Psychology2016

Learning 191

the nucleus accumbens. Remember our discussion of drug dependence and the reward
pathway in Chapter Four? to Learning Objective 4.11. The nucleus accumbens
was a part of that pathway, and both of these areas of the brain are involved in the release
of dopamine (Gale et al., 2016; Morita et al., 2013; Yavuz et al., 2015).
Given the role it plays in amplifying some input signals and decreasing the intensity
of others in the nucleus accumbens (Floresco, 2015), it makes sense that dopamine would
be involved in the process of reinforcement. Think about what happens when you hear the
particular sound from your cell phone when you have an incoming message, for example.
We like getting messages, so much so that we will often ignore the live person we are with
to look at the message. Have you ever been accused of being "addicted" to your phone? If
you think about it, that little sound—be it chime, ding, or whatever you have chosen—has
become a kind of conditioned stimulus. We find reading the messages themselves pleasur-
able, so the message could be seen as a kind of unconditioned stimulus for pleasure, and
the sound becomes a CS for the CR of pleasure. But what is happening in the brain when
you hear that sound followed by rewarding activities is excitatory activity in several areas,
accompanied by increased dopamine activity, to signal that the behavior was beneficial and
to do it again. Just as dopamine and the reward pathway are involved in drug dependency,
they also seem to be heavily involved in our "learned" addictions, too.

POSITIVE AND NEGATIVE REINFORCEMENT Reinforcers can also differ in the way they
are used. Most people have no trouble at all understanding that following a response
with some kind of pleasurable consequence (like a reward) will lead to an increase in
the likelihood of that response being repeated. This is called positive reinforcement,
the reinforcement of a response by the addition or experience of a pleasurable conse-
quence, such as a reward or a pat on the back.
But many people have trouble understanding that the opposite is also true: Following a
response with the removal or escape from something unpleasant will also increase the likelihood
of that response being repeated—a process called negative reinforcement. Remember the
idea that pain can be a primary reinforcer if it is removed? If a person’s behavior gets pain to
stop, the person is much more likely to do that same thing again—which is part of the reason
people can get addicted to painkilling medication. Watch the video Negative Reinforcement for
another example.

positive reinforcement

the reinforcement of a response by

the addition or eZReriencing of a

pleasurable stimulus.

CC

Watch the Video Negative Reinforcement

negative reinforcement

the reinforcement of a response by the

removal, escape from, or avoidance of

an unpleasant stimulus.