The ability to stop an already initiated action is paramount to adaptive behavior. Much scientific debate in the field of human action-stopping currently focuses on two interrelated questions. (1) Which cognitive and neural processes uniquely underpin the implementation of inhibitory control when actions are stopped after explicit stop signals, and which processes are instead commonly evoked by all salient signals, even those that do not require stopping? (2) Why do purported (neuro) physiological signatures of inhibition occur at two different latencies after stop signals? Here, we address both questions via two preregistered experiments that combined measurements of corticospinal excitability, EMG, and whole-scalp EEG. Adult human subjects performed a stop signal task that also contained "ignore" signals: equally salient signals that did not require stopping but rather completion of the Go response. We found that both stop-and ignore signals produced equal amounts of early-latency inhibition of corticospinal excitability and EMG, which took place ;150 ms following either signal. Multivariate pattern analysis of the whole-scalp EEG data further corroborated that this early processing stage was shared between stopand ignore signals, as neural activity following the two signals could not be decoded from each other until a later time period. In this later period, unique activity related to stop signals emerged at frontocentral scalp sites, reflecting an increased stop signal P3. These findings suggest a two-step model of action-stopping, according to which an initial, universal inhibitory response to the saliency of the stop signal is followed by a slower process that is unique to outright stopping.

We showed that judgments of learning (JOLs) were not affected by presentation modality in a list-learning task, although the typical font-size and loudness illusions emerged in that large-font visual presentations and loud auditory presentations elicited higher JOLs than their less intense counterparts. Further, when items were presented in both modalities simultaneously, largefont/quiet and small-font/loud items received similar JOLs (and were recalled similarly). Most importantly, when the intensity manipulation was compounded across modalities, the magnitude of the illusion increased beyond that observed in a single modality, showing the influence of combining cues. Whereas recall was still the same, large-font/loud items received higher JOLs than either small-font/loud items or large-font/quiet items, and not-intense items received very low JOLs. These differences emerged only when all conditions were presented within a single list and not in a between-subjects design, underscoring the importance of comparative judgments.

Varying item-specific features such as size (Rhodes & Castel, 2008) or blur (Yue, Castel, & Bjork, 2013) often produces metamemory illusions in which one type of item receives higher judgments of learning (JOLs) without being recalled better. In this study, we explored how similar manipulations to context would influence JOLs. When to-be-recalled words varying in size (or blur) were accompanied by backgrounds also varying in size (or blur), the traditional JOL illusions were reduced (Experiments 1, 2, 4, and 5) compared to when there were no backgrounds (Experiments 3a, 3b, and 4). Thus, the itemspecific and contextual cues were used interactively. Further, the background manipulations also sometimes themselves led to metamemory illusions regarding JOLs for the to-be-remembered items. In general, there were robust individual differences in how participants used the cues, including how they incorporated the contextual cues into their JOL decisions. In part, this may explain why interactive cue utilization did not always emerge at the group level. In sum, we showed that context may affect JOLs both directly and indirectly by influencing participants' use of item-specific cues. These findings broaden our understanding of how cues may be utilized (e.g., Koriat, 1997) and integrated (e.g., Undorf, Söllner, and Bröder, 2018) in JOLs.

The ability to stop an already initiated action is paramount to adaptive behavior. Most scientific debate in the field of human action-stopping currently focuses on two interrelated questions. First: Which mental and neural processes underpin the implementation of inhibitory control, and which reflect the attentional detection of salient stop-signals instead? Second: Why do physiological signatures of inhibition occur at two different latencies after stop-signals (for visual signals, either before or after ~150ms)? Here, we address both questions via two pre-registered experiments that combined transcranial magnetic stimulation, electromyography, and multi-variate pattern analysis of whole-scalp electroencephalography. Using a stop-signal task that also contained a second type of salient signal that did not require stopping, we found that both signals induced equal amounts of early-latency inhibitory activity, whereas only later signatures (after 175ms) distinguished the two. These findings resolve ongoing debates in the literature and strongly suggest a two-step model of action-stopping.