Guided visual search study with Magnetoencephalography, Rapid Invisible Frequency Tagging, Eye tracking

This dataset was collected as part of a Magnetoencephalography study investigating the neural correlates of visual search. The experiment and associated data analyses are described in Duecker et al., 2025a and 2025b (references below). Participants were asked to indicate whether a letter T was presented among several letters L. In the guided search condition, the participants were informed about the colour the T would have if it is presented on the screen. In the unguided search condition, participants did not know the colour of the T. The luminance of the letters on the screen was modulated sinusoidally at 60 and 67 Hz. This flickering of the letters was invisible to the participants, but evoked responses at those frequency in their visual cortex, as confimed by the Magnetoencephalography signal. The method, named Rapid Invisible Frequency Tagging, has been shown to serve as a read-out of where the participant is attending (see Zhigalov et al., 2019). In Duecker et al., 2025a, we show that the response to this flicker is modulated by the task: when the participant know that the target colour is yellow, the Rapid Invisible Frequency Tagging response to yellow will be enhanced, while the response to blue will be reduced, compared to the unguided search condition during which the participants don't know the colour. In Duecker et al., 2025b, we report the rhythmic neural activity in the pre-search interval correlates with the participants response times. When the participants show strong activity in the 8-12 Hz band, they will be faster at the task. The uploaded dataset contains the raw Magnetoencephalography data, behavioral responses, and eye-tracking data (transformed into a MATLAB structure). The data analysis scripts in MATLAB, MNE Python, and R can be accessed here. References: Duecker, Katharina, et al. "Guided visual search is associated with target boosting and distractor suppression in early visual cortex." Communications Biology 8.1 (2025a): 912. Duecker, Katharina, et al. "Higher baseline alpha power is associated with faster responses in visual search." bioRxiv (2025b): 2025-08. Zhigalov, Alexander, et al. "Probing cortical excitability using rapid frequency tagging." NeuroImage 195 (2019): 59-66.