Sham rage

Content sourced from Wikipedia, licensed under CC BY-SA 3.0.

Sham rage is rage-like behavior seen in animals after the cerebral cortex is removed. They may hiss, claw, bite, arch their back, and move their limbs violently in response to mild stimuli, even though they seem calm otherwise. This is accompanied by bodily arousal—higher heart rate, faster breathing, higher blood pressure, and increased blood sugar. Small lesions in the hypothalamus can stop these reactions, suggesting the hypothalamus drives sham rage.

The idea goes back to 1925, when Cannon and Britton studied how deep brain areas control emotion. In Bard’s work (1934), removing the neocortex in cats and dogs made them show extreme anger to tiny touches, implying the cortex normally inhibits rage circuits.

Neurochemical studies add detail. Reis and Gunne (1965) showed that stimulating the amygdala could trigger sham rage and disrupt chemical balance. Reis and Fuxe (1969) found that more severe sham rage after brainstem cuts tied to lower norepinephrine, and drugs that boost NE worsened it while NE blockers eased it, suggesting norepinephrine is involved.

In humans, sham rage can come from uninhibited hypothalamic discharge due to causes like brain stimulation, carbon monoxide, or severe hypoglycemia. While visible signs appear, it’s debated whether the person truly feels anger. Some researchers argue that animals do feel rage and that the cortex normally modulates it; others see sham rage as an old scientific artifact. Regardless, sham rage shows how the hypothalamus and other deep brain networks shape rage and its bodily signs.