Basic Math in Monkeys and College Students

Adult humans possess a sophisticated repertoire of mathematical faculties. Many of these capacities are rooted in symbolic language and are therefore unlikely to be shared with nonhuman animals. However, a subset of these skills is shared with other animals, and this set is considered a cognitive vestige of our common evolutionary history. Current evidence indicates that humans and nonhuman animals share a core set of abilities for representing and comparing approximate numerosities nonverbally; however, it remains unclear whether nonhuman animals can perform approximate mental arithmetic. Here we show that monkeys can mentally add the numerical values of two sets of objects and choose a visual array that roughly corresponds to the arithmetic sum of these two sets. Furthermore, monkeys' performance during these calculations adheres to the same pattern as humans tested on the same nonverbal addition task. Our data demonstrate that nonverbal arithmetic is not unique to humans but is instead part of an evolutionarily primitive system for mathematical thinking shared by monkeys

The evolution of quantitative sensitivity

This work was supported by the National Science Foundation Graduate Research Fellowship Programme grant no. DGE-1419118 to S.E.K., and NSF 2000759 from the Division of Research on Learning in Formal and Informal Settings (DRL) to S.T.P., the Austrian Science Fund (FWF project no. P33928_B) to F.R., the Alfred P. Sloan Foundation Fellowship grant no. 220020300 to J.F.C., National Institutes of Health grant no. R01 HD085996 to J.F.C. and S.T.P. and the James S. McDonnell Foundation.The ability to represent approximate quantities appears to be phylogenetically widespread, but the selective pressures and proximate mechanisms favouring this ability remain unknown. We analysed quantity discrimination data from 672 subjects across 33 bird and mammal species, using a novel Bayesian model that combined phylogenetic regression with a model of number psychophysics and random effect components. This allowed us to combine data from 49 studies and calculate the Weber fraction (a measure of quantity representation precision) for each species. We then examined which cognitive, socioecological and biological factors were related to variance in Weber fraction. We found contributions of phylogeny to quantity discrimination performance across taxa. Of the neural, socioecological and general cognitive factors we tested, cortical neuron density and domain-general cognition were the strongest predictors of Weber fraction, controlling for phylogeny. Our study is a new demonstration of evolutionary constraints on cognition, as well as of a relation between species-specific neuron density and a particular cognitive ability. This article is part of the theme issue 'Systems neuroscience through the lens of evolutionary theory'.Publisher PDFPeer reviewe

Functional Imaging of Numerical Processing in Adults and 4-y-Old Children

Adult humans, infants, pre-school children, and non-human animals appear to share a system of approximate numerical processing for non-symbolic stimuli such as arrays of dots or sequences of tones. Behavioral studies of adult humans implicate a link between these non-symbolic numerical abilities and symbolic numerical processing (e.g., similar distance effects in accuracy and reaction-time for arrays of dots and Arabic numerals). However, neuroimaging studies have remained inconclusive on the neural basis of this link. The intraparietal sulcus (IPS) is known to respond selectively to symbolic numerical stimuli such as Arabic numerals. Recent studies, however, have arrived at conflicting conclusions regarding the role of the IPS in processing non-symbolic, numerosity arrays in adulthood, and very little is known about the brain basis of numerical processing early in development. Addressing the question of whether there is an early-developing neural basis for abstract numerical processing is essential for understanding the cognitive origins of our uniquely human capacity for math and science. Using functional magnetic resonance imaging (fMRI) at 4-Tesla and an event-related fMRI adaptation paradigm, we found that adults showed a greater IPS response to visual arrays that deviated from standard stimuli in their number of elements, than to stimuli that deviated in local element shape. These results support previous claims that there is a neurophysiological link between non-symbolic and symbolic numerical processing in adulthood. In parallel, we tested 4-y-old children with the same fMRI adaptation paradigm as adults to determine whether the neural locus of non-symbolic numerical activity in adults shows continuity in function over development. We found that the IPS responded to numerical deviants similarly in 4-y-old children and adults. To our knowledge, this is the first evidence that the neural locus of adult numerical cognition takes form early in development, prior to sophisticated symbolic numerical experience. More broadly, this is also, to our knowledge, the first cognitive fMRI study to test healthy children as young as 4 y, providing new insights into the neurophysiology of human cognitive development

The evolution of self-control

This work was supported by the National Evolutionary Synthesis Center (NESCent) through support of a working group led by C.L.N. and B.H. NESCent is supported by the National Science Foundation (NSF) EF-0905606. For training in phylogenetic comparative methods, we thank the AnthroTree Workshop (supported by NSF BCS-0923791). Y.S. thanks the National Natural Science Foundation of China (Project 31170995) and National Basic Research Program (973 Program: 2010CB833904). E.E.B. thanks the Duke Vertical Integration Program and the Duke Undergraduate Research Support Office. J.M.P. was supported by a Newton International Fellowship from the Royal Society and the British Academy. L.R.S. thanks the James S. McDonnell Foundation for Award 220020242. L.J.N.B. and M.L.P. acknowledge the National Institutes of Mental Health (R01-MH096875 and R01-MH089484), a Duke Institute for Brain Sciences Incubator Award (to M.L.P.), and a Duke Center for Interdisciplinary Decision Sciences Fellowship (to L.J.N.B.). E.V. and E.A. thank the Programma Nazionale per la Ricerca–Consiglio Nazionale delle Ricerche (CNR) Aging Program 2012–2014 for financial support, Roma Capitale–Museo Civico di Zoologia and Fondazione Bioparco for hosting the Istituto di Scienze e Tecnologie della Cognizione–CNR Unit of Cognitive Primatology and Primate Centre, and Massimiliano Bianchi and Simone Catarinacci for assistance with capuchin monkeys. K.F. thanks the Japan Society for the Promotion of Science (JSPS) for Grant-in-Aid for Scientific Research 20220004. F. Aureli thanks the Stages in the Evolution and Development of Sign Use project (Contract 012-984 NESTPathfinder) and the Integrating Cooperation Research Across Europe project (Contract 043318), both funded by the European Community’s Sixth Framework Programme (FP6/2002–2006). F. Amici was supported by Humboldt Research Fellowship for Postdoctoral Researchers (Humboldt ID 1138999). L.F.J. and M.M.D. acknowledge NSF Electrical, Communications, and Cyber Systems Grant 1028319 (to L.F.J.) and an NSF Graduate Fellowship (to M.M.D.). C.H. thanks Grant-in-Aid for JSPS Fellows (10J04395). A.T. thanks Research Fellowships of the JSPS for Young Scientists (21264). F.R. and Z.V. acknowledge Austrian Science Fund (FWF) Project P21244-B17, the European Research Council (ERC) under the European Union’s Seventh Framework Programme (FP/2007–2013)/ERC Grant Agreement 311870 (to F.R.), Vienna Science and Technology Fund Project CS11-026 (to Z.V.), and many private sponsors, including Royal Canin for financial support and the Game Park Ernstbrunn for hosting the Wolf Science Center. S.M.R. thanks the Natural Sciences and Engineering Research Council (Canada). J.K.Y. thanks the US Department of Agriculture–Wildlife Services–National Wildlife Research Center. J.F.C. thanks the James S. McDonnell Foundation and Alfred P. Sloan Foundation. E.L.M. and B.H. thank the Duke Lemur Center and acknowledge National Institutes of Health Grant 5 R03 HD070649-02 and NSF Grants DGE-1106401, NSF-BCS-27552, and NSF-BCS-25172. This is Publication 1265 of the Duke Lemur Center.Cognition presents evolutionary research with one of its greatest challenges. Cognitive evolution has been explained at the proximate level by shifts in absolute and relative brain volume and at the ultimate level by differences in social and dietary complexity. However, no study has integrated the experimental and phylogenetic approach at the scale required to rigorously test these explanations. Instead, previous research has largely relied on various measures of brain size as proxies for cognitive abilities. We experimentally evaluated these major evolutionary explanations by quantitatively comparing the cognitive performance of 567 individuals representing 36 species on two problem-solving tasks measuring self-control. Phylogenetic analysis revealed that absolute brain volume best predicted performance across species and accounted for considerably more variance than brain volume controlling for body mass. This result corroborates recent advances in evolutionary neurobiology and illustrates the cognitive consequences of cortical reorganization through increases in brain volume. Within primates, dietary breadth but not social group size was a strong predictor of species differences in self-control. Our results implicate robust evolutionary relationships between dietary breadth, absolute brain volume, and self-control. These findings provide a significant first step toward quantifying the primate cognitive phenome and explaining the process of cognitive evolution.PostprintPeer reviewe

The evolutionary and developmental origins of human thought.

Thesis (Ph. D.)--University of Rochester. Department of Brain and Cognitive Sciences, 2018.Across cognitive domains, evolutionarily primitive mechanisms and cultural innovations combine to form complex human thought. However, the precise role of each of these factors as well as how and when they are combined are less well understood. Comparisons of how human children, adults from various backgrounds, and non-human animals think and understand the world can provide insight into how humans develop, how they evolved, and which aspects of human cognition are fundamental (common across all humans and shared with other species), uniquely human, or cultural specific. This thesis takes a comparative and developmental approach to test whether number logic (Chapter 2), recursive sequencing (Chapter 3), logical inference (Chapter 4), and metacognition (Chapter 5), are present in non-human primates as well as humans with different ages, education levels, and cultural backgrounds. The data provides evidence that the foundations for complex human logic and thought have early developing and evolutionarily primitive origins. Additionally, the results show that uniquely human factors like language, education, and human culture affect and build upon the basic foundations present in non-human primates and young children to form complex, uniquely human thought

The Cognitive neuroscience of mathematics : tuning up the number system.

Thesis (Ph. D.)--University of Rochester. Department of Brain and Cognitive Sciences, 2014.Living in today's society demands a functional control of math. Recent research suggests that adult mathematical skill is founded on an ontogenetically early emerging number sense, or ability to approximately estimate quantities. This ability is shared with many species, suggesting it represents a core and primitive approximate number system (ANS). Neuroimaging research in both monkeys and humans has linked the ANS to the to the neural responses of the intraparietal sulcus (IPS). As children mature, learn to count and calculate, the BOLD responses of the IPS bear the ratio-dependent signature of the approximate number system. These neural responses show longitudinal profiles that suggest the ANS is relatively stable and sharpens its numerical representations across development in a way that predict their behavioral performance (Emerson & Cantlon, 2014). Children also show math-specific functional connections between the IPS and areas of frontal cortex (Emerson & Cantlon, 2012). This suggests that the IPS plays a role in fine-tuning number and math skills during development. In adults, we have observed a segregation of number-related processes vs other quantitative processes (size/brightness) in the IPS. Regions of the IPS that show a selective response to number overlap with regions that show a ratio-dependent response profile, defining the right IPS as an area of the brain that supports non-verbal numerical skill. Furthermore, we find that cortical thickness correlates with scores on standardized math assessments (SAT) in an area of the right IPS, overlapping regions that are functionally related to number skill. In other words, anatomical and functional variability in the IPS is related to both the ANS and math skill in typical adults. When we tested this region in people with advanced math training, we observed both a heightened neural response to numerical ratio as well as significantly thinner cortex in the depth of the IPS. Compared to typical adults, experts are showing a stronger response of the ANS as well as thinner cortex in a region that correlates with math skills in non-experts (Emerson, Vo, Lussier, Kurtz, & Cantlon, submitted). Taken together, these data converge on the conclusion that our uniquely human ability to use symbolic arithmetic is critically linked to our primitive approximate number skill through a shared neural substrate in the intraparietal sulcus