The evolution of brain lateralization: A game theoretical analysis of population structure

In recent years, it has become apparent that behavioural and brain lateralization is the rule rather than the exception among vertebrates. The study of lateralization has been so far the province of neurology and neuropsychology. We show how such research can be integrated with evolutionary biology to more fully understand lateralization. In particular, we address the fact that, within a species, left- and right-type individuals are often in a definite proportion different from 1/2 (e.g., hand use in humans). We argue that traditional explanations of brain lateralization (that it may avoid costly duplication of neural circuitry and reduce interference between functions) cannot account for this fact, because increased individual efficiency is unre- lated to the frequency of left- and right-type individuals in a population. A further puzzle is that, if a majority of individuals are of the same type, individual behaviour becomes more predictable to other organisms. Here we show that alignment of the direction of behavioural asymmetries in a population can arise as an evolutionarily stable strategy (ESS), when individually asymmetrical organisms must coordinate their behaviour with that of other asymmetrical organisms. Thus, brain and behavioural lateralization, as we know it in humans and other vertebrates, may have evolved under basically "social" selection pressures

Lessons from miniature brains: Cognition cheap, memory expensive (sentience linked to active movement?)

Studies on invertebrate minds suggest that the neural machinery for basic cognition is cheap, and that bigger brains are probably associated with greater memory storage rather than more advanced cognition. Sentience may be linked to feedforward mechanisms (Reafferenzprinzip) that allow organisms with active movement to distinguish active and passive sensing. Invertebrates may offer special opportunities for testing these hypotheses

Sentience does not require “higher” cognition

I agree with Marino (2017a,b) that the cognitive capacities of chickens are likely to be the same as those of many others vertebrates. Also, data collected in the young of this precocial species provide rich information about how much cognition can be pre-wired and predisposed in the brain. However, evidence of advanced cognition — in chickens or any other organism — says little about sentience (i.e., feeling). We do not deny sentience in human beings who, because of cognitive deficits, would be incapable of exhibiting some of the cognitive feats of chickens. Moreover, complex problem solving, such as transitive inference, which has been reported in chickens, can be observed even in the absence of any accompanying conscious experience in humans

Distribution of antennal olfactory and non-olfactory sensilla in different species of bees

Several species of social bees exhibit population-level lateralization in learning odors and recalling olfactory memories. Honeybees Apis mellifera and Australian social stingless bees Trigona carbonaria and Austroplebeia australis are better able to recall short- and long-term memory through the right and left antenna respectively, whereas non-social mason bees Osmia rufa are not lateralized in this way. In honeybees, this asymmetry may be partially explained by a morphological asymmetry at the peripheral level—the right antenna has 5% more olfactory sensilla than the left antenna. Here we looked at the possible correlation between the number of the antennal sensilla and the behavioral asymmetry in the recall of olfactory memories in A. australis and O. rufa. We found no population-level asymmetry in the antennal sensilla distribution in either species examined. This suggests that the behavioral asymmetry present in the stingless bees A. australis may not depend on lateral differences in antennal receptor numbers

Animal welfare: neuro-cognitive approaches

Many people maintain a naive belief that non-human animals consciously experience pain and suffering in similar ways to humans. Others tend to assume a more sceptical or agnostic attitude. Drawing on recent advances in research on animal cognition and neuroscience, the science of animal welfare is now beginning to address these issues empirically. We describe recent advances that may contribute to the main questions of animal welfare, namely whether animals are conscious and how we can assess good and bad welfare in animals. Evidence from psychology is described which demonstrate that many complex actions in humans can be carried out quite unconsciously and that human patients with certain sorts of brain damage can behave and manipulate objects properly while at the same time o consciously denying experience of them. The relevance of these findings with respect to the issue of animal consciousness is discussed. Evidence from animal cognition is described concerning the possibility that animals monitor the state of their own memories, show episodic-like knowledge and exhibit self-medication. Evidence from neuroscience concerning brain lateralization in non-human animals and its relevance to animal welfare is described. It is argued that in animals raised for economic purposes (milk and meat production) differences in cognitive abilities and brain lateralization can affect adaptive behavioural, physiological and immune responses to environmental stressors

Individual-Level and Population-Level Lateralization: Two Sides of the Same Coin

Lateralization, i.e., the different functional roles played by the left and right sides of the brain, is expressed in two main ways: (1) in single individuals, regardless of a common direction (bias) in the population (aka individual-level lateralization); or (2) in single individuals and in the same direction in most of them, so that the population is biased (aka population-level lateralization). Indeed, lateralization often occurs at the population-level, with 60–90% of individuals showing the same direction (right or left) of bias, depending on species and tasks. It is usually maintained that lateralization can increase the brain’s efficiency. However, this may explain individual-level lateralization, but not population-level lateralization, for individual brain efficiency is unrelated to the direction of the asymmetry in other individuals. From a theoretical point of view, a possible explanation for population-level lateralization is that it may reflect an evolutionarily stable strategy (ESS) that can develop when individually asymmetrical organisms are under specific selective pressures to coordinate their behavior with that of other asymmetrical organisms. This prediction has been sometimes misunderstood as it is equated with the idea that population-level lateralization should only be present in social species. However, population-level asymmetries have been observed in aggressive and mating displays in so-called “solitary” insects, suggesting that engagement in specific inter-individual interactions rather than “sociality” per se may promote population-level lateralization. Here, we clarify that the nature of inter-individuals interaction can generate evolutionarily stable strategies of lateralization at the individual- or population-level, depending on ecological contexts, showing that individual-level and population-level lateralization should be considered as two aspects of the same continuum

‘Mind’ is an ill-defined concept: Considerations for future cephalopod research

Scientific discussions about the ‘mind’ of an octopus are empirically vacuous and should be confined to folk psychology. This form of labelling is unhelpful for science and should be replaced by specific mechanistic accounts of behavior and associated neural structures, which are amenable to rigorous scientific investigation. Mather provides a detailed review of octopus behavior, but rather than making unquantifiable assumptions about what orchestrates octopus behavior, efforts should focus on investigating cognitive mechanisms that can be measured. In this commentary, we outline two lines of research that include quantifiable methods to facilitate a more robust understanding of cephalopod behaviors and their cognitive underpinnings

‘Mind’ is an ill-defined concept: Considerations for future cephalopod research

Scientific discussions about the ‘mind’ of an octopus are empirically vacuous and should be confined to folk psychology. This form of labelling is unhelpful for science and should be replaced by specific mechanistic accounts of behavior and associated neural structures, which are amenable to rigorous scientific investigation. Mather provides a detailed review of octopus behavior, but rather than making unquantifiable assumptions about what orchestrates octopus behavior, efforts should focus on investigating cognitive mechanisms that can be measured. In this commentary, we outline two lines of research that include quantifiable methods to facilitate a more robust understanding of cephalopod behaviors and their cognitive underpinnings