Psyx 100is 1st Edition Lectures 10Current Lecture- Sensationo Experience associated with sound, light ,etc. and the initial steps by which the sense organs and neural pathways take in stimulus info Ex. Cells in retina of eye respond to light that hits them- Perceptiono The organizations of the info brought in by sensation and its meaningful interpretation  Ex. Person is consciously aware if seeing words on an overhead screen- 4 steps of pereceptiono Physical Stimulus  Physiological Response Sensory Experience Perceptual Experienceo Physical Stimulus is the matter or energy that contract our sense organso Physiological Response is a pattern of electrical activity that occurs in sense organs as a s result of a physical stimuluso Sensory Experience is a subjective sensation of sight sound tough etc- How many senses are there?o In elementary we learned 5…. Taste, touch, smell, sight,& hearingo We really have about 10-15 Some more pain, temp, balance, state of internal organs, etc.- Receptor Cellso A specialized cell that responds to physical stimulus by producing electrical changes hat can iniciate neural impulses- Transductiono Process in which a receptor cell produces a response to a physical Stimulus- Sensory Neuronso Carry neural impulses from receptor cells to the CNS- Receptor Potentialo An electrical change caused by transduction- Codingo The action potentials sent to the brain carry info aout the strength and type of stimulus- Qualatative Infoo The type or kind of energy or matter presentThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.o Determind by which neurons are firing- Quantitative Infoo o - Sensory Adaptationo A change in sensitivity Less results in more More results in less- Ex. Light adaptation & Sound Adaptation- Lincoln Park Concert and trip to White Castleo Loudness of Lincoln Park concert is loud and causes you to yell in order to hear yourself order your sliders from White Castle. Audition- sensory of hearing- Frequencyo Perceived Pitcho Low frequencies(bottom)o High Frequencies (top)o Measured in Hertz or Khertzso 20,000 Hz = 20 KHz- Amplitude o Corresponds to perceivedloudnesso Volume - Soundo A physical stimuluso Vibration of air caused by some object(vocal cords, speaker, & etc)- How the Ear Workso Sound Travels through the auditory canal & makes the tympanic membrane vibrateo The ear drum makes the hammer, anvil, & stirrup vibrateo Stirrup makes the oval window vibrate which makes the fluid in the cochlea vibrateo Fluid in the Cochlea triggers movement of sensitive hairs in the cochleao This finally triggers an electrical potential and a message is sent to the brain- Deafness o Conduction Deafness Hammer, Anvil, & Stirrup become rigid and can hear with a hearing aido Sensorineural Deafness Problem between the stirrup and the brain and hearing aids don’t help- Audition Continuedo How do we perceive loudness? More hairs move = Louder soundo How we perceive pitch?  Lower frequency of the sound, the farther along the basilar membrane Works above 4 kHz Below 4 kHz the timing of bursts of action potentials corresponds to the frequency of the sound & codes for pitch- Visiono Light Amplitude think intensity Wavelength(frequency) perceived colors- 400-700 nm is visible (below)- Parts of the eyeo Corneaclear tissue t focus lighto Iris opaque film that keeps out light and changes size to affect pupil sizeo Pupil hole in the Iriso Lensbehind the pupil, focuses light, & is adjustable over timeo Retina membrane in rear interior of the eye that contains millions of receptor cells - Sensationo Rods Black and white Works in dim light All over the retina 120 million High Sensitivityo Cones Color Works in bright light Most in foreva 6 million High acuity Low sensitivity- Photochemicalo When hit by light they cause an electrical change across the cell membrane Receptor Potential^(Rp)o Rp leads to Ap in other cells - Why do we see the colors we see?o Subtractive color mixing Different substances absorb different wavelengths of light Sunlight isn’t smooth across the spectrumo Additive color mixing Occurs when mixing lights and not pigments 3 primary laws- Using different intensities of 3 wavelengths of light one can create every color imaginable Law of complementary- For any color, you find another such that 2 put together will yield white light- Color Visiono Trichromatic theory Cells in retina have 3 pigments that absorb different wavelengths of light- Short 425 nm- Medium 525 nm- Long 560 nmLecture 12- Visiono Trichromatic theory is correct 3 types of cones Each cone has 3 types of pigments Not everyone has 3 types of coneso Color blindness When people only have 2 types of pigments Long or medium wavelengths don’t exist You can be color blind without even knowing it Genetic( on the X chromosome)- More common in men- Opponent –Process Theoryo Blue-Yellow Opponent Cells Excited by blue and inhibited by yellow or vice versao Red-Green Opponent Cells Excited by red and inhibited by green or vice versao Why? Law of complementary- 2 colors in additive make white light Complementary or afterimage - Trichromatic theory is correcto 3 types of pigments are in the cones of the retina- Opponent-Process Theory is correcto Opponent Cells are ganglion cell in the retina- Color Visono Question So we have color vision all figured out right?o Answer Wrong o The brain does some interesting things to the signals it gets from the retina- Visono Color & brightness constancy are not accounted for by either tri-C or tri-P theorieso Retinex Theory Cortex compares info from various parts of the retina to determine color and brightness- If a constant amount of yellow throughout the visual field then that amount of yellow is perceptually subtracted to yield the true colors of the objects- Perceptiono Getting meaning out of your sensationso 2 types of processes Top-Down Processes- When we use pre-existing knowledge to interpret sensory information Bottom-Up Processes- Help integrate sensory information into a percept using stimulus information but not prior