Elizabeth Brannon - Profile on Academia.edu (original) (raw)

Papers by Elizabeth Brannon

Children perform better on left than right targets in an ordinal task

Acta Psychologica, 2022

Neural basis of number word mapping in cardinal principle knowers

What makes our minds human? How did they evolve to be this way? This dissertation presents data f... more What makes our minds human? How did they evolve to be this way? This dissertation presents data from two complementary lines of research driven by these orienting questions. The first of these explores the 'what' of human cognitive evolution through comparative studies with chimpanzees and bonobos. The general aim of these studies is to understand which aspects of cognition are unique to humans, and which are shared with our closest living relatives. Chapters 2---3 test the hypothesis that humans have unique cognitive skills for reasoning about the attention of other individuals (theory of mind), and unique motivation to use these skills in cooperative contexts with conspecifics. In Chapter 2 I show that understanding others' attention is unlikely to be the 'small difference that makes the big difference', as some researchers have proposed. However, my data support the possibility that species differences in the ontogeny of these skills may have robust consequences for the adult cognitive phenotype. In Chapter 3 I show that (contrary to previous reports) nonhuman apes are also motivated to engage in some simple triadic social activities, which resemble those characteristic of human children. Again however, I identify important differences between humans and other apes in v their spontaneous preferences for these types of activities, and their attitudes toward a partner when cooperative behaviors are interrupted. The second half of this dissertation (Chapters 4---5) explores the 'why' and 'how' of cognitive evolution. Chapter 4 outlines the kind of research questions and methods that comparative psychologists will need to embrace in order to use the comparative method to its full potential in the study of cognitive evolution. Chapter 5 provides a proof of principle for this approach using a dataset including 33 species tested on two cognitive tasks measuring inhibitory control. Here I show that cognitive skills for inhibitory control are closely related to phylogeny across species, and strongly predicted by absolute (but not relative) brain size. Further, I show that two of the other leading hypotheses put forth to explain primate intelligence, namely sociality and diet, do not predict cognitive skills on these tasks. These data illustrate the power of the comparative method for understanding cognitive evolution, and provide a starting point for future studies embracing this approach. Collectively, this research refines our understanding of how human cognition differs from that of other primates, and illustrates the utility of studying cognitive evolution from an explicitly phylogenetic comparative framework. vi To my parents, Paul and Roberta MacLean.

It has been suggested that primate brains are inherently biased towards gathering and processing ... more It has been suggested that primate brains are inherently biased towards gathering and processing the social information present in the world. In fact, the neural network that mediates our engagement with the external world-the default mode network (DMN)-is strongly convergent with the neural circuitry for social cognition. The posterior cingulate (PCC) is believed to be a key node in both the DMN and in social cognition. Human and non-human primate studies have demonstrated a role for the PCC in outcome monitoring: it tracks rewards, subjective values of choices, task engagement and global choice strategies. It is also implicated in social cognition. Human studies show that PCC activity varies with the recall of autobiographical memories and exposure to social stimuli. While several electrophysiological studies explicate the response of PCC neurons to non-social outcome monitoring and valuation, there is a lack of similar studies for social valuation. This thesis is concerned with characterizing the neuronal responses in the PCC to social stimuli and determining whether social valuation occurs in the PCC in a manner similar to that previously described for nonsocial outcomes. I recorded the single unit activity of neurons in the PCC of rhesus macaques while they performed behavioral tasks that required attending to the faces of high-status or low-status individuals. Monkeys valued the faces of high-status individuals more than low-status individuals, though they were equally likely to v identity and overtly attend to faces of both social classes. This differential valuation of face stimuli was represented in the firing activity of PCC neurons, with higher neuronal activity seen in response to subordinate faces as compared to dominant ones. Cells in the PCC did not track the individual identity of the presented faces. Furthermore, neuronal activity in the PCC predominantly tracked social value, and not non-social reward delivery as previously reported. Neuronal activity also predicted task engagement, with higher firing rates being predictive of a decrease in task engagement. To summarize, the PCC is biased towards social information processing, and neuronal activity in the PCC tracks the salience of social information.

The Cognitive Animal, 2002

Cognitive Science, 2016

The approximate number system (ANS) is frequently considered to be a foundation for the acquisiti... more The approximate number system (ANS) is frequently considered to be a foundation for the acquisition of uniquely human symbolic numerical capabilities. However, the mechanism by which the ANS influences symbolic number representations and mathematical thought remains poorly understood. Here, we tested the relation between ANS acuity, cardinal number knowledge, approximate arithmetic, and symbolic math achievement in a one-year longitudinal investigation of preschoolers’ early math abilities. Our results suggest that cardinal number knowledge is an intermediary factor in the relation between ANS acuity and symbolic math achievement. Furthermore, approximate arithmetic performance contributes unique variance to math achievement that is not accounted for by ANS acuity. These findings suggest that there are multiple routes by which the ANS influences math achievement. Therefore, interventions targeting both the precision and manipulability of the ANS may prove to be more beneficial for i...

Journal of Vision, 2020

Several non-numerical factors influence the numerical estimation of visual arrays, including the ... more Several non-numerical factors influence the numerical estimation of visual arrays, including the spacing of items and whether they are arranged randomly or symmetrically. Here we report a novel numerosity illusion we term the coherence illusion. When items in an array have a coherent orientation (all pointing in the same direction) they seem to be more numerous than when items are oriented randomly. Participants show parametric effects of orientation coherence in three distinct numerical judgment tasks. These findings are not predicted by any current model of numerical estimation. We discuss array entropy as a possible framework for explaining both the coherence illusion and the previously reported regular-random illusion.

Cognition, 2020

Humans are thought to use the approximate number system (ANS) to make quick approximations based ... more Humans are thought to use the approximate number system (ANS) to make quick approximations based on quantity even before learning to count. However, there has long been controversy regarding the salience of number versus other stimulus dimensions throughout development, including a recent proposal that number sense is derived from a sense of general magnitude. Here, we used a regression approach to disentangle numerical acuity from sensitivity to total surface area in both 5-year-old children and adults. We found that both children and adults displayed higher acuity when making numerosity judgments than total surface area judgements. Adults were largely able to ignore irrelevant stimulus features when making numerosity or total area judgements. Children were more biased by numerosity when making total area judgments than by total area when making numerosity judgments. These results provide evidence that number is more salient than total surface area even before the start of formal education and are inconsistent with the Sense of Magnitude proposal.

Scientific Reports, 2020

concept learning provides a fundamental building block for many cognitive functions in humans. He... more concept learning provides a fundamental building block for many cognitive functions in humans. Here we address whether rhesus monkeys (Macaca mulatta) can learn the abstract concept of “middle” in a series of objects. First, we trained monkeys to select the middle dot in a horizontal series of three dots presented on a touchscreen. Monkeys maintained a preference to choose the middle dot despite changes in the appearance, location, and spacing of the horizontal series of dots. They maintained high performance when the color, shape and the length of the stimuli were new, indicating that their responses did not depend upon the particular appearance of the array items. Next, we asked whether monkeys would generalize the middle concept to a 7 dot series. Although accuracy decreased when the number of dots was increased, monkeys continued to preferentially select the middle dot. Our results demonstrate that rhesus macaques can learn to use a middle concept for a discrete set of items.

Non-symbolic division ability mediates the relation between visual number discrimination acuity and symbolic math skill

Journal of Vision, 2018

Automatic Encoding of Visual Numerosity

Journal of Vision, 2018

PloS one, 2017

The "number sense" describes the intuitive ability to quantify without counting. Single... more The "number sense" describes the intuitive ability to quantify without counting. Single neuron recordings in non-human primates and functional imaging in humans suggest the intraparietal sulcus is an important neuroanatomical locus of numerical estimation. Other lines of inquiry implicate the IPS in numerous other functions, including attention and decision making. Here we provide a direct test of whether IPS has functional specificity for numerosity judgments. We used muscimol to reversibly and independently inactivate the ventral and lateral intraparietal areas in two monkeys performing a numerical discrimination task and a color discrimination task, roughly equilibrated for difficulty. Inactivation of either area caused parallel impairments in both tasks and no evidence of a selective deficit in numerical processing. These findings do not support a causal role for the IPS in numerical discrimination, except insofar as it also has a role in the discrimination of color. W...

Language Learning and Development, 2017

In this article we first review evidence for the approximate number system (ANS), an evolutionari... more In this article we first review evidence for the approximate number system (ANS), an evolutionarily ancient and developmentally conservative cognitive mechanism for representing number without language. We then critically review five different lines of support for the proposal that symbolic representations of number build upon the ANS, and discuss potential causes of conflicting findings in the literature. Finally, we consider potential mechanisms that could drive a relationship between the ANS and symbolic math. We conclude that while there is considerable evidence the relationship between the ANS and symbolic math is meaningful, we are far from understanding the cognitive and neural mechanisms that underlie this relationship.

Cognition, 2017

Numerical acuity, frequently measured by a Weber fraction derived from nonsymbolic numerical comp... more Numerical acuity, frequently measured by a Weber fraction derived from nonsymbolic numerical comparison judgments, has been shown to be predictive of mathematical ability. However, recent findings suggest that stimulus controls in these tasks are often insufficiently implemented, and the proposal has been made that alternative visual features or inhibitory control capacities may actually explain this relation. Here, we use a novel mathematical algorithm to parse the relative influence of numerosity from other visual features in nonsymbolic numerical discrimination and to examine the strength of the relations between each of these variables, including inhibitory control, and mathematical ability. We examined these questions developmentally by testing 4-year-old children, 6-year-old children, and adults with a nonsymbolic numerical comparison task, a symbolic math assessment, and a test of inhibitory control. We found that the influence of non-numerical features decreased significantly over development but that numerosity was a primary determinate of decision making at all ages. In addition, numerical acuity was a stronger predictor of math achievement than either non-numerical bias or inhibitory control in children. These results suggest that the ability to selectively attend to number contributes to the maturation of the number sense and that numerical acuity, independent of inhibitory control, contributes to math achievement in early childhood.

NeuroImage, 2017

While parietal cortex is thought to be critical for representing numerical magnitudes, we recentl... more While parietal cortex is thought to be critical for representing numerical magnitudes, we recently reported an event-related potential (ERP) study demonstrating selective neural sensitivity to numerosity over midline occipital sites very early in the time course, suggesting the involvement of early visual cortex in numerosity processing. However, which specific brain area underlies such early activation is not known. Here, we tested whether numerosity-sensitive neural signatures arise specifically from the initial stages of visual cortex, aiming to localize the generator of these signals by taking advantage of the distinctive folding pattern of early occipital cortices around the calcarine sulcus, which predicts an inversion of polarity of ERPs arising from these areas when stimuli are presented in the upper versus lower visual field. Dot arrays, including 8-32 dots constructed systematically across various numerical and non-numerical visual attributes, were presented randomly in either the upper or lower visual hemifields. Our results show that neural responses at about 90 ms post-stimulus were robustly sensitive to numerosity. Moreover, the peculiar pattern of polarity inversion of numerosity-sensitive activity at this stage suggested its generation primarily in V2 and V3. In contrast, numerosity-sensitive ERP activity at occipito-parietal channels later in the time course (210-230 ms) did not show polarity inversion, indicating a subsequent processing stage in the dorsal stream. Overall, these results demonstrate that numerosity processing begins in one of the earliest stages of the cortical visual stream.

Developmental science, May 5, 2017

Adult neuroimaging studies have demonstrated dissociable neural activation patterns in the visual... more Adult neuroimaging studies have demonstrated dissociable neural activation patterns in the visual cortex in response to letters (Latin alphabet) and numbers (Arabic numerals), which suggest a strong experiential influence of reading and mathematics on the human visual system. Here, developmental trajectories in the event-related potential (ERP) patterns evoked by visual processing of letters, numbers, and false fonts were examined in four different age groups (7-, 10-, 15-year-olds, and young adults). The 15-year-olds and adults showed greater neural sensitivity to letters over numbers in the left visual cortex and the reverse pattern in the right visual cortex, extending previous findings in adults to teenagers. In marked contrast, 7- and 10-year-olds did not show this dissociable neural pattern. Furthermore, the contrast of familiar stimuli (letters or numbers) versus unfamiliar ones (false fonts) showed stark ERP differences between the younger (7- and 10-year-olds) and the older...

Journal of experimental child psychology, 2017

Ambiguity aversion arises when a decision maker prefers risky gambles with known probabilities ov... more Ambiguity aversion arises when a decision maker prefers risky gambles with known probabilities over equivalent ambiguous gambles with unknown probabilities. This phenomenon has been consistently observed in adults across a large body of empirical work. Evaluating ambiguity aversion in young children, however, has posed methodological challenges because probabilistic representations appropriate for adults might not be understood by young children. Here, we established a novel method for representing risk and ambiguity with physical objects that overcomes previous methodological limitations and allows us to measure ambiguity aversion in young children. We found that individual 5-year-olds exhibited consistent choice preferences and, as a group, exhibited no ambiguity aversion in a task that evokes ambiguity aversion in adults. Across individuals, 5-year-olds exhibited greater variance in ambiguity preferences compared with adults tested under similar conditions. This suggests that amb...

Journal of experimental child psychology, 2016

Math proficiency at early school age is an important predictor of later academic achievement. Thu... more Math proficiency at early school age is an important predictor of later academic achievement. Thus, an important goal for society should be to improve math readiness in preschool-age children, especially in low-income children who typically arrive in kindergarten with less mathematical competency than their higher income peers. The majority of existing research-based math intervention programs target symbolic verbal number concepts in young children. However, very little attention has been paid to the preverbal intuitive ability to approximately represent numerical quantity, which is hypothesized to be an important foundation for full-fledged mathematical thinking. Here, we tested the hypothesis that repeated engagement of non-symbolic approximate addition and subtraction of large arrays of items results in improved math skills in very young children, an idea that stems from our previous studies in adults. In the current study, 3- to 5-year-olds showed selective improvements in math...

Nonverbal Representations of Time and Number in Animals and Human Infants

Frontiers in Neuroscience, 2003

Page 191. 6 Nonverbal Representations of Time and Number in Animals and Human Infants Elizabeth M... more Page 191. 6 Nonverbal Representations of Time and Number in Animals and Human Infants Elizabeth M. Brannon and Jamie D. Roitman 6.1 INTRODUCTION Scientists from many disciplines have been intrigued by the topic ...

Children perform better on left than right targets in an ordinal task

Acta Psychologica, 2022

Neural basis of number word mapping in cardinal principle knowers

What makes our minds human? How did they evolve to be this way? This dissertation presents data f... more What makes our minds human? How did they evolve to be this way? This dissertation presents data from two complementary lines of research driven by these orienting questions. The first of these explores the 'what' of human cognitive evolution through comparative studies with chimpanzees and bonobos. The general aim of these studies is to understand which aspects of cognition are unique to humans, and which are shared with our closest living relatives. Chapters 2---3 test the hypothesis that humans have unique cognitive skills for reasoning about the attention of other individuals (theory of mind), and unique motivation to use these skills in cooperative contexts with conspecifics. In Chapter 2 I show that understanding others' attention is unlikely to be the 'small difference that makes the big difference', as some researchers have proposed. However, my data support the possibility that species differences in the ontogeny of these skills may have robust consequences for the adult cognitive phenotype. In Chapter 3 I show that (contrary to previous reports) nonhuman apes are also motivated to engage in some simple triadic social activities, which resemble those characteristic of human children. Again however, I identify important differences between humans and other apes in v their spontaneous preferences for these types of activities, and their attitudes toward a partner when cooperative behaviors are interrupted. The second half of this dissertation (Chapters 4---5) explores the 'why' and 'how' of cognitive evolution. Chapter 4 outlines the kind of research questions and methods that comparative psychologists will need to embrace in order to use the comparative method to its full potential in the study of cognitive evolution. Chapter 5 provides a proof of principle for this approach using a dataset including 33 species tested on two cognitive tasks measuring inhibitory control. Here I show that cognitive skills for inhibitory control are closely related to phylogeny across species, and strongly predicted by absolute (but not relative) brain size. Further, I show that two of the other leading hypotheses put forth to explain primate intelligence, namely sociality and diet, do not predict cognitive skills on these tasks. These data illustrate the power of the comparative method for understanding cognitive evolution, and provide a starting point for future studies embracing this approach. Collectively, this research refines our understanding of how human cognition differs from that of other primates, and illustrates the utility of studying cognitive evolution from an explicitly phylogenetic comparative framework. vi To my parents, Paul and Roberta MacLean.

It has been suggested that primate brains are inherently biased towards gathering and processing ... more It has been suggested that primate brains are inherently biased towards gathering and processing the social information present in the world. In fact, the neural network that mediates our engagement with the external world-the default mode network (DMN)-is strongly convergent with the neural circuitry for social cognition. The posterior cingulate (PCC) is believed to be a key node in both the DMN and in social cognition. Human and non-human primate studies have demonstrated a role for the PCC in outcome monitoring: it tracks rewards, subjective values of choices, task engagement and global choice strategies. It is also implicated in social cognition. Human studies show that PCC activity varies with the recall of autobiographical memories and exposure to social stimuli. While several electrophysiological studies explicate the response of PCC neurons to non-social outcome monitoring and valuation, there is a lack of similar studies for social valuation. This thesis is concerned with characterizing the neuronal responses in the PCC to social stimuli and determining whether social valuation occurs in the PCC in a manner similar to that previously described for nonsocial outcomes. I recorded the single unit activity of neurons in the PCC of rhesus macaques while they performed behavioral tasks that required attending to the faces of high-status or low-status individuals. Monkeys valued the faces of high-status individuals more than low-status individuals, though they were equally likely to v identity and overtly attend to faces of both social classes. This differential valuation of face stimuli was represented in the firing activity of PCC neurons, with higher neuronal activity seen in response to subordinate faces as compared to dominant ones. Cells in the PCC did not track the individual identity of the presented faces. Furthermore, neuronal activity in the PCC predominantly tracked social value, and not non-social reward delivery as previously reported. Neuronal activity also predicted task engagement, with higher firing rates being predictive of a decrease in task engagement. To summarize, the PCC is biased towards social information processing, and neuronal activity in the PCC tracks the salience of social information.

The Cognitive Animal, 2002

Cognitive Science, 2016

The approximate number system (ANS) is frequently considered to be a foundation for the acquisiti... more The approximate number system (ANS) is frequently considered to be a foundation for the acquisition of uniquely human symbolic numerical capabilities. However, the mechanism by which the ANS influences symbolic number representations and mathematical thought remains poorly understood. Here, we tested the relation between ANS acuity, cardinal number knowledge, approximate arithmetic, and symbolic math achievement in a one-year longitudinal investigation of preschoolers’ early math abilities. Our results suggest that cardinal number knowledge is an intermediary factor in the relation between ANS acuity and symbolic math achievement. Furthermore, approximate arithmetic performance contributes unique variance to math achievement that is not accounted for by ANS acuity. These findings suggest that there are multiple routes by which the ANS influences math achievement. Therefore, interventions targeting both the precision and manipulability of the ANS may prove to be more beneficial for i...

Journal of Vision, 2020

Several non-numerical factors influence the numerical estimation of visual arrays, including the ... more Several non-numerical factors influence the numerical estimation of visual arrays, including the spacing of items and whether they are arranged randomly or symmetrically. Here we report a novel numerosity illusion we term the coherence illusion. When items in an array have a coherent orientation (all pointing in the same direction) they seem to be more numerous than when items are oriented randomly. Participants show parametric effects of orientation coherence in three distinct numerical judgment tasks. These findings are not predicted by any current model of numerical estimation. We discuss array entropy as a possible framework for explaining both the coherence illusion and the previously reported regular-random illusion.

Cognition, 2020

Humans are thought to use the approximate number system (ANS) to make quick approximations based ... more Humans are thought to use the approximate number system (ANS) to make quick approximations based on quantity even before learning to count. However, there has long been controversy regarding the salience of number versus other stimulus dimensions throughout development, including a recent proposal that number sense is derived from a sense of general magnitude. Here, we used a regression approach to disentangle numerical acuity from sensitivity to total surface area in both 5-year-old children and adults. We found that both children and adults displayed higher acuity when making numerosity judgments than total surface area judgements. Adults were largely able to ignore irrelevant stimulus features when making numerosity or total area judgements. Children were more biased by numerosity when making total area judgments than by total area when making numerosity judgments. These results provide evidence that number is more salient than total surface area even before the start of formal education and are inconsistent with the Sense of Magnitude proposal.

Scientific Reports, 2020

concept learning provides a fundamental building block for many cognitive functions in humans. He... more concept learning provides a fundamental building block for many cognitive functions in humans. Here we address whether rhesus monkeys (Macaca mulatta) can learn the abstract concept of “middle” in a series of objects. First, we trained monkeys to select the middle dot in a horizontal series of three dots presented on a touchscreen. Monkeys maintained a preference to choose the middle dot despite changes in the appearance, location, and spacing of the horizontal series of dots. They maintained high performance when the color, shape and the length of the stimuli were new, indicating that their responses did not depend upon the particular appearance of the array items. Next, we asked whether monkeys would generalize the middle concept to a 7 dot series. Although accuracy decreased when the number of dots was increased, monkeys continued to preferentially select the middle dot. Our results demonstrate that rhesus macaques can learn to use a middle concept for a discrete set of items.

Non-symbolic division ability mediates the relation between visual number discrimination acuity and symbolic math skill

Journal of Vision, 2018

Automatic Encoding of Visual Numerosity

Journal of Vision, 2018

PloS one, 2017

The "number sense" describes the intuitive ability to quantify without counting. Single... more The "number sense" describes the intuitive ability to quantify without counting. Single neuron recordings in non-human primates and functional imaging in humans suggest the intraparietal sulcus is an important neuroanatomical locus of numerical estimation. Other lines of inquiry implicate the IPS in numerous other functions, including attention and decision making. Here we provide a direct test of whether IPS has functional specificity for numerosity judgments. We used muscimol to reversibly and independently inactivate the ventral and lateral intraparietal areas in two monkeys performing a numerical discrimination task and a color discrimination task, roughly equilibrated for difficulty. Inactivation of either area caused parallel impairments in both tasks and no evidence of a selective deficit in numerical processing. These findings do not support a causal role for the IPS in numerical discrimination, except insofar as it also has a role in the discrimination of color. W...

Language Learning and Development, 2017

In this article we first review evidence for the approximate number system (ANS), an evolutionari... more In this article we first review evidence for the approximate number system (ANS), an evolutionarily ancient and developmentally conservative cognitive mechanism for representing number without language. We then critically review five different lines of support for the proposal that symbolic representations of number build upon the ANS, and discuss potential causes of conflicting findings in the literature. Finally, we consider potential mechanisms that could drive a relationship between the ANS and symbolic math. We conclude that while there is considerable evidence the relationship between the ANS and symbolic math is meaningful, we are far from understanding the cognitive and neural mechanisms that underlie this relationship.

Cognition, 2017

Numerical acuity, frequently measured by a Weber fraction derived from nonsymbolic numerical comp... more Numerical acuity, frequently measured by a Weber fraction derived from nonsymbolic numerical comparison judgments, has been shown to be predictive of mathematical ability. However, recent findings suggest that stimulus controls in these tasks are often insufficiently implemented, and the proposal has been made that alternative visual features or inhibitory control capacities may actually explain this relation. Here, we use a novel mathematical algorithm to parse the relative influence of numerosity from other visual features in nonsymbolic numerical discrimination and to examine the strength of the relations between each of these variables, including inhibitory control, and mathematical ability. We examined these questions developmentally by testing 4-year-old children, 6-year-old children, and adults with a nonsymbolic numerical comparison task, a symbolic math assessment, and a test of inhibitory control. We found that the influence of non-numerical features decreased significantly over development but that numerosity was a primary determinate of decision making at all ages. In addition, numerical acuity was a stronger predictor of math achievement than either non-numerical bias or inhibitory control in children. These results suggest that the ability to selectively attend to number contributes to the maturation of the number sense and that numerical acuity, independent of inhibitory control, contributes to math achievement in early childhood.

NeuroImage, 2017

While parietal cortex is thought to be critical for representing numerical magnitudes, we recentl... more While parietal cortex is thought to be critical for representing numerical magnitudes, we recently reported an event-related potential (ERP) study demonstrating selective neural sensitivity to numerosity over midline occipital sites very early in the time course, suggesting the involvement of early visual cortex in numerosity processing. However, which specific brain area underlies such early activation is not known. Here, we tested whether numerosity-sensitive neural signatures arise specifically from the initial stages of visual cortex, aiming to localize the generator of these signals by taking advantage of the distinctive folding pattern of early occipital cortices around the calcarine sulcus, which predicts an inversion of polarity of ERPs arising from these areas when stimuli are presented in the upper versus lower visual field. Dot arrays, including 8-32 dots constructed systematically across various numerical and non-numerical visual attributes, were presented randomly in either the upper or lower visual hemifields. Our results show that neural responses at about 90 ms post-stimulus were robustly sensitive to numerosity. Moreover, the peculiar pattern of polarity inversion of numerosity-sensitive activity at this stage suggested its generation primarily in V2 and V3. In contrast, numerosity-sensitive ERP activity at occipito-parietal channels later in the time course (210-230 ms) did not show polarity inversion, indicating a subsequent processing stage in the dorsal stream. Overall, these results demonstrate that numerosity processing begins in one of the earliest stages of the cortical visual stream.

Developmental science, May 5, 2017

Adult neuroimaging studies have demonstrated dissociable neural activation patterns in the visual... more Adult neuroimaging studies have demonstrated dissociable neural activation patterns in the visual cortex in response to letters (Latin alphabet) and numbers (Arabic numerals), which suggest a strong experiential influence of reading and mathematics on the human visual system. Here, developmental trajectories in the event-related potential (ERP) patterns evoked by visual processing of letters, numbers, and false fonts were examined in four different age groups (7-, 10-, 15-year-olds, and young adults). The 15-year-olds and adults showed greater neural sensitivity to letters over numbers in the left visual cortex and the reverse pattern in the right visual cortex, extending previous findings in adults to teenagers. In marked contrast, 7- and 10-year-olds did not show this dissociable neural pattern. Furthermore, the contrast of familiar stimuli (letters or numbers) versus unfamiliar ones (false fonts) showed stark ERP differences between the younger (7- and 10-year-olds) and the older...

Journal of experimental child psychology, 2017

Ambiguity aversion arises when a decision maker prefers risky gambles with known probabilities ov... more Ambiguity aversion arises when a decision maker prefers risky gambles with known probabilities over equivalent ambiguous gambles with unknown probabilities. This phenomenon has been consistently observed in adults across a large body of empirical work. Evaluating ambiguity aversion in young children, however, has posed methodological challenges because probabilistic representations appropriate for adults might not be understood by young children. Here, we established a novel method for representing risk and ambiguity with physical objects that overcomes previous methodological limitations and allows us to measure ambiguity aversion in young children. We found that individual 5-year-olds exhibited consistent choice preferences and, as a group, exhibited no ambiguity aversion in a task that evokes ambiguity aversion in adults. Across individuals, 5-year-olds exhibited greater variance in ambiguity preferences compared with adults tested under similar conditions. This suggests that amb...

Journal of experimental child psychology, 2016

Math proficiency at early school age is an important predictor of later academic achievement. Thu... more Math proficiency at early school age is an important predictor of later academic achievement. Thus, an important goal for society should be to improve math readiness in preschool-age children, especially in low-income children who typically arrive in kindergarten with less mathematical competency than their higher income peers. The majority of existing research-based math intervention programs target symbolic verbal number concepts in young children. However, very little attention has been paid to the preverbal intuitive ability to approximately represent numerical quantity, which is hypothesized to be an important foundation for full-fledged mathematical thinking. Here, we tested the hypothesis that repeated engagement of non-symbolic approximate addition and subtraction of large arrays of items results in improved math skills in very young children, an idea that stems from our previous studies in adults. In the current study, 3- to 5-year-olds showed selective improvements in math...

Nonverbal Representations of Time and Number in Animals and Human Infants

Frontiers in Neuroscience, 2003

Page 191. 6 Nonverbal Representations of Time and Number in Animals and Human Infants Elizabeth M... more Page 191. 6 Nonverbal Representations of Time and Number in Animals and Human Infants Elizabeth M. Brannon and Jamie D. Roitman 6.1 INTRODUCTION Scientists from many disciplines have been intrigued by the topic ...