Understanding Psychology (10th Ed)

FIGURE 1 
Brain scans produced by diff erent techniques. (a) A computer-produced EEG 
image. (b) The fMRI scan uses a magnetic fi eld to provide a detailed view of brain activity on 
a moment-by-moment basis. (c) The PET scan displays the functioning of the brain at a given 
moment. (d) Transcranial magnetic stimulation (TMS), the newest type of scan, produces a 
momentary disruption in an area of the brain, allowing researchers to see what activities are 
controlled by that area. TMS also has the potential to treat some psychological disorders.
(c)
PET scan
(d)
TMS Apparatus
(b)
fMRI
(a)
EEG
Study Alert
Remember that EEG, fMRI, 
PET, and TMS diff er in terms 
of whether they examine 
brain 
structures
or brain 
functioning.
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“virtual lesion,” because it produces effects analogous to what would occur if areas 
of the brain were physically cut. The enormous advantage of TMS, of course, is that 
the virtual cut is only temporary. In addition to identifying areas of the brain that 
are responsible for particular functions, TMS has the potential to treat certain kinds 
of psychological disorders, such as depression and schizophrenia, by shooting brief 
magnetic pulses through the brain (Fitzgerald & Daskalakis, 2008; Rado, Dowd, & 
Janicak, 2008; Pallanti & Bernardi, 2009). 
Future discoveries may yield even more sophisticated methods of examining the 
brain. For example, the emerging fi eld of optogenetics involves genetic engineering 
and the use of special types of light to view individual circuits of neurons (Gradinaru 
et al., 2009; Miesenbock, 2008). 
Advances in our understanding of the brain also are paving the way for the 
development of new methods for harnessing the brain’s neural signals. We consider 
some of these intriguing fi ndings in Applying Psychology in the 21 st Century .
The Central Core: 
Our “Old Brain”
Although the capabilities of the human brain far exceed those of the brain of any 
other species, humans share some basic functions, such as breathing, eating, and 
sleeping, with more primitive animals. Not surprisingly, those activities are directed 
by a relatively primitive part of the brain. A portion of the brain known as the