Recently it has been found that area LIP (the lateral intraparietal area) does not command ocular responses (despite previous hypotheses, e.g., Mountcastle et al. 1975), since subjects subjected to the countermanding paradigm failed to qualify as a saccade command center (Brunamonti and Paré 2023); as well, LIP is not necessary for ocular responses (Schiller and Tehovnik 2003). Finally, LIP does not send direct projections to the saccade generator in the brain stem for direct control of the ocular musculature, but instead must access the generator via the superior colliculus. Both the frontal eye fields and superior colliculus (which are necessary for visually-guided saccades, Schiller et al. 1980) send direct projections to the saccade generator which permits direct command and control of the generator. In a like manner, the frontal eye fields along with MT/MST (middle temporal/middle superior temporal cortex) have command and control capabilities vis-à-vis pursuit eye movements since these regions send direct projections to brain stem sites critical for pursuit (Ilg 2008).
Up to 50% of the neocortex in humans is dedicated to language (Sarubbo et al. 2020; also see Footnote 1). Given such a vital function of the human brain, one might expect that the neurons in the neocortex subserving language also exhibit command and control properties over the vocal apparatus (innervated by cranial nerves: V, VII, X, and XII) and other motor centers dedicated to communication, e.g., the right/left hand for writing and the movement of the eyes for reading as the head remains relatively immobile. We already know that the hand area of M1 and the frontal eye fields have command status as they are necessary for writing and reading (Penfield and Roberts 1966). These areas, moreover, send direct projections to brain stem regions innervating the musculature that subserves writing and reading (Penfield and Roberts 1966; Schiller and Tehovnik 2015; Tehovnik et al. 2000). Furthermore, Broca’s area/M1 regions subserving the speech directly innervate brain stem regions controlling the vocal apparatus (Aboitiz 2018). Thus, the neocortex of humans has command and control of one’s English language, or any other language that may have been acquired during childhood. Interestingly, the neurons in facial regions of monkey frontal cortex do not send direct projections to the brain stem neurons that mediate the facial/vocal musculature therefore forfeiting a commanding influence over these muscles (Aboitiz 2018).
The evolution of human language came about once the neocortex of primates had command and control over the vocal apparatus some half a million years ago (Kimura 1993), which is much earlier than Chomsky’s presumption that language started 60,000 years ago (Chomsky 2012). In the end, it will be neuroscience not linguistics that will nail shut this issue (see Footnote 2).
Footnote 1: Semantic information is stored primarily in the neocortex where associations are made between words and objects in the form of sounds (i.e., syllables) and visual images (Kimura 1993; Ojemann 1991; Penfield and Roberts 1966), and the sound information is stored in the cerebellum in the form of syllables according to a muscle code for the generation of words using a vocal apparatus and associated muscles that can depend on 100 muscles for optimal performance (Tehovnik, Hasanbegović, and Chen 2024).
Footnote 2: The telencephalon directly innervates the brain stem nuclei controlling the vocal apparatus in songbirds (Schmidt and Wild 2014).
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