Garner’s paradigm and audiovisual correspondence in dynamic stimuli: Pitch and vertical direction

Abstract

Garner’s speeded discrimination paradigm is a central tool in studying crossmodal interaction, revealing automatic perceptual correspondences between dimensions in different modalities. To date, however, the paradigm has been used solely with static, unchanging stimuli, limiting its ecological validity. Here, we use Garner’s paradigm to examine interactions between dynamic (time-varying) audiovisual dimensions — pitch direction and vertical visual motion. In Experiment 1, 32 participants rapidly discriminated ascending vs. descending pitch glides, ignoring concurrent visual motion (auditory task), and ascending vs. descending visual motion, ignoring pitch change (visual task). Results in both tasks revealed strong congruence effects, but no Garner interference, an unusual pattern inconsistent with some interpretations of Garner interference. To examine whether this pattern of results is specific to dynamic stimuli, Experiment 2 (testing another 64 participants) used a modified Garner design with two baseline conditions: The irrelevant stimuli were dynamic in one baseline and static in the other, the test stimuli always being dynamic. The results showed significant Garner interference relative to the static baseline (for both the auditory and visual tasks), but not relative to the dynamic baseline. Congruence effects were evident throughout. We suggest that dynamic stimuli reduce attention to and memory of between-trial variation, thereby reducing Garner interference. Because congruence effects depend primarily on within-trial relations, however, congruence effects are unaffected. Results indicate how a classic tool such as Garner’s paradigm, used productively to examine dimensional interactions between static stimuli, may be readily adapted to probe the radically different behavior of dynamic, time-varying multisensory stimuli.