Longer SOAs Research Articles

Circadian modulation of the time course of automatic and controlled semantic processing

ABSTRACT We investigated whether chronotype and time-of-day modulate the time course of automatic and controlled semantic processing. Participants performed a category semantic priming task at either the optimal or non-optimal time of day. We varied the prime-target onset asynchrony (100-, 450-, 650-, and 850-ms SOAs) and kept the percentage of unrelated targets constant at 80%. Automatic processing was expected with the short SOA, and controlled processing with longer SOAs. Intermediate-types (Experiment 1) verified that our task was sensitive to capturing both types of processes and served as a reference to assess themin extreme chronotypes. Morning-type and evening-type participants (Experiment 2) differed in the influence of time of testing on priming effects. Morning-types applied control in all conditions, and no performance modulation by time-of-day was observed. In contrast, evening-types were most adversely affected by the time of day to shift from automatic-based to controlled-based responses. Also, they were considerably affected in successfully implementing controlled processing with long intervals, particularly at the non-optimal time of day, with inhibitory priming showing only a marginally significant effect at the longest SOA. These results suggest that extreme chronotypes may be associated with different styles of cognitive control. Morning-types would be driven by a proactive control style, whereas a reactive control style might be applied by evening-types.

Effect of presentation rate on auditory processing in Rett syndrome: event-related potential study

BackgroundRett syndrome (RS) is a rare neurodevelopmental disorder characterized by mutations in the MECP2 gene. Patients with RS have severe motor abnormalities and are often unable to walk, use hands and speak. The preservation of perceptual and cognitive functions is hard to assess, while clinicians and care-givers point out that these patients need more time to process information than typically developing peers. Neurophysiological correlates of auditory processing have been also found to be distorted in RS, but sound presentation rates were relatively quick in these studies (stimulus onset asynchrony, SOA < 1000 ms). As auditory event-related potential (ERP) is typically increased with prolongation of SOA we aim to study if SOA prolongation might compensate for observed abnormalities.MethodsWe presented a repetitive stimulus (1000 Hz) at three different SOAs of 900 ms, 1800 ms, and 3600 ms in children with RS (N = 24, Mean age = 9.0 ± 3.1) and their typical development (TD) peers (N = 27, Mean age = 9.7 ± 3.4) while recording 28-channels electroencephalogram, EEG. Some RS participants (n = 10) did not show clear ERP and were excluded from the analysis.ResultsMajor ERP components (here assessed as N1P1 and P2N1 peak-to-peak values) were smaller at SOA 900 than at longer SOAs in both groups, pointing out that the basic mechanism of adaptation in the auditory system is preserved in at least in RS patients with evident ERPs. At the same time the latencies of these components were significantly delayed in the RS than in TD. Moreover, late components (P2N1 and N2P2) were drastically reduced in Rett syndrome irrespective of the SOA, suggesting a largely affected mechanism of integration of upcoming sensory input with memory. Moreover, developmental stagnation of auditory ERP characterized patients with RS: absence of typical P2N1 enlargement and P1 and N1 shortening with age at least for shortest SOA.LimitationsWe could not figure out the cause for the high percentage of no-evident ERP RS participants and our final sample of the RS group was rather small. Also, our study did not include a control clinical group.ConclusionsThus, auditory ERPs inform us about abnormalities within auditory processing that cannot be fully overcomed by slowing presentation rate.

The role of primary motor cortex in manual inhibition of return: A transcranial magnetic stimulation study

Inhibition of return (IOR) is a behavioural phenomenon characterised by longer response times (RTs) to stimuli presented at previously cued versus uncued locations. The neural mechanisms underlying IOR effects are not fully understood. Previous neurophysiological studies have identified a role of frontoparietal areas including posterior parietal cortex (PPC) in the generation of IOR, but the contribution of primary motor cortex (M1) has not been directly tested.The present study investigated the effects of single-pulse transcranial magnetic stimulation (TMS) over M1 on manual IOR in a key-press task where peripheral (left or right) targets followed a cue at the same or opposite location at different SOAs (100/300/600/1000 ms). In Experiment 1, TMS was applied over right M1 on a randomized 50% of trials. In Experiment 2, active or sham stimulation was provided in separate blocks.In the absence of TMS (non-TMS trials in Experiment 1 and sham trials in Experiment 2), evidence of IOR was observed in RTs at longer SOAs. In both experiments, IOR effects differed between TMS and non-TMS/sham conditions, but the effects of TMS were greater and statistically significant in Experiment 1 where TMS and non-TMS trials were randomly interspersed. The magnitude of motor-evoked potentials was not altered by the cue-target relationship in either experiment.These findings do not support a key role of M1 in the mechanisms of IOR but suggest the need for further research to elucidate the role of the motor system in manual IOR effects.

Susceptibility to the sound-induced flash illusion is associated with gait speed in a large sample of middle-aged and older adults

BackgroundMultisensory integration is the ability to appropriately merge information from different senses for the purpose of perceiving and acting in the environment. During walking, information from multiple senses must be integrated appropriately to coordinate effective movements. We tested the association between a well characterised multisensory task, the Sound-Induced Flash Illusion (SIFI), and gait speed in 3255 participants from The Irish Longitudinal Study on Ageing. High susceptibility to this illusion at longer stimulus onset asynchronies characterises older adults, and has been associated with cognitive and functional impairments, therefore it should be associated with slower gait speed. MethodGait was measured under three conditions; usual pace, cognitive dual tasking, and maximal walking speed. A separate logistic mixed effects regression model was run for 1) gait at usual pace, 2) change in gait speed for the cognitive dual tasking relative to usual pace and 3) change in maximal walking speed relative to usual pace. In all cases a binary response indicating a correct/incorrect response to each SIFI trial was the dependent variable. The model controlled for covariates including age, sex, education, vision and hearing abilities, Body Mass Index, and cognitive function. ResultsSlower gait was associated with more illusions, particularly at longer temporal intervals between the flash-beep pair and the second beep, indicating that those who integrated incongruent sensory inputs over longer intervals, also walked slower. The relative changes in gait speed for cognitive dual tasking and maximal walking speed were also significantly associated with SIFI at longer SOAs. ConclusionsThese findings support growing evidence that mobility, susceptibility to falling and balance control are associated with multisensory processing in ageing.

350 INTEGRATION OF VISION AND HEARING IS ASSOCIATED WITH GAIT VELOCITY IN A LARGE SAMPLE OF MIDDLE-AGED AND OLDER ADULTS

Abstract Background Multisensory integration is the ability to appropriately merge information from several senses for the purpose of perceiving and acting in the environment. Its importance for higher level cognition and function has emerged in recent years. Walking requires to combine information from multiple senses to coordinate effective movements. In this study, we tested the association between a well characterised multisensory task, the Sound-Induced Flash Illusion (SIFI), and gait velocity in 3,255 participants from The Irish Longitudinal Study on Ageing. The SIFI is the illusory perception of two flashes when one flash is presented with two beeps. We hypothesised that high SIFI susceptibility would be associated with slower gait velocity Methods Gait was measured under three conditions; usual pace, cognitive dual tasking, and maximal walking speed. A separate logistic mixed effects regression was run for: (1) gait at usual pace, (2) change in gait speed for the cognitive dual-task relative to usual pace, and (3) change in maximal walking speed relative to usual pace. The model controlled for covariates including age, sex, education, vision and hearing abilities, Body Mass Index, and cognitive function. Results Slower gait was associated with more illusions, indicating that those who integrated incongruent sensory inputs over longer intervals, also walked slower. Relative change for cognitive dual tasking and maximal walking speed were also significantly associated with SIFI at longer SOAs. Conclusion These findings extend growing evidence showing that mobility is associated with multisensory processing in ageing; in particular, the mechanisms appear related to the temporal dynamics of sensory integration.

Moving distractors and moving targets: combining a response priming task with moving prime stimuli and a flanker task

ABSTRACT In response priming, responses are typically faster and more accurate if the prime calls for the same response as the target (i.e. compatible trials), than when primes and targets trigger different responses (i.e. incompatible trials). With moving rows-of-dots as primes for static arrow targets, participants instead responded faster to incompatible targets with longer SOAs (> 200 ms). In the present experiments, response priming with moving primes was combined with a flanker arrangement. Flankers were moving rows-of-dots. Targets were either static arrows or moving rows-of-dots. In seven experiments, there were positive compatibility effects with an SOA of 147 ms and negative compatibility effects with an SOA of 360 ms. Positive as well as negative effects were larger with moving compared to static targets, and negative effects were larger with primes compared to flankers. Theories on motor pre-activations and inhibition as well as on attention and the specific role of motion were discussed.

Guiding spatial attention by multimodal reward cues.

Our attention is constantly captured and guided by visual and/or auditory inputs. One key contributor to selecting relevant information from the environment is reward prospect. Intriguingly, while both multimodal signal processing and reward effects on attention have been widely studied, research on multimodal reward signals is lacking. Here, we investigated this using a Posner task featuring peripheral cues of different modalities (audiovisual/visual/auditory), reward prospect (reward/no-reward), and cue-target stimulus-onset asynchronies (SOAs 100-1,300 ms). We found that audiovisual and visual reward cues (but not auditory ones) enhanced cue-validity effects, albeit with different time courses (Experiment 1). While the reward-modulated validity effect of visual cues was pronounced at short SOAs, the effect of audiovisual reward cues emerged at longer SOAs. Follow-up experiments exploring the effects of visual (Experiment 2) and auditory (Experiment 3) reward cues in isolation showed that reward modulated performance only in the visual condition. This suggests that the differential effect of visual and auditory reward cues in Experiment 1 is not merely a result of the mixed cue context, but confirms that visual reward cues have a stronger impact on attentional guidance in this paradigm. Taken together, it seems that adding an auditory reward cue to the inherently dominant visual one led to a shift/extension of the validity effect in time - instead of increasing its amplitude. While generally being in line with a multimodal cuing benefit, this specific pattern highlights that different reward signals are not simply combined in a linear fashion but lead to a qualitatively different process.

Perceived and one’s own motion in response priming

AbstractIn response priming, motor pre-activations from a prime to the response to a target can be measured, as a function of whether they require the same (compatible) or different (incompatible) responses. With moving primes and static arrow targets, the results depend on the stimulus onset asynchrony between prime and target: with short SOAs, there were faster responses to compatible than incompatible targets, with longer SOAs, the pattern reverses. However, this reversal was not found with more biological motions. The current study comprised 3 experiments in order to replicate several findings from previous research and add evidence regarding the interplay of one’s own and perceived motions. Subjects performed a response priming task with moving prime stimuli while in motion themselves. With this paradigm, we tested the general influence of motion on responding and compatibility effects in response priming with moving prime stimuli. Furthermore, we assessed specific interactions of features of the perceived stimuli (e.g., moving vs. static; direction of the prime or target) and the own motion (e.g., walking vs. standing; direction of being rotated). We used two different own motions (walking on a treadmill, Exp. 1 &amp; 3; rotating in a human gyroscope, Exp. 2) and two different visual stimulus types (rows-of-dots, Exp. 1 &amp; 2; point light displays, Exp. 3). Compatibility effects were, in general, neither increased nor decreased during motion. Their size depended on the stimulus type, the velocity of one’s own motion, and several interactions of perceived and own motion. We discuss our findings with respect to perception-action interactions and previous findings on response priming with moving prime stimuli.

Mexican Hat Modulation of Visual Acuity Following an Exogenous Cue.

Classical models of exogenous attention suggest that attentional enhancement at the focus of attention degrades gradually with distance from the attended location. On the other hand, the Attentional Attraction Field (AAF) model (Baruch and Yeshurun, 2014) suggests that the shift of receptive fields toward the attended location, reported by several physiological studies, leads to a decreased density of RFs at the attentional surrounds and hence the model predicts that the modulation of performance by spatial attention may have the shape of a Mexican Hat. Motivated by these theories, this study presents behavioral evidence in support of a Mexican Hat shaped modulation in exogenous spatial tasks that appears only at short latencies. In two experiments participants had to decide the location of a small gap in a target circle that was preceded by a non-informative attention capturing cue. The distance between cue and target and the latency between their onsets were varied. At short SOAs the performance curves were cubic and only at longer SOAs- this trend turned linear. Our results suggest that a rapid Mexican Hat modulation is an inherent property of the mechanism underlying exogenous attention and that a monotonically degrading trend, such as advocated by classical models, develops only at later stages of processing. The involvements of bottom-up processes such as the attraction of RFs to the focus of attention are further discussed.

Endogenous modulation of compatibility effects: an Investigation into the temporal dynamics

ABSTRACTCompatibility effects (CEs) arise when multiple stimuli fall within the visual field, providing an indication of stimulus processing. Previous research demonstrated that exogenous factors (e.g., luminance) influence the magnitude of CEs and their time course. The current research investigated the influence of endogenous factors. We used a flanker paradigm with a variable temporal delay (SOA) between a flanker and a subsequent central stimulus appearing. To manipulate endogenous factors, we required responses to the flanker on either half or all of the trials. The results indicate that increasing the task relevance of the flanker strengthened the initial positive CE (measured at short SOAs), consistent with past findings related to exogenous factors. However, at longer SOAs, the CE did not reverse into a negative CE, which stands against findings related to exogenous factors. These results indicate that CEs are subject to endogenous modulation, but the temporal dynamics do not mimic exogenous modulation.

RT Slowing to Valid Cues on a Reflexive Attention Task in Children and Young Adults.

Peripheral cueing tasks can be used to measure reflexive (automatic) attention. In these tasks, increases in response time or RT (costs) typically follow contralateral (invalid) cues as attention must move from the location of the cue to the target. Reductions in RT (benefits) to a target typically follow ipsilateral (valid) cues because the cue draws attention to where the target will appear. Two exceptions to RT benefits are inhibition of return (IOR) and masking. IOR is the tendency to respond slower to targets that appear in locations attended within the last 200–2000 ms. Masking occurs when the visibility of a target is blocked by another stimulus (e.g., the cue). Herein, we describe two experiments, both using a modified Posner task with “earth rockets” as cues and “alien spaceships” as targets. Cues were equally likely to appear on the left or right side of a display following targets. Participants were instructed to press a left or right key corresponding to a left or right target. In Experiment 1, we obtained data from 203 children (10.58–16.55 years old). We discovered unexpected costs following cues that typically provide RT benefits. In Experiment 2, we explored IOR, masking, and age differences in the occurrence of these costs. We manipulated the cue-target temporal distance (“stimulus onset asynchrony” or SOA) to explore IOR and the cue-target spatial distance to explore masking. We also considered a wider age range. Sixty-three children and 41 young adults participated. Experiment 2 revealed a three-way interaction between SOA, spatial distance, and age. At the shorter SOA (100 ms) and moderate spatial distance, unexpected costs followed valid cues for younger children (7.07–10.15 years old). These costs also occurred in young adults (18.00–23.02 years old) following far distance cues at this SOA. At the longer SOA (200 ms), these costs followed moderate and far cues for younger children and near cues for young adults. Older children (10.31–14.92 years) did not have unexpected costs. We explain the findings in terms of masking, IOR, and possible developmental mechanisms.

Global shape integration and illusory form perception in the absence of awareness.

Previous research on perceptual organization operations still provides contradictory evidence on whether the integration of sparse local elements into coherently unified shapes and the construction of the illusory form are accomplished without the need of awareness. In the present study, three experiments were conducted in which participants were presented with masked (Experiment 1, SOA=27ms; Experiment 2; SOA=53ms) and unmasked (Experiment 3) primes consisting of geometric shapes (a square or a diamond) that could be congruent or incongruent with subsequent probe stimuli (square vs. diamond). Furthermore, the primes were divided into: a grouping condition (where local elements may group together into global shapes), an illusory condition (where the arrangement of local elements produced illusory shapes) and a hybrid condition (where both operations were presented simultaneously). While no priming effects were found for the shortest SOA (27ms), both grouping and illusory primes produced significant priming effects in the longer SOA (53ms). On the other hand, results in Experiment 3 (unmasked) showed strong priming effects for the grouping of the inducers in both the grouping and the hybrid conditions, and also a significant but weaker priming effect for the illusory condition. Overall, our results support the possibility of the integration of local visual features into a global shape in the absence of awareness and, likewise, they suggest an early -subliminal- construction of the illusory shape, implying that feedback projections from higher to lower visual areas are not crucial in the construction of the illusory form.

Response Priming with More or Less Biological Movements as Primes.

Response priming in general is a suitable tool in cognitive psychology to investigate motor preactivations. Typically, compatibility effects reflect faster reactions in cases in which prime and target suggest the same response (i.e., compatible trials) compared with cases in which prime and target suggest opposite responses (i.e., incompatible trials). With moving dots that were horizontally aligned, Bermeitinger (2013) found a stable pattern of results: with short SOAs, faster responses in compatible trials were found; with longer SOAs up to 250 ms, faster responses in incompatible trials were found. It is unclear whether these results are specific to the special motion used therein or whether it generalizes to other motions. We therefore used other motions realized by arrangements of dots. In four experiments, we tested point-light displays (biological coherent walkers vs. less biological scrambled/split displays) as primes. In two experiments, eye gaze motions realized by moving dots representing irises and pupils (i.e., biological) versus the same motion either without surrounding face information or integrated in an abstract line drawing (i.e., less biological) were used. We found overall large positive compatibility effects with biological motion primes and also positive-but smaller-compatibility effects with less biological motion primes. Most important, also with very long SOAs (up to 1320 ms), we did not find evidence for negative compatibility effects. Thus, the pattern of positive-followed-by-negative-compatibility effects found in Bermeitinger (2013) seems to be specific to the materials used therein, whereas response priming in general seems an applicable tool to study motion perception.

Deficits in the covert orienting of attention in children with Developmental Coordination Disorder: Does severity of DCD count?

Children with Developmental Coordination Disorder (DCD) show deficits in the covert orienting of visuospatial attention, suggesting an underlying issue in attentional disengagement and/or inhibitory control. However, an important theoretical issue that remains unclear is whether the pattern of deficits varies with DCD severity. Fifty-one children with moderate DCD (MDCD), 24 children with severe DCD (SDCD), and 38 typically developing (TD) children participated in the study. Their performance was compared on the covert orienting of visuospatial attention task (COVAT), specifically the voluntary control mode. Results showed that the pattern of performance differed between groups. At a short stimulus-response asynchrony (350 ms), the difference in response times for validly and invalidly cued trials was similar for all three groups. However, at the longer SOA (800 ms), both DCD groups continued to show a relative disadvantage for responses that followed invalid cues. This suggests that a deficit in response inhibition and/or attentional disengagement is manifest in children with both moderate and severe DCD. The implications of these findings for theory and treatment are discussed.

Attentional orienting and awareness: Evidence from a discrimination task

We used several cue-target SOAs (100, 500, 1000 ms) and three different degrees of cue predictability (Non-predictive-50%, Predictive-75%, Counter-predictive-25%), to investigate the role of awareness of cue-target predictability on cueing effects. A group of participants received instructions about the informative value of the cue, while another group did not receive such instructions. Participants were able to extract the predictive value of a spatially peripheral cue and use it to orient attention, whether or not specific instructions about the predictive value of the cue were given, and no matter their ability to correctly report it in a post-test questionnaire. In the non-predictive block, bad estimators who received no instructions showed regular cueing effects, while good estimators exhibited smaller and non-significant facilitatory effects at the short SOA and an absence of significant IOR at longer SOAs. However, for the instructions group, the pattern of results reversed.

Is inefficient multisensory processing associated with falls in older people?

Although falling is a significant problem for older persons, little is understood about its underlying causes. Spatial cognition and balance maintenance rely on the efficient integration of information across the main senses. We investigated general multisensory efficiency in older persons with a history of falls compared to age- and sensory acuity-matched controls and younger adults using a sound-induced flash illusion. Older fallers were as susceptible to the illusion as age-matched, non-fallers or younger adults at a short delay of 70 ms between the auditory and visual stimuli. Both older adult groups were more susceptible to the illusion at longer SOAs than younger adults. However, with increasing delays between the visual and auditory stimuli, older fallers did not show a decline in the frequency at which the illusion was experienced even with delays of up to 270 ms. We argue that this relatively higher susceptibility to the illusion reflects inefficient audio-visual processing in the central nervous system and has important implications for the diagnosis and rehabilitation of falling in older persons.

Accessing Semantic Person Knowledge: Temporal Dynamics of Nonstrategic Categorical and Associative Priming

Recent theories of semantic memory suggest a subdivision into several separate domains of knowledge. The present study examined the structure of semantic person knowledge by analyzing both behavioral and ERP correlates of associative priming (via co-occurrence and/or shared semantic information) versus purely categorical priming (via shared occupational information). Participants performed familiarity decisions for target faces, which were preceded by sandwich-masked prime names at either short (33 msec) or long (1033 msec) SOAs. Although masking effectively prevented explicit prime recognition, faster RTs were generally observed for both associative and categorical priming (relative to an unrelated prime-target condition). At the short SOA, both associatively and categorically primed targets similarly elicited more positive going ERPs compared with unrelated targets in the N400 time range (N400 priming effect), suggesting a common initial mechanism mediating both forms of priming. By contrast, at the long SOA, a typical N400 priming effect was observed for associative priming only, whereas the corresponding effect for categorical priming was small and restricted to a left parietal site. This hitherto unreported interaction of relatedness, and SOA in the N400 suggests an initial fast spreading of activation to a wide range of related targets, which subsequently focuses to more closely related people at longer SOAs. This ability of ERPs to trace the neural dynamics of activation for different forms of prime/target relatedness can be exploited for testing different models of semantic priming.

Irrelevant onsets cause inhibition of return regardless of attentional set

It is disputed whether onsets capture spatial attention either in a purely stimulus-driven fashion or only when they are contingent on one's attentional set. According to the latter assumption, interference from irrelevant onsets may result from nonspatial filtering costs. In the present study, we used inhibition of return (IOR) as a marker for spatial attention. IOR occurs mainly for locations that attention has visited before. Participants searched for a red object among white objects. An attentional set for redness was demonstrated by a spatial validity effect of red cues on response times. However, a stronger validity effect was found for irrelevant white onsets, which slowed responses when the onset contained a distractor, but speeded them when the onset contained a target. Most importantly, this onset benefit for targets turned into a deficit at longer SOAs, indicating IOR. We conclude that onset distractors capture spatial attention regardless of the observer's attentional set.

Attentional bias toward cigarette cues in active smokers

While it is well documented that substance users exhibit attentional bias toward addiction-related stimuli, the exact mechanism remains unclear. To differentiate between distinct aspects of attentional allocation in the smoking-cue attentional bias observed in smokers. Active smokers (AS) and non-smoking controls completed spatial cueing tasks with pairs of smoking and neutral pictorial cues to measure attentional capture, and an attentional blink task with either a smoking or neutral image appearing behind the first target (T1) to measure aspects of attention separate from capture. In addition, we tested groups of sports enthusiasts, and non-enthusiasts in corresponding tasks replacing smoking images with sports-related images to address the possibility that effects found in the smoking study were due simply to greater stimulus familiarity. Smoking cues reflexively capture smokers' attention, as AS showed a greater bias toward smoking cues in short stimulus-onset asynchrony (SOA; the time between the onset of two stimuli) trials, but not in trials with a longer SOA. These effects represent a facilitation of responding to smoking- versus neutral-cued targets, and were absent in the sports control task. The attentional blink effects were similar in the smoking- and sports-cue experiments: the special T1 resulted in better detection of the second target for the smokers and sports enthusiasts. Stimulus familiarity may contribute to some aspects of attentional bias in regular nicotine users, but selective quick capture of attention by smoking cues may be nicotine-habit specific.

On the nature of privileged visual stimuli: Partial immunity from within-class inhibition

In four experiments we examine whether upright and inverted faces are processed by a single class of neurons with identical response properties, or by two separate and non-interacting populations. In Experiment 1, we examined upright and inverted faces across two contrast levels and one signal to noise ratio, yielding a crossover interaction of the N170 amplitude: when presented in noise, the amplitude of the inverted face was smaller than the upright face, while the reverse is true without noise. In Experiment 2, we showed that the amplitude reversal was robust for full but not partial faces across all noise levels. In Experiment 3, we varied contrast to see if reversal was a result of degrading a face. We observed no reversal effects. Thus, across conditions, adding noise to full faces was a necessary and sufficient condition for the N170 reversal. This is consistent with a model in which inhibition occurs between neurons processing noise and inverted faces, but not upright faces. In Experiment 4, we delayed onset of the upright/inverted face presented in noise. We replicated the smaller N170 for inverted faces at no delay, but observed recovery of the N170 for inverted faces at longer delays. These data support a model in which neurons responding to noise inhibit those responding to inverted faces, with inhibition waning to produce selective recovery at longer SOAs. Thus, two visual stimuli processed by the same population may result in a competition via inhibition for neural representation, which spares stimuli processed by separate populations.