Decoding Digits and Dice with Magnetoencephalography: Evidence for a Shared Representation of Magnitude

Lina Teichmann, Tijl Grootswagers, Thomas Carlson, Anina N. Rich
2018 Journal of Cognitive Neuroscience  
1 Numerical format describes the way magnitude is conveyed, for example as a digit ('3') or 2 Roman Numeral ('III'). In the field of numerical cognition, there is an ongoing debate of 3 whether magnitude representation is independent of numerical format. Here, we examine the 4 time course of magnitude processing when using different symbolic formats. We presented 5 participants with a series of digits and dice patterns corresponding to the magnitudes of 1 to 6 6 while performing a 1-back task
more » ... magnitude. Magnetoencephalography (MEG) offers an 7 opportunity to record brain activity with high temporal resolution. Multivariate Pattern 8 Analysis (MVPA) applied to MEG data allows us to draw conclusions about brain activation 9 patterns underlying information processing over time. The results show that we can cross-10 decode magnitude when training the classifier on magnitude presented in one symbolic 11 format and testing the classifier on the other symbolic format. This suggests similar 12 representation of these numerical symbols. Additionally, results from a time-generalisation 13 analysis show that digits were accessed slightly earlier than dice, demonstrating temporal 14 asynchronies in their shared representation of magnitude. Together, our methods allow a 15 distinction between format-specific signals and format-independent representations of 16 magnitude showing evidence that there is a shared representation of magnitude accessed via 17 different symbols. 18 not peer-reviewed)
doi:10.1162/jocn_a_01257 pmid:29561240 fatcat:knd5dwwh7vg6fdxv7ngevss4oi