Biomedical Engineering Reference
In-Depth Information
Figure 10
. (
a
) Consolidated data from studies at one lab show common and divergent patterns of activation
(3,19,33,37,38) regarding the analysis of expectancy, or of outcome. Two separate cocaine infusion studies
are listed, as are positive and negative valuation results for the beautiful faces experiment and the thermal
pain experiment. Red up-arrows symbolize positive signal changes while blue down-arrows stand for nega-
tive signal change. Numeric notation that is raised indicates more than one focus of signal change in that
region, whereas brackets indicate the signal change was statistically subthreshold for that study. The right
GOb, right NAc, right SLEA, and potentially the left VT, are observed during the outcome conditions for
most of the experiments, while bilateral NAc and left GOb are observed in both studies with expectancy
conditions. Table adapted with permission from Breiter and Gasic (32). (
b
) The gray tone structural images
in the sagittal orientation (left), and in the coronal orientation (right; +6 mm anterior of the anterior com-
missure), juxtapose published human neuroimaging results in "classic" pain regions from rewarding and
from painful stimuli (19). Other regions illustrated include the thalamus (Thal = left image between ac and
pc), the cingulate cortex, and the anterior insula (INS = right image). The cingulate cortex is segmented
into four units following the standardized methods of the MGH Center for Morphometric Analysis
(158,175), and includes aCG1 and aCG2. Note the approximation of reported activation from stimuli of
opposite valance. Figure adapted with permission from Breiter and Gasic (32).
indicate that "classic" reward circuitry (i.e., NAc, SLEA, amygdala, VT, GOb)
is not uniquely involved with reward functions, given a proportionate number of
activations are also reported in the rest of the paralimbic girdle.
Some minor caveats need to be considered when evaluating the literature
around a generalized circuitry for the assessment of reward/aversion informa-
tion. One caveat is that none of these reward studies controlled for relative
valuations across stimulus categories, or controlled for the presence of a deficit
state, with the exception of a study using chocolate stimuli and a study that
