Show Summary Details

Page of

PRINTED FROM OXFORD HANDBOOKS ONLINE (www.oxfordhandbooks.com). © Oxford University Press, 2018. All Rights Reserved. Under the terms of the licence agreement, an individual user may print out a PDF of a single chapter of a title in Oxford Handbooks Online for personal use (for details see Privacy Policy and Legal Notice).

date: 26 February 2020

Abstract and Keywords

This article gives an overview on the various brain structures, other than neocortex, contributing to speech and language. The regions of the avian brain which are considered functionally homologous to human neocortex, are nuclear, as opposed to cortical, in their cellular arrangements. The functional significance of nuclear versus cortical neuronal arrangements remains unknown. The intelligence is best measured by ratios that explicitly and/or implicitly discount other neural areas. The most extreme such measure is Dunbar's neocortical ratio that is the ratio of the size of the neocortex to the size of the entire remainder of the brain. The ratio, which is based on the explicit assumption that the neocortex is the primary seat of intelligence, also rests on the implicit assumption that enlargement of non-neocortical brain structures lowers intelligence. The nuclei and basal ganglia contain neurons that are arranged in a non-layered fashion. Such structures may also lie entirely within the brain, and thus have no visible representation on the outer brain surface. The cerebellar lesions can be associated with a much wider range of cognitive and sensory defects, including defects in working memory, procedural learning, syntax, word order, word choice, and autism. The deficits in both the basal ganglia and the cerebellum accompany the orofacial dyspraxia that results from FOXP2 mutations.

Keywords: neocortex, FOXP2 mutations, Dunbar's neocortical ratio, intelligence, neural areas

Access to the complete content on Oxford Handbooks Online requires a subscription or purchase. Public users are able to search the site and view the abstracts and keywords for each book and chapter without a subscription.

Please subscribe or login to access full text content.

If you have purchased a print title that contains an access token, please see the token for information about how to register your code.

For questions on access or troubleshooting, please check our FAQs, and if you can''t find the answer there, please contact us.