Distinct representations of subtraction and multiplication in the neural systems for numerosity and language

• Published in: Human brain mapping Vol. 32; no. 11; pp. 1932 - 1947
• Main Authors: Prado, Jérôme, Mutreja, Rachna, Zhang, Hongchuan, Mehta, Rucha, Desroches, Amy S., Minas, Jennifer E., Booth, James R.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.11.2011; Wiley-Liss; John Wiley & Sons, Inc; Wiley
• Subjects: Acoustic Stimulation; Adult; Biological and medical sciences; Brain - physiology; Brain mapping; Cognitive science; Evolution; Female; fMRI; frontal gyrus; Frontal Lobe - physiology; Functional Laterality - physiology; Fundamental and applied biological sciences. Psychology; Humans; Image Processing, Computer-Assisted; Information processing; intraparietal sulcus; Investigative techniques, diagnostic techniques (general aspects); Language; Magnetic Resonance Imaging; Male; Mathematics; Medical sciences; Memory; Mental Processes - physiology; Miscellaneous; multiplication; Nervous system; Neural networks; neural recycling; Neuroscience; numerosity; Parietal Lobe - physiology; Perception; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Psychomotor Performance - physiology; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Speech Perception - physiology; subtraction; temporal gyrus; Temporal Lobe - physiology; Young Adult; fMRI; Nervous system diseases; numerosity; Subtraction; Language; Radiodiagnosis; neural recycling; Representation; multiplication; Nuclear magnetic resonance imaging
• ISSN: 1065-9471; 1097-0193; 1097-0193
• DOI: 10.1002/hbm.21159

It has been proposed that recent cultural inventions such as symbolic arithmetic recycle evolutionary older neural mechanisms. A central assumption of this hypothesis is that the degree to which a preexisting mechanism is recycled depends on the degree of similarity between its initial function and the novel task. To test this assumption, we investigated whether the brain region involved in magnitude comparison in the intraparietal sulcus (IPS), localized by a numerosity comparison task, is recruited to a greater degree by arithmetic problems that involve number comparison (single‐digit subtractions) than by problems that involve retrieving number facts from memory (single‐digit multiplications). Our results confirmed that subtractions are associated with greater activity in the IPS than multiplications, whereas multiplications elicit greater activity than subtractions in regions involved in verbal processing including the middle temporal gyrus (MTG) and inferior frontal gyrus (IFG) that were localized by a phonological processing task. Pattern analyses further indicated that the neural mechanisms more active for subtraction than multiplication in the IPS overlap with those involved in numerosity comparison and that the strength of this overlap predicts interindividual performance in the subtraction task. These findings provide novel evidence that elementary arithmetic relies on the cooption of evolutionary older neural circuits. Hum Brain Mapp, 2011. © 2011 Wiley‐Liss, Inc.