Understanding Psychology (10th Ed)

2.
The term absolute threshold refers to the 
inten-
sity of a stimulus that must be present for the stimulus to 
be detected.
3.
Weber discovered that for a difference between two stim-
uli to be perceptible, the stimuli must differ by at least a 
proportion.
4.
After completing a very diffi cult rock climb in the morn-
ing, Carmella found the afternoon climb unexpectedly 
easy. This example illustrates the phenomenon of 
.
R E T H I N K
1.
Do you think it is possible to have sensation without 
perception? Is it possible to have perception without 
sensation?
2.
From the perspective of a manufacturer: How might you need 
to take psychophysics into account when developing new 
products or modifying existing ones?
Answers to Evaluate Questions
1. 
Sensation; perception; 
2.
smallest; 
3. 
constant;
4. 
adaptation
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NEUROSCIENCE IN YOUR LIFE
This feature, 
which appears in each chapter, emphasizes 
the importance of neuroscientifi c research 
within the various subfi elds of the discipline 
and in students’ lives. Compelling brain 
scans, with both caption and textual explana-
tion, illustrate signifi cant neuroscientifi c fi nd-
ings that are increasingly infl uencing the 
fi eld of psychology. For example, one 
Neuroscience in Your Life
feature shows MRI 
techniques that illustrate how our brains pro-
cess information coming from each eye sepa-
rately. Another shows how the brains of 
smokers—even those who have quit—are 
activated when they see images related to 
smoking. Yet another discusses the eff ects of 
sleep on memory.