Table 1
Overall summary of the current experiments.
| METHODOLOGICAL DETAILS | EXPERIMENT | ||||||
|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | ||
| Participants | Mean age (SD) | 21.29 (1.85) | 20.33 (1.66) | 21.79 (2.25) | 21.63 (2.08) | 24.42 (4.64) | 21.13 (1.75) |
| Experiment language | Italian | Italian | Italian | English | English | Italian | |
| Design | Overall design | 2 (CL) × 2 (# Dist) | 2 (CL) × 2 (# Dist) | 2 (CL) × 2 (# Dist) | 2 (CL) × 2 (# Dist) | 2 (CL) × 2 (FT) | One-way: High CL/Low FT Low CL/High FT High CL/High FT |
| CL (low vs. high) | Location vs. Parity | Slow vs. Fast Pace | SRT vs. Parity | SRT vs. Parity | Slow vs. Fast pace | Slow vs. Fast pace | |
| # Dist (low vs. high) | 3 vs. 6 | 3 vs. 6 | 3 vs. 6 | 1 vs. 3 | – | – | |
| FT (low vs. high) | – | – | – | – | Short vs. Long | Short vs. Long | |
| Method | # Dist after each word | 3 or 6 | 3 or 6 | 3 or 6 | 1 or 3 | 2, 4, or 8 | 3 or 6 |
| Pace of each distractor | 700 ms | 1125 or 600 ms | 700 ms | 700 ms | 750 ms | 600 ms | |
| FT after each distractor | 300 ms | 375 or 200 ms | 300 ms | 300 ms | 500 or 250 ms | 400 or 200 ms | |
| Total FT/studied word | 900 or 1800 ms | from 600 to 2250 ms | 900 or 1800 ms | 300 or 900 ms | 2000 or 1000 ms | 1200 or 600 ms | |
| Immediate recall method | Typed | Typed | Typed | Aloud | Aloud | Typed | |
[i] Note: All design factors manipulated within-subjects, and blocked and counterbalanced across participants. CL = cognitive load, # Dist = number of distractors, FT = free time, SRT = serial reaction time.
Table 2
Mean (and standard deviations) of distractor response times (RTs, in ms) and immediate recall (proportion correct) as a function of cognitive load (CL) and the second manipulated factor (either distractors or free time) in each experiment.
| EXP. | SECOND FACTOR | RESPONSE TIMES (RTS, MS) | IMMEDIATE RECALL – SERIAL SCORING | |||
|---|---|---|---|---|---|---|
| LOW CL | HIGH CL | LOW CL | HIGH CL | |||
| 1 | Distractors | Low | 403.56 (56.87) | 549.62 (36.20) | 0.73 (0.14) | 0.65 (0.18) |
| High | 378.02 (42.75) | 547.93 (26.39) | 0.72 (0.21) | 0.61 (0.15) | ||
| 2 | Distractors | Low | 605.21 (83.19) | 514.43 (28.04) | 0.79 (0.15) | 0.68 (0.18) |
| High | 606.76 (74.98) | 521.82 (34.13) | 0.78 (0.16) | 0.62 (0.19) | ||
| 3 | Distractors | Low | 285.21 (53.03) | 542.99 (42.83) | 0.86 (0.12) | 0.70 (0.15) |
| High | 298.26 (56.26) | 540.41 (42.03) | 0.90 (0.12) | 0.63 (0.18) | ||
| 4 | Distractors | Low | 576.51 (108.28) | 709.07 (72.06) | 0.48 (0.24) | 0.38 (0.24) |
| High | 587.25 (130.59) | 686.73 (63.25) | 0.50 (0.24) | 0.33 (0.23) | ||
| 5 | Free time | Low | 737.75 (78.22) | 717.88 (64.77) | 0.44 (0.22) | 0.45 (0.18) |
| High | 736.01 (77.28) | 707.86 (60.36) | 0.47 (0.23) | 0.46 (0.26) | ||
| 6 | Free time | Low | – | 492.32 (22.20) | – | 0.69 (0.14) |
| High | 499.53 (38.66) | 497.38 (24.00) | 0.68 (0.17) | 0.62 (0.19) | ||
[i] Note: Exp. = experiment, CL = cognitive load.
Table 3
Results of the BANOVAs for each experiment.
| EXP. | DESIGN | MEASURE | MAIN EFFECT OF FACTOR 1 | MAIN EFFECT OF FACTOR 2 | BOTH MAIN EFFECTS | MAIN EFFECTS + INTERACTION |
|---|---|---|---|---|---|---|
| 1 | 2 (CL: location, parity) × 2 (Distractors: 3, 6) | Distractor RTs | 1.52 × 1036 | 0.27 | 2.65 × 1036 | 3.53 × 1036 |
| Immediate serial recall | 134.32 | 0.35 | 53.72 | 19.42 | ||
| Delayed recall overall | 0.32 | 0.87 | 0.30 | 0.14 | ||
| Delayed recall conditionalized | 0.23 | 1.15 | 0.27 | 0.09 | ||
| 2 | 2 (CL: slow, fast pace) × 2 (Distractors: 3, 6) | Distractor RTs | 1.00 ×1013 | 0.22 | 2.50 × 1012 | 7.55 × 1011 |
| Immediate serial recall | 2860.07 | 0.40 | 1453.28 | 603.75 | ||
| Delayed recall overall | 47.94 | 0.22 | 10.81 | 3.14 | ||
| Delayed recall conditionalized | 1.64 | 0.22 | 0.38 | 0.11 | ||
| 3 | 2 (CL: SRT, parity) × 2 (Distractors: 3, 6) | Distractor RTs | 6.29 ×1047 | 0.22 | 1.75 × 1047 | 8.12 × 1046 |
| Immediate recall | 2.36 × 1010 | 0.23 | 6.21 × 109 | 1.83 × 1010 | ||
| Delayed recall overall | 120.08 | 0.29 | 38.02 | 11.24 | ||
| Delayed recall conditionalized | 1.94 | 0.43 | 0.90 | 0.36 | ||
| 4 | 2 (CL: SRT, parity) × 2 (Distractors: 1, 3) | Distractor RTs | 3.44 ×108 | 0.21 | 7.61 × 107 | 4.72 × 107 |
| Immediate serial recall | 416.07 | 0.23 | 102.49 | 50.59 | ||
| Delayed recall overall | 2.98 | 0.58 | 1.94 | 0.69 | ||
| Delayed recall conditionalized | 0.30 | 8.83 | 2.87 | 0.83 | ||
| 5 | 2 (CL: slow, fast pace) × 2 (FT: short, long) | Distractor RTs | 25.56 | 0.28 | 7.73 | 2.61 |
| Immediate serial recall | 0.22 | 0.24 | 0.06 | 0.02 | ||
| Delayed recall overall | 0.43 | 0.43 | 0.19 | 0.06 | ||
| Delayed recall conditionalized | 1.98 | 0.50 | 1.08 | 0.32 | ||
| 6 | One-way (High CL/Low FT, Low CL/High FT, High CL/High FT) | Distractor RTs | 0.16 | – | – | – |
| Immediate serial recall | 0.67 | – | – | – | ||
| Delayed recall overall | 0.21 | – | – | – | ||
| Delayed recall conditionalized | 0.22 | – | – | – |
[i] Note: All models include participant as a random effect. The Bayes factor (BF) refers to the evidence for the alternative model (BF10) for each effect (shown in the different columns) relative to the null model (i.e., a model that includes only a random effect of participant). The best model in favor of the effect is shown in boldface in each row for each experiment/measure and is underlined when the BF for the best model relative to the next-best model exceeds 3. BANOVA = Bayesian analysis of variance, Exp. = experiment, CL = cognitive load, FT = free time, RTs = response times.
Figure 1
Mean overall and conditionalized delayed recall (and 95% within-subjects confidence intervals) as a function of cognitive load and number of distractors in Experiments 1–4.
Figure 2
Delayed recall (both overall and conditionalized) as a function of accumulated free time at each serial position (labeled 1–4) and each combination of cognitive load (CL) and number of distractors conditions in Experiments 1–4. See online article for a color version of this figure.
Figure 3
Mean overall and conditionalized delayed recall (and 95% within-subjects confidence intervals) as a function of cognitive load and free time in Experiments 5–6.
Figure 4
Delayed recall (both overall and conditionalized) as a function of accumulated free time at each serial position (labeled 1–4) and each combination of cognitive load (CL) and free time conditions in Experiments 5–6. See online article for a color version of this figure.