PSYC 304 part 2.pdf

Making Sense of Visual Input PSYC 304 Sonia Krol, PhD September 16th, 2024 1 Outline for Today Review of visual development Making sense of visual input intermodal perception categorization Motor development...

Making Sense of Visual Input PSYC 304 Sonia Krol, PhD September 16th, 2024 1 Outline for Today Review of visual development Making sense of visual input intermodal perception categorization Motor development 2 Which paradigm is this? 3 Where would you expect the baby to look longer? ⓘ Start presenting to display the poll results on this slide. 4 Quiz: Which paradigm is this? Show this picture many times Test 5 How will the infant likely behave? ⓘ Start presenting to display the poll results on this slide. 6 Back to Familiarity vs. Novelty Infants prefer to look at stimuli that are: More complex, more saturated in colour Familiar Natural familiarity: Stimuli infants experience often in their lives Lab-induced: Familiarize infant to a new stimulus by first exposing them to it for a brief amount of time Will then show a preference for the familiar stimulus when paired with a new stimulus 7 Lab-Induced Familiarity Familiarization: Infant shown this picture once or twice briefly Test: Infant will look longer at the stimulus that they’ve been familiarized to 8 Familiarity vs. Novelty in the Lab In lab settings, length of exposure time to an initial stimulus determines whether an infant will show a familiarity or novelty preference: Short exposure = familiarity preference Long/ repeated exposure = novelty preference 9 Making sense of visual input Humans create meaning out of their perceptions in 2 ways Intermodal perception Categorization 10 Intermodal Perception 11 Intermodal Perception The coordinated perception of a singular object or event through 2 or more sensory systems Often vision and at least one other sensory modality Intermodal perception is present very early on 12 Combining Vision and Touch Study: Can newborns integrate vision and touch? Familiarization: Infants sucked on a pacifier that they couldn’t see Preferential-looking procedure: Picture of the pacifier they had sucked on vs. picture of a pacifier of a different shape and texture Results: Newborns looked longer at the pacifier that they had sucked on i.e., looked at familiar pacifier Shows that ability to combine visual information with touch is present from birth 13 Kaye et al., 1994 Combining Vision and Auditory Info Study: Can infants combine vision with sound? Preferential looking procedure: 4-month olds simultaneously watched two videos side-by-side Video of someone playing peekaboo vs. video of someone playing drums At the same time, heard audio of person saying “peekaboo” i.e., audio is synchronized with only one video “peekaboo!” 14 Spelke et al., 1976 Combining Vision and Auditory Info Results: looked longer at the person playing peekaboo vs. person playing drums Shows that infants can integrate visual and auditory information Important for language development because children need to understand that speech sounds are linked with a moving mouth 15 Spelke et al., 1976 Categorization 16 17 Categorization in Infancy Habituation: Test: 18 Categorization in Infancy Categorization begins in infancy Study: Showed 3 month olds various pictures of cats Habituated to the general category of cat Looked at novel cat photos less and less Dog Test: photo of a dog Results: Infants looked longer at the dog Cat Suggests that infants saw all the cats as a single category and the dog as a different category 19 Quinn et al., 1996 Categorization in Infancy Infants also form more general categories than “cat” Study: Habituation: 6 month olds habituated to photos of mammals Then, on test trial, looked longer at non-mammals (i.e., bird or fish) Shows that infants had formed category of mammal by recognizing similarities between mammals 20 Behl-Chadha et al., 1996 Perceptual Categorization Infants group things together that are similar in appearance, focus on similarities in shape Study: Experimenter picked up target object and demonstrated that it rattles Infants were more likely to assume that an object of a similar shape also rattles vs. objects similar in colour or texture 21 Graham & Diesendruck, 2010 Pitfalls of Perceptual Categorization Focus on similarities in shape results in: Difficulties understanding exceptions E.g. Failure to categorize a snail as an animal because doesn’t have legs Mistakenly categorizing objects together E.g. Categorizing birds and planes together based on both having wings 22 Graham & Diesendruck, 2010 Conceptual Categorization Around 9-month-olds, children begin categorizing objects based on their shared function or behaviour But still mostly categorize based on perceptual similarities 9-month-olds divide objects into 3 broad categories: People Animals Inanimate Objects 23 Conceptual Categorization 9-month-olds distinguish between people, animals, and inanimate objects: Indexed by different reactions to members of each of these categories E.g., in lab settings, 9 month olds pay more attention to animals than inanimate objects, but smile less at animals than they do at people 24 Importance of Categorization Helps makes sense of the world by simplifying it Allows children to make inferences and predictions about objects of the same category E.g., If a child learns that a giraffe is an animal, knows that it breathes, moves, eats 25 Object Categorization Beyond Infancy By 2-3 years of age, children start to form category hierarchies Category hierarchies: organize object categories by set-subset relations Allow for finer distinctions among objects within each level Superordinate level Basic level Subordinate level 26 Category Hierarchies Children usually learn basic level first Objects at the basic level have obvious similarities 27  Subordinate level: Basic level: Maple Superordinate level: Plant Tree Subordinate level: Oak 28 Category Hierarchies Children usually learn basic level first Objects at the basic level have obvious similarities Similarities at superordinate level are less obvious and differences between subordinate levels are hard to detect 29 Summary of Intermodal Perception and Categorization Intermodal perception allows infants to integrate information from multiple sensory modalities. Auditory-visual information is particularly important for language learning Categorization enables children to make inferences about members of the same category Infants shift from categorizing objects based on perceptual features, especially shape, to categorizing based on conceptual features Conceptual categorization enables the formation of category hierarchies Children learn basic categories before they learn superordinate and subordinate categories 30  Motor Development PSYC 304 Sonia Krol, PhD September 16th, 2024 31 Outline Motor milestones Mechanisms behind motor development How motor development enables learning in other domains 32 Motor Milestones 33 Reflexes Innate, involuntary actions that occur in response to a particular stimulation Reflexes are adaptive Grasping Rooting Sucking Stepping 34 Reflexes Function of some is unclear E.g. tonic neck reflex: when an infant’s head is turned to the side, their arm on that side extends and the arm and knee on the other side flex 35 Reflexes Most reflexes disappear by 2 months of age Some don’t like coughing, sneezing, blinking, withdrawing from pain Absent reflexes or reflexes that persist for too long can mean the infant has neurological problems 36 Motor Milestones in Infancy Major motor developmental tasks of a period Happen in sequence, rarely out of order Huge individual variation in the ages these milestones are achieved 37 Motor Milestones in Infancy 38 What about crawling? 7 - 8 months of age: babies begin crawling 39 Different Crawling Styles 40 What about crawling? 7 – 8 months of age: babies begin crawling Crawling is not considered a motor milestone Many healthy babies never crawl and skip right to walking Why do some babies skip crawling? Upper body or core weakness Hypersensitive to the texture of the floor Insufficient opportunity 41 Motor Milestones in Infancy 42 Cultural Differences in Motor Development Average ages of milestones are based on WEIRD samples, but most infants in the world are not Only 15% of the world’s population is WEIRD Cultural practices lead to individual differences in when motor milestones are achieved 43 Example 1: Culture and Sitting 44 Example 1: Culture and Sitting Huge cross-cultural differences in how long 5-month-olds can sit independently 45 Karaski et al., 2015 Example 1: Culture and Sitting Huge cross-cultural differences in how long 5-month-olds can sit independently Why? Related to where infants’ are placed to sit 46 Karaski et al., 2015 Example 1: Culture and Sitting Little postural support Ground Adult furniture Lots of postural support Child furniture Being held by adult 47 Karaski et al., 2015 Example 1: Culture and Sitting Huge cross-cultural differences in how long 5-month-olds can sit independently Why? Related to where infants’ are placed to sit Earlier independent sitting in countries where infants spent more time in places with less postural support (e.g., ground) Later independent sitting in countries where infants spent more time in places with lots of postural support (e.g., child furniture or being held) 48 Karaski et al., 2015 Example 1: Culture and Sitting How much time an infant spends in places with less postural supports impacts when they’ll be able to sit independently 49 Karaski et al., 2015 Example 2: Culture and Encouragement of Motor Skills Motor milestones are affected by how many opportunities infants have to practice and how much motor development is actively encouraged E.g., in some countries, some infants are actively discouraged from crawling because of safety or hygiene concerns so crawl later or never crawl e.g., urban China E.g., motor exercises in sub-Saharan Africa Infants are more advanced in motor skill development than kids in North America 50 Motor Exercises 51 Example 3: Culture, Diapers and Walking Diapers affect infant walking Infants show more mature walking when naked vs. when wearing a diaper All infants were used to wearing a diaper Diapers may contribute to cross- cultural differences in walking 52 Cole et al., 2012 Implications of Cultural Differences Context plays an important role in motor development Differences in the course of motor development reflect the contexts in which infants are developing 53 Mechanisms Behind Motor Development 54 Mechanisms Behind Motor Development Motor development is governed by complex interplay between numerous factors: Brain maturation Increases in physical strength Physical abilities, like posture control and balance Perceptual skills Change in body proportions and weight Motivation All these factors contribute to individual differences in motor development 55 The Role of Weight Changes Infants are born with stepping reflex that disappears at 2 months but then start stepping again between 7-12 months of age when learning to walk Why does stepping reflex disappear? Hypothesis: Infants gain weight faster than they build leg muscles and thus have insufficient strength to lift heavier legs 56 Thelen et al., 1984 The Role of Weight Changes Evidence: Infants who no longer show stepping reflex resumed stepping when placed in a tank of water buoyancy of water supported weight Shows that disappearance of stepping reflex is due to weight change and not just cortical maturation 57 Thelen et al., 1984 The Role of Motivation Infants are highly, intrinsically motivated to explore and learn: Persistence despite failing Continue to practice new skills even though they possess skills that are more efficient that could accomplish the same goal e.g., practice walking even though they know how to crawl Look delighted when practicing new skills 58 The Role of Motivation 59 The Role of Motivation Individual differences in motivation predict when motor milestones are achieved Study: Compared low and high motivation infants on when they achieved motor milestones Low motivation infants: movements occur infrequently, prefer activities that require little energy, require lots of stimulation to change position High motivation infants: move often, prefer high energy activity, change position often, do not need clear stimulation to move 60 Atun-Einy et al., 2013 The Role of Motivation Highly motivated infants achieved all motor milestones earlier than less motivated infants 61 Atun-Einy et al., 2013 Summary of Motor Development So Far… Infants are born with reflexes, many of which disappear by 2 months Motor milestones are achieved in a predictable sequence Lots of individual differences due to numerous complex factors E.g., culture, weight gain, motivation, etc. 62 Implications of Motor Individual Differences Level of motor skills at 5 months predicted: Intelligence at 4 and 10 years old Academic achievement at 14 years old Findings controlled for parent’s intelligence, supportive caregiving, and quality of home environment Suggests that motor development influences cognitive development 63 Bornstein et al., 2013 Developmental Cascades from Motor Development 64 Motor Development is Critical for Learning Enables active learning about the world Allows children to learn by trial and error Facilitates development of skills in other domains 65 Reaching 7 months: able to sit independently and to reach for objects Has consequences for visual and social development 66 Reaching and 3D Object Perception Reaching enables object exploration which in turn fosters an understanding that objects are 3D 67 Reaching and 3D Object Perception Study: Habituation paradigm with 4-7.5 month olds Assessed sitting and reaching ability Habituation: Presented with rotating object with only 2 sides visible Does the infant perceive this shape as a complete 3D object? Test: Presented with rotating complete shape beside a rotating hollow shape 68 Soska et al., 2010 Reaching and 3D Object Perception Test shapes presented beside each other If infant saw shape as a complete 3D object, should look longer at incomplete display because novel 69 Soska et al., 2010 Reaching and 3D Object Perception Results: Infants that were more advanced in sitting and reaching were more likely to look at the incomplete display Suggests that motor skills development in sitting and reaching fosters 3D object perception 70 Soska et al., 2010 Reaching and Social Development Study: When watching a video of a person placing objects in a bucket, adults and 12-month-olds showed proactive gaze towards the bucket Indicates that they understand the person’s intention 6-month olds did not Have not yet developed the skilled object reaching and manipulation Shows that infants’ ability to predict others’ actions relies on them being able to perform these same actions 71 Falck-Ytter et al., 2006 Reaching and Language Development Skilled object reaching and manipulation enables: Greater interaction with caregivers Infants are more likely to reach for an object in the presence of a caregiver vs. alone Vocabulary growth Greater More vocabulary Reaching interaction with growth caregivers 72 Slone et al., 2019 Self-Locomotion 8 months: most infants begin moving around on their own (self- locomotion) by crawling Has consequences for visual and social development 73 Expansion of the Visual World 74 Integration of Self-Locomotion and Perception As infants develop self-locomotion, learn to integrate perception with action Study: Infants placed in front of walkways with either shallow or steep slopes and encouraged to crawl across Can babies tell the difference between slopes? 75 Adolph & Robinson, 2013 Integration of Self-Locomotion and Perception Results: Perception of slope depended on crawling experience Beginner crawlers (about 8 months) attempted to crawl down both shallow and steep slopes Experienced crawlers avoided steep slopes When these same babies started walking, they made the same mistake as with crawling Initially went down slopes that were too steep Failed to transfer what they had learned about slopes through crawling to walking Suggests that infants have to learn how to integrate perceptual information with each new motor skill developed 76 Adolph & Robinson, 2013 But sometimes infants make mistakes… 77 But sometimes infants make mistakes… Scale errors: attempt to perform an action on a miniature object that is impossible due to the huge difference in size between the child and the object Present until around 2 years of age Due to difficulty integrating visual information with action 78 Self-Locomotion and Language Development Walking enables: infants to carry objects to their caregivers increased interactions with caregivers and more sophisticated interactions with them vocabulary growth Greater More vocabulary Walking interaction with growth caregivers 79 Summary of Motor Development Infants are born with reflexes, many of which disappear by 2 months Motor milestones are achieved in a predictable sequence Lots of individual differences due to numerous complex factors E.g., culture, weight gain, motivation, etc. Early motor skills predict cognitive skill in later childhood Infant motor development facilitates development in other domains, including perception, social interactions, and language 80