Electrophysiological correlates of temporal numerosity adaptation

Abstract

IntroductionMuch research has revealed the human visual system is capable to estimate numerical quantities, rapidly and reliably, in both the spatial and the temporal domain. This ability is highly susceptible to short-term plastic phenomena related to previous exposure to visual numerical information (i.e., adaptation). However, while determinants of spatial numerosity adaptation have been widely investigated, little is known about the neural underpinnings of short-term plastic phenomena related to the encoding of temporal numerical information. In the present study we investigated the electrophysiological correlates of temporal numerosity adaptation.MethodsParticipants were asked to estimate the numerosity of a test sequence of flashes after being exposed to either a high or low numerous adapting sequence. Behavioral results confirmed the expected underestimation of test stimulus when this was preceded by a high numerous sequence as compared to when preceded by a low numerous sequence.ResultsElectrophysiological data revealed that this behavior was tightly linked to the amplitude of the steady-state visual evoked (ssVEP) response elicited by the test stimulus. When preceded by a high numerous sequence, the test stimulus elicited larger ssVEP responses as compared to when preceded by a low numerous sequence with this pattern being robustly correlated with behavior. Finally, topographical maps showed that this difference was mostly evident across two antero-posterior distributed clusters of electrodes and correlated with changes in functional connectivity.DiscussionTaken together, our results suggest that visual plastic phenomena related to the encoding of temporal numerosity information reflect changes in rhythmic evoked activity that are likely related to long range communications between distinct brain regions.

Identifying conceptual neural responses to symbolic numerals

“…Conceptual responses to numerical properties have been proposed in numerous EEG frequency-tagging studies (for numerosity/magnitude, e.g. [10,14,37,53,54]; parity, e.g. [37]; cross-format integration, e.g.…”

“…Our paradigm benefited from the advantages of EEG frequency-tagging, including automaticity, specificity, consistency and objectivity (in numerical cognition, e.g. [10,11,14,16,33,37,[53][54][55][56]). Automatic aspects of numerical processing, occurring without instruction or directed attention, can be measured because participants need not be assigned a (number-)related task.…”