PSY 1001 1nd Edition Lecture 11 Outline of Last Lecture I How do we experience sensory input a Sensation b Perception c Transduction d Sensory Adaptation e Psychophysics II Vision a Light b Sensory Organ Eye c Color perception d Basic Visual Pathways Outline of Current Lecture I Gnostic cell II When we can t see III Perception a Bottom up Top down processing b Perceptual Hypotheses c Motion Perception d Depth Perception IV Audition Hearing a Sensory organ Ear Cochlea b Frequency perception Current Lecture I II Gnostic cell a Neurons like groups of features which describe an object b Each cell absorbs information about one part of an object they then all come together so you can identify an object When we can t see a Blindness results in heightened touch reorganization of visual cortex b Blindsight above chance visual performance of cortically blind individuals with damage to area V1 cortex brain damaged c Visual agnosia object recognition deficit damage to higher visual cortical areas i Very specific things you can t identify These 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 III IV ii With touch can identify it Perception a Bottom up Top down processing i After being transduced our brains then organize the sensory data into meaningful concepts ii Our brains piece together what s in our sensory field what was there a moment ago and what we remember from the past iii Perception of a sensory experience can change even though the input remains the same iv Bottom up vs top down processing perception depends on sensory data and beliefs expectations b Perceptual hypotheses i Perceptual sets occur when our expectations influence our perceptions ii Perceptual constancy allows us to perceive stimuli consistency across conditions iii We don t see the size shape or color of an object changing despite the objective fact that they do iv Gestalt Principles 1 Rules that govern how we perceive objects as wholes within their overall context 2 The whole is more than the sum of its parts 3 Example a square is more than 4 lines 4 We use a variety of principles to help us organize the world proximity similarity continuity closure symmetry and figureground c Motion perception i To determine motion the brain compares visual frames of what is to what was ii Motion blindness inability to perceive seamless motion d Depth perception i Monocular depth cues rely on one eye 1 Relative size texture gradient interposition linear perspective height in plane light and shadow ii Binocular depth cues require both eyes 1 Binocular disparity and binocular convergence iii When perception deceives us 1 We often misperceive information around us and understanding why provides insight into how we make sense of our surroundings 2 Illusions Take home a There are a lot of brain areas devoted to visual processing b Our perception may be more or less what we see V c A lot of what we perceive is biased by our experience Audition Hearing a Sensory Organ Ear Cochlea i Audition our sense of hearing is the sense we rely on most after sight ii Sound is simply vibration traveling through a medium usually air and has 1 Pitch wave frequency Hz 2 Loudness amplitude of the sound waves dB 3 Timbre complexity of sound a Ex Different notes playing the same pitch iii Anatomy of ear 1 Pinna outer each channels sound into ear canal 2 Ear canal conducts sound waves to ear drum 3 Eardrum vibrates in response to sound waves 4 Cochlea converts vibration into neural activity a Transduction occurs in inner hair cell b Frequency perception i Place theory different tones excite different areas of the basilar membrane cochlea and primary auditory cortex 1 Explain perception of high pitched tone 5000 Hz to 20000 Hz ii Frequency theory 20 100 Hz and volley theory 100 5000 Hz neurons rate of firing reproduces the frequency of the sound 1 Explains perception of low and middle pitches iii Cochlear implant put electrode wires up spiral put a auditory sensory outside of ear takes place of hair cells