A mental process that is independent of conscious perception should run equally well with or without it. Previous investigations of unconscious processing have seldom included this comparison: They typically demonstrated only processing without conscious perception. In the research reported here, we showed that attentional capture is largely independent of conscious perception and that updating the episodic information stored about an object is entirely contingent on conscious perception. We used a spatial-cuing paradigm, in which the cue was a color-singleton distractor rendered liminal by continuous flash suppression or brief exposure. When the cue matched the participant's attentional set, it strongly captured attention whether it was subliminal or consciously perceived. In contrast, a nonmatching cue did not capture attention but instead produced a same-location cost, which was contingent on consciously perceiving the cue. Our findings demonstrate a dissociation between attention and conscious perception and unveil an important boundary condition of object-file updating.

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Temporal dynamics of attention have been in the spotlight of research since the earliest days of cognitive psychology. Typically, researchers describe two different aspects of the temporal fluctuations of attention: one is in intervals of milliseconds (phasic alertness), and the other over minutes or even hours (tonic alertness or sustained attention). In order to evaluate individual capacities for sustained attention and phasic alertness, most studies rely on variations of the Continuous Performance Task (CPT). Indices of sustained attention and phasic alertness are typically based on reaction times to targets; phasic alertness is related to the change in reaction times following a cue, and sustained attention is related to variability of reaction times during the task. In the following study, we attempted to establish a new approach for studying sustained attention and phasic alertness, not reliant solely on reaction time measures. We developed a new variation of the CPT with conjunctive feature targets and forward and backward masking to induce a higher variability in accuracy. This allowed us to assess an individual's ability to maintain the same level of sensitivity to targets (d-prime) across a ten minute period on the task as an index for sustained attention. We also assessed reaction times as a function of previous trial type, and suggest previous trial RT benefit might be a marker for an individual's phasic alertness. We demonstrated the use of this task with healthy aging controls and stroke survivors. As a demonstration of external validity of the novel paradigm, we present a correlation between how individual performance drops over time and individual reports of distractibility in everyday life on the Cognitive Failures Questionnaire. In addition, we found significant differences between the patient and control groups in our proposed marker of phasic alertness. We discuss the implications of our study for current assessment tools, as well as general differences in phasic alertness between clinical and neurologically unimpaired groups.

Visual search is a fundamental element of human behavior and is predominantly studied in a laboratory setting using static displays. However, real-life search is often an extended process taking place in dynamic environments. We have designed a dynamic-search task in order to incorporate the temporal dimension into visual search. Using this task, we tested how participants learn and utilize spatiotemporal regularities embedded within the environment to guide performance. Participants searched for eight instances of a target that faded in and out of a display containing similarly transient distractors. In each trial, four of the eight targets appeared in a temporally predictable fashion with one target appearing in each of four spatially separated quadrants. The other four targets were spatially and temporally unpredictable. Participants' performance was significantly better for spatiotemporally predictable compared to unpredictable targets (Experiments 1-4). The effects were reliable over different patterns of spatiotemporal predictability (Experiment 2) and primarily reflected long-term learning over trials (Experiments 3, 4), although single-trial priming effects also contributed (Experiment 4). Eye-movement recordings (Experiment 1) revealed that spatiotemporal regularities guide attention proactively and dynamically. Taken together, our results show that regularities across both space and time can guide visual search and this guidance can primarily be attributed to robust long-term representations of these regularities.

Sustained attention (SA) is among the most studied faculties of human cognition, and thought to be crucial for many aspects of behavior. Measuring SA often relies on performance on a continuous, low-demanding task. Such continuous performance tasks (CPTs) have many variations, and sustained attention is typically estimated based on variability in reaction times. While relying on reaction times may be useful in some cases, it can pose a challenge when working with clinical populations. To increase interpersonal variability in task parameters that do not rely on speed, researchers have increased demands for memory and response inhibition. These approaches, however, may be confounded when used to assess populations that suffer from multiple cognitive deficits. In the current study, we propose a new approach for increasing task variability by increasing the attentional demands. In order to do so, we created a new variation of a CPT – a masked version, where inattention is more likely to cause misidentifying a target. After establishing that masking indeed decreases target detection, we further investigated which task parameter may influence response biases. To do so, we contrasted two versions of the CPT with different target/distractor ratio. We then established how perceptual parameters can be controlled independently in a CPT. Following the experimental manipulations, we tested the MCCPT with aging controls and chronic stroke patients to assure the task can be used with target populations. The results confirm the MCCPT as a task providing high sensitivity without relying on reaction speed, and feasible for patients.