Article

Survival with asymmetrical brain: advantages and disadvantages of cerebral lateralization. Behav Brain Sci

Department of Psychology and B.R.A.I.N. Centre for Neuroscience, University of Trieste, 34123 Trieste, Italy.
Behavioral and Brain Sciences (Impact Factor: 20.77). 09/2005; 28(4):575-89; discussion 589-633. DOI: 10.1017/S0140525X05000105
Source: PubMed

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 population-level 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.

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Available from: Lesley J Rogers
    • "Birds are visually lateralized with a left hemispheric superiority for visual discrimination of form details (Güntürkün and Kesch, 1987;Güntürkün, 1997a;Vallortigara and Rogers, 2005;Manns and Ströckens, 2014). In pigeons, this functional asymmetry is especially obvious when the animals memorize (vonFersen and Güntürkün, 1990) or categorize stimuli (Yamazaki et al., 2007) that can only be discerned by attending to small pictorial features. "
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    • "The most prominent manifestation of lateralised behaviour in humans is that of handedness (i.e., the predominant use of one hand), with roughly 90% of people using their right hand for most activities (Annett, 1985;Porac and Coren, 1981). Studies of lateralised behaviour patterns in other species (e.g., amphibians, rodents, cats, primates, marsupials, whales) now suggest that cerebral functional asymmetry is not unique to humans, but, rather, may be a fundamental feature of all vertebrate, and even some invertebrate, brains (for reviews seeFrasnelli et al., 2012;MacNeilage et al., 2009;Rogers, 2002;Rogers et al., 2013;Vallortigara et al., 2010;Vallortigara and Rogers, 2005). What is less clear is whether non-human species exhibit lateralisation in their limb use in a manner that approximates human handedness or whether the prefered use of a specific hand, paw or similar appendage is related to other aspects of brain asymmetry (see reviews byCorballis, 2009;Rogers, 2009;Versace and Vallortigara, 2015). "
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    • "Given that laterally asymmetrical movements are ubiquitous among biological organisms, they are likely to have been adaptive and/or inevitable (Vallortigara and Rogers, 2005). It is impossible for a bilaterally symmetrical organism to maneuver through a two-or three-dimensional space until one side of the body leads, because the forces that cause the movements of the body are generated within the body (Glezer (1987) put forward this perspective as a comment on MacNeilage et al. (1987)). "
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