| A | B |
|---|
| norm | An average, or standard, measurement, calculated from the measurements of many individuals within a specific group or population. |
| head-sparing | A biological mechanism that protects the brain when malnutrition disrupts body growth. The brain is the last part of the body to be damaged by malnutrition. |
| neuron | One of billions of nerve cells in the central nervous system, especially in the brain. |
| cortex | The outer layers of the brain in humans and other mamals. Most thinking, feeling, and sensing involve the cortex. |
| axon | A fiber that extends from a neuron and transmits electrochemical impulses from that neuron to the dendrites of other neurons. |
| dendrite | A fiber that extends from a neuron and receives electrochemical impulses transmitted from other neurons via their axons. |
| synapse | The intersection between the axon of one neuron and the dendrites of other neurons. |
| neurotransmitter | A brain chemical that carries information from the axon of a sending neuron to the dendrites of a receiving neuron. |
| prefrontal cortex | the area of the cortex at the front of the brain that specializes in anticipation, planning, and impulse control. |
| shaken baby syndrome | A life-threatening injury that occurs when an infant is forcefully shaken back and forth, a motion that ruptures blood vessels in the brain and breaks neural connections. |
| REM (rapid eye movement) sleep | A stage of sleep characterized by flickering eyes behind closed lids, dreaming, and rapid brain waves. |
| reflex | An unlearned, involuntary action or movement emitted in response to a particular stimulus. A reflex is an automatic response that is built into the nervous system and occurs without conscious thought. |
| gross motor skills | Physical abilities involving large body movements, such as walking and jumping. |
| fine motor skills | Physical abilities involving small body movements, especially of the hands and fingers, such as drawing and picking up a coin. |
| sensation | The response of a sensory system (eyes, ears, skin, tongue, nose) when it detects a stimulus. |
| perception | The mental processing of sensory information when the brain interprets a sensation. |
| binocular vision | The ability to focus the two eyes in a coordinated manner in order to see one image. |
| immunization | A process that stimulates the body's immune system to defend against attack by a particular contagious disease. |
| sudden infant death syndrome (SIDS) | A situation in which a seemingly healthy infant, at least 2 months of age, suddenly stops breathing and dies unexpectedly while asleep. |
| sensorimotor intelligence | Piaget's term for the way infants think--by using their senses and motor skills--during the first period of cognitive development. |
| assimilation | Piagets term for a type of adaptation in which new experiences are interpreted to fit into, or assimilate with, old ideas. |
| accommodation | Piaget's term for a type of adaptation in which old ideas are restructured to include, or accommodate, new experiences. |
| object permanence | The realization that objects (including people) still exist when they can no longer be seen, touched, or heard. |
| "little scientest" | The stage-five toddler (age 12 to 18 months) who experiments without anticipating the results, using trial and error in active and creative exploration. |
| information-processing theory | A perspective that compares human thinking processes, by analogy, to computer analysis of data, including sensory input, connections, stored memories, and output. |
| visual cliff | An experimental apparatus that gives an illusion of a sudden dropoff between one horizontal surface and another |
| reminder session | A perceptual experience that is intended to help a person recollect an idea, a thing, or an experience, without testing whether the person remembers it at the moment. |
| child-directed speech | The high-pitched, simplified, and repetitive way adults speak to infants. (Also called baby talk or motherese.) |
| babbling | The extended repetition of certain syllables, such as ba-ba-ba, that begins when babies are between 6 and 9 months old. |
| naming explosion | A sudden increase in an infant's vocabulary, especially in the number of nouns, that begins at about 18 months of age. |
| holophrase | A single word that is used to express a complete, meaningul thought. |
| language acquisition device (LAD) | Chomsky's term for a hypothesized mental structure that enables humans to learn language, including the basic aspects of grammar, vocabulary, and intonation. |
| co-sleep | A custom in which parents and their children (usually infants) sleep together in the same bed. (Also called bed-sharing.) |
