title: The Neural Signatures of Processing Semantic End Values in Automatic Number Comparisons.
abstract: The brain activity associated with processing numerical end values has received limited research attention. The present study explored the neural correlates associated with processing semantic end values under conditions of automatic number processing. Event-related potentials (ERPs) were recorded while participants performed the numerical Stroop task, in which they were asked to compare the physical size of pairs of numbers, while ignoring their numerical values. The smallest end value in the set, which is a task irrelevant factor, was manipulated between participant groups. We focused on the processing of the lower end values of 0 and 1 because these numbers were found to be automatically tagged as the "smallest." Behavioral results showed that the size congruity effect was modulated by the presence of the smallest end value in the pair. ERP data revealed a spatially extended centro-parieto-occipital P3 that was enhanced for congruent versus incongruent trials. Importantly, over centro-parietal sites, the P3 congruity effect (congruent minus incongruent) was larger for pairs containing the smallest end value than for pairs containing non-smallest values. These differences in the congruency effect were localized to the precuneus. The presence of an end value within the pair also modulated P3 latency. Our results provide the first neural evidence for the encoding of numerical end values. They further demonstrate that the use of end values as anchors is a primary aspect of processing symbolic numerical information.
authors.affiliation: Department of Psychology, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev Beer Sheva, Israel ; Department of Behavioral Sciences, Ariel University Ariel, Israel.
authors.forename: Michal
authors.initials: M
authors.lastname: Pinhas
authors.affiliation: Department of Psychology, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev Beer Sheva, Israel.
authors.forename: Chananel
authors.initials: C
authors.lastname: Buchman
authors.affiliation: Department of Psychology, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev Beer Sheva, Israel.
authors.forename: Dmitri
authors.initials: D
authors.lastname: Lavro
authors.affiliation: Department of Psychology, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev Beer Sheva, Israel.
authors.forename: David
authors.initials: D
authors.lastname: Mesika
authors.affiliation: Department of Psychology, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev Beer Sheva, Israel ; Department of Brain and Cognitive Sciences, Ben-Gurion University of the Negev Beer Sheva, Israel.
authors.forename: Joseph
authors.initials: J
authors.lastname: Tzelgov
authors.affiliation: Department of Psychology, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev Beer Sheva, Israel.
authors.forename: Andrea
authors.initials: A
authors.lastname: Berger
keywords: P3; automatic numerical processing; end effect; event-related potential (ERP); precuneus; size congruity effect