the initial presentation and the repetitive trials of the target and the distractor stimuli. It is set up such that a set of distractor stimuli are constantly ignored in the process of target selection. In the previous example provided, prime refers to the repeated perception of the blue pen as the distractor. Probe trial in an experiment refers to the actual testing for negative priming effects. In this trial, the repeated distractor of the prime trial is presented as the target. The reaction time of the response for the probe target (prime distractor) is measured to quantify the negative priming effect. Some experiments may use additional interferences such as changing the position of the stimuli or presenting completely irrelevant stimuli during either of these trials. The magnitude of negative priming effects are found to be higher with these interferences. Interferences are used to investigate how the response to the distractor changes under conditions of a third interfering stimulus. Stimulus modality The primary two stimulus modalities used for negative priming research are visual and auditory stimulus materials. The stimulus presented varied from objects or symbols in visual field to human voices or artificial sounds. Stronger negative priming effects are found for auditory stimulus but the standardized effect sizes between the modalities did not vary. Evidence for negative priming has also been found across various modes of response including vocal naming, manual key press, and reaching. Negative priming was observed for various types of judgment such as identification, categorization, matching, counting and localization. The tasks used to find evidence for negative priming includes Stroop color–word task, lexical decision task, identification, matching, and localization tasks. The Stroop color–word task utilizes the Stroop effect to observe the distractor suppression and negative priming. Identification tasks present a set of images, sounds, words, symbols, or letters and require the subject to select the prime target based a particular feature that differentiates the target from the distractor. Lexical decision utilizes semantic knowledge of the subject and tests the subject ability to remember the multiple meanings and uses of one word. For example, the word "bank" has multiple meanings and can be referred in different contexts such as "bank is a place where money is deposited" or "banks of a river". Matching tasks require subjects to respond "same" or "different" by matching the target letters or shapes with the explicitly specified goal while ignoring the distractor. Localization tasks