buds • Supertasters are drawn to salt and sensitive to bitterness • Very picky eaters are often supertasters while very non-picky eaters might be non-tasters

20. Synesthesia • Disorder where one sensory input is involuntarily linked to another: hear colors, see sounds as shapes, etc. • http://www.youtube.com/watch?v=FTr1VnXKr4A • The artist Kandinsky: painting symphonies