The results of RT and accuracy
The RT results indicated that the difference between the autism trait groups was not significant, F(1, 43) = 0.70, p = 0.41, ηp² = 0.02. The main effect of cue validity was significant, F(1, 43) = 8.92, p = 0.005, ηp² = 0.17, 95% CI = [− 72.25, − 14.01], such that RT under valid cues was significantly lower than under invalid cues. The interaction effect among autistic traits, cue validity, and cue sociality was significant, F(1, 43) = 8.63, p = 0.005, ηp² = 0.17. The simple effects test found that the low-AQ group showed significantly lower RT for valid gaze cues compared to the RT for invalid gaze cues (p = 0.001, 95% CI = [− 162.21, − 47.96]) but did not differ significantly between valid and invalid dot cues (p = 0.28). The high-AQ group did not differ significantly between valid and invalid cues for both dot (p = 0.08) and gaze cues (p = 0.71). None of the other conditions showed significant differences (p > 0.05). The accuracy did not show any significant main effects or interactions. The RT and accuracy for each condition are shown in Fig. 2.
Figure 2. RT and accuracy of the high- and low-AQ groups under various conditions
Eye-tracking results
Eye-tracking indicators for the encoding interface
Statistical results of the first fixation duration for the encoding interface showed significant differences between the autistic trait groups, F(1, 38) = 4.36, p = 0.044, ηp² = 0.10, 95% CI = [0.45, 28.96], with the high-AQ group having a significantly higher first fixation duration than the low-AQ group. The main effect of visual field was significant, (F[1, 38] = 11.05, p = 0.002, ηp² = 0.23, 95% CI = [15.55, 64.01]), and the first fixation duration was significantly greater for memory items on the left than on the right. The differences were not significant in any of the other conditions (p > 0.05).
The statistical results for total fixation time showed a significant difference between the autistic trait groups, F(1, 38) = 4.52, p = 0.04, ηp² = 0.11, 95% CI = [0.77, 31.35]. This was significantly greater for the high-AQ group than for the low-AQ group. The visual field main effect was significant, F(1, 38) = 11.11, p = 0.002, ηp² = 0.23, 95% CI = [16.77, 68.64], and the total fixation time was significantly greater for memory objects on the left than on the right. The difference was not significant in any of the other conditions (p > 0.05).
Eye-tracking indicators for the cue interface
The statistical results for the percentage of accurate gaze shifts showed that there were no significant main effects or interactions (p > 0.05).
The statistical results for the percentage of fixation time on the ROI showed significant differences between the autistic trait groups, F(1, 38) = 4.85, p = 0.034, ηp² = 0.11, 95% CI = [0.005, 0.12], with the high-AQ group showing a significantly larger percentage of fixation time than the low-AQ group. This difference was not significant for any of the other conditions (p > 0.05).
The statistical results on the fixation counts for the ROI showed that the difference between the autistic trait groups was marginally significant, F(1, 38) = 4.10, p = 0.05, ηp² = 0.10, 95% CI = [− 0.008, 15.31], with the high-AQ group showing a trend toward a larger fixation count on the ROI than the low-AQ group. There was a significant main effect of cue congruence, F(1, 38) = 8.62, p = 0.006, ηp² = 0.19, 95% CI = [1.01, 5.49], and the total fixation counts were significantly greater for cued than for uncued ROIs.
Eye-tracking indicators for the post-cue blank screen
The statistical results for the percentage of fixation time showed that the difference between the autistic trait groups was not significant, F(1, 38) = 2.28, p = 0.139. The cue congruence main effect was significant, F(1, 38) = 20.17, p < 0.001, ηp² = 0.35, 95% CI = [0.06, 0.17], with cued ROIs showing a significantly greater percentage of fixation time than uncued ROIs. The three-way interaction among cue congruency, between-group factors, and cue sociality was marginally significant, F(1, 38) = 3.47, p = 0.07, ηp² = 0.084. For gaze-uncued ROIs, the percentage of fixation time was significantly greater in the high-AQ group than in the low-AQ group (p = 0.001, 95% CI = [0.05, 0.18]), whereas for dot-uncued ROIs, the difference between the two groups did not reach a significant level (p = 0.082). The high-AQ group had a significantly greater percentage of fixation time for dot-cued ROIs than for uncued ROIs (p = 0.035, 95% CI = [0.006, 0.15]), but the difference between gaze-cued and uncued ROIs was not significant (p = 0.16). The low-AQ group showed a significantly greater percentage of fixation time for gaze-cued ROIs than for uncued ROIs (p < 0.001, 95% CI = [0.11, 0.30]), and that for dot-cued ROIs was also significantly larger than uncued ROIs (p = 0.005, 95% CI = [0.04, 0.19]). The low-AQ group showed a significantly smaller percentage of fixation time for gaze-uncued ROIs than for dot-uncued ROIs (p = 0.037, 95% CI = [− 0.10, − 0.003]), but the difference between gaze-cued ROIs and dot-cued ROIs was not significant (p = 0.167). None of the other conditions showed significant differences (p > 0.05).
The statistical results for fixation counts indicated that the difference between the autistic trait groups was not significant, F(1, 38) = 1.63, p = 0.209. The cue congruency main effect was significant, F(1, 38) = 21.65, p < 0.001, ηp² = 0.36, 95% CI = [8.65, 21.96], with the fixation counts for cued ROIs being significantly greater than those for uncued ROIs. The main effect of cue sociality was marginally significant, F(1, 38) = 3.35, p = 0.075, ηp² = 0.08, 95% CI = [− 0.34, 6.85], showing a trend toward greater fixation counts for ROIs under gaze cues. There was a significant interaction effect between cue sociality and cue congruency, F(1, 38) = 4.87, p = 0.033, ηp² = 0.11, whereby the fixation counts for gaze-cued ROIs were significantly greater than those for uncued ROIs (p < 0.001, 95% CI = [10.72, 27.51]), while that for dot-cued ROIs was also significantly greater than that for uncued ROIs (p = 0.001, 95% CI = [4.96, 18.03]). In terms of cued ROIs, the fixation counts for the gaze condition were significantly greater than for the dot condition (p = 0.019, 95% CI = [1.22, 12.90]). In contrast, for uncued ROIs, the difference between the gaze and dot conditions was not significant (p = 0.78). The three-way interaction between cue congruency, between-group factors, and cue sociality was marginally significant, F(1, 38) = 3.52, p = 0.068, ηp² = 0.085. For gaze-uncued ROIs, the high-AQ group had significantly higher fixation counts than the low-AQ group (p = 0.003, 95% CI = [5.13, 23.57]), while gaze-cued ROIs did not differ significantly between the two groups (p = 0.695). The high-AQ group had significantly higher fixation counts for dot-cued ROIs than for dot-uncued ROIs (p = 0.047, 95% CI = [0.13, 18.15]), but the difference between the gaze-cued and uncued ROIs was not significant (p = 0.08). The low-AQ group had significantly greater fixation counts for gaze-cued ROIs than for uncued ROIs (p < 0.001, 95% CI = [15.79, 40.11]) and dot-cued ROIs compared to uncued ROIs (p = 0.005, 95% CI = [4.37, 23.31]). The low-AQ group showed significantly greater fixation counts for gaze-cued ROIs than for dot-cued ROIs (p = 0.018, 95% CI = [1.85, 18.78]), whereas the difference between gaze-uncued and dot-uncued ROIs was not significant (p = 0.196). None of the other conditions displayed significant differences (p > 0.05).
Eye-tracking indicators for the probe interface
The statistical results of the percentage of first gaze shifts showed a significant main effect of cue congruency, F(1, 38) = 19.90, p < 0.001, ηp² = 0.34, 95% CI = [0.10, 0.28], with a significantly greater percentage of first gaze shifts to cued ROIs than to uncued ROIs. The interaction between cue congruency and cue sociality was significant, F(1, 38) = 5.30, p = 0.027, ηp² = 0.12. Under gaze cues, the percentage of first gaze shifts to cued ROIs was significantly larger than to uncued ROIs (p < 0.001, 95% CI = [0.15, 0.34]). Under dot cues, the percentage of first gaze shifts was significantly greater for cued ROIs than for uncued ROIs (p = 0.009, 95% CI = [0.04, 0.24]). For cued ROIs, the percentage of first gaze shifts under gaze cues was significantly greater than that under dot cues (p = 0.027, 95% CI = [0.006, 0.10]), while for uncued ROIs, the percentage of first gaze shifts under gaze cues was significantly smaller than that under dot cues (p = 0.027, 95% CI = [− 0.10, − 0.006]). The interaction between cue congruency, between-group factors, and cue sociality was significant, F(1, 38) = 6.91, p = 0.012, ηp² = 0.15. For gaze-cued ROIs, the percentage of first gaze shifts was significantly greater for the low-AQ group than for the high-AQ group (p = 0.019, 95% CI = [0.02, 0.21]), whereas for gaze-uncued ROIs, the percentage for the low-AQ group was significantly smaller than for the high-AQ group (p = 0.019, 95% CI = [− 0.21, − 0.02]). The difference between the two groups was not significant for dot-cued (p = 0.907) or dot-uncued ROIs (p = 0.907). The high-AQ group showed a significantly larger percentage of first gaze shifts for dot-cued ROIs compared to that for uncued ROIs (p = 0.045, 95% CI = [0.003, 0.28]), while the difference between gaze-cued and uncued ROIs was not significant (p = 0.052). The low-AQ group had a significantly greater percentage of first gaze shifts for gaze-cued ROIs than for gaze-uncued ROIs (p < 0.001, 95% CI = [0.22, 0.49]), while the difference between the dot-cued and dot-uncued ROIs was not significant (p = 0.078). The low-AQ group showed a significantly greater percentage of first gaze shifts for gaze-cued ROIs than for dot-cued ROIs (p = 0.002, 95% CI = [0.05, 0.18]), and a significantly smaller percentage for gaze-uncued ROIs than for dot-uncued ROIs (p = 0.002, 95% CI = [− 0.18, − 0.05]). The high-AQ group did not show a significant difference between gaze-cued and dot-cued ROIs (p = 0.814) or between gaze-uncued and dot-uncued ROIs (p = 0.814). None of the other conditions showed significant differences (p > 0.05). The gaze trends for the cue interface, post-cue blank screen interface, and probe interface are shown in Fig. 3.
Figure 3. Fixation patterns of the high- and low-AQ groups at different interfaces
The statistical results on the entry time into the probe interface ROI showed no significant difference between the autistic trait groups, F(1, 38) = 0.13, p = 0.723. The main effect of cue validity was significant, F(1, 38) = 13.65, p = 0.001, ηp² = 0.26, 95% CI = [− 59.84, − 17.48 ], whereby the entry time under valid cues was significantly smaller than under invalid cues. The interaction between autistic trait groups and cue validity was marginally significant, F(1, 38) = 3.99, p = 0.053, ηp² = 0.10, the entry time for the low-AQ group was significantly lower in the valid condition than in the invalid condition (p < 0.001, 95% CI = [− 90.25, − 28.86]), whereas the difference in the high-AQ group was not significant (p = 0.23). The interaction between cue validity and cue sociality was significant, F(1, 38) = 5.71, p = 0.022, ηp² = 0.13, and entry time under the valid gaze condition showed a trend toward being lower than the valid dot condition (p = 0.06, 95% CI = [− 40.80, 0.88]), whereas the difference between the gaze and dot-invalid conditions was not significant (p = 0.176). The entry time was significantly lower in the valid gaze condition than in the invalid condition (p < 0.001, 95% CI = [− 85.92, − 28.89]), whereas the difference between the valid and invalid dot conditions was not significant (p = 0.105). The interaction between autistic traits, cue validity, and cue sociality was significant, F(1, 38) = 5.60, p = 0.023, ηp² = 0.13; in the valid gaze condition, the entry time for the low-AQ group showed a trend toward being smaller than that of the high-AQ group (marginally significant, p = 0.053, 95% CI = [− 0.48, 77.24]). In contrast, in the valid dot condition, the difference between the low and high AQ groups was not significant (p = 0.598). In the invalid gaze condition, the entry time was significantly greater for the low-AQ group than for the high-AQ group (p = 0.027, 95% CI = [76.25, 4.83]), whereas in the invalid dot condition, the difference between the low and high AQ groups was not significant (p = 0.680). The low-AQ group had significantly less entry time under the valid gaze condition than under the invalid gaze condition (p < 0.001, 95% CI = [− 138.20, − 55.55]), whereas the low-AQ group did not differ significantly between the valid and invalid dot conditions (p = 0.208). The low-AQ group showed significantly less entry time under valid gaze cues than under valid dot cues (p = 0.036, 95% CI = [− 62.69, − 2.28]), and significantly greater entry time under invalid gaze cues compared to invalid dot cues (p = 0.028, 95% CI = [4.85, 79.45]). In all other conditions, the differences were not significant (p > 0.05). See Fig. 4 for more details.
Figure 4. Entry time into the target ROI of the high- and low-AQ groups under various conditions
In terms of the first fixation time for the targets, none of the conditions showed significant differences (p > 0.05). The statistical results of the total fixation time on the target object showed significant differences between the high and low AQ groups, F(1, 38) = 5.49, p = 0.024, ηp² = 0.13, 95% CI = [18.47, 253.29], whereby the total fixation time on the probes was significantly greater for the high-AQ group than for the low-AQ group. None of the other conditions showed significant differences (p > 0.05).