Arousal and valence have dissociable effects on responses to schematic emotional faces.

Studies examining behavioural responses to emotional stimuli usually report one of two patterns of responses to negative stimuli. Some studies find faster responses to negative material. Other studies find slower responses to negative stimuli. While the attentional mechanisms proposed to explain these findings (attentional capture in the former case, delayed disengagement in the latter) are not at odds with one another, the behavioural findings do need to be reconciled. We posit that arousal, being the primary differentiator of threatening and nonthreatening stimuli, needs to be more carefully considered. To this end, two experiments were conducted evaluating the role of stimulus arousal and valence in the processing of schematic emotional faces. In Experiment 1, stimulus arousal was manipulated via the presence or absence of eyebrows in the schematic faces in a faces flanker task. Results showed faster responses to faces with eyebrows but no differences in the faces flanker asymmetry between faces with and without eyebrows. In Experiment 2, participants rated the faces on an evaluative space grid. Results showed the presence of the eyebrows had a greater impact on negative ratings for negative faces than for the other expressions. This suggests that stimulus valence and arousal were manipulated by the eyebrows and the reaction time differences could not be attributed purely to perceptual differences. Together these results suggests that both valence and arousal impact the processing of emotional schematic faces, and that these effects are dissociable. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Need for cross-level iterative re-entry in models of visual processing.

Two main hypotheses regarding the directional flow of visual information processing in the brain have been proposed: feed-forward (bottom-up) and re-entrant (top-down). Early theories espoused feed-forward principles in which processing was said to advance from simple to increasingly complex attributes terminating at a higher area where conscious perceptions occur. That view is disconfirmed by advances in neuroanatomy and neurophysiology, which implicate re-entrant two-way signaling as the predominant form of communication between brain regions. With some notable exceptions, the notion of re-entrant processing has had a relatively modest effect on computational models of perception and cognition, which continue to be predominantly based on feed-forward or within-level re-entrant principles. In the present work we describe five sets of empirical findings that defy interpretation in terms of feed-forward or within-level re-entrant principles. We conclude by urging the adoption of psychophysical, biological, and computational models based on cross-level iterative re-entrant principles.

Dissociating affective and perceptual effects of schematic faces on attentional scope.

Attention allocation to positive and negative stimuli differs. For example, the flanker-interference asymmetry describes a pattern of results on flanker tasks using emotional stimuli, where a typical flanker-interference effect is observed for positive targets but not for negative targets. There are two dominant explanations for the flanker-interference asymmetry. According to the emotion-first explanation, negative targets are preferentially processed to facilitate the processing of potentially threatening stimuli. In contrast, feature-first explanations argue that the asymmetry results from differences in perceptual complexity between positive and negative stimuli. Three experiments used schematic emotional faces in a flanker task to directly compare these explanations. To manipulate the perceptual complexity of the stimuli, an enclosing circle was present on half of the trials. In all three experiments, reaction times showed the expected flanker-interference asymmetry, but the pattern was not influenced by the presence of the circle. However, event-related potentials showed that perceptual complexity influenced both the structural encoding and evaluative processing of the faces in the N170 and P3b time windows. These results suggest that both perceptual complexity and emotional valence play an important role in the processing of schematic emotional faces, but that emotional valence may have a stronger effect at evaluative stages of processing. Other findings show that the enclosing circle may alter the perceived emotional expression of neutral faces. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Alerting effects occur in simple-But not in compound-Visual search tasks.

Alerting (e.g., a brief brightening of the screen just before a target display) is known to facilitate visual search in simple tasks that involve the single step of detecting a pop-out item within a stimulus array. What is not known is whether alerting facilitates performance also in compound search tasks which involve two steps: First, locate the pop-out item, then identify a detail of that item. In a series of five experiments, we show that alerting facilitates performance of each component of a compound task when tested separately, (Experiments 2a and 2b) but not when the components are combined in a compound task (Experiment 1). Yet, alerting does facilitate performance in a compound task when the pop-out item is displayed in the same location on successive trials (Experiment 3). We hypothesized that such spatial repetition allows attention to linger at that location, thus allowing the first component (locate the pop-out item) to be bypassed. In practice, this turns the compound task into a simple task. That hypothesis was confirmed in Experiment 4 using a reorienting cue to shift the focus of attention to another location. An overall account of the absence of alerting effects in compound search tasks is proposed in terms of the temporal relationship between a period of enhancement rendered as an ex-Gaussian function and the hypothesized sequence of processing stages in visual search. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Metacontrast masking reduces the estimated duration of visible persistence.

A brief visual display can give rise to a sensation that outlasts the duration of the physical stimulus. The duration of this visible persistence has been estimated with paradigms that require the temporal integration of two brief sequential displays (frames) separated by a blank temporal gap. Temporal integration is said to occur when the visible persistence generated by the first frame is sufficiently long to bridge the inter-frame temporal gap. The longest gap at which integration still occurs is taken as an estimate of the duration of visible persistence. In the present work, we show that the duration of visible persistence has been underestimated in at least some of the experiments involving the temporal integration of successive displays. This is because the trailing frame can act as a metacontrast mask that foreshortens the visibility of the leading frame. Specifically, we show that operations that reduce the strength of metacontrast masking yield longer estimates of visible persistence. The relationship between metacontrast masking and visible persistence had been mentioned in some individual studies, but a comprehensive examination of that relationship is currently unavailable. Finally, we show that estimates based on single displays (e.g., the Sperling paradigm) also fail to provide untainted estimates because, in single displays, visible persistence is confounded with informational persistence.

T1 difficulty does not modulate the magnitude of the attentional blink.

When the visual system is busy processing one stimulus, it has problems processing a subsequent stimulus if it arrives soon after the first. Laboratory studies of this second-stimulus impairment-known as attentional blink (AB)-have employed two targets (T1, T2) presented in rapid sequence, and have found identification accuracy to be nearly perfect for T1, but impaired for T2. It is commonly believed that the magnitude of the AB is related directly to the difficulty of T1: the greater the T1 difficulty, the larger the AB. A survey of the experimental literature disconfirms that belief showing it to have arisen from artificial constraints imposed by the 100% limit of the response scale. Removal of that constraint, either using reaction time (RT) instead of accuracy as the dependent measure, or in experiments in which the functions of T2 accuracy over lags do not converge to the limit of the response scale, reveals parallel functions for the easy-T1 and the hard-T1 conditions, consistent with the idea that T1 difficulty does not modulate AB magnitude. This finding is problematic for all, but the Boost and Bounce (B&B) and the Locus Coeruleus-Norepinephrine (LC-NE) theories in which T1 acts merely as a trigger for an eventual refractory period that leads to the failure to process T2, rendering T1 difficulty and its relationship to the AB an irrelevant consideration.

Are the inverse-duration and inverse-proximity effects in temporal integration subserved by independent mechanisms?

Displays shorter than about 100 ms are normally seen as lasting longer than their physical duration. This visible persistence can bridge a temporal gap between two sequential stimuli causing them to be temporally integrated into a single percept. We investigated two findings in the temporal-integration literature: the inverse duration effect (temporal integration is progressively impaired as the duration of the first stimulus is increased) and the inverse proximity effect (temporal integration is progressively impaired as the spatial proximity between the stimuli is increased). In two experiments we asked whether the two effects are separable (i.e., whether they are subserved by independent mechanisms) or interact with one another. To estimate the duration of visible persistence we used the missing element paradigm in Experiment 1 and directional stroboscopic motion between two lines in Experiment 2. In both experiments we manipulated the duration of the leading stimulus and the spatial gap between the elements of the two sequential displays. Additive-factors logic was employed to examine the separability of the effects of duration and proximity. Independence (separability) of the two factors would be evidenced in a graph in which the functions of duration over proximity are parallel. The results pointed uniformly to separability. A plausible mechanism for the inverse duration effect is the burst of processing activity time-locked to stimulus onset. A plausible mechanism for the inverse proximity effect is lateral inhibition that acts to reduce the visible persistence of the leading stimulus.

From alternation to repetition: Spatial attention biases contribute to sequential effects in a choice reaction-time task.

Observers often take longer to respond to a visual target when it appears at a recently stimulated location than when it appears at a new location in the visual field. This behavioral impairment - known as inhibition of return (IOR) - is mirrored by a reduction of an event-related potential (ERP) component called the N2pc that has been associated with attentional selection. Together, these findings indicate that the mechanism underlying IOR operates to bias covert attention against re-visiting the most recently attended location. The goal of the present study was to determine how this inhibitory attention bias evolves across successive trials of a two-item search task. Initially, targets appearing at previously attended locations were associated with behavioral IOR and a concomitant reduction of the N2pc. After several successive trials, this initial inhibitory bias was superseded by expectancy-based biases associated with "predictable" inter-trial patterns of location repeats or location changes, in some cases leading to faster responses and a larger N2pc when the target location repeated (facilitation of return).  These results provide evidence that biases in the covert deployment of attention are updated dynamically according to the recent selection history and contribute to well-known sequential effects in serial choice reaction-time tasks.

The attentional blink: why does Lag-1 sparing occur when the dependent measure is accuracy, but Lag-1 deficit when it is RT?

Perception of the second of two targets (T1, T2) displayed in rapid sequence is impaired if it comes shortly after the first (attentional blink, AB). In an exception, known as Lag-1 sparing, T2 is virtually unimpaired if it is presented directly after T1. Three experiments examined the seemingly inconsistent findings that Lag-1 sparing occurs in accuracy but Lag-1 deficit occurs in RT. Experiment 1 pointed to masking of T2 as the critical factor. When T2 was not masked, the results replicated the conventional findings. The novel finding was that Lag-1 sparing occurred in RT, provided that T2 was masked. An account was provided by a psychological refractory period-based model in which processing was said to occur in two broadly sequential stages: stimulus selection and response planning. Experiments 2 and 3 tested predictions from the PRP-based model regarding Lag-1 sparing/Lag-1 deficit. In Experiment 2, we increased T2 salience, notionally reducing the duration of the T2 selection stage, with corresponding reduction in Lag-1 sparing. In Experiment 3, we manipulated the compatibility between the T1 stimulus and the response to notionally decrease/increase the duration of the T1 response-planning stage with corresponding increment/decrement in Lag-1 sparing. The results of both experiments confirmed predictions from the PRP-based model.

Salience drives overt selection of two equally relevant visual targets.

In the present study, we investigated whether salience determines the sequence of selection when participants search for two equally relevant visual targets. To do this, attentional selection was tracked overtly as observers inspected two items of differing physical salience: one a highly salient color singleton, and the other a less salient shape singleton. Participants were instructed to make natural eye movements in order to determine whether two line segments contained within the two singletons were oriented in the same or in different directions. Because both singleton items were task-relevant, participants had no reason to inspect one item before the other. As expected, observers fixated both targets on the majority of trials. Critically, saccades to the color singleton preceded saccades to the less salient shape singleton on the majority of trials. This demonstrates that the order of attentional object selection is largely determined by stimulus salience when task relevance is equated.

Transition from feature-search to singleton-detection strategies in visual search: The role of number of target-defining options.

When searching for a uniquely colored target in an RSVP stream of homogeneously colored nontarget items, observers can use singleton-detection and/or feature-search modes. Using an attentional-capture paradigm, we varied systematically (a) the number of possible target colors from 1 to 4 and (b) the presence or absence of a colored ring surrounding the nontarget item displayed 200 ms before the target. When present, the ring was either the same color as 1 of the possible targets (color-match), or an irrelevant color (color-mismatch). Capture was measured as the impairment in target identification accuracy when the ring was present relative to when it was absent. Greater capture in the color-match than in the color-mismatch condition was regarded as evidence of feature-search mode. Capture in the color-mismatch condition was regarded as evidence for singleton-detection mode. We show that, as the number of target colors is increased, the relative prominence of feature-search mode decreases, and that of singleton-detection mode increases correspondingly. This novel finding shows that, when both feature-search and singleton-detection modes are possible, at least some degree of feature-search mode is used until the number of possible target-defining colors reaches about 4. This suggests that the weight assigned to singleton-detection mode increases, and that assigned to feature-search mode decreases correspondingly, as the difficulty of maintaining the target-defining features in mind is increased. (PsycINFO Database Record

Perception of temporal order during the attentional blink: Using stimulus salience to modulate prior entry.

When multiple targets are presented in rapid sequence, observers frequently confuse the order in which they were presented. The probability of order reversals is known to vary throughout the period of the attentional blink (AB), which refers to impairment in the perception of the second of two targets when it is presented within approximately 500 ms from the first. Our objective was to examine the principle of prior entry (in which perception of temporal order is said to be affected by the relative latency at which each target is processed) as a determinant of the perception of temporal order throughout the AB. In two experiments, three letter targets (T1, T2, T3) were inserted in a stream of digit distractors, with T3 always presented directly after T2. The T1-T2 lag was varied to assess the perception of T2-T3 temporal order throughout the period of the AB. Processing latency was manipulated by means of salience. In Experiment 1, salience of T2 and T3 was manipulated exogenously by coloring the salient target red with all other stimuli being green. In Experiment 2, salience was modulated endogenously by manipulating which of the two targets matched the contents of working memory. Consistent with the principle of prior entry, perception of temporal order in both experiments was enhanced throughout the period of the AB when T2 was salient, and impaired when T3 was salient. Simulations based on the Episodic Simultaneous Type, Serial Token (eSTST) model that incorporates prior-entry, matched the empirical results.

Visual search is postponed during the period of the AB: An event-related potential study.

In the phenomenon known as the attentional blink (AB), perception of the second of two rapidly sequential targets (T2) is impaired when presented shortly after the first (T1). Studies in which T2 consisted of a pop-out search array provided evidence suggesting that visual search is postponed during the AB. In the present work, we used behavioral and electrophysiological measures to test this postponement hypothesis. The behavioral measure was reaction time (RT) to T2; the electrophysiological measure was the onset latency of an ERP index of attentional selection, known as the N2pc. Consistent with the postponement hypothesis, both measures were delayed during the AB. The delay in N2pc was substantially shorter than that in RT, pointing to multiple sources of delay in the chain of processing events, as distinct from the single source postulated in current theories of the AB. Finally, the finding that the N2pc was delayed during the AB strongly suggests that attention is involved in the processing of pop-out search arrays.

Is pop-out visual search attentive or preattentive? Yes!

Is the efficiency of "pop-out" visual search impaired when attention is preempted by another task? This question has been raised in earlier experiments but has not received a satisfactory answer. To constrain the availability of attention, those experiments employed an attentional blink (AB) paradigm in which report of the second of 2 targets (T2) is impaired when it is presented shortly after the first (T1). In those experiments, T2 was a pop-out search display that remained on view until response. The main finding was that search efficiency, as indexed by the slope of the search function, was not impaired during the period of the AB. With such long displays, however, the search could be postponed until T1 had been processed, thus allowing the task to be performed with full attention. That pitfall was avoided in the present Experiment 1 by presenting the search array either until response (thus allowing a postponement strategy) or very briefly (making that strategy ineffectual). Level of performance was impaired during the period of the AB, but search efficiency was unimpaired even when the display was brief. Experiment 2 showed that visual search is indeed postponed during the period of the AB, when the array remains on view until response. These findings reveal the action of at least 2 separable mechanisms, indexed by level and efficiency of pop-out search, which are affected in different ways by the availability of attention. The Guided Search 4.0 model can account for the results in both level and efficiency.

Escape from temporal-integration masking: the roles of visible persistence and input filtering.

A brief target embedded in­and coterminating with­a noise mask is identified easily when the duration of the mask is long but not when it is short (Di Lollo, 1980; inverse-duration effect). Identification has been said to be mediated by the visible persistence of the target, which outlasted that of the mask. We tested an alternative account based on input filtering triggered by the onset and offset of the target, relative to those of the mask, without recourse to visible persistence. The results of Experiment 1 could not be explained wholly in terms of visible persistence but were entirely consistent with input filtering. Identification suffered in Experiment 2 when transient responses were attenuated by "ramping." In Experiment 3, accuracy improved gradually as a function of leading-mask duration. All results were consistent with a modified version of von Holst's (1954) hypothesis that a new stimulus (e.g., the present mask) establishes an input filter within the system. Any sudden onsets or offsets then lead to the perception of a new object only when they do not match the input filter, thus becoming segregated from the temporally leading stimulus.

Motorcyclist's lane position as a factor in right-of-way violation collisions: a driving simulator study.

A driver turning left and failing to notice an oncoming motorcyclist until too late is the most common cause of motorcycle collisions. Consequently, much previous research has focused on motorcycle properties, such as size, shape, and color to explain its inconspicuousness. However, collision statistics remain largely unchanged, suggesting that the issue may not be related solely to the motorcycle's static properties. In the present study, we examined a different characteristic of the motorcycle, namely its trajectory of approach. Seventeen participants faced oncoming traffic in a high-fidelity driving simulator and indicated when gaps were safe enough for them to turn left at an intersection. We manipulated the size of the gaps and the type of oncoming vehicle over 135 trials, with gap sizes varying from 3 to 5s, and vehicles consisting of either a car, a motorcycle in the left-of-lane position, or a motorcycle in the right-of-lane position. Our results show that drivers are more likely to turn in front of an oncoming motorcycle when it travels in the left-of-lane position than when it travels in the right-of-lane position.

Driving with the wandering mind: the effect that mind-wandering has on driving performance.

OBJECTIVE: The principal objective of the present work was to examine the effects of mind state (mind-wandering vs. on-task) on driving performance in a high-fidelity driving simulator. BACKGROUND: Mind-wandering is thought to interfere with goal-directed thought. It is likely, then, that when driving, mind-wandering might lead to impairments in critical aspects of driving performance. In two experiments, we assess the extent to which mind-wandering interferes with responsiveness to sudden events, mean velocity, and headway distance. METHOD: Using a car-following procedure in a high-fidelity driving simulator, participants were probed at random times to indicate whether they were on-task at that moment or mind-wandering. The dependent measures were analyzed based on the participant's response to the probe. RESULTS: Compared to when on-task, when mind-wandering participants showed longer response times to sudden events, drove at a higher velocity, and maintained a shorter headway distance. CONCLUSION: Collectively, these findings indicate that mind-wandering affects a broad range of driving responses and may therefore lead to higher crash risk. APPLICATION: The results suggest that situations that are likely associated with mind-wandering (e.g., route familiarity) can impair driving performance.

Route familiarity breeds inattention: a driving simulator study.

Inattention is a major cause of traffic accidents. Here, we show that, contrary to common-sense expectation, familiarity with a route is itself a source of driving impairment. This effect may be attributed to increased mind-wandering along familiar routes. In the present work, participants followed a vehicle along a route with which they were either familiar or unfamiliar. During the experimental session, the lead-vehicle braked at random locations, forcing participants to brake to avoid a collision. Participants were also required to respond with a button press when they noticed pedestrians heading toward the road from a sidewalk. In Experiment 1 we found that familiar drivers follow the lead vehicle more closely and are slower to notice approaching pedestrians. In Experiment 2, with following distance held constant, reaction times to central and peripheral events were longer for familiar drivers. Consistent with the mind-wandering hypothesis, all these effects were eliminated in Experiment 3 when drivers were made to focus on the driving task.

A novel paradigm reveals the role of reentrant visual processes in object substitution masking.

Object substitution masking (OSM) occurs when an initial display of a target and mask continues with the mask alone, creating a mismatch between the reentrant hypothesis, triggered by the initial display, and the ongoing low-level activity. We tested the proposition that the critical factor in OSM is not whether the mask remains in view after target offset, but whether the representation of the mask is sufficiently stronger than that of the target when the reentrant signal arrives. In Experiment 1, a variable interstimulus interval (ISI) was inserted between the initial display and the mask alone. The trailing mask was presumed to selectively boost the strength of the mask representation relative to that of the target. As predicted, OSM occurred at intermediate ISIs, at which the mask was presented before the arrival of the reentrant signal, creating a mismatch, but not at long ISIs, at which a comparison between the reentrant signal and the low-level activity had already been made. Experiment 2, conducted in dark-adapted viewing, ruled out the possibility that low-level inhibitory contour interactions (metacontrast masking) had played a significant role in Experiment 1. Metacontrast masking was further ruled out in Experiment 3, in which the masking contours were reduced to four small dots. We concluded that OSM does not depend on extended presentation of the mask alone, but on a mismatch between the reentrant signals and the ongoing activity at the lower level. The present results place constraints on estimates of the timing of reentrant signals involved in OSM.

The root cause of the attentional blink: first-target processing or disruption of input control?

Identification of the second of two targets (T2) is impaired when presented shortly after the first (T1). T1-based theories ascribe this attentional blink (AB) to a T1-initiated period of inattention. Distractor-based theories ascribe it to a disruption of input control caused by post-T1 distractors. The finding that an AB occurs without intertarget distractors (Nieuwenstein, Potter, & Theeuwes, Journal of Experimental Psychology: Human Perception and Performance 35:159-169, 2009) seemingly disconfirms distractor-based theories. The present experiments addressed different ways in which distractor-based theories might account for that finding. Intertarget events were varied in four experiments. Experiment 1 replicated Nieuwenstein, Potter, and Theeuwes's findings. The next two experiments tested two ways (lack of visual stimulation, violation of expectation) in which the blank intertarget interval might cause an AB. Experiment 4 explored whether backward-masking of T1 can account entirely for the larger AB obtained with intervening distractors or whether distractors also disrupt input control. The results disconfirm predictions from distractor-based theories and support the claim of T1-based theories that T1 processing alone is sufficient for the AB. Simulations based on the eSTST (Wyble, Bowman, & Nieuwenstein, Journal of Experimental Psychology: Human Perception and Performance 35:787-807, 2009) and the B&B models (Olivers & Meeter, Psychological Research, 115, 836-863 2008) were compared. Predictions were more accurate from the T1-based theory (eSTST) than from the distractor-based theory (B&B).