Electrophysiological correlates of temporal numerosity adaptation

Paolo A Grasso; Irene Petrizzo; Francesca Coniglio; Roberto Arrighi

doi:10.3389/fnins.2024.1349540

Electrophysiological correlates of temporal numerosity adaptation

Front Neurosci. 2024 Mar 5:18:1349540. doi: 10.3389/fnins.2024.1349540. eCollection 2024.

Authors

Paolo A Grasso^{1

2}, Irene Petrizzo¹, Francesca Coniglio¹, Roberto Arrighi¹

Affiliations

¹ Department of Neuroscience, Psychology, Pharmacology and Child Health, University of Florence, Florence, Tuscany, Italy.
² Department of Physics and Astronomy, University of Florence, Florence, Italy.

Abstract

Introduction: Much 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.

Methods: Participants 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.

Results: Electrophysiological 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.

Discussion: Taken 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.

Keywords: EEG; numerosity adaptation; numerosity perception; steady-state visual evoked potential; temporal numerosity.

Grants and funding

The author(s) declare that financial support was received for the research, authorship, and/or publication of this article. The study was conducted with the contribution of the researcher PG with a research contract co-funded by the European Union – PON Research and Innovation 2014–2020 in accordance with Article 24, paragraph 3a, of Law No. 240 of December 30, 2010, as amended, and Ministerial Decree No. 1062 of August 10, 2021. This research was funded from the European Union (EU) and Horizon 2020—grant agreement no. 832813—ERC Advanced ‘Spatio-temporal mechanisms of generative perception—GenPercept’; from the Italian Ministry of Education, University, and Research under the PRIN2017 programme (grant no. 2017XBJN4F—‘EnvironMag’ and grant no. 2017SBCPZY—‘Temporal context in perception: serial dependence and rhythmic oscillations’).