As animals learn a task, they become more reliant on their long-term memories as compared to the real-time sensory information to guide behavioral performance (Ahilan et al. 2018). This process is what creates the automaton, or as Sigmund Freud preferred to call it, the id (Freud 1899). The long-term storage of information in the brain, namely, the establishment of the automaton, is mediated by the cerebellum (Ito 2008; Schmahmann 1997), but all by way of the neocortex (Tehovnik, Hasanbegović, Chen 2024). Both the cerebellum and the neocortex are intimately connected functionally for both sensorimotor processing and cognition (Buckner et al. 2011). In mammals (from mice to men), the cerebellum contains some 70-80% of the neurons of the brain (Herculano-Houzel 2009), making it an ideal structure for the storage of large quantities of long-term information (Huang 2008). We now understand that this storage process entails not attaching information explicitly to neurons as happens in the neocortex (e.g., from face cells to place cells to text cells, etc., Ojemann 1991; Periera, Fedorenko et al. 2018; Schwarzlose, Kanwisher et al. 2005), but rather by creating neocortical-cerebellar loops (Gao et al. 2018; Guo, Hantman et al. 2021; Hasanbegović 2024; Zhu, Hasanbegović et al. 2023) that are programmed as independent executable motor routines centered at the Purkinje neurons (Bell et al. 1997; Chen 2019; Cullen 2015; De Zeeuw 2021; Fukutomi and Carlson 2020; Loyola et al. 2019; Miles and Lisberger 1981; Noda et al. 1991; Shadmehr 2020; Tehovnik, Patel, Tolias et al. 2021; Wang et al. 2023). The best example of this independence is realized by language in polyglots (see Figs. 1 and 2, Mariën et al. 2017; Ojemann 1983, 1991). Once mastered, a language—irrespective of the number learned—becomes an automatic affair: e.g., my colleague Dr. Zivanilson Teixeira e Silva, who knows ten languages, is able to shift from one to another effortlessly to suggest that each execution is mediated by independent channels.
Figure 1: When delivering a speech in a language, neocortical-cerebellar loops are engaged such that text stored in the neocortex is converted into executable code at the level of the cerebellum via the Purkinje neurons over time. A language command to speak is issued from the neocortex (cortex) which has access to the cerebellar cortex at the Purkinje cells (Purkinje) via the pons (Pons). The return portion of the loop passes through the cerebellar nuclei (Nuclei) and thalamus (Thal) en route to the neocortex. According to Ojemann (1983,1991) every language is stored separately in the neocortex according to electrical inactivation experiments done on human subjects. This is supported by work on stroke patients, whereby primary languages are often preserved over secondary languages (based on cerebellar stroke, Mariën et al. 2017). (auto_205.gif)
Figure 2: Neocortical-cerebellar loops per language. A language command to speak is issued from the neocortex (cortex) which has access to the cerebellar cortex at the Purkinje cells (Purkinje) via the pons (Pons). The return portion of the loop passes through the cerebellar nuclei (Nuclei) and thalamus (Thal) en route to the neocortex. Irrespective of the type of language, every language is transmitted at a comparable bit-rate of 39 bits per second, which is short of 1 trillion possibilities per second (Coupé et al. 2019). This dovetails with the idea of Chomsky that all humans have a universal-grammar capability (Chomsky 1965). Whether other mammals have a similar capability is not known, but machine learning is now being used to decipher communications between whales, which can have neocortical neurons numbering in the tens of billions, 40 billion for killer whales (Ridgway et al. 2019; humans have 16 billion neocortical neurons by comparison, Herculano-Houzel 2009). The loop configuration in the figure is based on the anatomical, unit recording, and optogenetic experiments of Hasanbegović (2024), all performed on the mouse and generalized to the primate (Thach et al. 1992). (auto_206.gif)
- Badges
- Science topic
- Similar topics
- Chemistry