Figure 1
An overview of the experimental procedure in Groningen.
Figure 2
The three tasks completed by participants in Groningen. A) An example of a trial of the matrix task used to assess fluid intelligence. B) An example of a trial of the Letter-Number-Sequencing task (LNS) used to assess working memory capacity (WMC). C) An example of the attentional-capture task used to assess attentional control. Note: In the actual task the background was dark and the line segments in the shapes were white. The colors are reversed here for illustration purposes.
Figure 3
Distribution of resting-state pupil size in mm, as recorded from the sample collected in Oslo (N = 122).
Table 1
Descriptive statistics of task scores.
| TASK | M | SD | N | MIN | MAX | SKEW. | KURT. |
|---|---|---|---|---|---|---|---|
| Matrix | 52% | 19% | 224 | 0% | 88% | –0.27 | 0.05 |
| LNS | 19.07 | 3.62 | 102 | 5 | 25 | –1.49 | 3.63 |
| Attentional control | 113.05 | 82.02 | 102 | –324.79 | 299.03 | –1.58 | 7.45 |
Table 2
Zero-order correlations between all measures.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | |
|---|---|---|---|---|---|---|---|---|---|
| 1. Average pupil size (z) | – | ||||||||
| 2. Pupil size CoV (z) | .01 | – | |||||||
| 3. Matrix task score | –.01 | –.03 | – | ||||||
| 4. LNS score | .05 | 0.11 | .09 | – | |||||
| 5. Attentional control score | .11 | –.06 | .12 | –.02 | – | ||||
| 6. Age | –.08 | –.05 | .01 | .00 | –.02 | – | |||
| 7. Sex | .05 | .14* | –.12 | –.06 | .08 | –.18* | – | ||
| 8. Nicotine consumption | –.13 | .01 | –.01 | .03 | .03 | .08 | –.18* | – | |
| 9. Caffeine consumption | –.02 | –.05 | –.18* | .07 | –.13 | –.06 | –.15 | .23* | – |
[i] *p < .05.
Figure 4
The relationship between baseline pupil size and fluid intelligence (as assessed with a matrix task). A) Average pupil size and fluid intelligence. B) Variability in pupil size and fluid intelligence.
Figure 5
Distribution of pupil sizes across levels of nicotine consumption in the full sample (“no” indicating no nicotine consumption on the day of the experiment (N = 197) and “yes” indicating nicotine consumed on the day of the experiment (N = 16)).
Figure 6
The relationship between baseline pupil size and working memory capacity (as assessed with a Letter-Number-Sequencing task). A) Average pupil size and WMC. B) Variability in pupil size and WMC.
Figure 7
The relationship between baseline pupil size and attentional control (as assessed with an attentional-capture task. A) Average pupil size and attentional control. B) Variability in pupil size and attentional control.
Figure 8
Distribution of pupil sizes across levels of nicotine consumption in the Groningen sample (“no” indicating no nicotine consumption on the day of the experiment (N = 94) and “yes” indicating nicotine consumed on the day of the experiment (N = 8)).
Appendix A
Letter-Number-Sequencing items and associated response times.
| STRING | RESPONSE TIME |
|---|---|
| 2-B | 7s |
| D-1 | 7s |
| 4-C | 7s |
| E-5 | 7s |
| 3-A | 7s |
| C-1 | 7s |
| 5-C-A | 7s |
| F-E-1 | 7s |
| 3-2-A | 7s |
| 1-G-7 | 7s |
| H-9-4 | 7s |
| 3-Q-7 | 7s |
| Z-8-N | 7s |
| M-6-U | 7s |
| P-2-N | 7s |
| V-1-J-5 | 10s |
| 7-X-4-G | 10s |
| S-9-T-6 | 10s |
| 8-E-6-F-1 | 12s |
| K-4-C-2-S | 12s |
| 5-Q-3-H-6 | 12s |
| M-4-P-7-R-2 | 14s |
| 6-N-9-J-2-S | 14s |
| U-6-H-5-F-3 | 14s |
| R-7-V-4-Y-8-F | 15s |
| 9-X-2-J-3-N-7 | 15s |
| M-1-Q-8-R-4-D | 15s |
| 6-P-7-S-2-N-9-A | 16s |
| U-1-R-9-X-4-K-3 | 16s |
| 7-M-2-T-6-F-9-A | 16s |