This paper, except for the “Preface for Zygon Readers,” will appear in Human by Nature: Origins and Destiny of Language, edited by V. Velichrovsky and D. M. Rumbaugh (Hillsdale, N.J.: Lawrence Erlbaum Publishers, in press).
WHY A BRAIN CAPABLE OF LANGUAGE EVOLVED ONLY ONCE: PREFRONTAL CORTEX AND SYMBOL LEARNING
Version of Record online: 15 DEC 2005
Volume 31, Issue 4, pages 635–670, December 1996
How to Cite
Deacon, T. W. (1996), WHY A BRAIN CAPABLE OF LANGUAGE EVOLVED ONLY ONCE: PREFRONTAL CORTEX AND SYMBOL LEARNING. Zygon, 31: 635–670. doi: 10.1111/j.1467-9744.1996.tb00954.x
- Issue online: 15 DEC 2005
- Version of Record online: 15 DEC 2005
- information processes;
- prefrontal cortex;
- symbolic reference
Abstract. Language and information processes are critical issues in scientific controversies regarding the qualities that epitomize humanness. Whereas some theorists claim human mental uniqueness with regard to language, others point to successes in teaching language skills to other animals. However, although these animals may learn names for things, they show little ability to utilize a complex framework of symbolic reference. In such a framework, words or other symbols refer not only to objects and concepts but also to sequential and hierarchical relationships with other symbols. This process is essential to human mental operations, including language, mathematics, and music. In humans, these operations may have coevolved with the prefrontal area of the cerebral cortex, which is proportionately much larger in humans than in other animals and more intricately linked with other areas of the brain. Analysis of the structure and function of the prefrontal area suggests that it is centrally involved in the operation of higher-order associative relationships involving the subordination of one set of associations to another. This alternate learning strategy apparently appeared at the cost of certain sensory, motor, or limbic abilities. The payoff was symbolic thinking. Humans thus are unique among species, not just for their highly developed language ability but for their odd style of thinking and learning.