Page 165 - Emotions through the eyes of our closest living relatives- Exploring attentional and behavioral mechanisms

Validation of the Pictorial Implicit Association Test
Tasks
Participants took part in two 7-block IATs; a word-IAT in which individuals categorized pictures into categories represented with words (WIAT) and our picture-only IAT (PIAT). In both IATs, there were initially two training blocks (block 1 and 2), each consisting of 20 trials. Next, participants continued through two critical blocks (block 3: 20 trials, block 4: 40 trials), followed by another training block (block 5: 40 trials). Finally, participants completed two critical blocks again (block 6: 20 trials, block 7: 40 trials). In contrast with Experiment 1 that was conducted on touchscreens, participants now performed the tasks online while using a keyboard. Participants used the “E” and “I” keys to indicate the left and right superordinate categories of the concepts (faces) and attributes (positive and negative images), respectively, and we used their reaction time on the key presses as a measure of bias. Furthermore, whereas on the touchscreen-based task participants had to press a dot to continue, participants were now shown a fixation cross in the middle of the screen for 300 ms before the next trial started.
The task design for the WIAT and PIAT was similar to Experiment 1, but the two
critical blocks each contained an extra 20 trials. In the first training block, participants
categorized perceived ethnic concepts (“Moroccan” vs. “Dutch”), and in the second
training block attributes (positive vs. negative). The third and fourth blocks, i.e.,
critical blocks, presented participants with the combined concepts and attributes. In
the fifth (training) block, participants had to categorize attributes again, but this time
the attributes switched positions on the screen (e.g., when the positive attribute was
presented on the left side of the screen in block 2, it was now positioned on the right 7 side of the screen). Critical blocks 6 and 7 once again presented participants with the
combined concepts and attributes, but this time the position of the attributes was
switched relative to the position in critical blocks 3 and 4 (i.e., if “Dutch” + negative
was presented on the left side in block 3 and 4, it was now presented on the right
side).
For both the WIAT and PIAT, participants were issued one of four versions that varied on the following randomized factors: the starting position of the concept (i.e., left side or right side of the screen), and whether the concept is expected to be congruent or incongruent with the outgroup negativity bias. See Table S3 for more details.
In the word-IAT, words were used to indicate the superordinate categories (concepts and attributes), and pictures for the to-be categorized stimuli. For the superordinate categories, the concepts were written in a black font as “Nederlands”
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