Efficient search termination without task experience.

Abstract

As a general rule, if it is easy to detect a target in a visual scene, it is also easy to detect its absence. To account for this, models of visual search explain search termination as resulting either from counterfactual reasoning over second-order representations of search efficiency, automatic extraction of ensemble statistics of a display, or heuristic adjustment of a search termination strategy based on previous trials. Traditional few-subjects/many-trials lab-based experiments render it impossible to disentangle the unique contribution of these different processes to absence pop-out -the immediate recognition that a feature is missing from a display. In 2 preregistered large-scale online experiments (N1 = 1187; N2 = 887) we show that search termination times are already aligned with target identification times in the very first trials of the experiment before any experience with target presence. Exploratory analysis reveals that explicit metacognitive knowledge about search efficiency is not necessary for efficient search termination. We conclude that for basic stimulus properties, efficient inference about absence is independent of task experience and of explicit metacognitive knowledge about visual search.

How Many Participants? How Many Trials? Maximizing the Power of Reaction Time Studies

“…Finally, in some situations constraints imposed by the research questions or setting may dictate the choices of and , in which case power considerations are moot. For example, Mazor and Fleming ( 2022 ) sought to examine the presence of a certain effect early in practice. This study necessarily used a small , because only the initial trials from each participant were relevant to the researchers’ questions, and this implied that a large would be needed to get stable results.…”

Prospective search time estimates reveal the strengths and limits of internal models of visual search.

“…This relates to recent theoretical and empirical advances underscoring the utility of keeping a mental self-model , or a self-schema for attention control (Wilterson et al, 2020), social cognition (Graziano, 2013), phenomenal experience (Metzinger, 2003), and inference about absence (Mazor, 2021; Mazor & Fleming, 2022). For example, knowing that a red berry would be easy to find among green leaves, a forager can quickly decide that a certain bush bears no ripe fruit.…”

“…In contrast, subjects that hold the erroneous belief that finding a color requires a serial search will take longer to conclude that a target is missing. Using this indirect approach, and focusing on the first trials of the experiment, before subjects have the opportunity to adapt their search termination strategies, Mazor and Fleming (2022) found that subjects immediately terminate a search when the target color is absent from the search array. This provides indirect evidence that the implicit metacognitive knowledge that is involved in guiding search termination is dissociable from the kind of explicit metacognitive knowledge that we measure here.…”

Outlier exclusion procedures for reaction time analysis: The cures are generally worse than the disease.

“…With a maximum of 600–800 trials typically available in a single-session study for practical reasons, it may only be possible to get tens—not hundreds—of trials in each of the many conditions. Another possibility is that the experimental comparison of interest may involve conditions with inherently low numbers of trials; for example, when studying RTs at restricted levels of practice (e.g., Beesley et al, 2016; Mazor & Fleming, 2022) or studying RTs to rare stimuli, responses, or conditions (e.g., Mowrer et al, 1940; Sali et al, 2022). In some designs, the experimental manipulation may require a training or habituation phase, after which the crucial comparison is only possible in a relatively short testing or transfer phase (e.g., Burke & Roodenrys, 2000; Lubczyk et al, 2022), or the testing session may have to be relatively short because the participant population of interest does not have enough patience or stamina for testing hundreds of trials (e.g., children, elderly, patient groups).…”