Hostname: page-component-7c8c6479df-7qhmt Total loading time: 0 Render date: 2024-03-17T18:16:01.603Z Has data issue: false hasContentIssue false

Survival with an asymmetrical brain: Advantages and disadvantages of cerebral lateralization

Published online by Cambridge University Press:  26 September 2005

Giorgio Vallortigara*
Affiliation:
Department of Psychology and B.R.A.I.N. Centre for Neuroscience, University of Trieste, 34123Trieste, Italyhttp://psico.univ.trieste.it/labs/acn-lab/
Lesley J. Rogers*
Affiliation:
Centre for Neuroscience and Animal Behaviour, School of Biological, Biomedical and Molecular Sciences, University of New England, Armidale, NSW2351, Australiahttp://www.sciences.une.edu.au/zoology/lesleyrogers.asp

Abstract

Recent evidence in natural and semi-natural settings has revealed a variety of left-right perceptual asymmetries among vertebrates. These include preferential use of the left or right visual hemifield during activities such as searching for food, agonistic responses, or escape from predators in animals as different as fish, amphibians, reptiles, birds, and mammals. There are obvious disadvantages in showing such directional asymmetries because relevant stimuli may be located to the animal’s left or right at random; there is no a priori association between the meaning of a stimulus (e.g., its being a predator or a food item) and its being located to the animal’s left or right. Moreover, other organisms (e.g., predators) could exploit the predictability of behavior that arises from populationlevel lateral biases. It might be argued that lateralization of function enhances cognitive capacity and efficiency of the brain, thus counteracting the ecological disadvantages of lateral biases in behavior. However, such an increase in brain efficiency could be obtained by each individual being lateralized without any need to align the direction of the asymmetry in the majority of the individuals of the population. Here we argue that the alignment of the direction of behavioral asymmetries at the population level arises as an “evolutionarily stable strategy” under “social” pressures occurring when individually asymmetrical organisms must coordinate their behavior with the behavior of other asymmetrical organisms of the same or different species.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2005

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)