Fig. 1

a The scheme of the data and samples study; b examples of face stimuli (upright and inverted), objects (upright and inverted), and target flowers used in our experiments; c schematic examples of trials used in each block. The block began with the presentation of a cross for 1000 ms. This was followed by 950–1050 ms of a blank screen and a sequence of 100 trials. Every block comprised the presentation of upright faces, upright tables, inverted faces, inverted tables, and targets. There were 20 trials in total. All stimuli were presented randomly with 250-ms durations and an inter-stimulus intervals randomized to range from 650 to 850 ms. Participants were asked to focus on the centre of the screen, to count the number of the target flowers in their minds, and to ignore other stimuli. At the end of each block, the subjects reported the number of flowers they had counted