Understanding Psychology (10th Ed)

 activation-synthesis theory 
focuses on the 
random electrical energy that the brain produces during 
REM sleep, possibly as a result of changes in the production 
of particular neurotransmitters. This electrical energy ran-
domly stimulates memories stored in the brain. Because we 
have a need to make sense of our world even while asleep, 
the brain takes these chaotic memories and weaves them into 
a logical story line, fi lling in the gaps to produce a rational 
scenario (Hobson, 2005; Porte & Hobson, 1996).
Activation-synthesis theory has been refi ned by the acti-
vation information modulation (AIM) theory. According to AIM, 
dreams are initiated in the brain’s pons, which sends random 
signals to the cortex. Areas of the cortex that are involved in 
particular waking behaviors are related to the content of 
dreams. For example, areas of the brain related to vision are 
involved in the visual aspects of the dream, while areas of the brain related to move-
ment are involved in aspects of the dream related to motion (Hobson, 2007). 
Activation-synthesis and AIM theories do not entirely reject the view that dreams 
refl ect unconscious wishes. They suggest that the particular scenario a dreamer produces 
is not random but instead is a clue to the dreamer’s fears, emotions, and concerns. 
Hence, what starts out as a random process culminates in something meaningful.
Sleep Disturbances: 
Slumbering Problems
At one time or another, almost all of us have diffi culty sleeping—a condition known 
as insomnia. It could be due to a particular situation, such as the breakup of a rela-
tionship, concern about a test score, or the loss of a job. Some cases of insomnia, 
however, have no obvious cause. Some people are simply unable to fall asleep easily, 
or they go to sleep readily but wake up frequently during the night. Insomnia is a 
problem that affl icts as many as one-third of all people. Women and older adults are 
more likely to suffer from insomnia, as well as people who are unusually thin or are 
depressed (Bains, 2006; Cooke & Ancoli-Israel, 2006; Henry et al., 2008). 
Some people who think they have sleeping problems actually are mistaken. For 
example, researchers in sleep laboratories have found that some people who report 
being up all night actually fall asleep in 30 minutes and stay asleep all night. Fur-
thermore, some people with insomnia accurately recall sounds that they heard while 
they were asleep, which gives them the impression that they were awake during the 
night (Semler & Harvey, 2005; Yapko, 2006). (Also see PsychWork .)