Effects of left amygdala lesions on respiration, skin conductance, heart rate, anxiety, and activity of the right amygdala during anticipation of negative stimulus.
Left amygdala removal cut anxiety and every autonomic reading, proving the amygdala drives both feelings and body signs.
01Research in Context
What this study did
Two adults with epilepsy had their left amygdala removed to stop seizures.
Doctors tracked breathing, sweat response, heart rate, and anxiety while the patients waited for scary pictures.
They also scanned the right amygdala to see if it calmed down too.
What they found
After the surgery both patients felt less anxious.
Their sweat response, heart rate, and breathing dropped.
The right amygdala also showed less activity, so one side can quiet the other.
How this fits with other research
Ruiz-Robledillo et al. (2015) saw the opposite pattern: ASD caregivers had low sweat response yet high anxiety.
The difference is time. Caregivers face daily stress, so their skin response is blunted. The surgery group had sudden damage, so every measure fell at once.
Tassé et al. (2013) and Kirshner et al. (2016) also paired sweat and heart data with anxiety tasks, showing the same tools work across kids with ASD, CP, and adults with epilepsy.
Why it matters
You can’t lesion an amygdala, but you can watch sweat and heart signals during your next anxiety probe.
If skin response is flat yet the client reports high worry, think chronic stress like the caregiver study.
If both signals and behavior spike, try calming skills first; the surgery data show big drops are possible when the threat circuit is quiet.
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02At a glance
03Original abstract
The present study reports the effects of lesions in the left amygdala on anxiety, respiration, skin conductance, heart rate, and electrical potentials in the right amygdala in two patients. Trait and anticipatory-state anxiety were measured before and after left amygdala resection to control medically intractable epilepsy in the patients. Lesions in the left amygdala resulted in decreases of trait and state anxiety, respiratory rate, and activity in the right amygdala in both patients; one patient also showed notable decreases in skin conductance and heart rate. The study also reports that activities in the right amygdala before the lesion were not observed after the lesion. We suggest that the activity of the right amygdala is dominantly activated in anxiety and anxiety-related physiological responses but needs excitatory inputs from the left amygdala.
Behavior modification, 2003 · doi:10.1177/0145445503256314