031:014 Lecture 5 Outline of Last Lecture I. Applying the Scientific MethodII. Research questions based on 7 themesIII. Research MethodsOutline of Current Lecture  Movie NotesI. GastrulationII. Proteins Lecture NotesI. How do we build a baby?II. Prenatal Development ProcessIII. OverviewIV. Prenatal Environment: Sensory experience and behavior matters too!V. How do we know early experience matters?VI. Fetal LearningVII. Habituation & DishabituationCurrent Lecture Movie NotesI. In humans, gastrulation happens deep inside the mother’s uterine liningThese 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.a. The blastocyst creates two oblong bubbles, one on top of the otherb. Sandwiched between them are the cells that one day become a babyc. 3 layers of cellsi. Lower layer: lungs, liver, lining of digestive tractii. Middle layer: heart, muscles, bones, bloodiii. Top layer: nervous system, spinal cord, hair, braind. Embryo at 4.5 weeks of development: 1/5 of an inch longII. Proteins are the molecules that build your bodya. i.e. collagen a fiber that makes up tendons and bone & crystalline which helps make your eyes clear Lecture NotesI. How do we build a baby?a. The simplistic solution: genetic programb. The challenge: every cell has the same genetic material… how do you “know” what they are?c. The solution: the environment tells them…i. 3 layers of cells formii. Different locations of these layers causes different cell types to formiii. Cells communicate with their neighbors via chemical signals that turn genes on/offII. Prenatal developmental processesa. Critical: it’s not all about nature/genesb. The prenatal cellular environment matters just as much…c. Dramatic example: teratogensi. Environmental agents that cause damage during prenatal developmentii. Damage can be physical or psychologicaliii. Common teratogens: 1. Alcohola. Fetal alcohol syndrome:i. Mental retardationii. Poor attentioniii. Slow physical growthb. Fetal alcohol effects:i. Some but not all abnormalitiesc. Alcohol interferes with cell duplication, migration of neuraltube, deprives fetus of oxygen2. cigarette smokinga. low birth weightb. each cigarette per day during 3rd quarter lowers birth weight by 20gc. possible miscarriage or infant deathd. less attentive to sounds and more muscle tensione. nicotine: constricts blood vessels, reducing transfer of blood & other nutrients3. illegal drugsa. cocaine & heroine:i. prematurityii. low birth weightiii. physical defectsiv. breathing difficultiesv. often die near birth AND, addicted at birth so cryingand tough to care foriv. When are teratogens most damaging?1. During periods when critical physical structures are undergoing rapid development:a. Zygote (1-2 weeks): probably will dieb. Embryo (3-8 weeks): Major structural damagec. Fetus (3rd month on): More resilient but damage is most damaging to brainIII. Overview thus far…a. Summary 1: prenatal development is not just about genes & biologyi. Cellular environment matters just as muchb. However, must also consider that the fetus is an active, learning critterIV. Prenatal Environment: Sensory experience and behavior matters too!a. Touch: grasping, sucking, rubbing, bumping walls of uterusb. Taste: swallows amniotic fluid, fetus has a sweet toothc. Smell: i. amniotic fluid has odor of what mom ateii. During fetal breathing, amniotic fluid comes into contact with olfactory receptorsd. Sight: negligiblee. Hearing (from at least 6 mos. Gestation): i. internally generated sounds (mom’s heartbeat, breathing, etc.)ii. externally generated sounds (mom’s voice and people talking to her)iii. fetus reacts by changes in heartbeat and movementV. How do we know early experience matters?a. Gottlieb: Mallard ducks & imprinting studyi. Opened eggs and devocalized chicks1. When the devocalized chicks were born they did not prefer their mother’s call2. No longer had auditory preferenceii. Introduced visual stimuli1. Disrupt auditory learning later in life2. Developmental sequence of sensation and behavior is criticala. The sequence of how we’re getting sensory stimuli matters; has a big impact on what the developing organismbecomes and the abilities the developing organism learns about and createsb. Turkewitz:i. If premature infants get too much visual stimulation1. Damage visual system2. Disrupt early auditory learningVI. Fetal Learninga. Habituationi. Before Birth:1. Around 32 weeks the fetus shows signs of habituation (measured by changes in heartbeat)2. Around 27 weeks the fetus shows signs of long-term memory and learningii. After Birth:1. Hearing: recognizes mom’s voice2. Sell: prefers own amniotic fluid3. Taste: recognizes carrot juice exposed as a fetus, but not since birthVII. Habituation &