5Reflexes Reflexes occur quickly after onset of stimuli. They involve a single or specific group of muscles (not the whole body).They resist habituation (at any one time).Persistence may indicate neurological problems.
6Purpose of Reflexes Built-in responses facilitate survival. They enable open dialogue with the environment.Reflexive movements result in sensory consequences (adaptation).Reflexes provide building blocks for future movement.
7Asymmetrical Tonic Neck Reflex Infant starts in supine position.Stimulus: turn head to one side.Response: same-side arm and leg extend.
8Symmetrical Tonic Neck Reflex Infant starts in supported sitting.Stimulus: extend head and neck or flex head and neck.Response: arms extend and legs flex, or arms flex and legs extend.
9Palmar Grasp Reflex Stimulus: touch palm with finger or object. Response: hand closes tightly around object.
10Moro Reflex Infant starts in supine position. Stimulus: shake head (e.g., by tapping pillow).Response: arms, legs, and fingers extend; then arms and legs flex.
11Stepping Reflex Stimulus: place soles of feet on flat surface. Response: walking pattern of legs.
12More Reflexes Sucking reflex Stimulus: touch face above or below the lips.Response: sucking motion begins.Babinski reflexStimulus: stroke sole of foot from heel to toe.Response: toes extend.
13Constraints What constraints exist during the reflexive period? StructuralFunctionalEnvironmental physicalEnvironmental socioculturalTask: goals, rules, equipmentClick to add notes
14Later Infancy Gain voluntary control of movements Understanding of environment, objects in the environmentMeaningful interactions with othersPostural reactions
15Postural Reactions Begin at around 4 months Help to maintain posture in a changing environmentInitially, similar to reflexes; later, incorporated into general repertoire
16Labyrinthine Righting Reflex Infant is supported upright.Stimulus: tilt infant.Response: head moves to stay upright.
17More Postural Reactions Derotative rightingInfant starts in supine position.Stimulus: turn head to one side, or turn legs and pelvis to other side.Response: body follows head in rotation, or trunk and head follow in rotation.ParachuteInfant held upright.Stimulus: lower infant toward ground rapidly.Response: legs and arms extend.
18Motor Milestones Fundamental motor skills Building blocksCumulative, sequentialLead to future complex motor skillsSpecific movements that lead to general actions
19Locomotor and Posture Motor Milestones: An Example Emily at 2 months(continued)
20Locomotor and Posture Motor Milestones (continued) 2 months: lifts head in prone3 months: lifts shoulders (turns head)(continued)
21Locomotor and Posture Motor Milestones (continued) 5 months: rolls over; sits unsupported(continued)
22Locomotor and Posture Motor Milestones (continued) 7 months: gets on hands and knees8 months: creeps on hands and knees(continued)
23Locomotor and Posture Motor Milestones (continued) 9 months:pulls to stand; cruises furnitureClick to add notes(continued)
24Locomotor and Posture Motor Milestones (continued) 10 months: stands alone12 months: walks alone
25Rate Limiters, or Controllers Individual constraints that inhibit or slow the attainment of a motor skillRapidly changing during early childhood periods