Humans can utilise different environmental regularities to optimise their behaviour. For example, regularities can form the basis of attentional guidance during visual search tasks. This guidance makes it easier to locate target objects in busy environments by selectively prioritising the most relevant information, while filtering out less relevant information. Both spatial regularities and non-spatial, featural regularities, such as colour, have been demonstrated to guide attention during traditional visual search tasks in which target and distractor stimuli remain static within trials. In reality, visual search often takes place within dynamic environments, where the set of visible stimuli varies over time. Recently, a dynamic visual-search task was developed to investigate whether spatial regularities operating conditionally alongside temporal regularities may guide visual search (Boettcher et al., 2021). In other words, whether the flow of time can be used as a basis for adaptively modulating spatial attentional guidance when searching within dynamic environments. During this task, target and distractor stimuli, defined by their orientation, fade in and out of view against a noisy background at different times and in different locations during trials. Participants are tasked with finding and clicking on as many targets as possible. Importantly, half of the targets to appear in each trial are spatiotemporally predictable, appearing at the same time and in the same spatial quadrant of the display on every trial. The other half of the targets, and the distractors, are spatiotemporally unpredictable, appearing at an unpredictable time and in an unpredictable quadrant of the display on every trial. Recently, a study was conducted using an online version of this dynamic visual-search task in which all stimuli appeared in one of four distinct colours (Williams et al., 2022). The colour of the stimuli here is irrelevant to the search task at hand. In-line with previous findings (Boettcher et al., 2021), this study found that participants’ performance was improved when identifying spatiotemporally predictable targets, compared to spatiotemporally unpredictable targets. These findings show that humans can utilise spatiotemporal regularities to guide visual search within dynamic contexts. The present study will use an adapted version of this online dynamic visual-search task to investigate whether time-dependent regularities that concern task-irrelevant, non-spatial features of items, specifically their colour, can also to guide attention during dynamic visual search. This version of the task will contain feature-temporal regularities, instead of spatiotemporal regularities. In contrast to the previous task, all targets and distractors will be spatially unpredictable, appearing at an unpredictable location (and hence quadrant) of the display on every trial. Each target and distractor stimulus will appear in one of four distinct colours. Half of the targets appearing in each trial will be feature-temporally predictable, appearing at the same time and in the same colour on every trial. The other half of the targets, and the distractors, will be feature-temporally unpredictable, appearing at an unpredictable time and in an unpredictable colour on every trial. Should participants learn these regularities and utilise relevant feature-temporal predictions accordingly, then they will perform better at detecting feature-temporally predictable targets, compared to feature-temporally unpredictable targets. This pattern of findings would indicate that feature-temporal regularities can serve as a source of guidance in dynamic visual-search. Furthermore, indicating that this is the case even when these regularities are independent of spatial regularities and when they concern features which are not directly task relevant. It is currently unclear whether any effect of feature-temporal predictability on search performance would be driven primarily by implicit or explicit memory systems. Evidence from similar tasks investigating the effects of environmental regularities on visual search performance, e.g., contextual cuing effects, has led to mixed conclusions regarding participants’ awareness of regularities. The present study will therefore aim to gain insight into the extent to which participants have explicit awareness of the feature-temporal regularities within the search task, and whether explicit awareness of these regularities relates to search performance. This will be done using a post-test questionnaire in which participants will be asked whether they used any particular strategies or noticed any patterns during the task. They will then be asked to indicate the order in which targets of each colour appeared during trials. If this order matches the temporal order of predictable targets appearing in each colour, then this will suggest that participants are aware of the feature-temporal regularities. Boettcher, S. E. P., Shalev, N., Wolfe, J. M., & Nobre, A. C. (2021). Right place, right time: Spatiotemporal predictions guide attention in dynamic visual search. Journal of Experimental Psychology: General. Advance online publication. https://doi.org/10.1037/xge0000901 Williams, G., Nobre, A. C., Shalev, N., & Boettcher, S. (2022, July 29). Spatiotemporal regularities in dynamic visual search with coloured targets and explicit awareness test. https://doi.org/10.17605/OSF.IO/FJA8B