When a person's brain perceives a threat, the cortex sends a signal to the part of the brain responsible for activating the stress response known as the

Sleep researchers want to use brain scans to study the brain area thought to be responsible for producing melatonin; they focus on the time of day when it is at peak production. They consult experts to ask for information on the brain area,

as well as the peak times for melatonin production. What information did the experts share with the sleep researchers? a) cerebellum in the afternoon b) pineal gland two hours before bedtime c) hypothalamus in the early evening d) corpus callosum at midnight

Children normally begin to say their first word and make connections between words and objects at about __________ months

a. six b. 12 c. 18 d. 24