In Experiment 1, our aim was to verify the extent to which the social self conceptually overlaps with the temporal self by utilizing a shape-label association paradigm [26, 27]. According to our hypothesis, we expected that the redundancy gain when responding to the temporal self associated stimulus while the social self associated stimulus is present will be stronger than the either way around (“Overlap” condition in Figure 2). To draw a fuller picture of the process, we measured perceptual, conceptual and overlap redundancy gain effects in all studies.
Materials and Methods
The experiments were programmed using PsychoPy version 2021.2.3. All materials are available on the open science framework (https://osf.io/k8jf5/).
Participants. To determine the sample size, we replicated the redundancy gain experiment involving shapes associated with self-relevant labels (Experiment 1; [26]) to test for the effect size using German translated labels with an Austrian sample. Based on the medium effect size we acquired, the sample size was calculated as thirty-six participants. We almost doubled the required sample size due to the high novelty of the present experimental design. Sixty-six participants (16 males; Mage = 20.33, Rangeage = 18 ~ 29) were recruited and participated in Experiment 1 for an exchange of course credits at the university of XXX
Stimuli. Participants were instructed to form associations between four geometric shapes (e.g., randomly chosen from six shapes: hexagon, horizontal ellipse, vertical rectangle, diamond, cross, and reversed triangle, each measuring approx. 4° × 4° of visual angle; [34]) and self-relevant labels. Two shapes were associated with the social self-label (i.e., myself) and two shapes were associated with the temporal self-label (i.e., [me] now), the remaining two shapes were neutral shapes (no association with a self-label). Two shapes were presented at the left and and right of the cross fixation (white) point each. All stimuli were white and shown on a gray background on a 19 in. monitor (1280 × 1024 pixel resolution at 60 Hz).
Matching Task (Redundancy Gain Paradigm). In the matching task, participants were presented with binary-choice trials to judge whether any shape(s) presented after the target self-label were matching (press “c”) or nonmatching (press “n”). The matching task was comprised of 4 conditions: 4 shape conditions (Single, Same, Different, Overlap) for each matching condition (matching vs. non-matching). In Single condition, one shape associated with the preceding self-label was presented in matching trials (see Figure 2). In Same condition, two of the identical shapes that were associated with the preceding self-label were presented in matching trials. In Different, condition, two different shapes that were associated with the preceding self-label were presented in matching trials. In Overlap condition, one shape associated with “yourself” and another shape associated with “now” were presented in matching trials. The position and the combination of the shapes were counterbalanced across all trials. In non-matching trials of Single, Same, and Different conditions, only neutral shapes were presented accordingly. In non-matching trials of Overlap condition, one neutral and one non-matching shape (not corresponding to the preceding self-label) were presented. Each condition had 64 matching and 64 non-matching trials spread across 4 blocks in a counterbalanced order (128 trials per block), tallying up to 512 trials per participant.
In each trial, participants were first presented with a label (myself or [me] now) for 500 ms followed by the shape presentation for 500ms. Participants were allowed 1200ms to respond. Once participants responded, a feedback screen was presented (correct, incorrect or too slow for responses that took longer than 1200ms). Participants were instructed to respond as fast and as accurate as possible.
Procedure. Participants were guided into experimental cubicles and given instructions on the screen after the informed consent was obtained. Participants reported gender and age. First, participants were instructed to learn associations between shapes and social and temporal self-labels; “myself” and “me now”. To clarify the meanings of social and temporal selves, participants were given the following explanations.
Social self (“myself”): You yourself as a social individual differentiated from other people. Think about you as a unique person among all the other people you know around you (family, friends, co-workers etc.). You have unique personalities, preferences and attitudes toward the world that can describe you as a single individual.
Temporal self (“me now”): You are an individual at this point of time but you might change across time. For example, you might have been the same or slightly different person in the past compared to who you are right now, you will perhaps become someone that is different from who you are at this given moment.
After learning the associations (two shapes for the social self and two shapes for the temporal self), participants proceeded to perform a matching task. The presentation of the two shapes corresponding to each label in the instruction was vertical (see Figure 2) to control for any effect of visual memory. The order of presenting social and temporal shape-label associations were randomized to control for any effect of the information processing order. Participants performed 15 practice trials before the actual experimental trials began.
Results
To control for any speed and accuracy trade-offs, we adjusted RTs via dividing the mean RT values by the mean accuracy scores per condition across participants (see Table 1 for Ms and 95% CIs for RT, accuracy, and adjusted RT values) to enter the main analyses. First, a 2 (social and temporal self-labels) by 2 (matching vs. non-matching) by 4 (conditions) repeated measures ANOVA on correct trials was performed. Responses shorter than 200 ms and longer than 1200 ms were excluded. The main effect of the self-label was significant, indicating that participants responded faster for temporal self-label trials compared to social self-label trials. F(1, 65) = 12.57, p < .001 effect size η2 = .02. The main effect of matching condition was significant F(1, 65) = 103.21, effect size, η2 = .07, indicating that overall, participants responded faster and more accurately for the matching trials than non-matching trials. The main effect of the condition was significant F(2.18, 141.35) = 25.74 (Greenhouse-Geisser correction applied due to the sphericity violation), p < .001 effect size η2 = .05, indicating that the responses significantly varied across conditions (see Figure 3). The interaction between the matching and condition was significant F(2.01, 130.90) = 57.10 (Greenhouse-Geisser corrected), p < .001, η2 = .08, indicating the varying responses across conditions were different between matching and non-matching trials. Following the analysis by Sui and Humphreys [26], non-matching trials were dropped for further analyses.
Table 1 Mean reaction times, accuracies, adjusted RT (RT/ACC) in Experiment 1 (N = 66)
Label
|
Matching
|
Condition
|
Mean
RT (ms)
|
Mean
ACC (%)
|
RT/ACC
|
Social self:
Myself
|
Matching
|
Single
|
508 (490, 526)
|
83 (79, 87)
|
647 (585, 708)
|
|
|
Same
|
530 (512, 548)
|
81 (77, 84)
|
710 (648, 771)
|
|
|
Different
|
493 (475, 511)
|
86 (82, 89)
|
609 (547, 670)
|
|
|
Overlap
|
504 (486, 522)
|
85 (81, 88)
|
632 (571, 694)
|
|
Non-matching
|
Single
|
505 (485, 526)
|
90 (87, 94)
|
582 (530, 635)
|
|
|
Same
|
520 (500, 541)
|
89 (85, 92)
|
612 (560, 665)
|
|
|
Different
|
541 (521, 562)
|
85 (82, 88)
|
654 (602, 707)
|
|
|
Overlap
|
543 (523, 563)
|
84 (81, 87)
|
683 (630, 735)
|
Temporal self:
(me) Now
|
Matching
|
Single
|
498 (483, 513)
|
90 (88, 93)
|
571 (539, 604)
|
|
|
Same
|
495 (479, 510)
|
91 (88, 93)
|
554 (521, 587)
|
|
|
Different
|
480 (464, 495)
|
91 (89, 94)
|
537 (505, 570)
|
|
|
Overlap
|
484 (469, 499)
|
92 (90, 95)
|
534 (502, 567)
|
|
Non-matching
|
Single
|
531 (509, 553)
|
90 (86, 94)
|
608 (485, 732)
|
|
|
Same
|
535 (512, 557)
|
89 (85, 93)
|
617 (494, 741)
|
|
|
Different
|
631 (608, 653)
|
61 (57, 65)
|
1225 (1101, 1348)
|
|
|
Overlap
|
638 (616, 660)
|
61 (57, 65)
|
1221 (1098, 1345)
|
RT = reaction time; ACC = Accuracy (proportion correct). 95% Confidence Intervals appear within parentheses.
Perceptual and conceptual redundancy gain (Same and Different conditions). Following the analyses by Sui and Humphreys [26], the perceptual redundancy gain was examined by contrasting the same shapes condition to the single shape condition for each self-label. Pairwise contrasts on adjusted RTs showed no difference between the same shapes and the single shape conditions in both social self t(65) = 2.02, 95% CI = -124, 1, p = 0.14; p values are reported after controlling for the False Discovery Rate (FDR) for performing three pairwise comparisons hereafter: single – same, single-different, single-overlap conditions per self-label condition; [35], and in temporal self conditions, t(65) = 1.48, p = 0.14, 95% CI = -6, 40. The conceptual redundancy gain was examined by contrasting the different shapes condition to the single shape condition. The adjusted RTs did not differ between the different shapes and single shape conditions in social self trials, t(65) = 1.22, p = 0.225, 95% CI = -24, 99 but significantly differed in the temporal self trials t(65) = 2.90, p = .0006, 95% CI = 3, 65, Cohen’s d = .25 , indicating a significant conceptual redundancy gain for the temporal condition (see Figure 3).
Overlap between social and temporal selves (Overlap condition). To examine the conceptual overlap between social and temporal selves, Overlap condition was contrasted to the single shape condition for each self-label condition. For social self trials, the adjusted RTs did not differ between the single and overlap shape conditions, t(65) = 0.46, p = 0.643, 95% CI = -47, 76, but a significant difference was observed in temporal self trials; participants’ performance was enhanced in the overlap shapes compared to the single shape condition, t(65) = 3.17, p = .0006, 95% CI = 14, 60, Cohen’s d = .28, indicating that the presence of the social self-associated shape boosted the redundancy gain for responding to the temporal self-associated shape but not the other way around.
Based on the results, social self-associated stimulus seemed to have acted as redundant information for processing temporal self-associated stimulus. This pattern supports our hypothesis that the representational structure the social self includes the representational properties of the temporal self.