scholarly journals Brain size predicts problem-solving ability in mammalian carnivores

2016 ◽  
Vol 113 (9) ◽  
pp. 2532-2537 ◽  
Author(s):  
Sarah Benson-Amram ◽  
Ben Dantzer ◽  
Gregory Stricker ◽  
Eli M. Swanson ◽  
Kay E. Holekamp

Despite considerable interest in the forces shaping the relationship between brain size and cognitive abilities, it remains controversial whether larger-brained animals are, indeed, better problem-solvers. Recently, several comparative studies have revealed correlations between brain size and traits thought to require advanced cognitive abilities, such as innovation, behavioral flexibility, invasion success, and self-control. However, the general assumption that animals with larger brains have superior cognitive abilities has been heavily criticized, primarily because of the lack of experimental support for it. Here, we designed an experiment to inquire whether specific neuroanatomical or socioecological measures predict success at solving a novel technical problem among species in the mammalian order Carnivora. We presented puzzle boxes, baited with food and scaled to accommodate body size, to members of 39 carnivore species from nine families housed in multiple North American zoos. We found that species with larger brains relative to their body mass were more successful at opening the boxes. In a subset of species, we also used virtual brain endocasts to measure volumes of four gross brain regions and show that some of these regions improve model prediction of success at opening the boxes when included with total brain size and body mass. Socioecological variables, including measures of social complexity and manual dexterity, failed to predict success at opening the boxes. Our results, thus, fail to support the social brain hypothesis but provide important empirical support for the relationship between relative brain size and the ability to solve this novel technical problem.

2018 ◽  
Vol 68 (3) ◽  
pp. 309-320 ◽  
Author(s):  
Chun Lin Zhao ◽  
Long Jin ◽  
Mao Jun Zhong ◽  
Feng Xie ◽  
Jian Ping Jiang ◽  
...  

AbstractThe ‘cognitive buffer’ hypothesis predicts that the costs of relatively large brains are compensated for later in life by the increased benefits of large brains providing a higher chance of survival under changing environments through flexible behaviors in the animal kingdom. Thus, animals that live in a larger range (with a higher probability of environmental variation) are expected to have larger brains than those that live in a restricted geographic range. Here, to test the prediction of the ‘cognitive buffer’ hypothesis that larger brains should be expected to occur in species living in geographic ranges of larger size, we analyzed the relationship between the size of the geographic range and brain size and the size of various brain regions among 42 species of anurans using phylogenetic comparative methods. The results show that there is no correlation between relative brain size and size of the species’ geographic range when correcting for phylogenetic effects and body size. Our findings suggest that the effects of the cognitive buffer and the energetic constraints on brains result in non-significant variation in overall brain size. However, the geographic range is positively correlated with cerebellum size, but not with optic tecta, suggesting that species distributed in a wider geographic range do not exhibit larger optic tecta which would provide behavioral flexibility to allow for an early escape from potential predators and discovery of new food resources in unpredictable environments.


2017 ◽  
Vol 122 (s1) ◽  
pp. S40-S48 ◽  
Author(s):  
Andrés Catena ◽  
Cristina Martínez-Zaldívar ◽  
Carolina Diaz-Piedra ◽  
Francisco J. Torres-Espínola ◽  
Pilar Brandi ◽  
...  

AbstractHead circumference in infants has been reported to predict brain size, total grey matter volume (GMV) and neurocognitive development. However, it is unknown whether it has predictive value on regional and subcortical brain volumes. We aimed to explore the relationship between several head circumference measurements since birth and distributions of GMV and subcortical volumes at later childhood. We examined seventy-four, Caucasian, singleton, term-born infants born to mothers randomised to receive fish oil and/or 5-methyltetrahydrofolate or placebo prenatal supplementation. We assessed head circumference at birth and at 4 and 10 years of age and cognitive abilities at 7 years of age. We obtained brain MRI at 10 years of age, on which we performed voxel-based morphometry, cortical surface extraction and subcortical segmentation. Analyses were controlled for sex, age, height, weight, family status, laterality and total intracranial volume. Prenatal supplementation did not affect head circumference at any age, cognitive abilities or total brain volumes. Head circumference at 4 years presented the highest correlation with total GMV, white matter volume and brain surface area, and was also strongly associated with GMV of frontal, temporal and occipital areas, as well as with caudate nucleus, globus pallidus, putamen and thalamus volumes. As relationships between brain volumes in childhood and several outcomes extend into adulthood, we have found that ages between 0 and 4 years as the optimal time for brain growth; postnatal factors might have the most relevant impact on structural maturation of certain cortical areas and subcortical nuclei, independent of prenatal supplementation.


2018 ◽  
Vol 285 (1890) ◽  
pp. 20181971 ◽  
Author(s):  
Caleb J. Axelrod ◽  
Frédéric Laberge ◽  
Beren W. Robinson

Variation in spatial complexity and foraging requirements between habitats can impose different cognitive demands on animals that may influence brain size. However, the relationship between ecologically related cognitive performance and brain size is not well established. We test whether variation in relative brain size and brain region size is associated with habitat use within a population of pumpkinseed sunfish composed of different ecotypes that inhabit either the structurally complex shoreline littoral habitat or simpler open-water pelagic habitat. Sunfish using the littoral habitat have on average 8.3% larger brains than those using the pelagic habitat. We found little difference in the proportional sizes of five brain regions between ecotypes. The results suggest that cognitive demands on sunfish may be reduced in the pelagic habitat given no habitat-specific differences in body condition. They also suggest that either a short divergence time or physiological processes may constrain changes to concerted, global modifications of brain size between sunfish ecotypes.


2019 ◽  
Author(s):  
Grace Elisabeth Shearrer ◽  
Kyle Stanley Burger ◽  
Jennifer R Sadler ◽  
Afroditi Papantoni

Onset of puberty has been associated with lower body mass index (BMI) in adulthood independent of childhood BMI. However, how the relationship between time of onset of puberty and BMI in adulthood is associated with neurocognitive outcomes is largely unstudied. Here, women were sampled from the Human Connectome Project 1200 PTN release. Inclusion criteria were: 4 (15 minute) resting state fMRI scans, current measured BMI, self-reported age at onset of menstruation (a proxy of age at onset of puberty), and no endocrine complications (e.g., polycystic ovarian syndrome). The effect of age at onset of menstruation, measured BMI at scan date, and the interaction of age at onset of menstruation by BMI on brain functional correlation was modeled using FSLnets controlling for race and age at scan. Corrected significance was set at pFWE<0.05. A final sample of n=510 (age 29.5y±3.6; BMI at scan 25.9±5.6; age at onset of menstruation 12.7±1.6) were included. Age at onset of menstruation was negatively associated with BMI at scan (r=-0.19, p<0.001). The interaction between age at onset of menstruation and BMI at scan was associated with stronger correlation between a somatosensory and visual network (t= 3.45, pFWE= 0.026), and a visual network and cingulo-opercular task control network (t= 4.74, pFWE= 0.0002). We show increased correlation between visual, taste-associated, and self-control brain regions in women at high BMI with later age at onset of menstruation. Together, this implies that the association between later menarche and lower BMI may impart improved self-control during exposure to visual cues.


2016 ◽  
Vol 283 (1827) ◽  
pp. 20152725 ◽  
Author(s):  
Jan Matějů ◽  
Lukáš Kratochvíl ◽  
Zuzana Pavelková ◽  
Věra Pavelková Řičánková ◽  
Vladimír Vohralík ◽  
...  

The social brain hypothesis (SBH) contends that cognitive demands associated with living in cohesive social groups favour the evolution of large brains. Although the correlation between relative brain size and sociality reported in various groups of birds and mammals provides broad empirical support for this hypothesis, it has never been tested in rodents, the largest mammalian order. Here, we test the predictions of the SBH in the ground squirrels from the tribe Marmotini. These rodents exhibit levels of sociality ranging from solitary and single-family female kin groups to egalitarian polygynous harems but feature similar ecologies and life-history traits. We found little support for the association between increase in sociality and increase in relative brain size. Thus, sociality does not drive the evolution of encephalization in this group of rodents, a finding inconsistent with the SBH. However, body mass and absolute brain size increase with sociality. These findings suggest that increased social complexity in the ground squirrels goes hand in hand with larger body mass and brain size, which are tightly coupled to each other.


1996 ◽  
Vol 169 (1) ◽  
pp. 86-92 ◽  
Author(s):  
A. B. Graves ◽  
J. A. Mortimer ◽  
E. B. Larson ◽  
A. Wenzlow ◽  
J. D. Bowen ◽  
...  

BackgroundRecent studies suggest that larger brain size may offer some protection against the clinical manifestations of Alzheimer's disease. However, this association has not been investigated in population-based studies.MethodThe relationship between head circumference, a measure of premorbid brain size, and score on the Cognitive Abilities Screening Instrument (CASI) was studied in a population of 1985 Japanese–Americans aged 65+ living in King County, Washington, USA.ResultsAfter adjusting for age, sex and education, head circumference was positively associated with CASI score (b=3.8, 95% CI: 2.2, 5.4; P=0.0000), but not with diagnosis of probable AD (odds ratio=0.87, 95% CI: 0.33, 1.87). When the data were stratified by AD status, no association was seen among controls (b=1.6, 95% CI: – 1.7, 5.1; P=0.4), whereas a strong effect was present among cases (b=35.3, 95% CI: 12.2, 58.4: P=0.006).ConclusionsThese results suggest that persons with AD with smaller head circumference either had the disease longer or progressed more rapidly than those with larger head circumference. Improvement in environmental factors in prenatal and early life that partially determine completed brain/head size may have consequences for the late-life expression of Alzheimer's disease in vulnerable individuals.


2010 ◽  
Vol 278 (1707) ◽  
pp. 923-929 ◽  
Author(s):  
James G. Burns ◽  
Julien Foucaud ◽  
Frederic Mery

Variation in learning and memory abilities among closely related species, or even among populations of the same species, has opened research into the relationship between cognition, ecological context and the fitness costs, and benefits of learning and memory. Such research programmes have long been dominated by vertebrate studies and by the assumption of a relationship between cognitive abilities, brain size and metabolic costs. Research on these ‘large brained’ organisms has provided important insights into the understanding of cognitive functions and their adaptive value. In the present review, we discuss some aspects of the fitness costs of learning and memory by focusing on ‘mini-brain’ studies. Research on learning and memory in insects has challenged some traditional positions and is pushing the boundaries of our understanding of the evolution of learning and memory.


2000 ◽  
Vol 48 (1) ◽  
pp. 99 ◽  
Author(s):  
Andrew N. Iwaniuk ◽  
John E. Nelson ◽  
Ian Q. Whishaw

A behavioural index of forelimb dexterity and comparative statistics were used to analyse the relationships between proximal (shoulder, upper and lower forelimb) and distal (wrist, forepaw, digits) forelimb dexterity and four aspects of brain morphology (overall brain, cortex, cerebellum and telencephalon sizes) in 18 species of marsupials. On the basis of the principle of proper mass, it was expected that an increase in forelimb dexterity (either proximal or distal) would be positively correlated with the size of the brain and the three brain components. Using independent contrast analysis to remove the effects of phylogeny revealed three significant correlations between: cortex size and distal dexterity, cerebellum size and proximal dexterity, and telencephalon size and distal dexterity. The relationship between cortex size and distal dexterity was subsequently corroborated by Spearman rank correlations. These results suggest that the execution of finely coordinated forelimb movements may not be dependent upon overall brain size, but may be dependent upon the size of brain components, thus supporting the principle of proper mass.


2021 ◽  
Author(s):  
Michael Griesser ◽  
Szymon M Drobniak ◽  
Sereina M Graber ◽  
Carel van Schaik

Larger brains should be adaptive because they support numerous eco- and socio-cognitive benefits, but these benefits explain only a modest part of the interspecific variation in brain size. Notably underexplored are the high energetic costs of developing brains, and thus the possible role of parental provisioning in the evolution of adult brain size. We explore this idea in birds, which show considerable variation in both socio-ecological traits and the energy transfer from parents to offspring. Comparative analyses of 1,176 bird species show that the combination of adult body mass, mode of development at hatching, relative egg mass, and the time spent provisioning the young in combination strongly predict relative brain size across species. Adding adult eco- and socio-cognitive predictors only marginally adds explanatory value. We therefore conclude that parental provisioning enabled bird species to evolve into skill-intensive niches, reducing interspecific competition and consequently promoting survival prospects and population stability. Critically, parental provisioning also explains why precocial bird species have smaller brains than altricial ones. Finally, these results suggest that the cognitive adaptations that provide the behavioral flexibility to improve reproductive success and survival are intrinsically linked to successful parental provisioning. Our findings also suggest that the traditionally assessed cognitive abilities may not predict relative brain size.


2021 ◽  
pp. 35-50
Author(s):  
Susan D. Healy

In this chapter, I examine the evidence for a role for the preeminent selection pressure, ecology, in shaping animal brains and in causing changes in brain size within and among species. I describe what ‘ecology’ has meant in comparative analyses, e.g. foraging, range size, and life history variables. I provide evidence for a clear association between ecology and the size of sensory-motor brain regions and go on to use the relationship between space and the hippocampus to show the generality of this relationship beyond food storing. I discuss the strength of the data showing that migration, foraging, and domestication have caused changes in brain size. I conclude that while there is evidence of domestication, in particular, having changed whole brain size, it is at the level of brain regions that there is overwhelming evidence for an effect of ecology on brain size.


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