Special Special Special Special issue: issue: issue: issue: Research Research Research Research report report report report Numerical Numerical Numerical Numerical Numerical encoding encoding encoding encoding encoding in in in in in early early early early early visual visual visual visual visual cortex cortex cortex cortex cortex Q1 Q1 Q1 Q11 1 1 1 Q1 Q1 Q1 Q10 0 0 0 Nicholas Nicholas Nicholas Nicholas K. K. K. K. DeWind DeWind DeWind DeWind a a a a, , , ,* * * * , , , , Joonkoo Joonkoo Joonkoo Joonkoo Park Park Park Park b b b b , , , , Marty Marty Marty Marty G. G. G. G. Woldorff Woldorff Woldorff Woldorff c c c c and and and and Elizabeth Elizabeth Elizabeth Elizabeth M. M. M. M. Brannon Brannon Brannon Brannon a a a a a a a a Department Department Department Department of of of of Psychology, Psychology, Psychology, Psychology, University University University University of of of of Pennsylvania, Pennsylvania, Pennsylvania, Pennsylvania, Philadelphia, Philadelphia, Philadelphia, Philadelphia, PA, PA, PA, PA, USA USA USA USA b b b b Department Department Department Department of of of of Psychological Psychological Psychological Psychological and and and and Brain Brain Brain Brain Sciences, Sciences, Sciences, Sciences, University University University University of of of of Massachusetts Massachusetts Massachusetts Massachusetts Amherst, Amherst, Amherst, Amherst, Amherst, Amherst, Amherst, Amherst, MA, MA, MA, MA, USA USA USA USA Q1 Q1 Q1 Q1 c c c c Department Department Department Department of of of of Psychology Psychology Psychology Psychology and and and and Neuroscience, Neuroscience, Neuroscience, Neuroscience, Duke Duke Duke Duke University, University, University, University, Durham, Durham, Durham, Durham, NC, NC, NC, NC, USA USA USA USA articleinfo articleinfo articleinfo articleinfo Article Article Article Article history: history: history: history: Received Received Received Received 17 17 17 17 December December December December 2017 2017 2017 2017 Reviewed Reviewed Reviewed Reviewed 23 23 23 23 January January January January 2018 2018 2018 2018 Revised Revised Revised Revised 13 13 13 13 March March March March 2018 2018 2018 2018 Accepted Accepted Accepted Accepted 27 27 27 27 March March March March 2018 2018 2018 2018 Published Published Published Published online online online online xxx xxx xxx xxx Keywords: Keywords: Keywords: Keywords: Numerosity Numerosity Numerosity Numerosity Intraparietal Intraparietal Intraparietal Intraparietal area area area area Early Early Early Early visual visual visual visual cortex cortex cortex cortex Q3 Q3 Q3 Q3 abstract abstract abstract abstract The The The The ability ability ability ability to to to to estimate estimate estimate estimate the the the the number number number number in in in in a a a a visual visual visual visual array array array array arose arose arose arose early early early early in in in in evolution, evolution, evolution, evolution, develops develops develops develops early early early early in in in in hu hu hu human man man man developme developme developme development, nt, nt, nt, and and and and is is is is correla correla correla correlated ted ted ted with with with with mathematical mathematical mathematical mathematical ability. ability. ability. ability. Previous Previous Previous Previous work work work work with with with with visually visually visually visually presented presented presented presented arrays arrays arrays arrays indicates indicates indicates indicates that that that that the the the the intraparietal intraparietal intraparietal intraparietal sulcus sulcus sulcus sulcus (IPS) (IPS) (IPS) (IPS) represents represents represents represents number. number. number. number. However, However, However, However, it it it it is is is is not not not not clear clear clear clear if if if if the the the the number number number number signal signal signal signal originates originates originates originates in in in in IPS IPS IPS IPS or or or or is is is is propagated propagated propagated propagated from from from from earlier earlier earlier earlier visual visual visual visual areas. areas. areas. areas. Previous Previous Previous Previous work work work work from from from from our our our our group group group group has has has has demons demons demons demonstrated trated trated trated a a a a rapidly rapidly rapidly rapidly instantiated instantiated instantiated instantiated rep- rep- rep- rep- resentation resentation resentation resentation of of of of number number number number in in in in low-level low-level low-level low-level regions regions regions regions of of of of visual visual visual visual cortex cortex cortex cortex using using using using the the the the high high high high temporal temporal temporal temporal reso- reso- reso- reso- lution lution lution lution of of of of event-related event-related event-related event-related electro-encephalography electro-encephalography electro-encephalography electro-encephalography (EEG (EEG (EEG (EEG). ). ). ). Here, Here, Here, Here, we we we we use use use use a a a a rapid rapid rapid rapid event-related event-related event-related event-related functional functional functional functional magnetic magnetic magnetic magnetic resonance resonance resonance resonance imaging imaging imaging imaging (fMRI) (fMRI) (fMRI) (fMRI) paradigm paradigm paradigm paradigm and and and and find find find find convergent convergent convergent convergent evidence evidence evidence evidence for for for for a a a a number number number number signal signal signal signal in in in in low-level low-level low-level low-level visual visual visual visual cortex cortex cortex cortex (areas (areas (areas (areas V1, V1, V1, V1, V2, V2, V2, V2, and and and and V3). V3). V3). V3). Employing Employing Employing Employing a a a a stringent stringent stringent stringent set set set set of of of of stimulus stimulus stimulus stimulus controls, controls, controls, controls, we we we we demonstrate demonstrate demonstrate demonstrate that that that that this this this this signal signal signal signal cannot cannot cannot cannot be be be be explaine explaine explaine explained d d d by by by by the the the the total total total total extent extent extent extent of of of of the the the the array, array, array, array, the the the the density density density density of of of of the the the the items items items items in in in in the the the the array, array, array, array, the the the the aggregate aggregate aggregate aggregate visual visual visual visual area area area area of of of of the the the the items, items, items, items, the the the the size size size size of of of of individual individual individual individual items, items, items, items, the the the the proportion proportion proportion proportion of of of of the the the the array array array array covered covered covered covered by by by by items, items, items, items, nor nor nor nor the the the the overall overall overall overall scale scale scale scale of of of of the the the the array array array array and and and and items. items. items. items. Our Our Our Our findings findings findings findings thus thus thus thus provide provide provide provide strong strong strong strong support support support support for for for for the the the the hy- hy- hy- hy- pothesis pothesis pothesis pothesis that that that that number number number number is is is is rapidly rapidly rapidly rapidly and and and and directly directly directly directly encoded encoded encoded encoded early early early early in in in in the the the the visual visual visual visual processing processing processing processing stream. stream. stream. stream. © © © © 2018 2018 2018 2018 Elsevier Elsevier Elsevier Elsevier Ltd. Ltd. Ltd. Ltd. All All All All rights rights rights rights reserved. reserved. reserved. reserved. 1. 1. 1. 1. Introduction Introduction Introduction Introduction The The The The number number number number sense sense sense sense describes describes describes describes our our our our ability ability ability ability to to to to estimate estimate estimate estimate the the the the number number number number of of of of objects objects objects objects or or or or events events events events without without without without counting counting counting counting them them them them ( ( ( (Dehaene, Dehaene, Dehaene, Dehaene, 1997 1997 1997 1997). ). ). ). Symbolic Symbolic Symbolic Symbolic mathematics mathematics mathematics mathematics is is is is unique unique unique unique to to to to educated educated educated educated adult adult adult adult humans, humans, humans, humans, but but but but we we we we share share share share the the the the number number number number sense sense sense sense with with with with infants infants infants infants ( ( ( (Izard, Izard, Izard, Izard, Sann, Sann, Sann, Sann, Spelke, Spelke, Spelke, Spelke, Streri, Streri, Streri, Streri, 2009; 2009; 2009; 2009; Xu Xu Xu Xu Spelke, Spelke, Spelke, Spelke, 2000 2000 2000 2000 & & & & & & & & ), ), ), ), adults adults adults adults from from from from cultures cultures cultures cultures that that that that lack lack lack lack a a a a verbal verbal verbal verbal counting counting counting counting system system system system ( ( ( (Pica, Pica, Pica, Pica, Lemer, Lemer, Lemer, Lemer, Izard, Izard, Izard, Izard, & & & & Dehaene, Dehaene, Dehaene, Dehaene, 2004 2004 2004 2004), ), ), ), and and and and diverse diverse diverse diverse vertebrate vertebrate vertebrate vertebrate taxa taxa taxa taxa including including including including monkeys monkeys monkeys monkeys ( ( ( ( ), ), ), ), rodents rodents rodents rodents ( ( ( ( Brannon Brannon Brannon Brannon Terrace, Terrace, Terrace, Terrace, 1998 1998 1998 1998 & & & & Meck Meck Meck Meck Church, Church, Church, Church, & & & & 1983 1983 1983 1983 Honig Honig Honig Honig Stewart, Stewart, Stewart, Stewart, 1989 1989 1989 1989 ), ), ), ), and and and and birds birds birds birds ( ( ( ( & & & & ). ). ). ). Although Although Although Although the the the the number number number number sense sense sense sense is is is is distinct distinct distinct distinct from from from from symbolic symbolic symbolic symbolic calculation, calculation, calculation, calculation, the the the the acuity acuity acuity acuity of of of of nu- nu- nu- nu- merical merical merical merical estimation estimation estimation estimation is is is is correlated correlated correlated correlated with with with with math math math math achievement achievement achievement achievement (e.g., (e.g., (e.g., (e.g., Chen Chen Chen Chen Li, Li, Li, Li, 2014; 2014; 2014; 2014; Halberda, Halberda, Halberda, Halberda, Mazzocco, Mazzocco, Mazzocco, Mazzocco, Feigenson, Feigenson, Feigenson, Feigenson, 2008, 2008, 2008, 2008, 2012 2012 2012 2012 & & & & & & & & ), ), ), ), and and and and the the the the number number number number sense sense sense sense is is is is theorized theorized theorized theorized to to to to provide provide provide provide a a a a cognitive cognitive cognitive cognitive scaffold scaffold scaffold scaffold for for for for more more more more complex complex complex complex mathematical mathematical mathematical mathematical concepts concepts concepts concepts ( ( ( (Feigenson, Feigenson, Feigenson, Feigenson, Dehaene, Dehaene, Dehaene, Dehaene, Spelke, Spelke, Spelke, Spelke, 2004; 2004; 2004; 2004; Spelke, Spelke, Spelke, Spelke, 2003 2003 2003 2003 & & & & ). ). ). ). Research Research Research Research into into into into the the the the neural neural neural neural basis basis basis basis of of of of the the the the number number number number sense sense sense sense has has has has implicated implicated implicated implicated a a a a parieto-frontal parieto-frontal parieto-frontal parieto-frontal network network network network in in in in approximate approximate approximate approximate enumeration enumeration enumeration enumeration ( ( ( ( ). ). ). ). The The The The number number number number of of of of items items items items is is is is thought thought thought thought to to to to Nieder, Nieder, Nieder, Nieder, 2016 2016 2016 2016 be be be be encoded encoded encoded encoded in in in in the the the the intraparietal intraparietal intraparietal intraparietal sulcus sulcus sulcus sulcus Q4 Q4 Q4 Q4 (IPS) (IPS) (IPS) (IPS) and and and and utilized utilized utilized utilized for for for for * * * * Corresponding Corresponding Corresponding Corresponding author author author author. . . . 425 425 425 425 South South South South University University University University Avenue, Avenue, Avenue, Avenue, Room Room Room Room 352, 352, 352, 352, Philadelp Philadelp Philadelp Philadelphia, hia, hia, hia, PA PA PA PA 19104, 19104, 19104, 19104, USA USA USA USA Q2 Q2 Q2 Q2 . . . . E-mail E-mail E-mail E-mail address: address: address: address: (N.K. (N.K. (N.K. (N.K. DeWind). DeWind). DeWind). DeWind). ndewind@gma ndewind@gma ndewind@gma ndewind@gmail.com il.com il.com il.com Available Available Available Available online online online online at at at at www.sciencedirect.com www.sciencedirect.com www.sciencedirect.com www.sciencedirect.com ScienceDirec ScienceDirec ScienceDirec ScienceDirec ScienceDirec t t t t Jour Jour Jour Jour nal nal nal nal home home home homepage page page page: : : : www. www. www. www. else else else elsevier vier vier vier .com .com .com .com/loc /loc /loc /locate/ ate/ ate/ ate/corte corte corte cortex x x x 1 1 1 1 2 2 2 2 3 3 3 3 4 4 4 4 5 5 5 5 6 6 6 6 7 7 7 7 8 8 8 8 9 9 9 9 10 10 10 10 11 11 11 11 12 12 12 12 13 13 13 13 14 14 14 14 15 15 15 15 16 16 16 16 17 17 17 17 18 18 18 18 19 19 19 19 20 20 20 20 21 21 21 21 22 22 22 22 23 23 23 23 24 24 24 24 25 25 25 25 26 26 26 26 27 27 27 27 28 28 28 28 29 29 29 29 30 30 30 30 31 31 31 31 32 32 32 32 33 33 33 33 34 34 34 34 35 35 35 35 36 36 36 36 37 37 37 37 38 38 38 38 39 39 39 39 40 40 40 40 41 41 41 41 42 42 42 42 43 43 43 43 44 44 44 44 45 45 45 45 46 46 46 46 47 47 47 47 48 48 48 48 49 49 49 49 50 50 50 50 51 51 51 51 52 52 52 52 53 53 53 53 54 54 54 54 55 55 55 55 56 56 56 56 57 57 57 57 58 58 58 58 59 59 59 59 60 60 60 60 61 61 61 61 62 62 62 62 63 63 63 63 64 64 64 64 65 65 65 65 66 66 66 66 67 67 67 67 68 68 68 68 69 69 69 69 70 70 70 70 71 71 71 71 72 72 72 72 73 73 73 73 74 74 74 74 75 75 75 75 76 76 76 76 77 77 77 77 78 78 78 78 79 79 79 79 80 80 80 80 81 81 81 81 82 82 82 82 83 83 83 83 84 84 84 84 85 85 85 85 86 86 86 86 87 87 87 87 88 88 88 88 89 89 89 89 90 90 90 90 91 91 91 91 92 92 92 92 93 93 93 93 94 94 94 94 95 95 95 95 96 96 96 96 97 97 97 97 98 98 98 98 99 99 99 99 10 10 10 100 0 0 0 10 10 10 101 1 1 1 10 10 10 102 2 2 2 10 10 10 103 3 3 3 10 10 10 104 4 4 4 10 10 10 105 5 5 5 10 10 10 106 6 6 6 10 10 10 107 7 7 7 10 10 10 108 8 8 8 10 10 10 109 9 9 9 11 11 11 110 0 0 0 111 111 111 111 11 11 11 112 2 2 2 11 11 11 113 3 3 3 11 11 11 114 4 4 4 11 11 11 115 5 5 5 11 11 11 116 6 6 6 117 117 117 117 118 118 118 118 11 11 11 119 9 9 9 12 12 12 120 0 0 0 121 121 121 121 12 12 12 122 2 2 2 12 12 12 123 3 3 3 12 12 12 124 4 4 4 12 12 12 125 5 5 5 12 12 12 126 6 6 6 127 127 127 127 12 12 12 128 8 8 8 12 12 12 129 9 9 9 cortex cortex cortex cortex xxx xxx xxx xxx (2018) (2018) (2018) (2018) 1 1 1 1 e e e e e e e14 14 14 14 COR COR COR CORTEX2291_proof TEX2291_proof TEX2291_proof TEX2291_proof 16 16 16 16 April April April April 2018 2018 2018 2018 1/14 1/14 1/14 1/14 ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ https://doi.org/10.1016/j.cortex.2018.03.027 https://doi.org/10.1016/j.cortex.2018.03.027 https://doi.org/10.1016/j.cortex.2018.03.027 https://doi.org/10.1016/j.cortex.2018.03.027 0010-9452/ 0010-9452/ 0010-9452/ 0010-9452/ 2018 2018 2018 2018 Elsevier Elsevier Elsevier Elsevier Ltd. Ltd. Ltd. Ltd. All All All All rights rights rights rights reserved. reserved. reserved. reserved. © © © © Please Please Please Please cite cite cite cite this this this this article article article article in in in in press press press press as: as: as: as: DeWind, DeWind, DeWind, DeWind, N. N. N. N. K., K., K., K., et et et et al., al., al., al., Numerical Numerical Numerical Numerical encoding encoding encoding encoding in in in in early early early early visual visual visual visual cortex, cortex, cortex, cortex, Cortex Cortex Cortex Cortex (2018), (2018), (2018), (2018), https://doi. https://doi. https://doi. https://doi.org/10.1016/ org/10.1016/ org/10.1016/ org/10.1016/ j.cortex.2018.03.027 j.cortex.2018.03.027 j.cortex.2018.03.027 j.cortex.2018.03.027