Another series of experiments (conducted by Barry Sessle and co.) studied rhythmical jaw movement in macaque monkeys. While fully conscious, these animals were restrained and, over time, thousands of electrodes were inserted into their brains. The experimenters produced electrical stimulation in various parts of the cortex, thereby eliciting jaw movement such as chewing and opening and closing of the mouth. After 12 weeks of experimentation, the animals were killed and their brains examined.
The researchers concluded from this experiment that “the cortex plays an important role in mastication in primates”. Hardly mind-blowing news.
Such “swallowing” experiments have been going on for 15 years. In September of 1999, a report was finally published in the Journal of Neurophysiology titled “Features of Cortically Evoked Swallowing in the Awake Primate”. I plodded through heavily-padded science-babble sentences like “Reports of swallowing deficits in humans after hemispheric stroke, cortical ablation studies in animal models, cortical stimulation studies, neuroanatomic tracing studies, and neuronal recording studies examining the activity patterns and propensities of swallow-related cortical neurons have suggested that the lateral pericentral cortex, the anterolateral frontal cortex, the frontal and parietal opercula, and the insula mediate swallowing as well as a number of related functions such as sucking, mastication, and salivation.
The confusing wording is a pretty good bluff (rare is the individual who is scientifically well-versed enough to understand — much less challenge, the code language). If one bothers to translate, it actually means that they did not find anything definite or substantial. The study does however, suggest that throat muscles push food down the esophagus.
“The researchers concluded from this experiment that “the cortex plays an important role in mastication in primates”. Hardly mind-blowing news.”