Figure 1
Left Panels: Cartooned conventional Familiar Size Stroop Task Displays. (A) ‘Congruent’ display – the larger image depicts a larger object than the smaller image, (B) ‘Incongruent’ display – the larger image depicts a smaller real-world object than the smaller image. Centre Panel (C): Cartoon of a B&F ‘visual anagram’ – the top and bottom images are identical, other than being rotated by 90 degrees from one another, yet the perceived category of the stimulus shifts from category (elephant to rabbit). Right Panels: (D) When the larger visual stimulus, the visual anagram from C, is perceived as an elephant – a larger real-world object than the horse – this is a congruent trial display. (E) When it is perceived as a rabbit, this becomes an Incongruent trial display (a rabbit is a smaller real-world object than a horse). These displays can therefore manipulate perceived categories of the depicted objects, while controlling many (rotationally-invariant) low-level features.
Figure 2
(A) In B&F’s stimulus set, rotating each stimulus such that it shifts from being perceived as a small object to a large object is always associated with a rise in its CoM. (B) Shape pairs (visual ‘anagrams’) in the current experiment: these were designed to be silhouettes with similar CoMs to B&F’s stimuli, but to be less easily categorised as familiar objects, (C) Congruent trial display in Experiment 1: the larger image has a higher CoM than the smaller image, (D) Incongruent trial display: the larger image has a lower CoM than the smaller image.
Figure 3
Displays from Experiment 1. A) Instructions Display, B) Initial task-reminder that initiated each trial, C) Stroop Task Display, D) Initial Display asking Participants whether they had recognised any of the shapes as familiar objects, E) Example display asking about each of the shapes individually, in turn, and F) Display with text box allowing participants to enter labels of objects they perceived the shapes to resemble, following a ‘Yes’ response to the display in E.
Figure 4
Stroop Effects in Experiment 1. A) Mean RTs (95% CI bars for paired designs) for Congruent and Incongruent Trials, when All trials were included (Blue Bars), only trials in which explicit recognition probably did not explain the effect (Red bars, see text), and B&F’s Experiment 1, for comparison. B) Box plots of Stroop Effects (Incongruent RT – Incongruent RT) with individual participants’ difference scores; format as for Figure 4A.
Supplementary Table 1
Labels entered by individual participants when asked whether each individual shape had reminded them of a specific real-world, familiar object (participants who reported no recognition are not included above, for brevity). A “>” symbol indicates where a decision was made that the label was a larger real-world object than the other version of that same visual anagram. Note, participants categorising shapes was considered problematic if they categorised the high CoM shape as a larger familiar object than the low CoM object (see text). Second, categorising only one of the two shapes in a pair was typically considered problematic because such an effect could not be ruled out (except in 2 cases when ‘tooth’ was judged ‘small’).
| PARTICIPANT | ANAGRAM 1 HIGH CoM | ANAGRAM 1 LOW CoM | ANAGRAM 2 HIGH CoM | ANAGRAM 2 LOW CoM | ANAGRAM 3 HIGH CoM | ANAGRAM 3 LOW CoM | ANAGRAM 4 HIGH CoM | ANAGRAM 4 LOW CoM |
|---|---|---|---|---|---|---|---|---|
| 1 | Tooth | Tooth | Kiwi (Animal) | Kiwi (Animal) | ||||
| 2 | tap | Duck > | chair | buffalo | buffalo | kiwi bird | ||
| 3 | tap | Duck > | tooth | dog > | bird | bunny > | ||
| 4 | duck | duck | tooth with root | cat or rabbit > | bird | Rabbit > | ||
| 5 | Intestines | A country | Tooth | A bra > | A bird | Rabbit > | ||
| 6 | duck | tooth | cat > | rabbit | rabbit | |||
| 10 | tap | Duck > | dog | bird | rabbit > | |||
| 11 | Chair > | Duck | Tooth | Plastic bag > | Bird (kiwi) | Rabbit > | ||
| 12 | duck | cat | bird | rabbit > | ||||
| 15 | tap | Duck > | molar | Dog > | bird | Rabbit > | ||
| 16 | Tap > | snail | teeth or cow | Puppy > | Rabbit > | |||
| 17 | duck | upside down america | Upside down america | bird | rabbit > | |||
| 18 | duck | book | tooth Tooth=Small | rabbit | rabbit | |||
| 19 | Duck | Duck | Elephant | Elephant | Kiwi | Rabbit > | ||
| 20 | duck | tooth | tooth | Swan > | rabbit | |||
| 21 | folded paper duck or swan | plastic bag upside down | plastic bag > | bird statue | Rabbit > | |||
| 22 | Duck | Tooth | Dog > | Bird | Rabbit > | |||
| 23 | Duck | Bison | Bison | Bird | Rabbit > | |||
| 24 | rubber duck | rubber duck | tooth | tooth | rabbit | rabbit | ||
| 25 | origami swan | Elephant > | cat | kiwi bird | Rabbit > | |||
| 27 | duck | dog | rabbit | |||||
| 28 | Duck | Duck | The state of Missouri | Tooth (*small*) | Tooth (when it was shown the other way around) | Bird | Rabbit > | |
| 30 | Chair > | duck | Elephant > | Tiny dog | bird of prey > | bunny | ||
| 31 | Duck | America | Cow | Cow | Bird | Bird |