Invalid Trials Research Articles

Does a history of involuntary selection generate attentional biases?

Voluntarily allocating attention to task-relevant features engenders attentional biases for frequently attended stimuli, even when they become irrelevant (ie., selection history). Little is known, however, to what extent effortful, voluntary attention is a necessary component in the formation of such selection biases. Do task-irrelevant, abrupt onsets, which reflexively draw attention to a particular location, engender attentional selection biases for involuntarily attended locations, biases that persist in the absence of explicit exogenous cues? Using a preregistered data collection and analysis plan (accepted, Psychonomic Bulletin & Review, final manuscript in preparation), we manipulated spatial attention during an orientation discrimination task: two Gabor patches (randomly and independently rotated clockwise or counterclockwise of vertical) were simultaneously presented (8° left/right of fixation); a postcue indicated which was the target. To generate different selection histories for left/right locations, we delivered precues more often to one location (2:1 ratio) during the first half of the study (most-cued side counterbalanced across observers, equal numbers valid and invalid trials at each location). In the second half, no precues were presented, and observers continued the orientation discrimination task. If exogenous attentional selection generates persistent biases, performance should be better on the previously most-cued side, relative to least-cued side. As expected, abrupt onsets reflexively modulated visual processing in the first half: task accuracy increased, and RTs decreased, when the precue appeared near the forthcoming target (valid trials), relative to the distractor (invalid trials). When precues were removed in the second half, however, we found no evidence that exogenous selection history modulated task performance: task accuracy and RTs at previously most/least cued sides were statistically indistinguishable; precue-free follow-up sessions (one day and one week later) also showed indistinguishable performance at left/right locations. Thus, unlike voluntarily directed attention, reflexively allocating attention may not be sufficient to engender historically-contingent selection biases.

Is the Deductive Falsification Approach a Better Basis for Clinical Trial Appraisal?

Inductive reasoning relies on an infinite regress without sufficient factual basis and verification is at any time vulnerable to single contrary observation. Thus, appraisal based on inductive verification, as applied in current clinical trial appraisal scales, checklists or grading systems, cannot prove or justify trial validity. Trial appraisal based on deductive falsification can identify invalid trials and give evidence for the recommendation to exclude these from clinical decision-making. Such appraisal remains agnostic towards corroborated trials that pass all appraisal criteria. The results of corroborated trials cannot be considered more robust than falsified trials since nothing within a particular set of complied trial criteria can give certainty for trial compliance with any other appraisal criterion in future. A corroborated trial may or may not reflect therapeutic truth and may thus be the basis for clinical guidance, pending results of any future trial re-appraisal. Trial grading following appraisal based on deductive falsification should be binary (0 = Invalid or 1 = Unclear) and single component scores should be multiplied. Appraisal criteria for the judgment of trial characteristics require a clear rationale, quantification of such rationale and empirical evidence concerning the effect of trial characteristics on trial results.

The peripheral preview effect with faces: Combined EEG and eye-tracking suggests multiple stages of trans-saccadic predictive and non-predictive processing

The world appears stable despite saccadic eye-movements. One possible explanation for this phenomenon is that the visual system predicts upcoming input across saccadic eye-movements based on peripheral preview of the saccadic target. We tested this idea using concurrent electroencephalography (EEG) and eye-tracking. Participants made cued saccades to peripheral upright or inverted face stimuli that changed orientation (invalid preview) or maintained orientation (valid preview) while the saccade was completed. Experiment 1 demonstrated better discrimination performance and a reduced fixation-locked N170 component (fN170) with valid than with invalid preview, demonstrating integration of pre- and post-saccadic information. Moreover, the early fixation-related potentials (FRP) showed a preview face inversion effect suggesting that some pre-saccadic input was represented in the brain until around 170 ms post fixation-onset. Experiment 2 replicated Experiment 1 and manipulated the proportion of valid and invalid trials to test whether the preview effect reflects context-based prediction across trials. A whole-scalp Bayes factor analysis showed that this manipulation did not alter the fN170 preview effect but did influence the face inversion effect before the saccade. The pre-saccadic inversion effect declined earlier in the mostly invalid block than in the mostly valid block, which is consistent with the notion of pre-saccadic expectations. In addition, in both studies, we found strong evidence for an interaction between the pre-saccadic preview stimulus and the post-saccadic target as early as 50 ms (Experiment 2) or 90 ms (Experiment 1) into the new fixation. These findings suggest that visual stability may involve three temporal stages: prediction about the saccadic target, integration of pre-saccadic and post-saccadic information at around 50-90 ms post fixation onset, and post-saccadic facilitation of rapid categorization.

Attentional disengagement from negative natural sounds for high-anxious individuals

ABSTRACTBackground and objectives: Previous studies have not consistently concluded whether high-anxious persons exhibit attentional bias towards negative natural auditory stimuli. The present study explores whether auditory negative stimuli could induce attentional bias to negative sounds in real life and investigates the exact nature of these biases using an emotional spatial cueing task.Design: Experimental study with a mixed factorial design.Method: We created two groups according to the state-trait anxiety scale, namely high and low trait anxiety. Participants (N = 68 undergraduate students) were required to respond to an auditory target after receiving a negative (aversive sounds from natural life) or neutral auditory stimuli.Results: A 2 (Validity: valid/invalid) × 2 (Cue Valence: negative/neutral) × 2 (Anxiety Group: LA/HA) repeated-measures ANOVA on reaction times revealed that participants with high trait anxiety exhibited slower reaction times in invalid trials following negative cues than following neutral cues. Higher levels of trait anxiety were associated with more difficult attentional disengagement from negative auditory information.Conclusions: The results demonstrate that impaired attentional disengagement was one of the mechanisms by which high-anxious participants exhibited auditory attentional bias to natural negative information.

No experimental evidence for emotion-specific gaze cueing in a threat context

ABSTRACTWe examined the utility of a gaze cueing paradigm to examine sensitivity to differences among negatively valenced expressions. Participants judged target stimuli (dangerous or safe), the location of which was cued by the gaze direction of a central face. Dawel et al. reported that gaze cueing effects (faster response times on valid vs. invalid trials) were larger when the central face displayed fear than when it displayed happiness. Our aim was to determine whether this effect was specific to fear, to all threat-related expressions (fear, anger), or to all negatively valenced expressions (fear, anger, sadness, disgust) with the aim of using this protocol to study the development of implicit discrimination of negatively valenced expressions. Across five experiments in which we varied the number of models (1 vs. 4), the number of expressions (2 vs. 5), and the country of residence of participants (Canada vs. Australia) we found no evidence that the magnitude of gaze cueing effects is modulated by expression. We discuss our failure to replicate in the context of the broader literature.

The success of the representation maintenance affects the memory-guided search processing: an ERP study

Previous evidence showed that working memory (WM) contents can bias visual selection. However, less is known about how the WM effects change when the WM representation is not held successfully. Here, we investigated this problem using event-related potentials. Subjects maintained a color in WM while performing a search task. The color cue contained the target (valid) or the distractor (invalid). Subjects could either remember the color accurately (correct WM) or not (incorrect WM). An N2-posterior contralateral component and a sustained posterior contralateral negativity (SPCN) were recorded in the valid and incorrect WM condition, while only an attenuated SPCN was elicited in the valid and correct WM condition. No reliable lateralized components were found for the invalid trials. These findings suggest that the WM effects on visual search are affected by the resource interchange between WM and search processes.

The influence of the global/local probability effect on the neural processing of cues and targets. A functional systems approach.

Global and local probability effects were explored in a visuo-auditory version of the central cue Posner's paradigm through the analysis of the neural Event-Related Potentials (ERPs) generated in the interaction between validity sequence effects (local probability) and block validity effects (global probability). Four behavioral measures (response times, correct/incorrect anticipations, and incorrect responses), three pre-target ERPs (visual P1/N1 and Contingent Negative Variation (CNV)), and six post-target ERPs (auditory N1, P2, Processing Negativity (PN), P3a, P3b and Late Slow Positivity (LSP)) were considered. Four types of trial-sequences (Valid-Valid, Invalid-Valid, Invalid-Invalid, Valid-Invalid) and three types of trial-blocks, with different validity/invalidity proportions (50%, 68%, and 86% of valid trials), were employed. Present data replicate previous reports on the validity sequence effects on ERPs (local probability): (i) higher CNV on trials preceded by valid trials; (ii) higher PN on valid trials preceded by invalid trials compared to valid trials preceded by valid trials; and (iii) higher P3a/P3b and LSP on invalid trials preceded by valid trials compared to invalid trials preceded by invalid trials. In summary, local probability showed more effects modulating the brain responses than global probability and/or their interaction. Among a number of other hypotheses, the functional systems theory would account for the ability of the previous trial to modify processing in the current trial.

Probabilistic retro-cues do not determine representational state in visual working memory

To circumvent the capacity limitations of visual working memory (VWM), mechanisms exist that govern how information is represented in memory to ensure that the most relevant information guides behaviour. Retroactively cueing an item in VWM, for instance, affects both memory quality and representational state: A retro cue that indicates with 100% validity which item will later be probed enhances memory of that item, and 'activates' its representation such that it will bias selection towards perceptually similar inputs during visual search. However, when the retro-cue is less than 100% valid (i.e., probabilistic rather than deterministic) the effect of the cue on memory performance varies with manipulations to the proportion of valid trials. Here we investigated whether probabilistic and deterministic retro-cues also differ in their influence over representational state. Participants encoded two colored squares for a subsequent memory test. Following encoding, a spatial cue indicated to participants which item was most likely to be probed at the end of the trial. Cue validity was manipulated across blocks to be either deterministic (100% valid) or probabilistic (70% valid). On a subset of trials, no memory probe was presented and the trial instead ended with a visual search task in which a colored distractor—matching either the cued memory item, the non-cued item, or neither—was presented. As expected, in the deterministic retro-cue condition, the presence of a search distractor that matched the color of the cued item reliably slowed response times relative to trials with non-matching distractors. In the probabilistic retro-cue condition, however, search response times were comparable across all three distractor conditions, despite a reliable benefit to memory performance on valid relative to invalid trials. We suggest that, while probabilistic retro-cues improve memory of the cued item, they do not bias its representational state in VWM. Meeting abstract presented at VSS 2018

Copycat of dynamic facial expressions: Superior volitional motor control for expressions of disgust

In social situations facial expressions are often strategically employed. Despite the many research on motor control of limb movements, little is known about the control over facial expressions. Using a response-priming task, we investigated motor control over three facial expressions, smiles, disgust and emotionally neutral jaw drops. Prime stimuli consisted of videos of a facial expression to be prepared or – as a neutral prime – an abstract symbol superimposed to a scrambled face. In valid trials an equal symbol (=) indicated to produce the primed expression. In invalid trials, an unequal symbol (‡) prompted participants to produce an alternative, unprimed expression. We examined the impact of emotion in preparing and revoking a prepared expression, and possible facilitation for dynamic facial expressions relative to symbolic primes. Participants' facial responses were scored using automated analyses of facial expressions with computer software. The underlying neurocognitive processes were tracked with event-related-potentials. Reprogramming costs, in the form of longer reaction times (RTs) in trials where participants had prepared an invalidly primed expression and had to quickly switch to the correct one, were more pronounced for smiles and jaw drops than for disgust, possibly indicating the need for being fast when showing disgust. Data from the P3 component related the behavioral effect to a more efficient updating of the correct response in brain systems responsible for motor control. Priming participants with dynamic facial expressions as examples for imitation, improved performance accuracy as compared to the symbolic abstract stimuli, but it not did affect RTs. Priming with dynamic videos also resulted in larger validity effects of the P3 component when disgust was the target response, indicating that the perceptual system might trigger automatic emotional responses, at least for negative affect.

Attentional bias in MDD: ERP components analysis and classification using a dot-probe task

Background and ObjectiveStrands of evidence have supported existence of negative attentional bias in patients with depression. This study aimed to assess the behavioral and electrophysiological signatures of attentional bias in major depressive disorder (MDD) and explore whether ERP components contain valuable information for discriminating between MDD patients and healthy controls (HCs). MethodsElectroencephalography data were collected from 17 patients with MDD and 17 HCs in a dot-probe task, with emotional-neutral pairs as experimental materials. Fourteen features related to ERP waveform shape were generated. Then, Correlated Feature Selection (CFS), ReliefF and GainRatio (GR) were applied for feature selection. For discriminating between MDDs and HCs, k-nearest neighbor (KNN), C4.5, Sequential Minimal Optimization (SMO) and Logistic Regression (LR) were used. ResultsBehaviorally, MDD patients showed significantly shorter reaction time (RT) to valid than invalid sad trials, with significantly higher bias score for sad-neutral pairs. Analysis of split-half reliability in RT indices indicated a strong reliability in RT, while coefficients of RT bias scores neared zero. These behavioral effects were supported by ERP results. MDD patients had higher P300 amplitude with the probe replacing a sad face than a neutral face, indicating difficult attention disengagement from negative emotional faces. Meanwhile, data mining analysis based on ERP components suggested that CFS was the best feature selection algorithm. Especially for the P300 induced by valid sad trials, the classification accuracy of CFS combination with any classifier was above 85%, and the KNN (k = 3) classifier achieved the highest accuracy (94%). ConclusionsMDD patients show difficulty in attention disengagement from negative stimuli, reflected by P300. The CFS over other methods leads to a good overall performance in most cases, especially when KNN classifier is used for P300 component classification, illustrating that ERP component may be applied as a tool for auxiliary diagnosis of depression.

P17. Impaired auditory attention in adolescents with developmental dyslexia

Theoretical background Developmental dyslexia (DD) refers to the pathological impairment in the acquisition of reading and/or writing skills that is not accounted for by biological age, intelligence or inadequate schooling (WHO, 2011). It is hypothesized that DD relies, at least in part, on the impaired ability to shift attention to relevant information (Hari and Renvall, 2001). On a neurophysiological level, attention is represented by alpha oscillations (about 8–12 Hz). In adults with DD, recent studies showed altered alpha oscillations during the processing of auditory and visual stimuli (Dhar et al., 2010) but also in resting state (Papagiannopoulou and Lagopoulos, 2016). However, until today, there is only sparse knowledge on auditory attention and the underlying neural mechanisms in adolescents with DD. Methods A sample of adolescents with diagnosed DD (Mean age: 14.29 years, SD: 1.46) and an age-matched control group (CG) participated in this study. In balanced order they performed two auditory spatial-cueing paradigms. In the exogenous paradigm, cue and target tones were presented monaurally at Stimulus onset Asynchrony (SOA) 100 ms and 250 ms. 50% of the trials consisted of valid cues. Catch trials (cue only) were intermittently presented. Participants had to respond as fast as possible whenever a target tone was presented. In the endogenous paradigm, cue and target tones were presented at SOAs between 1000 ms and 1500 ms. 80% of the trials consisted of valid cues. During both tasks EEG data was continuously recorded. Results While the CG showed an inhibition of return (IOR) i.e. reduced RT at invalid compared to valid cues with SOA 250 ms, no such effect was present in the DD sample. ERPs measured at the vertex electrode revealed prolonged peak latencies for target stimuli for both valid and invalid trials at SOA 250 ms in DD compared to CG. In the endogenous task, we found increased alpha desynchronization in the post-cue phase over left auditory cortex (AC) regions in DD compared to CG. Notably, this pattern was found irrespective of the site at which the cue was presented. Discussion The lack of an IOR in adolescents with DD demonstrates a decreased withdrawal of attention and suggests reduced orienting towards novel locations. Considering the endogenous task, our findings indicate a maladaptive inhibition of the left AC in DD that, in turn, might account for dysfunctional processing of incoming acoustic information. Our findings suggest altered auditory attention as potential basis for higher order language skills. Future studies investigating attention processes in pre-reading children will shed more light on whether attention is a cause of impaired language skills rather than the consequence of a maladaptive compensation over the course of reading/ writing acquisition.

Alpha Oscillations Are Causally Linked to Inhibitory Abilities in Ageing.

Aging adults typically show reduced ability to ignore task-irrelevant information, an essential skill for optimal performance in many cognitive operations, including those requiring working memory (WM) resources. In a first experiment, young and elderly human participants of both genders performed an established WM paradigm probing inhibitory abilities by means of valid, invalid, and neutral retro-cues. Elderly participants showed an overall cost, especially in performing invalid trials, whereas younger participants' general performance was comparatively higher, as expected.Inhibitory abilities have been linked to alpha brain oscillations but it is yet unknown whether in aging these oscillations (also typically impoverished) and inhibitory abilities are causally linked. To probe this possible causal link in aging, we compared in a second experiment parietal alpha-transcranial alternating current stimulation (tACS) with either no stimulation (Sham) or with two control stimulation frequencies (theta- and gamma-tACS) in the elderly group while performing the same WM paradigm. Alpha- (but not theta- or gamma-) tACS selectively and significantly improved performance (now comparable to younger adults' performance in the first experiment), particularly for invalid cues where initially elderly showed the highest costs. Alpha oscillations are therefore causally linked to inhibitory abilities and frequency-tuned alpha-tACS interventions can selectively change these abilities in the elderly.SIGNIFICANCE STATEMENT Ignoring task-irrelevant information, an ability associated to rhythmic brain activity in the alpha frequency band, is fundamental for optimal performance. Indeed, impoverished inhibitory abilities contribute to age-related decline in cognitive functions like working memory (WM), the capacity to briefly hold information in mind. Whether in aging adults alpha oscillations and inhibitory abilities are causally linked is yet unknown. We experimentally manipulated frequency-tuned brain activity using transcranial alternating current stimulation (tACS), combined with a retro-cue paradigm assessing WM and inhibition. We found that alpha-tACS induced a significant improvement in target responses and misbinding errors, two indexes of inhibition. We concluded that in aging alpha oscillations are causally linked to inhibitory abilities, and that despite being impoverished, these abilities are still malleable.

The Joint Effects of Spatial Cueing and Transcranial Direct Current Stimulation on Visual Acuity.

The present study examined the mutual influence of cortical neuroenhancement and allocation of spatial attention on perception. Specifically, it explored the effects of transcranial Direct Current Stimulation (tDCS) on visual acuity measured with a Landolt gap task and attentional precues. The exogenous cues were used to draw attention either to the location of the target or away from it, generating significant performance benefits and costs. Anodal tDCS applied to posterior occipital area for 15 min improved performance during stimulation, reflecting heightened visual acuity. Reaction times were lower, and accuracy was higher in the tDCS group, compared to a sham control group. Additionally, in post-stimulation trials tDCS significantly interacted with the effect of precuing. Reaction times were lower in valid cued trials (benefit) and higher in invalid trials (cost) compared to neutrally cued trials, the effect which was pronounced stronger in tDCS group than in sham control group. The increase of cost and benefit effects in the tDCS group was of a similar magnitude, suggesting that anodal tDCS influenced the overall process of attention orienting. The observed interaction between the stimulation of the visual cortex and precueing indicates a magnification of attention modulation.

Attentional Bias to Beauty with Evolutionary Benefits: Evidence from Aesthetic Appraisal of Landscape Architecture.

Substantial evidence suggests that beauty is associated with the survival and reproduction of organisms. Landscape architecture is composed of a series of natural elements that have significant evolutionary implications. The present study used one pilot material ratings and three experiments to examine the mechanisms of aesthetic appraisals of landscape architecture. The results confirmed that landscape architecture elicited a sense of beauty and captured visual attention more easily than other types of architecture during explicit aesthetic rating task (Experiment 1) and implicit aesthetic perception task (dot-probe paradigm, Experiment 2). Furthermore, the spatial cueing paradigm revealed that response latencies were significantly faster for landscape architecture than non-landscape architecture on valid trials, but there was no significant difference in this contrast on invalid trials at 150-ms stimulus onset asynchrony (SOA, Experiment 3a). At 500-ms SOA (Experiment 3b), participants responded significantly faster for landscape architecture on valid trials, but reacted significantly slower for landscape architecture on invalid trials. The findings indicated that the beauty of landscape architecture can be perceived implicitly, and only faster orienting of attention, but not delayed disengagement of attention was generated at early stages of the processing of landscape architecture. However, the attentional bias at later stages of attentional processes may be resulted from both faster orienting of attention and delayed disengagement of attention from landscape architecture photographs.

A retrospective pilot study comparing data from monitoring reports to identify staffing influence on protocol deviation rates

<p class="abstract"><strong>Background:</strong> Clinical research sites are hiring more non-licensed personnel to coordinate clinical trials and to replace licensed nurse counterparts. Revised regulatory documents heavily emphasize research staff training and research activity delegation of authority. <em>The Scope and Standards of Practice for Clinical Research Nursing</em>, published by the American Nurses’ Association and based on role delineation studies for nurses, is the guidance document for clinical research nurses participating in research activities. Policy making related to research activity delegation of authority would be informed by data that correlate protocol deviation rates with licensure and education of research staff. Protocol deviations can lead to invalid clinical trial results, adverse events, and ethical concerns related to participant risk exposure. Outcome data are lacking, which directly compare frequency of protocol deviations by licensed nurse study coordinators to deviation rates of non-licensed study coordinators.</p><p class="abstract"><strong>Methods:</strong> This pilot study reviewed 45 monitoring reports for 3 clinical research studies and associated research sites staffed with licensed RN study coordinators and research sites staffed with non-licensed, non-RN study coordinators to compare deviation rates related to informed consent, protocol endpoints, participant eligibility and adverse events.</p><p class="abstract"><strong>Results:</strong> We identified 101 deviations. Adverse event and endpoint deviations were the highest frequency. Differences were evident in overall deviation rates; however, specific deviation comparisons failed to show statistical significance due to low sample size. </p><p><strong>Conclusions:</strong> This study illustrates a useful method for planning future studies using monitoring reports for deviation tracking and comparison across staffing levels.</p>

Mind perception modulates social attention in real-time human-robot interaction

Mind perception modulates social attention in real-time human-robot interaction

Perceived robot personality affects social attention in real-time human-robot interaction

Perceived robot personality affects social attention in real-time human-robot interaction

Effects of embodiment on social attention mechanisms in human-robot interaction

Effects of embodiment on social attention mechanisms in human-robot interaction

Selective Attention Compensates Detrimental Effect of Auditory Noise on Performance in Posner Experiment

Environmental noise has a degrading effect on individual’s capacity to pay attention. In this paper, we revealed that the individual’s impaired performance under noise can be counterpoised by recollecting and recalling his attention. We studied the effect of auditory white noise on individual’s performance in Posner experiment; and examined if actively reorienting the individual’s attention to stimuli would mitigate the effects of auditory noise. Our subjects, ten undergraduate students, participated in the classical Posner experiment, while auditory white noise was being played for them through earphone. We varied the intensity of the auditory noise and studied subject’s performance in three conditions: neutral, valid cued, and invalid cued trials. Our results showed that the presence of auditory noise degraded subject’s performance in neutral trials. However, subject’s performance was not affected by auditory noise in valid cued trials.

Investigating the contribution of task and response repetitions to the sequential modulations of attentional cueing effects

We tested the nature of validity sequence effects. During visual search for targets, target-preceding peripheral cues at target position (valid condition) facilitate search relative to cues away from the target (invalid condition). This validity effect (i.e., advantage in valid compared to invalid conditions) is observed for cues that are not predictive of the target, and it reflects the cue’s capture of attention. Importantly, the validity effect is stronger following valid than invalid trials. The underlying causes of this validity sequence effect are unknown. We, therefore, tested if the validity sequence effect reflected trial-to-trial priming or event-file coding. According to these explanations, full trial-to-trial repetitions and full changes of all stimulus features or of all stimulus and response features, respectively, would account for the validity sequence effect. However, the validity sequence effect could also reflect the participants’ retention of a recently helpful cue (i.e., after a valid trial) and/or their suppression of a recently harmful cue (i.e., after an invalid trial). Here, to contrastively test these theories, from trial to trial, the tasks are repeated or switched. The results demonstrated that, under certain conditions, the validity sequence effect can survive task-switching (Experiments 1 and 2), which supports the retention/suppression account. When the tasks were strongly distinguished, however, the validity sequence effect did not survive task-switching (Experiment 3), which supports the event-coding account. Together, the results suggest that task structure can determine the impact of cue processing on subsequent trials, and the extent to which it reflects event-file coding.