Is the sound of 30 dB 30 times greater than the threshold of hearing, or 103 (a thousand) times greater?
2-18-16 Cochlea: Hair Cells Outer hair cells Inner hair cells Scars How Do We Code the Pitch of Sound Place Theory: hair cells @ a particular place on basilar membrane respond most to a particular frequency of sound -best describes how we hear HIGH frequencies -the higher the frequency of sound, the higher up -can’t easily explain why we hear LOW frequency Frequency matching theory: firing rate of an auditory nerve matches a sound wave’s frequency -BEST describes how we hear LOW frequency Other Senses/ Perceptual Organization: Olfactory Bulb Receptor Cells Olfactory Bulb Olfactory Area Vomeronasal Organ Tongue Olfaction (smell) -the only sense that does not send its messages through the thalamus -Axons from neurons in the nose have a synapse in the olfactory bulb -Connections from olfactory bulb are especially plentiful in the amygdala Gustation (taste) -taste receptors are concentrated on the tongue (papillae) -Receptors can only discriminate 5 sensations (sweet – sour –salty –bitter – umama(close to salty, but not quite salty) (meso soup at chinese rest.) (fresh chicken)) Perception: -How do we perceive different objects in the environment -aking raw sensation & adding meaning from our knowledge, & experience of the world. Ex: (which line is longer) (but both really the same) Perceptual Organization: -How do we differentiate an object from its background -Figure-Ground organization -Grouping Figure-Ground Figure: -part of visual field that has meaning Ground: -visual field w/ less meaning Edges Determine: -the figure/ground border Perceptual Grouping: Gestalt Laws of Organization: -….the whole is greater than the sum…because we add meaning. -What properties of stimuli cause us to group them together, into an object Gestalt Laws: -Law of Proximity-things that are close together (in close proximity) will be grouped together/perceived as one group -Law of Similarity-things that look similar will be grouped together/assume they belong together --Law of Continuity-things that are smoothly/continuous with each other will be perceived as similar objects -Law of Closure: Law of Common Region Law of Connectedness Depth Perception -How do we perceive a 3-D world from a 2-D image (the projection on our retina). -Depth cues! Monocular Depth Cues (One Eye) -Interposition (occlusion) -Relative Size -Height in the Visual Field -extural Gradient -Linear Perspective -Reduced Clarity -Light & Shadow Binocular Depth Cues (2 eyes) : Accommodation -Information about the muscle activity involved in accommodation serves as one cue -Convergence-A Depth cue resulting from rotation of the eyes so that the image can be projected on each retina -Binocular Disparity: A depth cue based on the difference b/t the retinal images received by each eye Motion Perception: -optical flow -the constantly changing image on the retina -when in motion -Patterns of optical flow -Looming-rapid expansion in the size of an image so that it fills the retina -Stroboscopic Motion-tendency to perceive movement when a series of still images appear, one at a time, in rapid succession Perceptual Constancy -The perception of objects as constant in size, shape, brightness, etc . . .even when the retina image changes Color Constancy -perceiving familiar objects as having consistent color even when changing illumination filters the light reflected by the object.