Brain Lateralization and Cognitive Capacity

Abstract

One way to increase cognitive capacity is to avoid duplication of functions on the left and right sides of the brain. There is a convincing body of evidence showing that such asymmetry, or lateralization, occurs in a wide range of both vertebrate and invertebrate species. Each hemisphere of the brain can attend to different types of stimuli or to different aspects of the same stimulus and each hemisphere analyses information using different neural processes. A brain can engage in more than one task at the same time, as in monitoring for predators (right hemisphere) while searching for food (left hemisphere). Increased cognitive capacity is achieved if individuals are lateralized in one direction or the other. The advantages and disadvantages of individual lateralization are discussed. This paper argues that directional, or population-level, lateralization, which occurs when most individuals in a species have the same direction of lateralization, provides no additional increase in cognitive capacity compared to individual lateralization although directional lateralization is advantageous in social interactions. Strength of lateralization is considered, including the disadvantage of being very strongly lateralized. The role of brain commissures is also discussed with consideration of cognitive capacity.

Cortical asymmetries at different spatial hierarchies relate to phonological processing ability

“…Hemispheric asymmetries are widely thought to confer a processing advantage through specialization of functions, particularly when an animal must process different types of information simultaneously [ 69 ]. The cerebral lateralization hypothesis proposes that left hemisphere representation for language, due to structural asymmetries, confers a language processing advantage.…”

The Difficult Integration between Human and Animal Studies on Emotional Lateralization: A Perspective Article

“…As a result of this effort, these authors have also tried to identify the hemispheric asymmetries that could be detected in each of these stages. A similar focalization on the components of emotional processing has less frequently been attempted by authors interested in animal emotions, who have rather centered their attention on the most appropriate methods of study of the behavioral asymmetries, see [19][20][21], and on the basic mechanisms underlying these asymmetries at the individual or the species level, see [84]. From a rather simplistic point of view, it could be said that the main components of the emotional process consist of: (a) a quick computation of poorly processed sensory data, sufficient to decide if an external situation has a pleasant or dangerous meaning; (b) an integration of these sensory data within the central nervous system to select the most appropriate behavioral response; (c) an automatic instantiation of action schemata that must include expressive-communicative components, postural changes, bodily movements and a sizeable recruitment of the autonomic nervous system.…”

“…However, since the interest of researchers is seldom attracted by papers that do not belong to their specific area of research, this has not been sufficient to establish a dialogue between human and animal disciplines. An important factor that has contributed to discouraging this dialogue lies in the fact that, due to the diverging brain organizations of different animal species, methods of study of behavioral asymmetries have been inconsistent between human and animal studies (see [19][20][21] for recent reviews of methods used in the study of animal lateralization). Now, since a good knowledge of the advantages and limitations of different methods is necessary to make a critical assessment of a research paper, scholars of human asymmetries have rarely been attracted by results obtained in the study of animal lateralization.…”

Aprendizagem do medo por observação em pombos (Columba livia)

“…A experiência de observar o comportamento de outro pombo numa situação de discriminação de pares de estímulos, facilita a aprendizagem da discriminação pelo observador 8 . Pesquisadores relataram que os pombos que observaram outro pombo (pombo-modelo) durante a aprendizagem de como empurrar uma porta corrediça com o bico para ter acesso ao alimento, exibiram maior proporção de respostas de empurrar do que os pombos-controles 9 Outros estudos confirmaram tais evidências e, ao mesmo tempo, estenderam a investigação para a análise desse tipo de aprendizagem de esquiva inibitória em pintainhos de substratos neurais, demonstrando a participação de estruturas dos dois hemisférios cerebrais, com um curso temporal de eventos neurais que indicam um papel crucial para o hemisfério direito [12][13][14] .…”