Amygdala involvement in human avoidance, escape and approach behavior Page: 5
This article is part of the collection entitled: UNT Scholarly Works and was provided to UNT Digital Library by the UNT College of Public Affairs and Community Service.
Extracted Text
The following text was automatically extracted from the image on this page using optical character recognition software:
Schlund and Cataldo Page 5
whole brain analyses were p < 0.0001, uncorrected for multiple comparisons, and an extent
threshold of 50 contiguous voxels, yielding an uncorrected cluster-level threshold ofp = .004.
To highlight overlapping brain regions between conditions, an inclusive masking technique
Z was used to determine the intersection (conjunction) of SPM {T} maps for the contrasts
Approach>Baseline and Avoidance>Baseline, as well as Approach>Baseline and Escape
"u >Baseline. This highlighted suprathreshold voxels for the approach cue that were also
suprathreshold for avoidance and escape cues. As our a priori region of interest was the
Samygdala, our ROI analysis was centered on the local maxima (5 mm sphere with SVC)
" identified in the whole brain analysis. The location of voxels with significant activation was
summarized by their local maxima separated by at least 8 mm, and by converting the maxima
coordinates from MNI to Talairach coordinate space using recommended transformations
S(Lancaster et al, 2007). These coordinates were finally assigned neuroanatomic labels using
the Talairach brain atlas (Talairach and Tournoux, 1998) and the Talairach Daemon database
(Lancaster et al, 2000). Resulting statistical parametric maps were then overlaid onto a
reference brain using MRlcron software (http://www.sph.sc.edu/comd/rorden/mricron/).
Results
Behavioral
Response accuracy during neuroimaging to cues prompting avoidance, escape and approach
Z behavior exceeded 95% for all subjects. The cue signaling punishment resulted in complete
. response suppression, highlighting that response-dependent money loss remained aversive
throughout. Mean number of responses per trial for avoidance was 18.3 (SE= 1.45), escape 17.8
> (SE= 1.45) and approach 14.06 (SE=1.75). Results of one-sample t-tests revealed no difference
between avoidance and escape responding (t(17) = 0.40, p > .05), but increased responding
during avoidance relative to approach (t(17)= 2.55, p < .05) and escape relative to approach
o (t(17) = 2.68, p < .05) suggesting greater motivation to avoid and escape.
Brain Activation
cm Conjunction analyses presented in Table 1 show cues prompting avoidance, escape and
Approach behavior recruited a similar fronto-striatal-parietal network. Bilateral activation was
noted in the amygdala as well as in the striatum, inferior and middle frontal gyri, inferior and
superior parietal lobules, paracentral lobule, postcentral gyrus, posterior cingulate, precuneus,
superior temporal gyrus, supramarginal gryus and posterior lobes of the cerebellum. Results
of our ROI analysis centering on the amygdala are presented in panel A in Figure 2 and show
bilateral amygdala activation to cues prompting avoidance, escape and approach behavior. The
inserted plot highlights mean contrast values---difference between parameter estimates. Post-
hoc one-sample t-tests revealed no significant differences between conditions. A positive
Z correlation between number of avoidance responses (i.e., response rate) and left amygdala
activation which approached significance was also observed (r = +.47; p = .051). Frequency
distributions for each amygdala by condition in panel B of Figure 2 highlight the extent of
between-subject variability and reveal most subjects exhibited positive contrast values.
To examine the consistency of amygdala responses within-subjects, Figure 3 shows individual
-- subject contrast values for the left amygdala (top plot) and right amygdala (bottom plot) for
all conditions. Results were arbitrarily rank-ordered by escape contrast values for presentation
Purposes and show the magnitude of amygdala responses was relatively consistent within each
cm subject. Results also show variability in response magnitude between-subjects, with a subset
_. of subjects showing marked activation to avoidance, escape and approach cues. A further
examination of the consistency of within-subject responses appears in Figure 4. Panel A shows
moderate positive relationships between left and right amygdala activation within all conditions
(r's ranging from +.47-+.50). Panel B shows positive relationships between conditions forNeuroimage. Author manuscript; available in PMC 2011 November 1.
Upcoming Pages
Here’s what’s next.
Search Inside
This article can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Article.
Schlund, Michael W. & Cataldo, Michael F. Amygdala involvement in human avoidance, escape and approach behavior, article, November 1, 2010; [Amsterdam, Netherlands]. (https://digital.library.unt.edu/ark:/67531/metadc77178/m1/5/: accessed April 25, 2024), University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu; crediting UNT College of Public Affairs and Community Service.