Brains, Lifestyles and Cognition: Are There General Trends?

Abstract

portion remains when these variables are factored out. What is behind this remaining variance? Because the brain is an organ that processes, stores and integrates sensory, motor and information, the most obvious hypothesis is that there are cognitive advantages in affording larger brains [Jerison, 1973]. Important advances have been made since Jerison's pioneering work, but several unresolved issues still stimulate debates among contemporary researchers. Are cognitive activities selected as independent modules or can they be part of more general processes that cause some animals to consistently outrank others in several cognitive measures? What are the evolutionary forces that select for larger brains? Are there convergent principles that govern the evolution of brain size in different taxa? Do whole brain size differences, as opposed to finer measures, mean anything in terms of cognitive performance?Several research strategies have been used to answer these questions. Some use principles derived from work on humans, others focus on specialized behaviors (e.g., food storing) seen only in a few non-human taxa. In this paper, we review an approach initially developed with birds and based on field observations of innovative behaviors. We first discuss a series of operational measures of cognition, and ask whether variation in the measures suggests correlated or independent evolution. Next, we test whether these cognitive measures co-vary with the size of neural structures. Finally, we discuss some ecological contexts in which the cognitive measures associated with size of neural structures might be Key WordsBrain ؒ Evolution ؒ Neuroecology ؒ Cognition AbstractComparative and experimental approaches to cognition in different animal taxa suggest some degree of convergent evolution. Similar cognitive trends associated with similar lifestyles (sociality, generalism, new habitats) are seen in taxa that are phylogenetically distant and possess remarkably different brains. Many cognitive measures show positive intercorrelations at the inter-individual and inter-taxon level, suggesting some degree of general intelligence. Ecological principles like the unpredictability of resources in space and time may drive different types of cognition (e.g., social and non-social) in the same direction. Taxa that rank high on comparative counts of cognition in the field are usually the ones that succeed well in experimental tests, with the exception of avian imitation. From apes to birds, fish and beetles, a few common principles appear to have influenced the evolution of brains and cognition in widely divergent taxa.

Mice selectively bred for high voluntary wheel running have larger midbrains: support for the mosaic model of brain evolution

“…A number of hypotheses have been generated to explain how selection may have driven changes in brain size (Francis, 1995;Barton and Harvey, 2000; de Winter and Oxnard, 2001;Hutcheon et al, 2002; Byrne and Corp, 2004;Lefebvre et al, 2004;Marino, 2005;Sol et al, 2005;Lefebvre and Sol, 2008;Rehkämper et al, 2008;Sol et al, 2008; Chittka and Niven, 2009;Roth and Pravosudov, 2009). Most, if not all, of these hypotheses suggest that selection is acting on behavior [e.g.…”

“…Most, if not all, of these hypotheses suggest that selection is acting on behavior [e.g. behavioral flexibilityenvironmental change hypothesis (Sol et al, 2005;Lefebvre and Sol, 2008;Sol et al, 2008), social brain hypothesis (Byrne and Whiten, 1988; Brothers, 1990; Byrne and Corp, 2004)], rather than directly on brain size per se (see also Kruska, 2005). The primary question in the present study is whether selection on a particular behavioral trait (voluntary exercise), using an experimental evolution paradigm (Garland and Rose, 2009), has resulted in a change in brain size.…”

Neuronal factors determining high intelligence

“…One could also look for neurobiologically more meaningful traits like the number of neurons in the entire brain or in the pallium or cortex, the degree of connectivity, axonal conduction velocity, etc., relevant for 'information processing capacity (IPC)' of the brain or of the pallium or cortex, respectively [4]. IPC is coincident with the notion of 'general intelligence' as largely defined by the efficiency of working memory and, accordingly, mental manipulation abilities [5][6][7][8]. Finally, one could look for 'unique' properties that could best explain the observed differences in intelligence in the context of 'mosaic brain evolution '.…”

Adjusting foraging strategies: a comparison of rural and urban common mynas (Acridotheres tristis)

“…Within these contexts, behavioural flexibility has often been viewed as the 25 phenotypical expression of a cognitive ability to adjust behaviour when ecological conditions change 26 (reviwed by Lefebvre and Sol 2008;Lefebvre 2013). Another means of measuring behavioural 27 flexibility experimentally, therefore, is discrimination reversal learning, a standard psychology 28 learning task used to measure the propensity to change behaviour when the environment changes 29 (Schusterman 1966 Guillette et al 2011;Logan 2016).…”