Interstimulus Interval Conditions Research Articles

From spontaneous rhythmic engagement to joint drumming: A gradual development of flexible coordination at approximately 24 months of age.

Humans have a flexible and accurate ability to coordinate their movement in time with external rhythms. However, it remains unclear when and how, during their development, human children acquire the ability to adjust tempo and control the timing of their movement toward others. A previous study suggested that such self-regulation of coordination develops at around 18 and 30 months after birth. In this study, we investigated the performance of 24-month-old children and compared their data with those of 18- and 30-month-olds provided in our previous study. In the joint-drumming task, each child was enticed to drum under four conditions [partner: mother or robot; speed: 400 or 600 ms inter-stimulus-interval (ISI)]. The most pivotal test condition was the 600 ms ISI speed condition (slower than children’s spontaneous motor tempo in these age groups). We found that from the age of 24 months, children try to slow down their drumming tempo toward the 600 ms ISI speed condition, regardless of the drumming partner. On the other hand, significant timing control toward the onset of the 600 ms ISI condition was observed from the age of 30 months. This implies that both motor and cognitive mechanisms are required for flexible tempo adjustment and accurate synchronization and that these develop gradually among 18-, 24-, and 30-month-olds.

The subsequent interruptive effects of pain on attention.

Pain is known to interrupt attentional performance selectively. In a previous study, we showed that the interruptive effect of thermal pain on attention could persist up to 1500ms after painful stimulus offset, but whether the pain modality affects this subsequent interruptive effect remains unclear. The present study was conducted to determine the time course of the interruptive effect of electrically induced pain on orienting and executive attention using various intervals between electric stimulation and attentional tasks (0, 250, 500, 750, 1000, 1250 and 1500ms) and three study groups (pain, non-pain and control). We performed two separate experiments in which participants performed a spatial cue task (Experiment 1) and the Stroop task (Experiment 2). Participants in the pain and non-pain groups received brief electric somatosensory stimulation, and those in the control group received no physical stimulus. We compared the performance of the three groups under the interstimulus interval (ISI) conditions. The impairment of orienting attention prevailed under the first six ISI conditions in the pain and non-pain groups (F2, 63 =5.72, p<0.01); executive attention was not affected (F1,66 =1.64, p=0.20), confirming the persistence of the interruptive effect after stimulus offset. This study demonstrated the interruptive effect of somatic stimulation on subsequent orienting attention performance, with no effect on executive attention. These findings suggest that pain has differential effects on the components of attention, depending on its modality and salience. This study confirmed that pain had a selective subsequent interruptive effect on attention and found that the time course of the interruption depended on the modality of pain and the component of attention.

Registered Replication Report on Fischer, Castel, Dodd, and Pratt (2003)

The attentional spatial-numerical association of response codes (Att-SNARC) effect (Fischer, Castel, Dodd, &amp; Pratt, 2003)—the finding that participants are quicker to detect left-side targets when the targets are preceded by small numbers and quicker to detect right-side targets when they are preceded by large numbers—has been used as evidence for embodied number representations and to support strong claims about the link between number and space (e.g., a mental number line). We attempted to replicate Experiment 2 of Fischer et al. by collecting data from 1,105 participants at 17 labs. Across all 1,105 participants and four interstimulus-interval conditions, the proportion of times the effect we observed was positive (i.e., directionally consistent with the original effect) was .50. Further, the effects we observed both within and across labs were minuscule and incompatible with those observed by Fischer et al. Given this, we conclude that we failed to replicate the effect reported by Fischer et al. In addition, our analysis of several participant-level moderators (finger-counting habits, reading and writing direction, handedness, and mathematics fluency and mathematics anxiety) revealed no substantial moderating effects. Our results indicate that the Att-SNARC effect cannot be used as evidence to support strong claims about the link between number and space.

Processing of Paired Click-Tone Stimulation in the Mice Inferior Colliculus.

The inferior colliculus (IC) is known as a neuronal structure involved in the integration of acoustic information in the ascending auditory pathway. However, the processing of paired acoustic stimuli containing different sound types, especially when they are applied closely, in the IC remains poorly studied. We here firstly investigated the IC neuronal response to the paired stimuli comprising click and pure tone with different inter-stimulus (click-tone) intervals using in vivo loose-patch recordings in anesthetized BALB/c mice. It was found that the total acoustic evoked spike counts decreased under certain click-tone interval conditions on some neurons with or without click-induced supra-threshold responses. Application of click could enhance the minimum threshold of the neurons responding to the tone in a pair without changing other characteristics of the neuronal tone receptive fields. We further studied the paired acoustic stimuli evoked excitatory/inhibitory inputs, IC neurons received, by holding the membrane potential at -70/0 mV using in vivo whole-cell voltage-clamp techniques. The curvature and peak amplitude of the excitatory/inhibitory post-synaptic current (EPSC/IPSC) could be almost unchanged under different inter-stimulus interval conditions. Instead of showing the summation of synaptic inputs, most recorded neurons only had the EPSC/IPSC with the amplitude similar as the bigger one evoked by click or tone in a pair when the inter-stimulus interval was small. We speculated that the IC could inherit the paired click-tone information which had been integrated before reaching it.

Effects of Inter-Stimulus Interval on Speech-Evoked Frequency-Following Response in Elderly Adults.

Background: The speech-evoked frequency following response (FFR) has shown to be useful in assessing complex auditory processing abilities and in different age groups. While many aspects of FFR have been studied extensively, the effect of timing, as measured by inter-stimulus-interval (ISI), especially in the older adult population, has yet to be thoroughly investigated.Objective: The purpose of this study was to examine the effects of different ISIs on speech evoked FFR in older and younger adults who speak a tonal language, and to investigate whether the older adults’ FFR were more susceptible to the change in ISI.Materials and Methods: Twenty-two normal hearing participants were recruited in our study, including 11 young adult participants and 11 elderly participants. An Intelligent Hearing Systems Smart EP evoke potential system was used to record the FFR in four ISI conditions (40, 80, 120 and 160 ms). A recorded natural speech token with a falling tone /yi/ was used as the stimulus. Two indices, stimulus-to-response correlation coefficient and pitch strength, were used to quantify the FFR responses. Two-way analysis of variance (ANOVA) was used to analyze the differences in different age groups and different ISI conditions.Results: There was no significant difference in stimulus-to-response correlation coefficient and pitch strength among the different ISI conditions, in either age groups. Older adults appeared to have weaker FFR for all ISI conditions when compared to their younger adult counterparts.Conclusion: Shorter ISIs did not result in worse FFRs from older adults or younger adults. For speech-evoked FFR using a recorded natural speech token that is 250 ms in length, an ISI of as short as 40 ms appeared to be sufficient and effective to record FFR for elderly adults.

Modulation of auditory sensory memory by chronic clinical pain and acute experimental pain: a mismatch negativity study

Pain, especially chronic pain, can lead to cognitive deficits. Mismatch negativity (MMN) is a change-specific component of the auditory event-related brain potential (ERP) that is thought to provide a unique window into sensory memory processes. The present study was designed to determine how chronic and acute pain affects auditory sensory memory. In experiment 1, MMNs elicited by standard and deviant auditory stimuli at short and long inter-stimulus intervals (ISIs) were compared between trigeminal neuralgia (TN) patients and demographically matched healthy controls (HCs). The TN patients were found to have stronger attenuation of the MMN at longer ISIs than HCs. Correlation analysis revealed a significant positive correlation between the sensory subscale of McGill Pain Questionnaire and MMN amplitude reduction across ISI conditions. In experiment 2, MMNs recorded before, during, and after the cold pressor test were compared in healthy subjects. MMN amplitude was significantly reduced during pain exposure and recovered immediately thereafter. These results suggest that both chronic pain and acute pain can interfere with automatic change detection processes in the brain. This study provides the first evidence that chronic pain patients have a faster auditory memory trace decay than HCs.

Training-Induced Changes in Rapid Auditory Processing in Children With Specific Language Impairment: Electrophysiological Indicators.

The brain’s ability to recognize acoustic changes occurring in rapid temporal succession is important for speech and successful language development. Children with specific language impairment (SLI) are characterized by deficient dynamics of temporal information processing (TIP) in the millisecond time range accompanied by disordered language development. Furthermore, previous studies have found that intervention based on amelioration of TIP resulted in improvement of both language and other cognitive functions. This study aimed to explain the changes associated with TIP training from the perspective of event-related potentials (ERPs). Thirty-six children aged 5–8 years (26 boys, 10 girls) diagnosed with SLI underwent two types of intense audio-visual computer intervention: experimental TIP training targeted at the millisecond time range (n = 18) or control non-TIP training (n = 18). Paired 50 ms tones of 1000 Hz and 1200 Hz were presented with inter-stimulus intervals (ISIs) of either 50 ms (Short ISI Condition) or 200 ms (Long ISI Condition). Auditory ERPs were measured in a passive oddball paradigm before and after each type of training. The mismatch negativity (MMN) paradigm was applied as an electrophysiological indicator of the brain’s ability to automatically detect violations of regularity in paired tones presented in rapid succession. Moreover, the P3a component was also analyzed. After 24 sessions of temporal training (in the experimental group) MMN amplitude enhancement was observed in both ISI conditions, reflecting increased efficiency in perceiving changes in rapid auditory sequences. In both experimental and control groups, P3a amplitude was enhanced in both ISIs. This may be due to the improvement of involuntary attention shifting to the auditory events involved in each training type. To conclude, temporal training, compared to non-temporal control training, improved the ability to detect changes in a rapid auditory stream in children with SLI.

The Duration of Auditory Sensory Memory for Vowel Processing: Neurophysiological and Behavioral Measures.

Speech perception behavioral research suggests that rates of sensory memory decay are dependent on stimulus properties at more than one level (e.g., acoustic level, phonemic level). The neurophysiology of sensory memory decay rate has rarely been examined in the context of speech processing. In a lexical tone study, we showed that long-term memory representation of lexical tone slows the decay rate of sensory memory for these tones. Here, we tested the hypothesis that long-term memory representation of vowels slows the rate of auditory sensory memory decay in a similar way to that of lexical tone. Event-related potential (ERP) responses were recorded to Mandarin non-words contrasting the vowels /i/ vs. /u/ and /y/ vs. /u/ from first-language (L1) Mandarin and L1 American English participants under short and long interstimulus interval (ISI) conditions (short ISI: an average of 575 ms, long ISI: an average of 2675 ms). Results revealed poorer discrimination of the vowel contrasts for English listeners than Mandarin listeners, but with different patterns for behavioral perception and neural discrimination. As predicted, English listeners showed the poorest discrimination and identification for the vowel contrast /y/ vs. /u/, and poorer performance in the long ISI condition. In contrast to Yu et al. (2017), however, we found no effect of ISI reflected in the neural responses, specifically the mismatch negativity (MMN), P3a and late negativity ERP amplitudes. We did see a language group effect, with Mandarin listeners generally showing larger MMN and English listeners showing larger P3a. The behavioral results revealed that native language experience plays a role in echoic sensory memory trace maintenance, but the failure to find an effect of ISI on the ERP results suggests that vowel and lexical tone memory traces decay at different rates.Highlights:We examined the interaction between auditory sensory memory decay and language experience.We compared MMN, P3a, LN and behavioral responses in short vs. long interstimulus intervals.We found that different from lexical tone contrast, MMN, P3a, and LN changes to vowel contrasts are not influenced by lengthening the ISI to 2.6 s.We also found that the English listeners discriminated the non-native vowel contrast with lower accuracy under the long ISI condition.

Evaluating the feasibility of the steady-state visual evoked potential (SSVEP) to study temporal attention.

Improvements in perceptual performance can be obtained when events in the environment are temporally predictable-and temporal predictability improves attention and sensory processing. The amplitude of the steady-state visual evoked potential (SSVEP) has been shown to correlate with attention paid to a flickering stimulus even if the flickering stimulus is irrelevant for the task. However, to our knowledge, the validity of the SSVEP to study temporal attention has not been established. Therefore, we designed an SSVEP temporal attention task to evaluate whether the SSVEP and its temporal dynamics can be used to study temporal attention. We used a forced-choice perceptual detection task while presenting task-irrelevant visual flicker at alpha (10 Hz) and two surrounding frequencies (6 or 15 Hz). Temporal predictability was manipulated by having the interstimulus intervals (ISI) be constant or variable. Behavioral results replicated previous studies confirming the benefits of temporal expectations on performance for trials with constant ISI. EEG analyses revealed robust SSVEP amplitudes for all flicker frequencies, although a main effect of temporal expectations on SSVEP amplitude was not significant. Additional analyses revealed temporal predictability-related modulations of SSVEP amplitude at 10 Hz and its second harmonic (20 Hz). The effect of temporal predictability was also observed for the 6 Hz flicker, but not for 15 Hz for any ISI condition. These results provide some evidence for the feasibility of the SSVEP technique to study temporal attention for stimuli with flicker frequencies around the alpha band.

The Orienting Response in Healthy Aging: Novelty P3 Indicates No General Decline but Reduced Efficacy for Fast Stimulation Rates.

Automatic orienting to unexpected changes in the environment is a pre-requisite for adaptive behavior. One prominent mechanism of automatic attentional control is the Orienting Response (OR). Despite the fundamental significance of the OR in everyday life, only little is known about how the OR is affected by healthy aging. We tested this question in two age groups (19–38 and 55–72 years) and measured skin-conductance responses (SCRs) and event-related brain potentials (ERPs) to novels (i.e., short environmental sounds presented only once in the experiment; 10% of the trials) compared to standard sounds (600 Hz sinusoidal tones with 200 ms duration; 90% of the trials). Novel and standard stimuli were presented in four conditions differing in the inter-stimulus interval (ISI) with a mean ISI of either 10, 3, 1, or 0.5 s (blocked presentation). In both age groups, pronounced SCRs were elicited by novels in the 10 s ISI condition, suggesting the elicitation of stable ORs. These effects were accompanied by pronounced N1 and frontal P3 amplitudes in the ERP, suggesting that automatic novelty processing and orientation of attention are effective in both age groups. Furthermore, the SCR and ERP effects declined with decreasing ISI length. In addition, differences between the two groups were observable with the fastest presentation rates (i.e., 1 and 0.5 s ISI length). The most prominent difference was a shift of the peak of the frontal positivity from around 300 to 200 ms in the 19–38 years group while in the 55–72 years group the amplitude of the frontal P3 decreased linearly with decreasing ISI length. Taken together, this pattern of results does not suggest a general decline in processing efficacy with healthy aging. At least with very rare changes (here, the novels in the 10 s ISI condition) the OR is as effective in healthy older adults as in younger adults. With faster presentation rates, however, the efficacy of the OR decreases. This seems to result in a switch from novelty to deviant processing in younger adults, but less so in the group of older adults.

Neurophysiological and Behavioral Responses of Mandarin Lexical Tone Processing.

Language experience enhances discrimination of speech contrasts at a behavioral- perceptual level, as well as at a pre-attentive level, as indexed by event-related potential (ERP) mismatch negativity (MMN) responses. The enhanced sensitivity could be the result of changes in acoustic resolution and/or long-term memory representations of the relevant information in the auditory cortex. To examine these possibilities, we used a short (ca. 600 ms) vs. long (ca. 2,600 ms) interstimulus interval (ISI) in a passive, oddball discrimination task while obtaining ERPs. These ISI differences were used to test whether cross-linguistic differences in processing Mandarin lexical tone are a function of differences in acoustic resolution and/or differences in long-term memory representations. Bisyllabic nonword tokens that differed in lexical tone categories were presented using a passive listening multiple oddball paradigm. Behavioral discrimination and identification data were also collected. The ERP results revealed robust MMNs to both easy and difficult lexical tone differences for both groups at short ISIs. At long ISIs, there was either no change or an enhanced MMN amplitude for the Mandarin group, but reduced MMN amplitude for the English group. In addition, the Mandarin listeners showed a larger late negativity (LN) discriminative response than the English listeners for lexical tone contrasts in the long ISI condition. Mandarin speakers outperformed English speakers in the behavioral tasks, especially under the long ISI conditions with the more similar lexical tone pair. These results suggest that the acoustic correlates of lexical tone are fairly robust and easily discriminated at short ISIs, when the auditory sensory memory trace is strong. At longer ISIs beyond 2.5 s language-specific experience is necessary for robust discrimination.

The inter-stimulus interval critical value in backward masking testing

Backward masking (BM) has been studied both as a psychoacoustic phenomenon and as a potential diagnostic indicator of auditory processing difficulty. In BM assessment, the subject responds to a brief tonal signal followed by an inter-stimulus interval (ISI) of silence and then by a noise masker. In all previous studies, an adaptive auditory threshold is obtained at each ISI. This study used unique instrumentation that allowed the adaptive ISI to maintain threshold. Twelve subjects were utilized. All had normal hearing with an age range of 18–30 years. The critical ISI was varied with an adaptive procedure in 2 ms steps. The critical ISI value was obtained for stimulus intensity levels above the tonal threshold found in a longer ISI condition. This procedure allowed less fatigue and provided an easier task for the subject compared to the tonal intensity tracking task.

A spatiotemporal signature of cortical pain relief by tactile stimulation: An MEG study

Recently, the cortical mechanisms of tactile-induced analgesia have been investigated; however, spatiotemporal characteristics have not been fully elucidated. The insular–opercular region integrates multiple sensory inputs, and nociceptive modulation by other sensory inputs occurs in this area. In this study, we focused on the insular–opercular region to characterize the spatiotemporal signature of tactile-induced analgesia using magnetoencephalography in 11 healthy subjects. Aδ (intra-epidermal electrical stimulation) inputs were modified by Aβ (mechanical tactile stimulation) selective stimulation, either independently or concurrently, to the right forearm. The optimal inter-stimulus interval (ISI) for cortical level modulation was determined after comparing the 40-, 60-, and 80-ms ISI conditions, and the calculated cortical arrival time difference between Aδ and Aβ inputs. Subsequently, we adopted a 60-ms ISI for cortical modulation and a 0-ms ISI for spinal level modulation. Source localization using minimum norm estimates demonstrated that pain-related activity was located in the posterior insula, whereas tactile-related activity was estimated in the parietal operculum. We also found significant inhibition of pain-related activity in the posterior insula due to cortical modulation. In contrast, spinal modulation was observed both in the posterior insula and parietal operculum. Subjective pain, as evaluated by the visual analog scale, also showed significant reduction in both conditions. Therefore, our results demonstrated that the multisensory integration within the posterior insula plays a key role in tactile-induced analgesia.

Effects of stimulus order on discrimination sensitivity for short and long durations.

Previous studies have shown that discrimination sensitivity in 2AFC tasks depends on the presentation order of the standard and comparison stimulus. The present study examined whether this so-called Type B effect generalizes across different standard magnitudes. Therefore, Experiment 1 employed an auditory duration discrimination task with short (100 ms) and long (1,000 ms) standard durations and a constant interstimulus interval (ISI) of 1,000 ms. For both standard durations, a clear Type B effect emerged. In Experiment 2, discrimination sensitivity was assessed for short (300 ms) and long (1,000 ms) ISIs and a constant standard duration of 100 ms, in order to examine whether the Type B effect diminishes or even reverses when both stimuli are presented in rapid succession, as was suggested by previous studies. In the short, but not the long ISI condition, the Type B effect was virtually eliminated. Taken together, the present experiments suggest that the Type B effect is robust across standard magnitude, but diminishes when the time interval between both stimuli is reduced. This result pattern is discussed within the framework of the Internal Reference Model and the Sensation Weighting Model. It is also demonstrated that both models provide a quantitative account of the present results.

Neural adaptation of visual ERP components: Effects of adaptor stimulus duration and interstimulus interval

Event Abstract Back to Event Neural adaptation of visual ERP components: Effects of adaptor stimulus duration and interstimulus interval Daniel Feuerriegel1*, Owen Churches2, Mark Kohler1 and Hannah Keage1 1 University of South Australia, Cognitive Neuroscience Laboratory, Australia 2 Flinders University, Brain and Cognition Laboratory, Australia Neural adaptation paradigms inform us of how our perceptual system dynamically changes in response to our environment. Systematically testing experimental variables that affect adaptation can further develop neural models of visual processing over time. The degree of neural response to a stimulus (S2) is affected by the presentation duration of the previous/adaptor stimulus (S1) and the interstimulus interval (ISI) duration, however there appears to be no systematic examination of the effects and interaction of these factors in ERP research. We systematically varied both S1 duration and ISI and assessed effects on the P1, N170 and P2 ERP components in face and object perception. Greyscale images of faces and chairs were presented at S1 and S2 level while EEG was recorded. In each trial an S1 stimulus was presented, followed by an ISI and an S2 stimulus. S1 stimuli were presented for 200ms, 500ms or 1000ms. The ISI was set at 200ms or 500ms. Peak amplitude measures were derived from ERPs to S2 stimuli in each condition. ISI affected all ERP component amplitudes, and S1 duration affected the N170 and P2 only. P1 and P2 components were smaller in the 200ms than 500ms ISI conditions, whereas the N170 was larger after 200ms ISIs. No effects of S1 duration were observed for the P1, however N170 and P2 amplitudes were smaller for longer S1 durations, particularly after shorter (200ms) ISIs. Effects of S1 duration on the N170 were specific to repetitions of the same stimuli category. The overall results demonstrate that effects of S1 duration and ISI are not consistent across ERP components, suggesting differential modulation of low and high-level vision over time. These results do not support a singular mechanism of adaptation across visual areas, but rather a complex pattern of neural activity modulations with continued processing of a visual stimulus. Keywords: face perception, Event-related potentials, P1, N170, P2, Neural adaptation Conference: XII International Conference on Cognitive Neuroscience (ICON-XII), Brisbane, Queensland, Australia, 27 Jul - 31 Jul, 2014. Presentation Type: Poster Topic: Sensation and Perception Citation: Feuerriegel D, Churches O, Kohler M and Keage H (2015). Neural adaptation of visual ERP components: Effects of adaptor stimulus duration and interstimulus interval. Conference Abstract: XII International Conference on Cognitive Neuroscience (ICON-XII). doi: 10.3389/conf.fnhum.2015.217.00150 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 19 Feb 2015; Published Online: 24 Apr 2015. * Correspondence: Mr. Daniel Feuerriegel, University of South Australia, Cognitive Neuroscience Laboratory, Adelaide, Australia, Daniel.feuerriegel@unisa.edu.au Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Daniel Feuerriegel Owen Churches Mark Kohler Hannah Keage Google Daniel Feuerriegel Owen Churches Mark Kohler Hannah Keage Google Scholar Daniel Feuerriegel Owen Churches Mark Kohler Hannah Keage PubMed Daniel Feuerriegel Owen Churches Mark Kohler Hannah Keage Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Pattern dot quantity affects auditory facilitation effects on visual object representations.

Auditory stimuli often facilitate visual perception. Audiovisual integration requires spatial and/or temporal proximity between visual and auditory stimuli; additionally, sensory processing speed affects the audiovisual integration process. In the present study we examined the relationship between processing speed and the auditory facilitation effect on visual representations by manipulating dot quantity patterns. We hypothesized that the auditory facilitation effect would be observed in longer interstimulus interval conditions with more dot quantities. This is because more processing time would be required to integrate visual and auditory stimuli. During a backward masking paradigm used in experiment 1, the auditory facilitation effect depended on dot quantity among patterns and the interval between visual stimuli and masks. Moreover, differences in processing time required to integrate visual and auditory stimuli between dot quantities was confirmed from a same-different discrimination task in experiment 2. Therefore, dot quantity affects sensory processing time, and a longer processing time is required for integrating visual and auditory stimuli when visual dot quantity is high.

Modulating younger and older adults’ performance in ignoring pictorial information during a word matching task

Using both behavioural and event-related potential (ERP) data, the current study sought to examine the neurophysiological underpinnings for the effect of distracting pictorial information on semantic word matching performance in younger and older adults. This was tested in the context of semantic relations between task-relevant word pairs, a task-irrelevant picture and the resultant N400 differences in ERP. Younger and older adults were shown a context word superimposed on a to-be-ignored picture, followed by a test word. Their task was to determine whether the prime and test words were semantically related. The to-be-ignored pictures were interfering (for ‘No’ trials), facilitating (for ‘Yes’ trials), or neutral (for both ‘Yes’ and ‘No’ trials) to the expected responses. The interfering and facilitatory effects of to-be-ignored pictures were assessed under more automatic and more controlled conditions by manipulating the context–test interstimulus-interval (ISI) as 50ms and 1000ms, respectively. The analysis of the N400 at centro-parietal sites during test word display revealed similar N400 amplitudes for the ‘No’ response trials at the two ISIs, suggesting that younger and older adults showed an equivalent effect from interfering pictures. In contrast, younger adults showed greater reductions in the N400, as compared to older adults, for ‘Yes’ trials indicating differential effects in facilitation from to-be-ignored pictorial information, but only in the long ISI condition. The data are discussed in terms of age differences in resource demanding strategy use during a semantic word matching task, specifically during controlled retrieval.

Adaptation of the N170: Effects of stimulus category, presentation time and interstimulus interval

Event Abstract Back to Event Adaptation of the N170: Effects of stimulus category, presentation time and interstimulus interval Daniel C. Feuerriegel1*, Owen Churches2, Mark J. Kohler1 and Hannah A. Keage1 1 University of South Australia, School of Psychology, Social Work and Social Policy, Australia 2 Flinders University, School of Psychology, Australia Background Event-related potential neural adaptation studies of the N170 in face and object perception have been used to delineate the time course of neural processes in high-level vision. However, study designs have varied widely in regards to the duration of the adaptor stimulus and the interstimulus interval (ISI). If adaptor duration and ISI influence the extent of neural adaptation then these variables may explain discrepancies between past studies. We measured ERPs to faces and chairs (representing nonface objects) over different adaptor duration and ISI conditions to assess the independent and combined effects of these on the extent of neural adaptation. We also tested whether these adaptation effects were stimulus specific or reflected a general property of repeated high-level object processing. Methods A Double Pulse paradigm was used. In each an adaptor stimulus was followed by an interstimulus interval and then a test stimulus. Adaptor stimuli were presented for 200ms, 500ms or 1000ms and the ISI was set at 200ms or 500ms. Greyscale images of face and chair stimuli were presented at the adaptor and test level. Neural responses to stimuli were recorded using 64-channel EEG. N170 peak amplitude and peak latency measures were derived from responses to adaptor and test stimuli in each condition. Results Test stimulus evoked N170s were smaller (more positive) following longer adaptor stimulus durations and longer (500ms) ISIs. Face and chair test N170 amplitudes differed by adaptor duration only when adapted by the same stimulus, although this sensitivity was found in faces but not chairs when the ISI was 500ms. N170 peak latencies were slower with longer adaptor durations and shorter ISIs. N170 peak latency differences between test faces and chairs were only found with face adaptor stimuli, and only in 200ms ISI conditions and when the adaptor duration was 1000ms in the 500ms ISI condition. Discussion Findings indicate that N170 peak amplitude and peak latency are differently affected by adaptor duration and ISI. These results appear to be category selective; that is that face and chair adaptors have different adapting effects on face and chair test stimuli. Keywords: Neural adaptation, N170, face perception, repetition suppression, object perception, ERPs (Event-Related Potentials) Conference: ACNS-2013 Australasian Cognitive Neuroscience Society Conference, Clayton, Melbourne, Australia, 28 Nov - 1 Dec, 2013. Presentation Type: Poster Topic: Sensation and Perception Citation: Feuerriegel DC, Churches O, Kohler MJ and Keage HA (2013). Adaptation of the N170: Effects of stimulus category, presentation time and interstimulus interval. Conference Abstract: ACNS-2013 Australasian Cognitive Neuroscience Society Conference. doi: 10.3389/conf.fnhum.2013.212.00064 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 15 Oct 2013; Published Online: 25 Nov 2013. * Correspondence: Mr. Daniel C Feuerriegel, University of South Australia, School of Psychology, Social Work and Social Policy, Adelaide, South Australia, Australia, dfeuerriegel@unimelb.edu.au Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Daniel C Feuerriegel Owen Churches Mark J Kohler Hannah A Keage Google Daniel C Feuerriegel Owen Churches Mark J Kohler Hannah A Keage Google Scholar Daniel C Feuerriegel Owen Churches Mark J Kohler Hannah A Keage PubMed Daniel C Feuerriegel Owen Churches Mark J Kohler Hannah A Keage Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Masked Priming Effects in Aphasia: Evidence of Altered Automatic Spreading Activation

Previous research has suggested that impairments of automatic spreading activation may underlie some aphasic language deficits. The current study further investigated the status of automatic spreading activation in individuals with aphasia as compared with typical adults. Participants were 21 individuals with aphasia (12 fluent, 9 nonfluent) and 31 typical adults. Reaction time data were collected on a lexical decision task with masked repetition primes, assessed at 11 different interstimulus intervals (ISIs). Masked primes were used to assess automatic spreading activation without the confound of conscious processing. The various ISIs were used to assess the time to onset and duration of priming effects. The control group showed maximal priming in the 200-ms ISI condition, with significant priming at a range of ISIs surrounding that peak. Participants with both fluent and nonfluent aphasia showed maximal priming effects in the 250-ms ISI condition and primed across a smaller range of ISIs than did the control group. Results suggest that individuals with aphasia have slowed automatic spreading activation and impaired maintenance of activation over time, regardless of fluency classification. These findings have implications for understanding aphasic language impairment and for development of aphasia treatments designed to directly address automatic language processes.

Visual Backward Masking Performance in Young Adult Emmetropes and Myopes

To investigate how temporal processing is altered in myopia and during myopic progression. In backward visual masking, a target's visibility is reduced by a mask presented quickly after the target. Thirty emmetropes, 40 low myopes, and 22 high myopes aged 18 to 26 years completed location and resolution masking tasks. The location task examined the ability to detect letters with low contrast and large stimulus size. The resolution task involved identifying a small letter and tested resolution and color discrimination. Target and mask stimuli were presented at nine short interstimulus intervals (12 to 259 ms) and at 1000 ms (long interstimulus interval condition). In comparison with emmetropes, myopes had reduced ability in both locating and identifying briefly presented stimuli but were more affected by backward masking for a low contrast location task than for a resolution task. Performances of low and high myopes, as well as stable and progressing myopes, were similar for both masking tasks. Task performance was not correlated with myopia magnitude. Myopes were more affected than emmetropes by masking stimuli for the location task. This was not affected by magnitude or progression rate of myopia, suggesting that myopes have the propensity for poor performance in locating briefly presented low contrast objects at an early stage of myopia development.