5 - Prenatal influences Flashcards
Average gestational length
38.5 weeks but there is much variation
Rate of neuron growth
250k neurons/minute in fetal brain. 2.5k synapses per neuron at birth; 15k/neuron at 2 yrs
Period with most rapid brain growth
Just prior and just after birth
Growth spurts in brain regions early in development
Newborn: motor cortex (reflexive to voluntary). 2-3: frontal motor cortex and visual/auditory cortex. 8 months: motor (crawl). 12 months: motor cortex (stand and walk)
Growth spurts in brain later in development
18-24 months: frontal/temporal (language). 5-7 yrs: prefrontal (executive like planning, control). Adolescence: Limbic/paralimbic (amygdala for emotional regulation and processing)
Biological preparedness for social interaction
Newborns ready to force you to care and engage with them
Circadian rhythm development
Emerges in around 30 weeks. Results from integration of inhibitory and excitatory mechanisms (thalamus and cortex connect). Ultradian <24 hours at first.
Sleeping of babies
Newborns wake very often for food - especially human milk because easily digestible. Usually can sleep thru night by 3.5-5 months.
Vagal Tone Development
Activity of the vagus nerve (parasympathetic cranial nerve that regulates resting state). Develops around 33-35 weeks. Higher tone means baby can slow down heart rate; more variability in time between heartbeats. Associated with improved social and emotional regulation.
Mother-infant synchrony
Mother and infant respond to each other appropriately and with predictable degree of responsiveness. Degree of sleep-wake cycle and vagal tone maturity predict mother-infant synchrony at 3 months.
Tactile development
8 weeks cheeks are sensitive. Every part of body sensitive to hairstroke by 32 WGA. Fetuses in early stages touch upper face and heads; later the touch lower faces and mouth. By 36 weeks open mouths before touching them - anticipation.
Kangaroo Care of Preemies
Good for premature infants to get skin-to-skin contact - more autonomic functioning, mother attachment, cognitive development, better stress response.
Auditory Development
At around 27 weeks the auditory cortex rapidly organizes, becomes fully developed. Questionable what sounds can be heard by fetus - probably low-pitch sounds and rhythm of speech. Evidence of learning native language tone, familiar melodies, fragments of stories, mother’s voice. Measure these things via sucking, heart rate, ERP.
Olfactory and gustatory development
Newborns with strong preference for sweet. Grimace when sour and bitter, with motor restlessness and sucking disruption. Intermediate results for sale. Prefer amniotic fluid odor, maternal milk odor (learned perhaps thru skin contact. Learn preferences for odors - chamomile while feeding.
Vision development
Newborns can focus on objects up to 10 inches away. 3 months develop hand-eye coordination, track moving objects, reach. 8 months improved control of eye movements, depth perception, color vision.
