SNARC-like effects for time in the auditory modality

The Spatial-Numerical Association of Response Codes (SNARC) effect provides evidence of an association between response position and number magnitude, with faster left-key responses to small numbers (e.g., 1,2) and faster right-key responses to large numbers (e.g., 8,9). Similarly, previous studies revealed a SNARC-like effect for time (expressed as “early/late” onset timing), with faster left-key responses to early onset timing and faster right-key responses to late onset timing (Ishihara et al., 2008) and for music tempo (expressed as the speed of an auditory sequence) with faster left-key responses to slow tempo and faster right-key responses to fast tempo (De Tommaso and Prpic, 2020). Specifically, the present thesis includes three experimental studies that further investigate the occurrence of the SNARC-like effect for time (Study 1) and music tempo (Study 2 and 3), by addressing some open questions and methodological issues from previous literature. The first study was a systematic investigation of the work by Ishihara et al. (2008) aiming (1) to conceptually replicate the SNARC-like effect for time in a direct task and (2) to investigate the automaticity of the SNARC-like effect in indirect tasks. Overall, the results replicated the SNARC-like effect in the direct task (Study1; Experiment 1). Conversely, the effect did not emerge in the indirect tasks (Study 1; Experiment 2,3,4) suggesting that the SNARC-like effect for time is driven by specific task requirements rather than by the automatic processing of temporal stimuli. The second study was a follow up study based on the work by De Tommaso and Prpic (2020) aiming to disambiguate the role of temporal speed (i.e., “slow” or “fast”) from that of interval duration (i.e., “short” or “long”) of an auditory beats sequence. By employing a novel paradigm, the results revealed a consistent SNARC-like effect in both conditions (i.e., “temporal speed” and “interval duration”). Importantly, the direction of the SNARC-like effect was driven by temporal speed, suggesting that tempo was processed even when participants were explicitly required to focus on interval duration. The third study was as a conceptual replication of the work by De Tommaso and Prpic (2020) aiming (1) to extend the SNARC-like effect for music tempo in a full tempo range and (2) to further investigate whether slow and fast tempo ranges are differently associated with space. The results extended the SNARC-like effect in the full tempo range (Study 3; Experiment 1). Additionally, the effect was confirmed in the fast tempo range, whereas contradictory results emerged in the slow tempo range (Study 3; Experiment 2). Notably, despite the absence of a significant effect in the slow tempo range, overall analyses indicated no significant difference between slow and fast tempo ranges, suggesting a plausible weak SNARC-like effect in the slow tempos.