Object permanence is understanding that objects exist even when hidden. Piaget studied infants' reactions to covered objects. Infants develop object permanence by end of sensorimotor stage. Six stages: reflex schema (0-1 months), primary circular reactions (1-4 months). A-not-B errors occur when infants reach for objects in unexpected locations
Central sulcus separates parietal and frontal lobes in vertebrate brains. Divides primary motor and somatosensory cortices. Forms "hand knob" (KNOB) region in central sulcus
Primitive reflexes are present in infants but not neurologically intact adults. These reflexes are suppressed by frontal lobe development during childhood. Reflexes may reappear in adults with neurological conditions
REM sleep is characterized by rapid eye movements and low muscle tone. Occurs 4 times in 7-hour sleep cycle, lasting about 90 minutes. Core body and brain temperatures increase, skin temperature decreases. Brain acts as if awake with high activity during REM
Baby drops lower into pelvis, causing increased pelvic pressure. Frequent urination and swollen legs are common symptoms. Tingling and numbness in hands may indicate carpal tunnel syndrome. Back pain and pigmentation changes are common. Stretch marks may appear on skin
Forbes Health reviewed 11 free pregnancy tracking apps for iOS and Android. Flo Pregnancy Tracker offers fetal development milestones and health reports. Apps include fetal development photos, community features and symptom tracking