Understanding Psychology (10th Ed)

optic nerve

 
A bundle of ganglion axons that 
carry visual information to the brain (Module 11).

oral stage

 
According to Freud, a stage from 
birth to age 12 to 18 months, in which an 
infant’s center of pleasure is the mouth 
(Module 40).

orgasm

 
The peak of sexual excitement, during 
which rhythmic muscular contractions occur in 
the genitals (Module 33).

overgeneralization

 
The phenomenon by 
which children apply language rules even 
when the application results in an error 
(Module 25).

mode

 
The most frequently occurring score in a 
set of scores (Module 56).

mood disorder

 
A disturbance in emotional 
experience that is strong enough to intrude on 
everyday living (Module 47).

mood stabilizers

 
Drugs used to treat mood 
disorders that prevent manic episodes of bipo-
lar disorder (Module 51).

motivation

 
The factors that direct and energize 
the behavior of humans and other organisms 
(Module 29).

motor area

 
The part of the cortex that is largely 
responsible for the body’s voluntary movement 
(Module 9).

motor (efferent) neurons

 
Neurons that com-
municate information from the nervous system 
to muscles and glands (Module 8).

myelin sheath

 
A protective coat of fat and pro-
tein that wraps around the axon (Module 7).

narcissistic personality disorder

 
A personality 
disturbance characterized by an exaggerated 
sense of self-importance (Module 47).