PSY2020 Human Development: Prenatal, Infancy and Brain Development PDF

PSY2020 Human Development across the Lifespan Lecture 2 Prenatal, Infancy & Brain development Ting-Yat Wong, PhD Date: 15-Jan-2024 | Time: 13:30-16:20 | Venue: D...

PSY2020 Human Development across the Lifespan Lecture 2 Prenatal, Infancy & Brain development Ting-Yat Wong, PhD Date: 15-Jan-2024 | Time: 13:30-16:20 | Venue: D4-G/F-04 Housekeeping 1. Group Presentation (Due: 12 March) Guideline for Movie Character Development Analysis (15 to 20-minute presentation + 2-minute Q&A) The objective of this group project is to analyze the development of a chosen movie character through the lens of developmental psychology. Each group (6 members) will analyze the development of a chosen movie character through the lens of developmental psychology theories and research findings. The analysis should focus on a key aspect of the character's psychological growth, shifts in behavior or thinking, and the role of external factors such as family dynamics, relationships, or societal pressures. This task requires integrating theoretical frameworks with empirical evidence to provide a comprehensive and nuanced understanding of the character's developmental journey. 2 Housekeeping 2. Individual Paper (Due: 9 April) Autobiographic Analysis Report You are required to write an autobiographical analysis report that demonstrates an in-depth understanding of psychological theories and concepts relevant to personal development. This assessment is designed to help you personalize your learning by connecting it to your life experiences. The report, limited to 1,200 words (excluding appendices and references), should summarize and reflect on your own developmental journey. In this assessment, you are expected to relate the knowledge gained from this course to your personal development experiences. Key: Reflect on your experiences and analyze how developmental theories and research findings can explain your developmental journey. 3 Question and Discussion Question: True (T) or False (F)? Babies who walk early are inclined to be False especially bright. The average 2-year-old is already about half of True his or her adult height. Half the nerve cells in the average baby’s brain True die over the first few years of life. Most children walk when they are ready, and no amount of encouragement will enable a True 6-month-old to walk alone. 4 An Overview of Maturation and Development Changes in Height and Weight Rapid increase in height and weight over first two years Growth is more gradual during middle childhood Puberty (early adolescence) there is another rapid growth spurt 5 An Overview of Maturation and Development Gain in height per year by males and females from birth through adolescence. At age 10 ½ , girls begin their growth spurt. Boys follow some 2 ½ years later and grow faster than girls once their growth begins. Question: What happen during age between 10 and 15? 6 An Overview of Maturation and Development Changes in Body Proportions Cephalocaudal: head downward growth ○ At birth, head and legs each represent 25% of body length ○ At adulthood, head is 12%, legs 50% Proximodistal: center outward growth ○ Internal organs followed by limbs ○ Trend reverses in puberty – hands and feet followed by limbs, then trunk 7 An Overview of Maturation and Development Proportions of the human body from the fetal period through adulthood. The head represents 50 percent of body length at 2 months after conception but only 12 to 13 percent of adult stature. In contrast, the legs constitute about 12 to 13 percent of the total length of a 2-month-old fetus, but 50% of the height of 8 a 25-year-old adult. Human Brain 9 Human Brain Facts The human brain weighs about 2% of the body but consumes roughly 20% of the body’s total energy (glucose and oxygen) The human brain contains approximately 86 billion neurons, each connected to around 7,000 other neurons that send between ten and 100 signals every second 10  Neuron Basic Unit of Brain Neuron Nerve cell Axons send electrical signals away from the central part of the neuron, across synaptic gaps, via chemical substances called neurotransmitters. Dendrites of different neurons receive the signals. Myelin sheath : Layer of fat cells that helps impulses travel faster along the axon Glia: nourish neurons and encase them in myelin; form throughout life 11 Myelinization The process by which axons are coated with a fatty substance called myelin Myelin sheaths act as electrical insulators, speeding up neural signal transmission Faster and more efficient neural communication Critical for cognitive, motor, and sensory functioning Disruptions in myelinization can lead to neurological disorders (e.g., multiple sclerosis) Timeline & Development Begins prenatally, continues through childhood and adolescence Different brain regions undergo myelinization at different rates (e.g., sensory and motor areas before higher-order regions) Key Notes Myelinization is vital for normal brain and behavioral development Early experiences (nutrition, stimulation) can influence myelin growth Understanding myelinization helps in diagnosing and treating myelin-related disorders 12  Neuron Brain Development during Pregnancy 13 The Development Brain of Dendritic Connectivity during Spreading Early Life further information: https://www.youtube.com/watch?v=cMim0uU1yzA 14 Neural Plasticity: The Role of Experience Reisen (1947; Science) – raising young chimpanzees in complete darkness Objective: Investigate the impact of sensory deprivation (lack of visual experience) on visual and cognitive development Method: Chimpanzees were reared without exposure to light during critical developmental stages Findings: Prolonged dark rearing led to permanent deficits in vision and perceptual abilities Normal visual function could not be fully restored, even with later exposure to light Beyond seven months, atrophy of retina and optic nerve was irreversible Significance: Demonstrated the crucial role of early visual stimulation in establishing and maintaining normal sensory and cognitive growth Riesen A. The development of visual perception in man and chimpanzee. Science, 106 (1947), pp. 107-108 15  FourStructure Brain lobes of the cortex Frontal lobes: Govern voluntary movement, thinking, personality, and intentionality or purpose Occipital lobes: Control vision Temporal lobes: Govern hearing, language illustration credit: processing, and memory https://courses.lumenlearning.com/waymaker-psych ology/chapter/reading-parts-of-the-brain/ Parietal lobes: Govern spatial location, attention, and motor control 16  FourStructure Brain lobes of the cortex gray matter and white matter were coined based on the visual appearance of brain tissue during dissection and early anatomical studies, long before MRI technology was developed Gray Matter: The part of the brain composed primarily of neuronal cell bodies, dendrites, and synapses Function: ○ Processes information ○ Controls muscle movements and sensory perception (e.g., seeing, hearing, memory, emotions, decision-making) Color: Grayish due to the lack of myelin White Matter: Composed of myelinated axons that connect different regions of gray matter Function: ○ Facilitates communication between different brain areas. ○ Enables the fast transmission of signals across the brain and spinal cord Color: White due to the myelin sheath covering the axons 17 Brain Development Across Lifespan Bethlehem, et al., 2022, Nature 18 Learning the World Sensation Perception Sensation: the detection of sensory stimulation Perception: the interpretation of sensory input Sensation is the physical stimulation of the sense organs, and perception is the mental process of sorting out, interpreting, analyzing, and integrating stimuli from the sense organs and brain. 19 Sensation 20 Visual Acuity during Infancy Visual acuity refers to the clarity or sharpness of vision, i.e., the ability to perceive fine detail Detect changes in brightness Least mature sense Early visual acuity shapes how infants perceive and interact with their environment Recognizing developmental milestones helps caregivers and professionals identify potential vision issues early 21 Visual Acuity during Infancy Visual Acuity Narrowest stripes newborn can see Narrowest black and white stripes 30 times wider than adults. detected Development If difference detected, longer looking – Birth: 1/10 inch (2.54mm) wide 1 at stripes foot (30.48cm) away – 2 months: 1/2 of the width seen at birth (see above) – 4 months: 1/4 of the width seen at birth (see above) – 8 months: 1/8 of the width seen Preferential Looking at birth (see above) – 4-5 years: Adult-like (i.e., 1/30 of the width seen at birth) 22 Color Perception during Infancy The ability to distinguish and categorize different wavelengths of light as distinct colors Newborns: Limited color discrimination, mostly sensitive to high-contrast patterns (e.g., black and white) First 2–3 Months: Rapid improvements—infants begin to distinguish between red, green, blue, and yellow 3-4 months: Adult-like 23 Color Perception during Infancy Skelton, A.E., Franklin, A. Infants look longer at colours that Infants often show a preference for bright, saturated colors adults like when colours are highly saturated. Psychon Bull Rev 27, 78–85 (2020). 24 over pastels https://doi.org/10.3758/s13423-019-01688-5 Depth Perception during Infancy Infancy Development in use of 3 classes of cues Kinetic Cues (from birth) Infants are sensitive to motion-based depth cues—things like looming (where an object grows larger as it approaches) Binocular Cues (around 3–4 months) Infants develop stereopsis around this time, integrating slightly different images from each eye to perceive depth. Monocular (Pictorial) Cues (around 6–7 months) Infants begin using cues like linear perspective, interposition, and texture gradients to judge depth from static images 25 Depth Perception during Infancy Infancy Kinetic Cues: arise from movement—either movement of objects in the environment or the infant’s own motion sensitive to kinetic cues from birth play a foundational role in early spatial awareness and depth perception Examples: Looming: An object appears to get larger as it approaches, signaling that it’s moving closer Motion Parallax: Objects closer to you move across your field of vision faster than distant objects 26 Depth Perception during Infancy Infancy Binocular cues – Convergence: Eyes rotate inward to focus on closer objects. – Binocular disparity slight differences in the images between the two eyes different retinal images of an object in each eye different signals being sent to the brain distance computed based on binocular disparity 27 Depth Perception during Infancy Infancy Monocular (Pictorial) Cues Depth cues that can be perceived with one eye. They rely on pictorial or static information in the visual field Helps infants interpret depth from two-dimensional images Complements binocular and kinetic cues for comprehensive depth Common Types: Linear Perspective: Parallel lines appear to converge with distance. Interposition (Occlusion): Objects that block others are perceived as closer. Relative Size: Larger objects are perceived as closer than smaller ones, given similar actual sizes. Texture Gradient: Denser or more tightly packed texture signals greater distance. Shading and Lighting: Changes in light and shadow can indicate depth and contours 28 Depth Perception during Infancy Infancy Visual Cliff Experiments (Gibson & Walk, 1960) Investigate depth perception in infants A table covered with a sturdy piece of transparent glass or plexiglass One side appears “shallow,” the other “deep,” creating the illusion of a cliff Procedure: Infants are placed on the “shallow” side of the platform A caregiver or researcher calls the infant from the “deep” side Observers watch to see if the infant will crawl over the “deep” area 29 Depth Perception during Infancy Infancy Visual cliff (Campos et al. 1970): – Two groups: 15 infants in each group Experienced crawlers (9 months) Beginning crawlers (7 months) Results – Experienced crawlers: 15/15 cross shallow, 0/15 cross deep – Beginning crawlers: 15/15 cross shallow, 10/15 cross deep! – 7-month-olds: Perceive depth, but don’t fear height! 30 Perception Infancy of Patterns and Forms during Infancy Infants show an early preference for high-contrast patterns (e.g., black-and-white stripes) Face-like stimuli often capture infants’ attention more than abstract patterns Early Pattern Perception (0 to 2 Months) ○ Prefer high contrast patterns ○ Prefer moderately complex patterns ○ Prefer patterns that move Later Form Perception (2 months – 1 year) ○ More sensitive to movement ○ Begin to perceive objects as whole forms ○ Use subjective contours ○ Results from interaction between visual sense, biological maturation, and learning 31 Perception Infancy of Patterns and Forms during Infancy Fantz’s test (1961) of young infants’ pattern preferences Infants preferred to look at complex stimuli (A+B) rather than at a simpler black-and-white oval (C) the infants did not prefer the facelike figure (C) to the scrambled face (B) 32 Perception Infancy of Patterns and Forms during Infancy What patterns look like to the young eye. By the time these two checkerboards are processed by eyes with poor vision, only the checkerboard on the left may have any pattern left to it Poor vision in early infancy helps to explain a preference for moderately complex rather than highly complex stimuli 33 Hearing Infancy during Infancy Hearing is relatively well-developed at birth Plays a crucial role in language acquisition and social interaction Prenatal Sensitivity: Fetuses can respond to sounds in the womb (from around the third trimester) Newborn Sensitivity: Can distinguish loudness, pitch, and duration of sounds. Show a startle (Moro) reflex to sudden, loud noises Discriminate sounds based on loudness, duration, direction, and frequency Prefer mother’s voice to other women At 3–6 months, sensitive to phonemes, even better than adults (if sounds are not part of the adult’s spoken language) Recognize words they hear often Hearing loss can adversely affect development (often due to ear infections) 34 Smell And Taste during Infancy Infancy 35 35 Smell And Taste during Infancy Infancy 36 36 Smell And Taste during Infancy Both senses are well-developed at birth ○ Infants can distinguish between different odors and tastes shortly after birth Preferences Smell: Newborns show preference for the smell of their own mother’s breast milk over that of other mothers. Avoid unpleasant odors Taste: Infants generally prefer sweet tastes and can discriminate sweet, sour, bitter, and salty flavors 37 37 Touch during Infancy Touch is one of the earliest senses to develop (even before birth) Newborns respond to various tactile stimuli (e.g., light touch, pain) Skin-to-skin contact promotes caregiver-infant bonding. Releases hormones (e.g., oxytocin) that help regulate infant stress and foster emotional connection Gentle touch and massage can help calm infants, promote better sleep, and support healthy growth Even newborns can detect changes in warmth or cold Through touch, infants learn about their bodies and surroundings, fostering cognitive and motor development. 38 38 Intermodal Infancy Perception during Infancy Intermodal perception: ability to recognize by one sensory modality that which is familiar through another Are the Senses Integrated at Birth? – Yes: reaching for objects that are seen – Yes: looking in the direction of sounds – Yes: expecting to see source of sound, or to feel objects that were reached for 39 Intermodal Infancy Perception during Infancy Auditory-visual perception: How infants integrate visual information (e.g., facial movements) with auditory information (e.g., speech sounds) Spelke & Owsley (1979): ○ Do infants know what sights and sounds go together? ○ 3.5 months and older ○ observed looking time or gaze preference to see if infants looked longer at the face that matched the heard sound ○ Even by 3.5 months, infants look more at the face whose mouth movements match the speech sounds they hear 40 Intermodal Infancy Perception during Infancy Kuhl & Meltzoff (1982) 4-month-olds Infants were shown videos of people mouthing different vowel sounds, while a single vowel sound was played over a speaker See silent videos of a woman saying “a” vs. “e”; hear “a” or “e” Infants tended to look longer at the face whose lip movements matched the vowel sound they heard, indicating an early ability to integrate what they see (lip shape/movement) with what they hear (speech sounds) infants can match mouth movements to speech sounds 41 Intermodal Infancy Perception during Infancy Development: – 1-month-olds – weak oral-to-visual perception – 4 months – intermodal matching between vision and hearing – 4–6 months – match tactile and visual sensations 42 Intersensory Infancy Redundancy Hypothesis (IRH) 1. Amodal Properties – Features can be detectable by multiple senses (e.g., tempo, rhythm, intensity, duration) – Intersensory redundancy highlights these amodal properties by presenting them in multiple modalities at once, making them more salient to infants 2. Enhanced Learning in Redundant Conditions – When information is presented redundantly across two or more senses (e.g., a rattle’s sound rhythm matches its visual movement), infants are better able to: Detect and learn about the amodal aspects (like the tempo of the shake) Form stronger perceptual and memory traces because the information is reinforced via multiple channels 3. Selective Attention – IRH suggests that infants allocate greater attention to amodal properties when they are redundantly specified in multiple modalities, compared to when that same information is presented through just one sense – Early in development, infants are especially sensitive to these redundant cues, which guide their attention toward the most important and consistent features of the environment Bahrick LE, Lickliter R. Intersensory redundancy guides early perceptual and cognitive development. Adv Child Dev Behav. 2002;30:153-87. doi: 43 10.1016/s0065-2407(02)80041-6. PMID: 12402674. Cultural Influences On Infant Perception Language – become sensitive to sounds important to specific language – English versus Chinese and “r” and “l” – Japanese: r vs l – Korean: f vs p Music – familiar with own culture’s music – Western major/minor versus Javanese scale Growth of perceptual skills includes adding new skills and losing unnecessary ones Culture determines which sensory inputs are distinctive and how to interpret those inputs 44 Reflexes in Infancy involuntary, automatic responses to specific stimuli serve critical functions that support an infant’s immediate survival and longer-term development Grasp reflex 45 45 Reflexes in Infancy 1. Feeding and Nutritional Intake Rooting Reflex: When a baby’s cheek is gently stroked, they turn their head and open their mouth. This helps them find a breast or bottle, aiding in feeding Sucking Reflex: Touching the roof of an infant’s mouth triggers rhythmic sucking motions. This ensures that a baby can take in milk and receive necessary nutrients 2. Protection from Harm Moro (Startle) Reflex: In response to a sudden noise or sensation of falling, a baby will fling their arms out and then bring them back in. It’s believed this reflex once helped infants cling to their caregivers or brace themselves for impact. Blink Reflex: Infants (like adults) blink if something approaches the eyes quickly. This helps protect the eyes from foreign objects or sudden bright light. 46 46 Reflexes in Infancy 3. Establishing Early Movement Stepping Reflex: When held upright with feet touching a surface, a baby appears to “take steps.” Although they can’t walk yet, this reflex marks an early rehearsal of the movements necessary for walking later. Palmar Grasp Reflex: An infant’s fingers wrap tightly around anything placed in their palm. Over time, this reflex transitions into more controlled, voluntary grabbing that’s crucial for exploring objects and self-feeding. 4. Communication of Needs Crying Reflex: Though not always categorized in the same way as “newborn reflexes,” crying is a built-in response to discomfort or hunger. It ensures that infants can quickly alert caregivers when something is wrong. 47 47 Basic Learning Processes In Infancy Infancy Learning is generally understood as a relatively permanent change in knowledge, behavior, or capacity that results from experience or practice – Change in behavior that Produces a new way to think about, perceive, or react to the environment Is the result of experience Is relatively permanent This process involves encoding new experiences, storing them in memory, and being able to recall or apply that knowledge to adapt to new challenges or environments. 48 Basic Learning Processes In Infancy “Anything gets boring with repetition…” “Hey, look, this is different!” 3- and 4-month-olds! 49 49 Basic Learning Processes In Infancy Key processes researchers use to study infant cognition and learning Habituation: Decreased response to a repeated stimulus over time ○ Decrease in looking time Dishabituation: Renewed response when a stimulus changes or when a new stimulus is introduced ○ Renewed interest or increased looking time 50 50 Basic Learning Processes In Infancy Infancy Developmental Trends in Dishabituation – Possible before birth – 4 months – may take long exposure – 5–12 months – need a few seconds – 10–14 months – habituate to objects and relationships between objects Individual Differences in Habituation – Some habituate slowly and forget rapidly – Rapid habituation between 6–8 months Better language skills in second year: processing sensory information more efficiently Higher IQ later in childhood: may be related to processing speed 51 Basic Learning Processes In Infancy Infancy Pavlov’s classical conditioning Before Classical Conditioning – Unconditioned stimulus (UCS) Saliva elicits an unconditioned response (UCR) No Saliva – Neutral conditioned stimulus During Classical Conditioning (CS) paired with (UCS) – Eventually CS elicits a Saliva conditioned response (CR) After Classical Conditioning Saliva 52 Basic Learning Processes In Infancy Infancy Skinner’s operant conditioning Specific consequences are associated with a voluntary behavior Designed Skinner box to test learned behavior Put hungry rat in box with lever that would release food Rat would soon learn to press lever to get food. Behavior Positive reinforcement Negative reinforcement The behavior is more likely The behavior is less likely to to be repeated be repeated 53 Basic Learning Processes In Infancy Infancy 54 Basic Learning Processes In Infancy Infancy Can Infants Remember What They Have Learned? When ribbons are attached to their ankles, 2- to 3-month-old infants soon learn to make a mobile move by kicking their legs. But do they remember how to make the mobile move when tested days or weeks after the original learning? These are the questions that Rovee-Collier has explored in her fascinating research on infant memory. 55 Basic Learning Processes In Infancy Infancy Can Infants Remember What They Have Learned? 2- to 3-month-old infants and to run a ribbon from the mobile to the infant’s ankle Within a matter of minutes, these young participants discovered that they could make the mobile move by kicking their legs 2-month-old infants remembered how to make the mobile move for up to 3 days after the original learning whereas 3-month-olds recalled this kicking response for more than a week. 56 Basic Learning Processes In Infancy Infancy Observational Learning Attend to a model and form a symbolic representation of model’s behavior (encoding) ○ Newborn imitation – possible at 7 days old, if part of behavioral repertoire ○ Imitation of novel responses – reliable between 8 and 12 months old ○ Immediate imitation at first, deferred imitation later 57 Basic Learning Processes In Infancy Infancy Albert Bandura believes that we learn a great deal through imitation by observing models and mentally coding what we see Reciprocal interactions among three factors: ○ Personal factor ○ Behavioral factor ○ Environmental factor Person Behavior Environment 58 Basic Learning Processes In Infancy Infancy Observational Learning 14–26 months old Emulation is possible – observational learning without a model 59 Basic Learning Processes In Infancy Infancy 60 Basic Learning Processes In Infancy Infancy Bobo Doll Experiment 61 Basic Learning Processes In Infancy Infancy Bobo Doll Experiment Bandura wanted to prove that behavior such as aggression is learned through observing and imitating others People who view aggression in society (consciously or unconsciously) think that the behavior is acceptable for them to imitate Design and procedure: observation, two groups Group A: Watched an adult hitting doll with a mallet Group B: Watched an adult play nicely with the doll After witnessing the adult's behavior, the children would then be placed in a room without the model and were observed to see if they would imitate the behaviors they had witnessed earlier 62 Basic Learning Processes In Infancy Infancy Bobo Doll Experiment Results – Children exposed to the violet model tended to imitate the exact behavior they had observed when the adult was no longer present – The researchers were also correct in their prediction that boys would behave more aggressively than girls. Boys engaged in more than twice as many acts of aggression than the girls Conclusion – the experiment demonstrates how specific behaviors can be learned through observation and imitation – "social imitation may hasten or short-cut the acquisition of new behaviors without the necessity of reinforcing successive approximations as suggested by Skinner." 63 Online Materials Facts on Infant Hearing Loss - https://www.ndaap.com/hearing.html ○ Maintained by the North Dakota chapter of the American Academy of Pediatrics, this website provides a comprehensive review of infant auditory development and the causes of infant hearing loss. National Sudden and Unexpected Infant/Child Infant & Pregnancy Loss - https://www.sidscenter.org/ ○ The National Sudden and Unexpected Infant/Child Death Resource Center (Resource Center) serves as a central source of information on sudden infant death and on promoting healthy outcomes for infants from the prenatal period through the first year of life and beyond. Newborn Senses - https://www.chop.edu/pages/newborn-senses ○ This site presents an overview of infant sensory capabilities and suggestions for simple activities for testing. 64 64