Cue Onset Research Articles

Age-related Differences in Prestimulus Subsequent Memory Effects Assessed with Event-related Potentials.

Prestimulus subsequent memory effects (preSMEs)-differences in neural activity elicited by a task cue at encoding that are predictive of later memory performance-are thought to reflect differential engagement of preparatory processes that benefit episodic memory encoding. We investigated age differences in preSMEs indexed by differences in ERP amplitude just before the onset of a study item. Young and older adults incidentally encoded words for a subsequent memory test. Each study word was preceded by a task cue that signaled a judgment to perform on the word. Words were presented for either a short (300 msec) or long (1000 msec) duration with the aim of placing differential benefits on engaging preparatory processes initiated by the task cue. ERPs associated with subsequent successful and unsuccessful recollection, operationalized here by source memory accuracy, were estimated time-locked to the onset of the task cue. In a late time window (1000-2000 msec after onset of the cue), young adults demonstrated frontally distributed preSMEs for both the short and long study durations, albeit with opposite polarities in the two conditions. This finding suggests that preSMEs in young adults are sensitive to perceived task demands. Although older adults showed no evidence of preSMEs in the same late time window, significant preSMEs were observed in an earlier time window (500-1000 msec) that was invariant with study duration. These results are broadly consistent with the proposal that older adults differ from their younger counterparts in how they engage preparatory processes during memory encoding.

Dynamics of fixational eye position and microsaccades during spatial cueing: the case of express microsaccades

Microsaccades are systematically modulated by peripheral spatial cues, and these eye movements have been implicated in perceptual and motor performance changes in cueing tasks. However, an additional oculomotor factor that may also influence performance in these tasks, fixational eye position itself, has been largely neglected so far. Using precise eye tracking and real-time retinal-image stabilization, we carefully analyzed fixational eye position dynamics and related them to microsaccade generation during spatial cueing. As expected, during baseline fixation, microsaccades corrected for a foveal motor error away from the preferred retinal locus of fixation (the so-called ocular position "set point" of the oculomotor system). However, we found that this relationship was violated during a short period immediately after cue onset; a subset of cue-directed "express microsaccades" that were highly precise in time and direction, and that were larger than regular microsaccades, occurred. These movements, having <100-ms latencies from cue onset, were triggered when fixational eye position was already at the oculomotor set point when the cue appeared; they were thus error-increasing rather than error-decreasing. Critically, even when no microsaccades occurred, fixational eye position itself was systematically deviated toward the cue, again with ~100-ms latency, suggesting that the oculomotor system establishes a new set point at different postcue times. This new set point later switched to being away from the cue after ~200-300 ms. Because eye position alters the location of retinal images, our results suggest that both eye position and microsaccades can be associated with performance changes in spatial cueing tasks. NEW & NOTEWORTHY Covert spatial cueing tasks are a workhorse for studying cognitive processing in humans and monkeys, but gaze is not perfectly stable during these tasks. We found that minute fixational eye position changes, independent of the more studied microsaccades, are not random in cueing tasks and are thus not "averaged out" in analyses. These changes can additionally dictate microsaccade times. Thus, in addition to microsaccadic influences, retinal image changes associated with fixational eye position are relevant for performance in cueing tasks.

The Effect of Eye Contact Is Contingent on Visual Awareness.

The present study explored how eye contact at different levels of visual awareness influences gaze-induced joint attention. We adopted a spatial-cueing paradigm, in which an averted gaze was used as an uninformative central cue for a joint-attention task. Prior to the onset of the averted-gaze cue, either supraliminal (Experiment 1) or subliminal (Experiment 2) eye contact was presented. The results revealed a larger subsequent gaze-cueing effect following supraliminal eye contact compared to a no-contact condition. In contrast, the gaze-cueing effect was smaller in the subliminal eye-contact condition than in the no-contact condition. These findings suggest that the facilitation effect of eye contact on coordinating social attention depends on visual awareness. Furthermore, subliminal eye contact might have an impact on subsequent social attention processes that differ from supraliminal eye contact. This study highlights the need to further investigate the role of eye contact in implicit social cognition.

Is reappraisal always effective in modifying emotional reactions in females? The role of regulatory timing and goals.

IntroductionNumerous studies have explored the effect of cognitive reappraisal before or after emotion‐inducing events. However, only a few studies have examined the influence of regulatory timing on the effectiveness of reappraisal. Thus, the aim of this study was to investigate the role of regulatory timing and goals in reappraisal regulation, which would help promote the specific application of cognitive reappraisal in emotion regulation. We hypothesized that decrease reappraisal would be more effective when initiated early rather than late, but increase reappraisal would be more effective when initiated in the emotional high‐activation phase.MethodsThis study, via event‐related potential (ERP) technique, probed the influence of the timing and regulatory goal on negative emotion when reappraisal was introduced, respectively 500 ms before (anticipatory), 2,000 ms after (online 2,000 ms) picture onset (in Experiment 1), 500 ms after (online 500 ms) picture onset, and 1,500 ms after (online 1,500 ms) picture onset (in Experiment 2).ResultsBased on the ERP results, under the anticipatory regulation condition, the LPP amplitude in the parietal area was significantly reduced by decrease reappraisal during 700–2,100 ms after picture onset, and under the online 500 ms regulation condition, the LPP in central and parietal areas was significantly enhanced by increase reappraisal during 450–750 ms after regulatory cue onset. Moreover, our results showed that increase reappraisal evoked a larger prefrontal or frontal LPP than decrease reappraisal beginning at about 700 ms after picture onset under the anticipatory regulation condition and beginning at 450 ms after regulatory cue onset under the online 500 ms regulation condition, which may reflect increased cognitive effort and mental conflict associated with increase reappraisal.ConclusionThe anticipatory reappraisal successfully decreased negative emotion, and online 500 ms reappraisal successfully increased negative emotion. Our results support the hypothesis.

The lexical or sub-lexical locus of facilitation by phonemic cueing in aphasic speakers: the effect of onset cohort size

ABSTRACTBackground: While the facilitation of word production by phonological cueing is used in clinical practice to evaluate the integrity of the lexical representations in anomia, the mechanisms by which phonological cueing facilitates oral production remain poorly understood. Most interpretations in psycholinguistic studies favor the phonological (sub-lexical) hypothesis, whereas results from studies on aphasia report evidence suggesting a lexical locus.Aims: This study aims to directly test the impact of phonological cues on lexical retrieval in participants with aphasia by manipulating the size of the cohort of nouns sharing the onset provided by the cue.Methods & Procedure: Fourteen aphasic participants presenting either a lexico-semantic or a phonological anomic profile performed a noun/object picture-naming task preceded by congruent or incongruent phonological cues. We manipulated the size of the lexical cohort of the words starting with the cue, reasoning that if phonological cues facilitate at the lexical level, a cue corresponding to a small number of words should be more effective than a cue compatible with a larger cohort.Outcomes & Results: The cue only improved accuracy in participants with lexico-semantic impairment, with a reduction of errors as a function of the cohort size (facilitation restricted to cues associated with a small onset cohort). In contrast, the cue onset cohort size only affects production latencies in participants with phonological impairment (shorter latencies for cues related to a small noun-onset cohort size).Conclusions: The observed effect of the cohort size associated with the cue favors a lexical locus of facilitation by phonological cueing. The fact that this effect is observed in different groups corresponding to different underlying impairments in error and in latencies suggests that the analyses of latencies reflect spared processes, whereas the analyses of errors tap into the impaired process.

FUNCTIONAL NETWORK ACTIVITY MEDIATING THE SHIFT OF ATTENTIONAL RESOURCES DURING INATTENTIONAL DEAFNESS IN AN AVIATION PURSUIT TASK

FUNCTIONAL NETWORK ACTIVITY MEDIATING THE SHIFT OF ATTENTIONAL RESOURCES DURING INATTENTIONAL DEAFNESS IN AN AVIATION PURSUIT TASK

Effect of Cue-target Onset Asynchrony (CTOA) and Cue Validity on Visual Vigilance Task Performance

Effect of Cue-target Onset Asynchrony (CTOA) and Cue Validity on Visual Vigilance Task Performance

Correction to: Dissociating the capture of attention from saccade activation by subliminal abrupt onsets.

Attentional capture and effects on saccade metrics by subliminal abrupt onset cues have been studied with peripheral cues at one out of several (two to four) display locations, swiftly followed by additional onsets at the other display locations. The lead time of the cue was too short to be seen. Here, we were interested in whether such subliminal onset cues influenced saccades primarily by way of attention or by way of direct saccade activation. In separate blocks, participants made speeded pro-saccades towards a black target or anti-saccades away from the target. Prior to the targets, an abrupt onset cue was presented either at the same side as the target (valid condition) or at the opposite side (invalid condition). If cues influenced performance by way of attentional capture, we expected facilitation of target processing in valid compared to invalid conditions (cueing effect) in the pro- as well as in the anti-saccade task. If the cues activated saccades in their direction, we expected the cueing effect to drop in the anti-saccade task compared to the pro-saccade task because in the anti-saccade task the invalid cue would activate the finally required response, whereas the valid cue would activate the alternative response, leading to interference. Results were in line with the former of these possibilities suggesting that subliminal abrupt onsets influenced saccades by way of attention with no or little direct activation of saccades.

Pre-stimulus pupil dilation and the preparatory control of attention.

Task preparation involves multiple component processes, including a general evaluative process that signals the need for adjustments in control, and the engagement of task-specific control settings. Here we examined the dynamics of these different mechanisms in preparing the attentional control system for visual search. We explored preparatory activity using pupil dilation, a well-established measure of task demands and effortful processing. In an initial exploratory experiment, participants were cued at the start of each trial to search for either a salient color singleton target (an easy search task) or a low-salience shape singleton target (a difficult search task). Pupil dilation was measured during the preparation period from cue onset to search display onset. Mean dilation was larger in preparation for the difficult shape target than the easy color target. In two additional experiments, we sought to vary effects of evaluative processing and task-specific preparation separately. Experiment 2 showed that when the color and shape search tasks were matched for difficulty, the shape target no longer evoked larger dilations, and the pattern of results was in fact reversed. In Experiment 3, we manipulated difficulty within a single feature dimension, and found that the difficult search task evoked larger dilations. These results suggest that pupil dilation reflects expectations of difficulty in preparation for a search task, consistent with the activity of an evaluative mechanism. We did not find consistent evidence for relationship between pupil dilation and search performance (accuracy and response timing), suggesting that pupil dilation during search preparation may not be strongly linked to ongoing task-specific preparation.

Does the Effort of Processing Potential Incentives Influence the Adaption of Context Updating in Older Adults?

A number of aging studies suggest that older adults process positive and negative information differently. For instance, the socioemotional selectivity theory postulates that older adults preferably process positive information in service of emotional well-being (Reed and Carstensen, 2012). Moreover, recent research has started to investigate whether incentives like gains or losses can influence cognitive control in an ongoing task. In an earlier study (Schmitt et al., 2015), we examined whether incentive cues, indicating potential monetary gains, losses, or neutral outcomes for good performance in the following trial, would influence older adults’ ability to exert cognitive control. Cognitive control was measured in an AX-Continuous-Performance-Task (AX-CPT) in which participants had to select their responses to probe stimuli depending on a preceding context cue. In this study, we did not find support for a positivity effect in older adults, but both gains and losses led to enhanced context processing. As the trial-wise presentation mode may be too demanding on cognitive resources for such a bias to occur, the main goal of the present study was to examine whether motivational mindsets, induced by block-wise presentation of incentives, would result in a positivity effect. For this reason, we examined 17 older participants (65–76 years) in the AX-CPT using a block-wise presentation of incentive cues and compared them to 18 older adults (69–78 years) with the trial-wise presentation mode from our earlier study (Schmitt et al., 2015). Event-related potentials were recorded to the onset of the motivational cue and during the AX-CPT. Our results show that (a) older adults initially process cues signaling potential losses more strongly, but later during the AX-CPT invest more cognitive resources in preparatory processes like context updating in conditions with potential gains, and (b) block-wise and trial-wise presentation of incentive cues differentially influenced cognitive control. When incentives were presented block-wise, the above described valence effects were consistently found. In contrast, when incentives were presented trial-wise, the effects were mixed and salience as well as valence effects can be obtained. Hence, how positive and negative incentive cues influence cognitive control in older adults is dependent on demands of cue processing.

Immunity to attentional capture at ignored locations.

Certain stimuli have the power to rapidly and involuntarily capture spatial attention against our will. The present study investigated whether such stimuli capture spatial attention even when they appear in ignored regions of visual space. In other words, which force is more powerful: attentional capture or spatial filtering? Participants performed a spatial cuing task, searching for a letter target defined by color (e.g., green) and then reporting that letter's identity. Two of the four search locations were always irrelevant. Unlike many previous experiments, participants were forced to ignore these locations because they always contained a target-colored distractor letter. Experiment 1 assessed capture by a salient-but-irrelevant abrupt onset cue appearing 150 ms before the search display. One might expect onset cues to capture attention even at ignored locations given that the main function of capture, presumably, is to rapidly alert observers to unexpected yet potentially important stimuli. However, they did not. Experiment 2 replicated this result with a different neutral baseline condition. Experiment 3 replicated the absence of capture effects at ignored locations with an even more potent stimulus: a relevant cue possessing the target color. We propose that people are effectively immune to attentional capture by objects in ignored locations - spatial filtering dominates attentional capture.

Prefrontal Cortex Stimulation Enhances Fear Extinction Memory in Humans

BackgroundAnimal fear conditioning studies have illuminated neuronal mechanisms of learned associations between sensory stimuli and fear responses. In rats, brief electrical stimulation of the infralimbic cortex has been shown to reduce conditioned freezing during recall of extinction memory. Here, we translated this finding to humans with magnetic resonance imaging–navigated transcranial magnetic stimulation (TMS). MethodsSubjects (N = 28) were aversively conditioned to two different cues (day 1). During extinction learning (day 2), TMS was paired with one of the conditioned cues but not the other. TMS parameters were similar to those used in rat infralimbic cortex: brief pulse trains (300 ms at 20 Hz) starting 100 ms after cue onset, total of four trains (28 TMS pulses). TMS was applied to one of two targets in the left frontal cortex, one functionally connected (target 1) and the other unconnected (target 2, control) with a human homologue of infralimbic cortex in the ventromedial prefrontal cortex. Skin conductance responses were used as an index of conditioned fear. ResultsDuring extinction recall (day 3), the cue paired with TMS to target 1 showed significantly reduced skin conductance responses, whereas TMS to target 2 had no effect. Further, we built group-level maps that weighted TMS-induced electric fields and diffusion magnetic resonance imaging connectivity estimates with fear level. These maps revealed distinct cortical regions and large-scale networks associated with reduced versus increased fear. ConclusionsThe results showed that spatiotemporally focused TMS may enhance extinction learning and/or consolidation of extinction memory and suggested novel cortical areas and large-scale networks for targeting in future studies.

O27 Wavelet analysis of EEG recorded during unconscious expectation of angry vs. neutral faces in patients with major depression and healthy controls

Objectives Patients with major depressive disorder (MDD) show attention bias to the negative emotional stimuli. We aimed at studying the EEG-correlates of unconscious expectation of angry human faces in MDD patients compared to healthy controls. Methods 128-channel EEG was recorded in MDD (23 female and 7 male) and in healthy volunteers (22 female and 8 male) while they categorized pictures as humans or animals. Half of the pictures were neutral and half were showing the faces of angry humans or animals. The pictures were preceded by cues (one for each category), which meaning was not explained to the participants. We performed the wavelet analysis of EEG recorded during the face expectation period: 1000–2000 ms from the cue onset. Results We found the emotional modulation (EM) in EEG rhythms during the expectation of angry vs. neutral faces in both groups. Statistical comparison of the spectral power using 2 × 2 factorial design showed that the EM differences (p Discussion The unconscious expectation of angry vs. neutral faces resulted in EM differences between the MDD and healthy controls in the right frontal and bilateral parietal areas mostly in beta range, and also in alpha and gamma. Conclusions The EEG from the parietal locations can be a better indicator for the differences between MDD and healthy controls. Significance Unconscious emotional processing in patients may become a prospective biomarker for depression.

Prediction and uncertainty in associative learning: examining controlled and automatic components of learned attentional biases.

It has been suggested that attention is guided by two factors that operate during associative learning: a predictiveness principle, by which attention is allocated to the best predictors of outcomes, and an uncertainty principle, by which attention is allocated to learn about the less known features of the environment. Recent studies have shown that predictiveness-driven attention can operate rapidly and in an automatic way to exploit known relationships. The corresponding characteristics of uncertainty-driven attention, on the other hand, remain unexplored. In two experiments we examined whether both predictiveness and uncertainty modulate attentional processing in an adaptation of the dot probe task. This task provides a measure of automatic orientation to cues during associative learning. The stimulus onset asynchrony of the probe display was manipulated in order to explore temporal characteristics of predictiveness- and uncertainty-driven attentional effects. Results showed that the predictive status of cues determined selective attention, with faster attentional capture to predictive than to non-predictive cues. In contrast, the level of uncertainty slowed down responses to the probe regardless of the predictive status of the cues. Both predictiveness- and uncertainty-driven attentional effects were very rapid (at 250 ms from cue onset) and were automatically activated.

Dissociating the capture of attention from saccade activation by subliminal abrupt onsets

Attentional capture and effects on saccade metrics by subliminal abrupt onset cues have been studied with peripheral cues at one out of several (two to four) display locations, swiftly followed by additional onsets at the other display locations. The lead time of the cue was too short to be seen. Here, we were interested in whether such subliminal onset cues influenced saccades primarily by way of attention or by way of direct saccade activation. In separate blocks, participants made speeded pro-saccades towards a black target or anti-saccades away from the target. Prior to the targets, an abrupt onset cue was presented either at the same side as the target (valid condition) or at the opposite side (invalid condition). If cues influenced performance by way of attentional capture, we expected facilitation of target processing in valid compared to invalid conditions (cueing effect) in the pro- as well as in the anti-saccade task. If the cues activated saccades in their direction, we expected the cueing effect to drop in the anti-saccade task compared to the pro-saccade task because in the anti-saccade task the invalid cue would activate the finally required response, whereas the valid cue would activate the alternative response, leading to interference. Results were in line with the former of these possibilities suggesting that subliminal abrupt onsets influenced saccades by way of attention with no or little direct activation of saccades.

Saccadic eye movements do not disrupt the deployment of feature-based attention.

The tight link of saccades to covert spatial attention has been firmly established, yet their relation to other forms of visual selection remains poorly understood. Here we studied the temporal dynamics of feature-based attention (FBA) during fixation and across saccades. Participants reported the orientation (on a continuous scale) of one of two sets of spatially interspersed Gabors (black or white). We tested performance at different intervals between the onset of a colored cue (black or white, indicating which stimulus was the most probable target; red: neutral condition) and the stimulus. FBA built up after cue onset: Benefits (errors for valid vs. neutral cues), costs (invalid vs. neutral), and the overall cueing effect (valid vs. invalid) increased with the cue-stimulus interval. Critically, we also tested visual performance at different intervals after a saccade, when FBA had been fully deployed before saccade initiation. Cueing effects were evident immediately after the saccade and were predicted most accurately and most precisely by fully deployed FBA, indicating that FBA was continuous throughout saccades. Finally, a decomposition of orientation reports into target reports and random guesses confirmed continuity of report precision and guess rates across the saccade. We discuss the role of FBA in perceptual continuity across saccades.

An input-output linear time invariant model captures neuronal firing responses to external and behavioral events.

Investigating how neurons in different motor regions respond to external stimuli and behavioral events provides insight into motor control. A recent approach to studying neuronal activity is to construct a zero-input linear time invariant (ZI-LTI) state-space model, wherein the state vector consists of firing rate signals for different populations of neurons across motor regions. This approach allows for the populations to influence each other in a dynamical manner given an initial firing rate condition, and the model can accurately reconstruct firing rates within a limited epoch in the motor task during which no event occurs. Here, we generalize this LTI modeling approach to characterize firing responses of neurons to two events (a go cue and movement onset) in a movement task with a non-zero input LTI state-space model, herein referred to as input-output LTI (IO-LTI). Specifically, responses from 196 neurons in the primary motor (M1), ventral premotor (PMv), and dorsal premotor cortex (PMd) were recorded and modeled in two nonhuman primates executing a reach-to-grasp task. We found that a single IO-LTI model can reconstruct neuronal firing rate patterns of six populations of these neurons across the three areas in the presence of multiple events (go cue, movement onset). This is the first step towards constructing generative models of neuronal firing rates in the presence of multiple events, which then can be used to construct better decoders for brain machine interactive control.

Simultaneous Processing of Noun Cue and to-be-Produced Verb in Verb Generation Task: Electromagnetic Evidence.

A long-standing but implicit assumption is that words strongly associated with a presented cue are automatically activated in the memory through rapid spread of activation within brain semantic networks. The current study was aimed to provide direct evidence of such rapid access to words’ semantic representations and to investigate its neural sources using magnetoencephalography (MEG) and distributed source localization technique. Thirty-three neurotypical subjects underwent the MEG recording during verb generation task, which was to produce verbs related to the presented noun cues. Brain responses evoked by the noun cues were examined while manipulating the strength of association between the noun and the potential verb responses. The strong vs. weak noun-verb association led to a greater noun-related neural response at 250–400 ms after cue onset, and faster verb production. The cortical sources of the differential response were localized in left temporal pole, previously implicated in semantic access, and left ventrolateral prefrontal cortex (VLPFC), thought to subserve controlled semantic retrieval. The strength of the left VLPFC’s response to the nouns with strong verb associates was positively correlated to the speed of verbs production. Our findings empirically validate the theoretical expectation that in case of a strongly connected noun-verb pair, successful access to target verb representation may occur already at the stage of lexico-semantic analysis of the presented noun. Moreover, the MEG results suggest that contrary to the previous conclusion derived from fMRI studies left VLPFC supports selection of the target verb representations, even if they were retrieved from semantic memory rapidly and effortlessly. The discordance between MEG and fMRI findings in verb generation task may stem from different modes of neural activation captured by phase-locked activity in MEG and slow changes of blood-oxygen-level-dependent (BOLD) signal in fMRI.

If not When, then Where? Ignoring Temporal Information Eliminates Reflexive but not Volitional Spatial Orienting

A tremendous amount of research has been devoted to understanding how attention can be committed to space or time. Until recently, relatively little research has examined how attention to these two domains combine. The present study addressed this issue. We examined how implicitly manipulating whether participants used a cue to orient attention in time impacts reflexive or volitional shifts in spatial attention. Specifically, participants made speeded manual responses to the detection of a peripherally presented target that appeared either 100, 500, or 1000 ms after the onset of a central cue. Cues were either spatially non-predictive arrows (p = 0.50) or spatially-predictive (p = 0.80) letter cues. Whereas arrow cues can reflexively orient spatial attention even when non-predictive of a target’s spatial location, letters only orient spatial attention when they reliably predict a target location, i.e., the shift is volitional. Further, in one task, a target was presented on every trial, thereby encouraging participants to use the temporal information conveyed by the cue to prepare for the appearance of the target. In another task, 25% of trials contained no target, implicitly discouraging participants from using the cue to direct attention in time. Results indicate that when temporal information is reliable and therefore volitionally processed, then spatial cuing effects emerge regardless of whether attention is oriented reflexively or volitionally. However, when temporal information is unreliable, spatial cuing effects only emerge when spatial cue information is reliable, i.e., when spatial attention is volitionally shifted. Reflexive cues do not elicit spatial orienting when their temporal utility is reduced. These results converge on the notion that reflexive shifts of spatial attention are sensitive to implicit changes in a non-spatial domain, whereas explicit volitional shifts in spatial attention are not.

An obesogenic refined low-fat diet disrupts attentional and behavioral control processes in a vigilance task in rats

Diets consisting of refined foods (REF) are associated with poor physical (e.g., obesity and diabetes) and mental (e.g., depression) health and impaired cognition. Few animal studies have explored the causal links between diet processing and health. Instead, most studies focus on the role of macronutrients, especially carbohydrate and fat concurrently with how processed are the ingredients. We previously showed that a REF low fat diet (LFD) caused greater adiposity and impaired motivation compared to an unrefined control (CON) diet consisting of similar macronutrient ratios (Blaisdell et al., 2014). Here we test the hypothesis that the same REF LFD adversely affects attentional processes and behavioral control relative to the CON diet.Rats with ad libitum access to the REF diet for two months gained greater adiposity than rats consuming the CON diet. Rats then completed training on a vigilance task involving pressing the correct lever signaled by a brief visual cue whose onset varied across trials. A REF diet reduced accuracy when there was a delay between the start of the trial and cue onset. Poorer accuracy was due to increased premature responses, reflecting impulsivity, and omissions, indicating an inability to sustain attention. These results corroborate the links between consumption of refined foods, obesity, and poor cognition in humans. We discuss the possible causal models that underlie this link.