Figure 1
Experimental Trial Sequence Example.
Note. The short straight arrows indicate the direction of movement for each corresponding image, either horizontally to the left or to the right. The dashed line boxes represent the smooth trajectory along which each image moves. The position of the second identical image along the direction of the short straight arrow marks the final destination and disappearance point of the initial image. This spot is also where participants, upon detecting the target face, were required to focus their gaze to provide their response. Each of the four potential identities of critical faces is represented in distinct colored boxes. For instance, in this example, the target face, highlighted in a red box, depicts a male face next to female distractor faces. The probe face, encased in a green box, is an image of the participant’s mother (actual image not shown for privacy reasons). Meanwhile, the control 1 and control 2 faces, presented in a blue and a purple box separately, are two randomly selected faces. It is important to note that in any given trial, only one critical face was displayed, and its position was pseudo-randomly assigned between the fifth and eighth spot in the stream.
Figure 2
Frequency Estimation in the Memory Task.
Note. Each color corresponds to a type of face, with the corresponding types and their actual frequencies marked on the X-axis. The vertical black lines in each violin represent the specific estimates given by the participants for the frequency of occurrence of this type of face, while the white dots show the average value.
Figure 3
Average Eye Movement Distances.
Note. Panel a) shows the average traces of eye movement distances over time for the four face conditions: the target face (a red line), familiar face (a green line), control 1 face (a blue line), and control 2 face (a purple line). Panel b) shows the average eye movement traces for each participant in the target-face condition. The point marked ‘0’ on the x-axis denotes the onset of the critical faces presentation. Shaded regions around each line illustrate the standard error of the mean. In panel a), colored bars at the bottom highlight significant time intervals identified by the sample-by-sample linear mixed-effect regression analysis with FDR correction (q = .05, minimum cluster length = 200 ms). Specifically, the red bar indicates the interval where responses to the target face differed significantly from those to the averaged control faces. No significant intervals were observed for the familiar face condition.
Figure 4
Individual Leave-one-out Analysis on Eye Movement Distance.
Note. The eye movement differences of each participant towards the familiar face and average control faces in 0–1000 ms after the onset of the critical face are displayed in section a), and the differences in eye movements towards the average control faces and familiar face in 1000–2500 ms are presented in section b). Error bars represent the 95% confidence interval for each participant’s data. Participants whose differences reached statistical significance (p < .05) in the corresponding direction are denoted with an asterisk (*).
Figure 5
Average Pupil size and Rate of Pupil Size Change.
Note. The graph displays average traces for a group of 29 participants over time. It features the target face (red line), the familiar face (green line), the control 1 face (blue line), and the control 2 face (purple line), showing the data for a) pupil size, and b) the rate of pupil size change. The colored bars represent significant time intervals where the data for the corresponding colored lines (conditions) differed significantly from the data for the averaged control conditions. The shaded regions around the lines illustrate the standard error of the mean.
Figure 6
Individual Leave-one-out Analysis on Pupil Size and Rate of Pupil Size Change.
Note. The chart illustrates the difference between responses to the familiar face and the average of the control faces for each participant in terms of a) mean pupil size, and b) mean rate of pupil size change. For each participant, the comparison point was determined by the moment where the response to the familiar face was the largest compared to the averaged control faces, based on data from the other 28 participants. Participants with significant differences in their responses are highlighted with an asterisk (*). Error bars represent the 95% confidence intervals for each individual’s measurements.
Figure 7
Frequency Estimation in the Memory Task.
Note. Each color corresponds to a type of face, with the corresponding types and actual frequencies marked on the X-axis. The vertical black lines in each violin represent the specific estimates given by the participants for the frequency of occurrence of this type of face, while the white dots show the average value.
Figure 8
Average Eye Movement Distances.
Note. The graph illustrates the average eye movement distances across time for various face types: the target face (red line), familiar face (green line), control 1 face (blue line), and control 2 face (purple line). The ‘0’ point on the x-axis denotes the onset of the critical face presentations. The shaded areas surrounding each line indicate the standard error of the mean. Colored bars at the bottom of the graph indicate significant time intervals identified by the sample-by-sample linear mixed-effect regression analysis with FDR correction (q = .05, minimum cluster length = 200 ms). Specifically, the red bars denote intervals where eye movements in response to target faces differed significantly from those to the averaged control faces.
Figure 9
Individual Leave-one-out Analysis on Eye Movement Distance.
Note. The eye movement differences for each participant, comparing the familiar face to the average control faces within the first 0–1000 ms after the critical face’s onset, are shown in a). The eye movements differences directed toward the average control faces compared to the familiar face in the subsequent time window of 1000–2500 ms are shown in b). Error bars have been included to depict the 95% confidence intervals. Those participants whose eye movement differences were significant in the designated direction are marked with an asterisk (*).
Figure 10
Average Pupil size and Rate of Pupil Size Change.
Note. The chart presents the average pupil traces of over time for 27 participants. It shows the responses to the target face (indicated by a red line), familiar face (green line), control 1 face (blue line), and control 2 face (purple line) with regards to a) pupil size, and b) the rate of pupil size change. The shaded areas surrounding each line represent the standard error of the mean. Colored bars highlight the significant time periods where the responses to the corresponding conditions significantly diverged from those to the averaged control conditions.
Figure 11
Individual Leave-one-out Analysis on Pupil Size and Rate of Pupil Size Change.
Note. The differences in responses for each participant (n = 27) when comparing the familiar face with the average of the control faces are presented in terms of a) mean pupil size, and b) mean rate of pupil size change. The specific moment chosen for comparison for each participant was the one where the difference in response to the familiar face was at its peak compared to the averaged control faces, as determined by the data from the other 26 participants. Those participants whose response differences reached statistical significance are marked with an asterisk (*). Error bars are included to denote the 95% confidence intervals.
Supplementary Figure S1
Average Pupil Size and Rate of Pupil Size Change in Experiment 1 (Models including Horizontal Gaze Position as a Covariate).
Note. The figure displays group-average time courses (N = 29) for the target face (red line), familiar face (green line), control 1 (blue line), and control 2 (purple line), for (a) pupil size and (b) the rate of pupil size change. In this supplementary analysis, horizontal gaze displacement (x-position) was added as a covariate in the sample-by-sample linear mixed-effects models to control for potential effects of eye position on pupil measurements. Colored bars indicate significant intervals: red and green bars mark time windows in which the target or familiar face differed from the averaged control faces, and blue bars indicate intervals in which horizontal gaze displacement exerted a significant effect. Shaded regions reflect the standard error of the mean.
Supplementary Figure S2
Average Pupil Size and Rate of Pupil Size Change in Experiment 2 (Models including Horizontal Gaze Position as a Covariate).
Note. The figure shows group-averaged time courses (N = 27) for the target face (red), familiar face (green), control 1 (blue), and control 2 (purple), for (a) pupil size and (b) the rate of pupil size change. As in Experiment 1, horizontal gaze displacement (x-position) was included as a covariate in the sample-by-sample linear mixed-effects models to control for potential effects of eye position on pupil measurements. Colored bars indicate significant intervals: red and green bars mark time windows in which the target or familiar face differed from the averaged control faces, and blue bars indicate intervals in which horizontal gaze displacement exerted a significant effect. Shaded regions represent the standard error of the mean.