Order Of Stimulus Presentation Research Articles

Controlling response order without relying on stimulus order - evidence for flexible representations of task order.

In dual-task situations, both component tasks are typically not executed simultaneously but rather one after another. Task order is usually determined based on bottom-up information provided by stimulus presentation order, but also affected by top-down factors such as instructions and/or differentially dominant component tasks (e.g., oculomotor task prioritization). Recent research demonstrated that in the context of a randomly switching stimulus order, task order representations can be integrated with specific component task information rather than being coded in a purely abstract fashion (i.e., by containing only generic order information). This conclusion was derived from observing consistently smaller task-order switch costs for a preferred (e.g., oculomotor-manual) versus a non-preferred (e.g., manual-oculomotor) task order (i.e., order-switch cost asymmetries). Since such a representational format might have been especially promoted by the sequential stimulus presentation employed, we investigated task-order representations in situations without any bottom-up influence of stimulus order. To this end, we presented task stimuli simultaneously and cued the required task-order in advance. Experiment 1 employed abstract order transition cues that only indicated a task-order repetition (vs. switch) relative to the previous trial, while Experiment 2 used explicit cues that unambiguously indicated the task-order. Experiment 1 revealed significant task-order switch costs only for the second task (of either task order) and no order-switch cost asymmetries, indicating a rather generic representation of task order. Experiment 2 revealed task-order switch costs in both component tasks with a trend toward order-switch cost asymmetries, indicating an integration of task order representations with component task information. These findings highlight an astonishing flexibility of mental task-order representations during task-order control.

An Examination of the Orienting and Defensive Responses Using HR and HF-HRV

Abstract: Psychophysiological researchers have demonstrated that the orienting response is characterized by heart rate (HR) decreases and high-frequency heart rate variability (HF-HRV) increases. The defensive response is characterized by HR increases and HF-HRV decreases. In this study, HR and HF-HRV reactivity to a visual stimulus designed to elicit an orienting response (surgery video) and a cognitive task designed to elicit a defensive response (Trier Social Stress Test, math task) were measured among 81 undergraduate students. The order of stimuli presentation was counterbalanced. The expected pattern of reactivity was observed (decreased HR and increased HF-HRV during the video condition; increased HR and decreased HF-HRV during the cognitive math task). The order of stimulus presentation significantly influenced HF-HRV reactivity. When the video stimulus was presented first, a large and significant increase in HF-HRV was observed which indicated vagal activation. When the video stimulus followed the cognitive math task stimulus, lower levels of HF-HRV reactivity and vagal activation were observed. This suggests exposure to the cognitive math task elicited a defensive response that suppressed subsequent orienting responses. Theoretical, psychophysiological, and practical implications of the observed results and future psychophysiological research directions are discussed.

An Invited Reply to: A Comment on: The exploitation of sexual signals by predators: a meta-analysis (2022) White et al.

An Invited Reply to: A Comment on: The exploitation of sexual signals by predators: a meta-analysis (2022) White et al.

Perceptual warping exposes categorical representations for speech in human brainstem responses

The brain transforms continuous acoustic events into discrete category representations to downsample the speech signal for our perceptual-cognitive systems. Such phonetic categories are highly malleable, and their percepts can change depending on surrounding stimulus context. Previous work suggests these acoustic-phonetic mapping and perceptual warping of speech emerge in the brain no earlier than auditory cortex. Here, we examined whether these auditory-category phenomena inherent to speech perception occur even earlier in the human brain, at the level of auditory brainstem. We recorded speech-evoked frequency following responses (FFRs) during a task designed to induce more/less warping of listeners’ perceptual categories depending on stimulus presentation order of a speech continuum (random, forward, backward directions). We used a novel clustered stimulus paradigm to rapidly record the high trial counts needed for FFRs concurrent with active behavioral tasks. We found serial stimulus order caused perceptual shifts (hysteresis) near listeners’ category boundary confirming identical speech tokens are perceived differentially depending on stimulus context. Critically, we further show neural FFRs during active (but not passive) listening are enhanced for prototypical vs. category-ambiguous tokens and are biased in the direction of listeners’ phonetic label even for acoustically-identical speech stimuli. These findings were not observed in the stimulus acoustics nor model FFR responses generated via a computational model of cochlear and auditory nerve transduction, confirming a central origin to the effects. Our data reveal FFRs carry category-level information and suggest top-down processing actively shapes the neural encoding and categorization of speech at subcortical levels. These findings suggest the acoustic-phonetic mapping and perceptual warping in speech perception occur surprisingly early along the auditory neuroaxis, which might aid understanding by reducing ambiguity inherent to the speech signal.

Interhemispheric communication during haptic self-perception.

During the haptic exploration of a planar surface, slight resistances against the hand's movement are illusorily perceived as asperities (bumps) in the surface. If the surface being touched is one's own skin, an actual bump would also produce increased tactile pressure from the moving finger onto the skin. We investigated how kinaesthetic and tactile signals combine to produce haptic perceptions during self-touch. Participants performed two successive movements with the right hand. A haptic force-control robot applied resistances to both movements, and participants judged which movement was felt to contain the larger bump. An additional robot delivered simultaneous but task-irrelevant tactile stroking to the left forearm. These strokes contained either increased or decreased tactile pressure synchronized with the resistance-induced illusory bump encountered by the right hand. We found that the size of bumps perceived by the right hand was enhanced by an increase in left tactile pressure, but also by a decrease. Tactile event detection was thus transferred interhemispherically, but the sign of the tactile information was not respected. Randomizing (rather than blocking) the presentation order of left tactile stimuli abolished these interhemispheric enhancement effects. Thus, interhemispheric transfer during bimanual self-touch requires a stable model of temporally synchronized events, but does not require geometric consistency between hemispheric information, nor between tactile and kinaesthetic representations of a single common object.

Beyond Recognition: Visual Contributions to Verbal Working Memory.

It is well recognized that adding the visual to the acoustic speech signal improves recognition when the acoustic signal is degraded, but how that visual signal affects postrecognition processes is not so well understood. This study was designed to further elucidate the relationships among auditory and visual codes in working memory, a postrecognition process. In a main experiment, 80 young adults with normal hearing were tested using an immediate serial recall paradigm. Three types of signals were presented (unprocessed speech, vocoded speech, and environmental sounds) in three conditions (audio-only, audio-video with dynamic visual signals, and audio-picture with static visual signals). Three dependent measures were analyzed: (a) magnitude of the recency effect, (b) overall recall accuracy, and (c) response times, to assess cognitive effort. In a follow-up experiment, 30 young adults with normal hearing were tested largely using the same procedures, but with a slight change in order of stimulus presentation. The main experiment produced three major findings: (a) unprocessed speech evoked a recency effect of consistent magnitude across conditions; vocoded speech evoked a recency effect of similar magnitude to unprocessed speech only with dynamic visual (lipread) signals; environmental sounds never showed a recency effect. (b) Dynamic and static visual signals enhanced overall recall accuracy to a similar extent, and this enhancement was greater for vocoded speech and environmental sounds than for unprocessed speech. (c) All visual signals reduced cognitive load, except for dynamic visual signals with environmental sounds. The follow-up experiment revealed that dynamic visual (lipread) signals exerted their effect on the vocoded stimuli by enhancing phonological quality. Acoustic and visual signals can combine to enhance working memory operations, but the source of these effects differs for phonological and nonphonological signals. Nonetheless, visual information can support better postrecognition processes for patients with hearing loss.

Neurophysiological Correlates of Asymmetries in Vowel Perception: An English-French Cross-Linguistic Event-Related Potential Study.

Behavioral studies examining vowel perception in infancy indicate that, for many vowel contrasts, the ease of discrimination changes depending on the order of stimulus presentation, regardless of the language from which the contrast is drawn and the ambient language that infants have experienced. By adulthood, linguistic experience has altered vowel perception; analogous asymmetries are observed for non−native contrasts but are mitigated for native contrasts. Although these directional effects are well documented behaviorally, the brain mechanisms underlying them are poorly understood. In the present study we begin to address this gap. We first review recent behavioral work which shows that vowel perception asymmetries derive from phonetic encoding strategies, rather than general auditory processes. Two existing theoretical models–the Natural Referent Vowel framework and the Native Language Magnet model–are invoked as a means of interpreting these findings. Then we present the results of a neurophysiological study which builds on this prior work. Using event-related brain potentials, we first measured and assessed the mismatch negativity response (MMN, a passive neurophysiological index of auditory change detection) in English and French native-speaking adults to synthetic vowels that either spanned two different phonetic categories (/y/vs./u/) or fell within the same category (/u/). Stimulus presentation was organized such that each vowel was presented as standard and as deviant in different blocks. The vowels were presented with a long (1,600-ms) inter-stimulus interval to restrict access to short-term memory traces and tap into a “phonetic mode” of processing. MMN analyses revealed weak asymmetry effects regardless of the (i) vowel contrast, (ii) language group, and (iii) MMN time window. Then, we conducted time-frequency analyses of the standard epochs for each vowel. In contrast to the MMN analysis, time-frequency analysis revealed significant differences in brain oscillations in the theta band (4–8 Hz), which have been linked to attention and processing efficiency. Collectively, these findings suggest that early-latency (pre-attentive) mismatch responses may not be a strong neurophysiological correlate of asymmetric behavioral vowel discrimination. Rather, asymmetries may reflect differences in neural processing efficiency for vowels with certain inherent acoustic-phonetic properties, as revealed by theta oscillatory activity.

Higher-Order Musical Temporal Structure in Bird Song.

Bird songs often display musical acoustic features such as tonal pitch selection, rhythmicity, and melodic contouring. We investigated higher-order musical temporal structure in bird song using an experimental method called “music scrambling” with human subjects. Recorded songs from a phylogenetically diverse group of 20 avian taxa were split into constituent elements (“notes” or “syllables”) and recombined in original and random order. Human subjects were asked to evaluate which version sounded more “musical” on a per-species basis. Species identity and stimulus treatment were concealed from subjects, and stimulus presentation order was randomized within and between taxa. Two recordings of human music were included as a control for attentiveness. Participants varied in their assessments of individual species musicality, but overall they were significantly more likely to rate bird songs with original temporal sequence as more musical than those with randomized temporal sequence. We discuss alternative hypotheses for the origins of avian musicality, including honest signaling, perceptual bias, and arbitrary aesthetic coevolution.

Effects of Noise and Serial Position on Free Recall of Spoken Words and Pupil Dilation during Encoding in Normal-Hearing Adults.

This preliminary study assessed the effects of noise and stimulus presentation order on recall of spoken words and recorded pupil sizes while normal-hearing listeners were trying to encode a series of words for a subsequent recall task. In three listening conditions (stationary noise in Experiment 1; quiet versus four-talker babble in Experiment 2), participants were assigned to remember as many words as possible to recall them in any order after each list of seven sentences. In the two noise conditions, lists of sentences fixed at 65 dB SPL were presented at an easily audible level via a loudspeaker. Reading span (RS) scores were used as a grouping variable, based on a median split. The primacy effect was present apart from the noise interference, and the high-RS group significantly outperformed the low-RS group at free recall measured in the quiet and four-talker babble noise conditions. RS scores were positively correlated with free-recall scores. In both quiet and four-talker babble noise conditions, sentence baselines after correction to the initial stimulus baseline increased significantly with increasing memory load. Larger sentence baselines but smaller peak pupil dilations seemed to be associated with noise interruption. The analysis method of pupil dilation used in this study is likely to provide a more thorough understanding of how listeners respond to a later recall task in comparison with previously used methods. Further studies are needed to confirm the applicability of our method in people with impaired hearing using multiple repetitions to estimate the allocation of relevant cognitive resources.

Further examination of the effects of order of stimulus presentation on receptive discrimination

AbstractRecent research has demonstrated that the order of stimulus presentation during auditory‐visual discrimination training may influence the rate of skill acquisition. Results of some studies have suggested that presenting the sample auditory stimulus prior to the comparison visual stimuli may enhance learning for typically developing children. However, replication efforts in individuals with autism spectrum disorder (ASD) in structured discrete‐trial formats have produced mixed results. The purpose of the current study was to further evaluate the role of stimulus order during auditory‐visual discrimination training to learners with ASD or speech delays during discrete trial instruction. Five of the six children who participated in the study acquired the skills faster during the sample‐first stimulus condition.

Describing the structure of concepts through different feature levels

ABSTRACT It has been suggested that concepts can be recognised based on at least some amount of highly shared features across individuals (i.e. core features). However, the boundaries between those features and less-shared ones remain unclear. Therefore, the main purpose of this paper is to operationalise the different levels of the structure of a concept's meaning and to test the effect of those levels on semantic decision latencies. First, we performed a feature based cued-recall task. Then, we designed two speeded verification tasks in which features were presented before and after the concept (i.e. feature-concept and concept-feature condition, respectively). Results of the cued-recall task allowed us to operationalise core features. Furthermore, we observed that core features were verified faster than partially shared, followed by features, and partially shared features faster than idiosyncratic ones, being features, and that this effect is independent of the order of stimulus presentation.

Replicating stimulus-presentation orders in discrimination training.

Children with autism spectrum disorder (ASD) are taught conditional discriminations often during early intervention. Auditory-visual conditional discrimination (AVCD) training requires the presentation of multiple antecedent stimuli, and the order of stimulus presentation varies in the literature. This series of studies replicated previous literature on stimulus-presentation order in AVCD training. In Experiment 1, we compared sample-first and comparisons-first arrangements in 8 comparisons with 4 participants with ASD. For 3 participants, both presentations were efficacious. For 1 participant, the sample-first order was more likely to be efficacious. In Experiment 2, we added a sample-first-with-repetition arrangement and conducted 6 comparisons with 5 participants with ASD. Across comparisons, all 3 presentations were efficacious. Considerations for teaching AVCD to children with ASD and suggestions for further evaluation and examination of efficacy and efficiency are discussed.

Attractive serial dependence between memorized stimuli

Attractive serial dependence – a bias whereby the current stimulus appears more similar to the previous ones – is thought to reflect a stability mechanism integrating past and current visual signals. Prior work suggests that serial dependence originates from both perceptual and cognitive mechanisms, but the conditions under which this attractive bias occurs remain to be studied. In particular, whether serial dependence can occur solely from memory interference remains unclear. Here, we address this question by testing the hypothesis that if memory interference is sufficient to generate serial dependence, it should occur within memorized stimuli irrespective of the order of stimulus presentation. In Exp. 1, we used a numerosity estimation task in which participants estimated the number of dots of a briefly flashing dot-array comprising 8 to 32 dots. The pattern of serial dependence was found in that numerical estimates of a dot array were biased towards the numerosity of the preceding dot array. In Exp. 2, we presented a series of three such dot arrays, and cued the one to be estimated only after the whole series was presented, making the participants first form a memorized representation of the three dot arrays. The results show a pattern of attractive biases both in the forward (the stimulus presented before biases the one presented after) and the backward (the stimulus presented after biases the one presented before) directions. Overall, our results demonstrate that serial dependence can be induced solely from memory interference and that this interference can operate irrespective of the chronological order of the stimulus presentation.

Investigating the validity of muscle response testing: Blinding the patient using subliminal visual stimuli

Research objectiveTo determine if Muscle Response Testing (MRT) can be used to distinguish lies from truths using blind test patients. DesignA prospective study of diagnostic test accuracy was carried out using MRT to distinguish lies from truth. MethodsTwenty practitioners who routinely practised MRT were paired with 20 blind test patients (TPs). TPs were asked to speak simple true and false statements about visual stimuli presented subliminally (at 20 ms). In the subliminal phase, pairs performed 20 MRTs and 20 Intuitive Guesses (IG), consisting of 2 blocks of 10 statements each. In the Supraliminal Phase, the same picture-statement pairs were repeated. The order of stimuli presentation was randomly assigned so that each pair was presented with a unique series of stimuli. ResultsIn the Subliminal Phase, MRT accuracy (as percent correct) was found to be 48.5% (95% CI 42.8–54.2), which was no different from IG accuracy (47.8%; 95% CI 43.2–52.3; p = 0.68) or chance (50.0%; p = 0.59), and no different from MRT accuracy during the supraliminal phase (59.0%; 95% CI 50.4–67.6; p = 0.05). However, supraliminal MRT accuracy was significantly different from chance (p = 0.04), indicating that the pairs could perform MRT proficiently. ConclusionThe main reason for finding no effect is suspected to be due to an inadequate subliminal methodology, a process which is quite complex. Other explanations of results include: (1) MRT is not a valid test when the TP is blind, (2) Blinding TPs during MRT will produce ambiguous or unpredictable results, or (3) Nonconscious beliefs cannot be elicited using subliminal stimuli. Future research may wish to focus on exploring these possibilities. More specifically, subsequent studies may wish to use different methods to blind TPs, and establish whether MRT can be used to detect nonconscious processes, a generally held consensus among MRT practitioners.

Development of Online Integrative Medicine Research Curriculum

To determine if Muscle Response Testing (MRT) can be used to distinguish lies from truths using blind test patients.A prospective study of diagnostic test accuracy was carried out using MRT to distinguish lies from truth.Twenty practitioners who routinely practised MRT were paired with 20 blind test patients (TPs). TPs were asked to speak simple true and false statements about visual stimuli presented subliminally (at 20 ms). In the subliminal phase, pairs performed 20 MRTs and 20 Intuitive Guesses (IG), consisting of 2 blocks of 10 statements each. In the Supraliminal Phase, the same picture-statement pairs were repeated. The order of stimuli presentation was randomly assigned so that each pair was presented with a unique series of stimuli.In the Subliminal Phase, MRT accuracy (as percent correct) was found to be 48.5% (95% CI 42.8–54.2), which was no different from IG accuracy (47.8%; 95% CI 43.2–52.3; p = 0.68) or chance (50.0%; p = 0.59), and no different from MRT accuracy during the supraliminal phase (59.0%; 95% CI 50.4–67.6; p = 0.05). However, supraliminal MRT accuracy was significantly different from chance (p = 0.04), indicating that the pairs could perform MRT proficiently.The main reason for finding no effect is suspected to be due to an inadequate subliminal methodology, a process which is quite complex. Other explanations of results include: (1) MRT is not a valid test when the TP is blind, (2) Blinding TPs during MRT will produce ambiguous or unpredictable results, or (3) Nonconscious beliefs cannot be elicited using subliminal stimuli. Future research may wish to focus on exploring these possibilities. More specifically, subsequent studies may wish to use different methods to blind TPs, and establish whether MRT can be used to detect nonconscious processes, a generally held consensus among MRT practitioners.

Influence of visibility of wind farms on noise annoyance – A laboratory experiment with audio-visual simulations

Noise annoyance reactions in the population due to wind farms are related to visual as well as noise-related impacts of the farms. Improved understanding of these effects may support the planning of better accepted wind farms. Recently, tools for visualization and auralization of wind farms have been developed that allow mutually studying audio-visual effects on annoyance. The objective of this study was to investigate the audio-visual effects of different wind turbine noise situations on short-term noise annoyance in a psychophysical laboratory experiment, considering serial position effects (simple order and differential carryover effects). A set of 24 audio-visual situations covering a range of acoustical characteristics (sound pressure level, periodic amplitude modulation) and visual settings (landscape with visible wind turbine, landscape only, grey background) was created. The factorial design of the experiment allowed separating audio-visual effects from serial position effects on noise annoyance. Both visual and acoustical characteristics were found to affect noise annoyance, besides the participants’ attitude towards wind farms. Sound pressure level and amplitude modulation increased annoyance, the presence of a visualized landscape decreased annoyance, and the visibility of a wind turbine increased annoyance. While simple order effects could be eliminated by counterbalancing, the initial visual setting strongly affected the annoyance ratings of the subsequent settings. Due to this differential carryover effect, visual effects could be assessed reliably only as long as the participants saw the initial visual setting. Therefore, the presentation order of audio-visual stimuli should be carefully considered in experimental studies and in participatory landscape planning.

Individual differences in learning social and nonsocial network structures.

How do people acquire knowledge about which individuals belong to different cliques or communities? And to what extent does this learning process differ from the process of learning higher-order information about complex associations between nonsocial bits of information? Here, the authors use a paradigm in which the order of stimulus presentation forms temporal associations between the stimuli, collectively constituting a complex network. They examined individual differences in the ability to learn community structure of networks composed of social versus nonsocial stimuli. Although participants were able to learn community structure of both social and nonsocial networks, their performance in social network learning was uncorrelated with their performance in nonsocial network learning. In addition, social traits, including social orientation and perspective-taking, uniquely predicted the learning of social community structure but not the learning of nonsocial community structure. Taken together, the results suggest that the process of learning higher-order community structure in social networks is partially distinct from the process of learning higher-order community structure in nonsocial networks. The study design provides a promising approach to identify neurophysiological drivers of social network versus nonsocial network learning, extending knowledge about the impact of individual differences on these learning processes. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Remembering the order of serially presented objects: A matter of time?

Remembering the sequence, in which stimuli are encountered or events have occurred, is a key process in episodic memory and can also facilitate recognition memory. Rodents, when presented with a sequence of objects, will explore the object encountered first; yet, whether this behaviour is because the rodents spontaneously encode the order of stimuli presentation or because of relative familiarity or temporal decay is unknown. Here, we tested sequence memory in rats using a series of spontaneous preference tasks. Experiment 1 demonstrated that when rats are presented with a sequence of four objects, with an inter-sample interval of 5 min or 1 h, they preferentially explored the object presented earlier in the list irrespective of the inter-sample interval. We then demonstrated that such memory for order was not affected by increasing or decreasing the inter-sample interval between the middle objects (Experiment 2). Finally, we showed that memory for order is not a function of absolute object familiarity, as animals showed clear discrimination between the objects presented in the sample phases and a novel object, independent of the sample objects’ position in the sequence (Experiment 3). These results show that animals are able to encode the order of objects presented in a sequence, and as such temporal order memory is not achieved using the process of relative or absolute familiarity or temporal decay.

Effects of stimulus presentation order during auditory-visual conditional discrimination training for children with autism spectrum disorder.

Children with autism spectrum disorder are typically taught conditional discriminations using a match-to-sample arrangement. Consideration should be given to the temporal order in which antecedent stimuli (the sample and comparison stimuli) are presented during match-to-sample trials, as various arrangements have been used in the extant literature. The purpose of the current study was to compare the effects of four stimulus presentation orders on the acquisition of auditory-visual conditional discriminations. The study included participants from a clinically relevant population (three children with autism spectrum disorder), employed clinically relevant teaching procedures, and included two presentation formats not included in previous comparison evaluations (simultaneous and sample-first with re-presentation conditions). Results were found to be learner-specific; that is, a different stimulus presentation format was most efficient for each participant. We provide suggestions to evaluate stimulus control topographies and enhance experimental control in match-to-sample arrangements.

Visual Simultaneity Judgments Activate a Bilateral Frontoparietal Timing System.

In everyday life, we often make judgments regarding the sequence of events, for example, deciding whether a baseball runner's foot hit the plate before or after the ball hit the glove. Numerous studies have examined the functional correlates of temporal processing using variations of the temporal order judgment and simultaneity judgment (SJ) tasks. To perform temporal order judgment tasks, observers must bind temporal information with identity and/or spatial information relevant to the task itself. SJs, on the other hand, require observers to detect stimulus asynchrony but not the order of stimulus presentation and represent a purer measure of temporal processing. Some previous studies suggest that these temporal decisions rely primarily on right-hemisphere parietal structures, whereas others provide evidence that temporal perception depends on bilateral TPJ or inferior frontal regions (inferior frontal gyrus). Here, we report brain activity elicited by a visual SJ task. Our methods are unique given our use of two orthogonal control conditions, discrimination of spatial orientation and color, which were used to control for brain activation associated with the classic dorsal ("where/how") and ventral ("what") visual pathways. Our neuroimaging experiment shows that performing the SJ task selectively activated a bilateral network in the parietal (TPJ) and frontal (inferior frontal gyrus) cortices. We argue that SJ tasks are a purer measure of temporal perception because they do not require observers to process either identity or spatial information, both of which may activate separate cognitive networks.