1. Neurophysiological investigation of inhibitory processes involved in forward masking.
- Author
-
Türker, Afife and Kafalıgönül, H. Hulusi
- Subjects
- *
ELECTROENCEPHALOGRAPHY , *EXPERIMENTAL design - Abstract
Objective: Forward masking is a commonly used paradigm to investigate the temporal dynamics of visual processing. The neural correlates of this paradigm, however, are not fully understood. In particular, there is no study to our knowledge that systematically investigated the associated ERP components. Methods: We designed two experiments using the paracontrast masking paradigm. In both experiments, EEG (Electroencephalography) activity was recorded while the participants performed a contour discrimination task. In addition to the mask-to-target onset timing (SOA), the mask-to-target (M/T) contrast ratio was manipulated in the first experiment, and the contrast polarity (same and opposite polarities) of the mask was manipulated in the second experiment. Results: Behavioral results showed that the perceived visibility was dependent on SOA, and the mask caused strong brief-inhibition on target visibility at short SOA values. The brief-inhibition was also found to be significantly modulated by the M/T contrast ratio and polarity. The EEG analyses revealed SOAdependent non-linear interactions between the target and mask in the P1, N1, and late components. Moreover, the M/T contrast ratio significantly modulated the interactions in the N1 component range. Conclusion: In summary, this study points to the neurophysiological correlates of forward masking and particularly provides important insights into the ERP components associated with brief inhibition. The findings also contribute to our understanding of cortical dynamics underlying perceived visibility. This work was supported by The Scientific and Technological Research Council of Türkiye (TUBITAK Project Number. 119K368). [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF