PSYCH 2410 1st EditionExam # 2 Study Guide Lectures: 9 - 13Lecture 9 - Sensation vs. perception – be able to define and recognize eacho Sensation is the processing of basic information from the world through sense organs (eyes, ears, skin, etc.), the actual energy coming ino Perception is the process of organizing and interpreting sensory information into something meaningful- Visual perception o Know what acuity is and how it is tested in infants, and when they reach adult acuity levels  Acuity is the ability to see fine detail. Preferential looking is used to test infants’ visual acuity, among other things Infants have very poor acuity at first, but by 8 months, their acuity is as sharp as adultso Contrast sensitivity – know how they test for it, know why it is poor early on  Contrast sensitivity is when babies, especially in the first few months of life, can see things best only if they are very high contrast It is poor early on due to the size, shape, and spacing of cones (light sensitive neurons) in the eye. Babies catch only 2% of the light hitting the eye compared to 65% in adults.o Know early limitations, contrast sensitivity, color vision, scanning patterns (i.e., where they look in a complex shape Limitations in the early months (0-3 months):- Preference for high contrast patterns—contrast sensitivity- Very poor color vision in the first montho Prefer red and blue colors, which they still prefer as adults- Relatively poor visual scanningo Short, jerky movementso Have trouble tracking moving objectso Scanning is restricted to the high contrast areas, such as the border/edge of faces and eyes o Pattern perception  Face perception in newborns – know experiment and main finding by Johnson- Babies spend most of their time looking at faces, which suggests that we are born prepared to find the pattern of a face—this is evolutionary, because we rely on other people (faces) for survival- Preferences for certain faces: 12 hours after birth, prefer Mom’s face- No initial preferences for particular facial expressions, but by 9-12 months, infants prefer smiling over angry - Infants like attractive faces: prefer faces that are judged by adults as highly attractiveo Perceptual constancy and size constancy – understand phenomena Perceptual constancy phenomenon is objects appear to maintain shape and size despite constant changes in retinal image (objects moving closer or farther away) Infants have size constancy by 1 month o Object segregation – know cues and which is most important  Possible cues to tell where one object begins and another ends include:- Color- Shape- Texture- Gaps- MOTION  most importanto Common motion is if things move together, they are likely part of the same object Know Kellman & Spelke experiment with rods and main finding- First, infants were presented with a display, which adults perceive as a single rod moving back and forth behind a block of wood- Then, infants were shown two different test displays: a long single rod and two shorter rods- The infants looked longer at the two rod segments because they expected to see a single rod behind the block, and seeing two rod segments was new Lecture 10- Development of depth perception, dependent on self-locomotion o To navigate through our environment, we need to know where we are with respect to the objects and landmarks around us—dependent on self-locomotiono Optical expansion—a depth cue emerging very early on in which an object occludes increasingly more of its background, indicating that the object is approachingo Binocular disparity—another depth cue emerging early on, which is the difference between the retinal image of an object in each eye that results in two slightly different signals being sent to the brain. The closer the object we are looking at, the greater the disparity between the two images, and vice versa.o Stereopsis—the process by which the visual cortex combines the differing neural signals caused by binocular disparity, resulting in the perception of depth Emerges suddenly at around 4 months of age and is complete within a few weeks, due to the maturation of the visual cortexo Monocular/Pictorial cues—the perceptual cues of depth (such as relative size and interposition) that can be perceived by one eye alone Emerges around 6 or 7 months of age- Intermodal perception – know definitiono Intermodal perception is integrating input from two or more sensory systems (modalities) Babies are born with thiso Visual to auditory, touch to vision – know experimental findings  Auditory to visual: speech sounds and lip movements- You match what you’re hearing with what you’re seeing Tactual to visual: touch and sight- An object should feel what it looks like- Motor developmento Perception guides motor action – know evidence showing this with reaching (where cues to objects segregation guide infants reaches to center of object) Reaching takes perception into account Babies tend to reach to the middle of objectso Crawling and walking – know rough ages these abilities appear  Crawling: between ages of 7 and 10 months Walking: 11-12 monthso Knowledge about safety of surfaces, gaps NOT transferred from crawling to walking  Self-locomotion: things learned while crawling are not generalized to walking The mechanism behind the learning seems to be guided by the perceptual information at each stage The way we decide if something is risky or safe is by how it looks—to babies, the world looks different from a sitting posture, crawling posture, and walking posture. They have to re-learn what is risky and what is not at each stage.- Rule = Comprehension precedes production, understand difference between these and evidence for ruleo Language comprehension is understanding what others sayo Language production is the actual speaking/signing (manually producing language)o Kids can understand the meaning of words before they can say them At 4.5 months, babies can recognize their own name At 6 months, babies look at “mommy” or “daddy” At 12-14 months, babies attend longer to a normal word order vs. a scrambled word order Before talking, babies use pre-speech gesturing- Generativity – know what this term means o An infinite number of sentences and ideas can be expressed through language- Components of language – know what they are and be able to