Answers to Concept Checks

• 4.1
  1. The three steps in the information processing model are encoding, storage, and retrieval.
  2. The elderly man most likely has delirium. The time course is incompatible with the slow decline of dementia.
     
     

  3. Stage	Key Features
     Sensorimotor	Focuses on manipulating environment for physical needs; circular reactions; ends with object permanence
     Preoperational	Symbolic thinking, egocentrism, and centration
     Concrete operational	Understands conservation and the feelings of others; can manipulate concrete objects logically
     Formal operational	Can think abstractly and problem solve

• 4.2
  1. Functional fixedness
  2. Algorithm
  3. Belief perseverance
  4. The availability heuristic is used for making decisions based on how easily similar instances can be imagined. The representativeness heuristic is used for making decisions based on how much a particular item or situation fits a given prototype or stereotype.
• 4.3

  1. Stage	EEG Waves	Features
     Awake	Beta and alpha	Able to perceive, process, access information, and express that information verbally
     Stage 1	Theta	Light sleep and dozing
     Stage 2	Theta	Sleep spindles and K complexes
     Stage 3	Delta	Slow-wave sleep; dreams; declarative memory consolidation; sleep-wake disorders occur in this stage
     Stage 4	Delta	Slow-wave sleep; dreams; declarative memory consolidation; sleep-wake disorders occur in this stage
     REM	Mostly beta	Appears awake physiologically; dreams; procedural memory consolidation; body is paralyzed

  2. The two hormones most associated with maintaining circadian rhythms are melatonin and cortisol.
  3. Dyssomnias are disorders in which the duration or timing of sleep is disturbed. Examples include insomnia, narcolepsy, and sleep apnea. Parasomnias are disorders in which abnormal behaviors occur during sleep. Examples include night terrors and sleepwalking (somnambulism).
• 4.4
  1. Drugs known to increase GABA activity in the brain include alcohol, barbiturates, benzodiazepines, and marijuana.
  2. Drugs known to increase dopamine, norepinephrine, and serotonin activity in the brain include amphetamines, cocaine, and ecstasy (MDMA). Ecstasy is a designer amphetamine; it is mentioned separately here because of its hallucinogenic properties.
  3. The three main structures in the mesolimbic reward pathway are the nucleus accumbens, medial forebrain bundle, and ventral tegmental area. The neurotransmitter of this pathway is dopamine.
• 4.5
  1. Controlled (effortful) processing is used when maintaining undivided attention on a task, and is usually used for new or complex actions. Automatic processing is used for less critical stimuli in divided attention, and is usually used for familiar or repetitive actions.
  2. The filter in selective attention permits us to focus on one set of stimuli while scanning other stimuli in the background for important information (such as our name or a significant change in the environment).
• 4.6

  1. Age	Milestone(s)
     9 to 12 months	Babbling
     12 to 18 months	Increase of about one word per month
     18 to 20 months	“Explosion of language” and combining words (two-word sentences)
     2 to 3 years	Longer sentences of three or more words
     5 years	Language rules largely mastered

  2. The primary trigger in the nativist theory is an innate ability to pick up language via the language acquisition device. In the learning theory, it is operant conditioning with reinforcement by parents and caregivers. In the social interactionist theory, it is a desire to communicate and act socially.
  3. Broca’s aphasia is marked by difficulty producing language, with hesitancy and great difficulty coming up with words. Wernicke’s aphasia is fluent, but includes nonsensical sounds and words devoid of meaning; language comprehension is lost. Conduction aphasia is marked by difficulty repeating speech, with intact speech production and comprehension.