stimulusonsetasynchronie

Stimulus-onset-asynchrony, often abbreviated SOA, refers to the temporal interval between the onset of one stimulus and the onset of another. In German-language literature, the term stimulusonsetasynchronie is used to denote this concept. SOA is usually expressed in milliseconds and describes how far apart successive events are in time. It is a central parameter in psychophysics and cognitive psychology, shaping how stimuli are perceived and processed over time.

In priming tasks, a prime stimulus is presented and, after a defined SOA, a target stimulus follows. The SOA modulates the strength and nature of priming effects, with shorter intervals often linked to automatic, unconscious influences and longer intervals allowing for more controlled processing. In masking experiments, a target’s visibility is affected by a mask presented with a specific SOA, where certain intervals maximize or minimize masking.

SOA is applied across sensory modalities and task contexts, including temporal order judgments, multisensory integration, and sensory adaptation studies. Its interpretation depends on factors such as stimulus duration, response requirements, and the temporal integration window of the task.

Methodological considerations are important: precise timing requires calibrated hardware and software, synchronization to display latency, and reporting of timing variability. Small timing errors can influence effect sizes and interpretations. Researchers typically report mean SOA values with dispersion across trials or blocks.

In sum, stimulusonsetasynchronie is a foundational timing parameter that governs how closely successive stimuli are presented and thereby shapes the temporal dynamics of perception and cognitive processing.