Differences In Temporal Structure Research Articles

Temporal Structure in Sensorimotor Variability: A Stable Trait, But What For?

Human performance shows substantial endogenous variability over time, and this variability is a robust marker of individual differences. Of growing interest to psychologists is the realisation that variability is not fully random, but often exhibits temporal dependencies. However, their measurement and interpretation come with several controversies. Furthermore, their potential benefit for studying individual differences in healthy and clinical populations remains unclear. Here, we gather new and archival datasets featuring 11 sensorimotor and cognitive tasks across 526 participants, to examine individual differences in temporal structures. We first investigate intra-individual repeatability of the most common measures of temporal structures — to test their potential for capturing stable individual differences. Secondly, we examine inter-individual differences in these measures using: (1) task performance assessed from the same data, (2) meta-cognitive ratings of on-taskness from thought probes occasionally presented throughout the task, and (3) self-assessed attention-deficit related traits. Across all datasets, autocorrelation at lag 1 and Power Spectra Density slope showed high intra-individual repeatability across sessions and correlated with task performance. The Detrended Fluctuation Analysis slope showed the same pattern, but less reliably. The long-term component (d) of the ARFIMA(1,d,1) model showed poor repeatability and no correlation to performance. Overall, these measures failed to show external validity when correlated with either mean subjective attentional state or self-assessed traits between participants. Thus, some measures of serial dependencies may be stable individual traits, but their usefulness in capturing individual differences in other constructs typically associated with variability in performance seems limited. We conclude with comprehensive recommendations for researchers.

The strategy–identity nexus: The relevance of their temporal interplay to climate change

Grand Challenges have stimulated a search for new solutions at the interplay between fields and disciplines which previously have been separated. In this essay, I argue that a further development of temporal interplay between strategy and organizational identity may enrich studies of Grand Challenges, exemplified by how actors respond to climate change. This interplay is motivated by recent elaborations of the differences in temporality between strategy and organizational identity from a distinction between a dominant focus on the future (strategy) or the past (organizational identity) to a conceptualization of the differences in temporal structures between them. Using management research to contribute to the fight against climate change, sustained temporal interplay between strategy and organizational identity can advance our understanding of how organizations may act now for future climate goals. I suggest questions for future research focused on making an impact.

Neural Response Selectivity to Natural Sounds in the Bat Midbrain

Little is known about the neural mechanisms that mediate differential action–selection responses to communication and echolocation calls in bats. For example, in the big brown bat, frequency modulated (FM) food-claiming communication calls closely resemble FM echolocation calls, which guide social and orienting behaviors, respectively. Using advanced signal processing methods, we identified fine differences in temporal structure of these natural sounds that appear key to auditory discrimination and behavioral decisions. We recorded extracellular potentials from single neurons in the midbrain inferior colliculus (IC) of passively listening animals, and compared responses to playbacks of acoustic signals used by bats for social communication and echolocation. We combined information obtained from spike number and spike triggered averages (STA) to reveal a robust classification of neuron selectivity for communication or echolocation calls. These data highlight the importance of temporal acoustic structure for differentiating echolocation and food-claiming social calls and point to general mechanisms of natural sound processing across species.

Temporal interplay between strategy and identity: Punctuated, subsumed, and sustained modes

Although strategy and identity are recognized as exhibiting different temporalities, research has yet to show how their temporal differences influence their mutual interplay. Based on a longitudinal case study, we make three contributions to understanding how temporal differences influence the interplay between strategy and identity. First, we articulate their temporal differences as differences in temporal structures, defined as the ordering of their past and future time horizons and the temporal depth between those horizons. Second, we show how different combinations of temporal structures lead to different modes of interplay, which we label “punctuated,” “subsumed,” and “sustained.” Third, we show how sustained interplay happens when strategy includes multiple horizons and greater temporal depth, while identity has more defined horizons and a temporal depth spanning the distant past and future. In a sustained mode of interplay, strategy is meaningfully framed by identity, while strategy serves to enact identity. These findings, we argue, have major implications for how organizations can comply with short-term business cycles while addressing long-term concerns.

Temporal variability in sung productions of adolescents who stutter

Singing has long been used as a technique to enhance and reeducate temporal aspects of articulation in speech disorders. In the present study, differences in temporal structure of sung versus spoken speech were investigated in stuttering. In particular, the question was examined if singing helps to reduce VOT variability of voiceless plosives, which would indicate enhanced temporal coordination of oral and laryngeal processes. Eight German adolescents who stutter and eight typically fluent peers repeatedly spoke and sang a simple German congratulation formula in which a disyllabic target word (e.g., /’ki:ta/) was repeated five times. Every trial, the first syllable of the word was varied starting equally often with one of the three voiceless German stops /p/, /t/, /k/. Acoustic analyses showed that mean VOT and stop gap duration reduced during singing compared to speaking while mean vowel and utterance duration was prolonged in singing in both groups. Importantly, adolescents who stutter significantly reduced VOT variability (measured as the Coefficient of Variation) during sung productions compared to speaking in word-initial stressed positions while the control group showed a slight increase in VOT variability. However, in unstressed syllables, VOT variability increased in both adolescents who do and do not stutter from speech to song. In addition, vowel and utterance durational variability decreased in both groups, yet, adolescents who stutter were still more variable in utterance duration independent of the form of vocalization. These findings shed new light on how singing alters temporal structure and in particular, the coordination of laryngeal-oral timing in stuttering. Future perspectives for investigating how rhythmic aspects could aid the management of fluent speech in stuttering are discussed. Learning outcomesReaders will be able to describe (1) current perspectives on singing and its effects on articulation and fluency in stuttering and (2) acoustic parameters such as VOT variability which indicate the efficiency of control and coordination of laryngeal-oral movements. They will understand and be able to discuss (3) how singing reduces temporal variability in the productions of adolescents who do and do not stutter and 4) how this is linked to altered articulatory patterns in singing as well as to its rhythmic structure.

Auditory temporal pattern learning by songbirds using maximal stimulus diversity and minimal repetition

The sequential patterning of complex acoustic elements is a salient feature of bird song and other forms of vocal communication. For European starlings (Sturnus vulgaris), a songbird species, individual vocal recognition is improved when the temporal organization of song components (called motifs) follows the normal patterns of each singer. This sensitivity to natural motif sequences may underlie observations that starlings can also learn more complex, unnatural motif patterns. Alternatively, it has been proposed that the apparent acquisition of abstract motif patterning rules instead reflects idiosyncrasies of the training conditions used in prior experiments. That is, that motif patterns are learned not by recognizing differences in temporal structures between patterns, but by identifying serendipitous features (e.g., acoustical cues) in the small sets of training and testing stimuli used. Here, we investigate this possibility, by asking whether starlings can learn to discriminate between two arbitrary motif patterns, when unique examples of each pattern are presented on every trial. Our results demonstrate that abstract motif patterning rules can be acquired from trial-unique stimuli and suggest that such training leads to better pattern generalization compared with training with much smaller stimulus subsets.

Selective encoding of conspecific signals in a noisy habitat

Event Abstract Back to Event Selective encoding of conspecific signals in a noisy habitat Manfred Hartbauer1*, Marian E. Siegert1 and Heiner Römer1 1 Karl-Franzens University Graz, Zoology, Austria In a habitat with multiple sound-producing species, such like the nocturnal tropical rainforest, conspecific signals sometimes overlap in the time and frequency domain with heterospecific signals, which challenges the detection of relevant signals and their discrimination from irrelevant noise by receivers. We studied this problem in two tropical katydid species of the genus Mecopoda where males of one species produce chirps in regular intervals of 2 s (species “S” named after Sismondo 1990), whereas the other produces long-lasting continuous trills with a rather similar frequency spectrum (3-95 kHz). We investigated the neuronal basis of detecting conspecific signals in the chirping species during simultaneous playbacks of either natural nocturnal habitat noise or varying levels of the calling song of the trilling species. We monitored the activity of TN-1, an afferent auditory interneuron known for its reliable chirp responses from previous studies [1]. Conspecific chirps are reliably represented as bursts of AP´s in this neuron even at a signal-to-noise-ratio of 0 dB (background noise or the trilling song broadcast at the same amplitude as the chirp, 65 dB SPL). Although TN-1 responses gradually declined with increasing levels of the song of the trilling species, TN-1 still discharged with 2 APs/chirp at a S/N ratio of -5 dB. Interestingly, rainforest background noise or the song of the trilling species alone hardly ever elicited a response, except after stimulus onset. Modifying either the frequency content of the chirp or the species-specific temporal pattern in the amplitude modulation of the syllable sequence within the chirp resulted in a reduced TN-1 response during simultaneous playback of the trilling song. Therefore, the selective response of TN-1 to conspecific signals appears to depend on differences in temporal structure and frequency content of conspecific signals and natural maskers. Acknowledgements Research was funded by the Austrian Science Fund (FWF): P21808-B09.

Differential sensitivity of different sensory cortices to behaviorally relevant timing differences

Event Abstract Back to Event Differential sensitivity of different sensory cortices to behaviorally relevant timing differences Yang Yang1 and Anthony Zador1* 1 Cold Spring Harbor Laboratory, United States Animals can detect the fine timing of some stimuli. For example, in subcortical structures, submillisecond interaural time differences are computed to determine the spatial localization of sound. Although cortical neurons have not been shown to achieve comparable submillisecond precision, neurons in auditory, visual and barrel cortex can lock with millisecond precision to the fine timing of some stimuli. However, the ability of these cortical neurons to fire precisely does not demonstrate such fine timing is behaviorally relevant. To bridge the gap between physiology and behavior, we have previously used electrical microstimulation to determine the temporal precision with which fine differences in cortical spike timing could be used to drive decisions. We found that in rat auditory cortex, animals could be trained to use timing differences as short as 3 msec to drive decisions (Yang et al, Nat Neurosci 11, 1262-3). Is the auditory cortex unique in its ability to utilize such fine timing differences to drive behavior? Because audition is often considered to be a "fast" modality—one in which subtle differences in temporal structure can be behaviorally relevant—it would not be unreasonable to speculate that the auditory cortex had evolved special mechanisms for rapid processing. On the other hand, it is appealing to hypothesize that the cortex operates according to general principles shared across different regions; in this view, the ability to make use of millisecond-scale differences in neuronal activity would not be unique to the auditory cortex. To distinguish these hypotheses, we compared the ability of different sensory areas to resolve subtle differences in neural timing. In the visual cortex, we found that although animals could be trained to resolve differences as short as 15 msec in neuronal activity, they could not resolve differences as short as 5 msec. This lower limit of 5-15 msec was significantly higher than the limit of 3 msec we observed in auditory cortex, and is consistent with the view that visual cortex is "slower" than auditory cortex. Surprisingly, we found that the barrel cortex was even "faster" than auditory cortex, with a lower limit below 1 msec. Our results suggest that different cortical areas are differentially able to derive behaviorally relevant information from the fine timing of neural activity. Conference: Computational and Systems Neuroscience 2010, Salt Lake City, UT, United States, 25 Feb - 2 Mar, 2010. Presentation Type: Oral Presentation Topic: Oral presentations Citation: Yang Y and Zador A (2010). Differential sensitivity of different sensory cortices to behaviorally relevant timing differences. Front. Neurosci. Conference Abstract: Computational and Systems Neuroscience 2010. doi: 10.3389/conf.fnins.2010.03.00040 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: 18 Feb 2010; Published Online: 18 Feb 2010. * Correspondence: Anthony Zador, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, United States, zador@cshl.edu 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 Yang Yang Anthony Zador Google Yang Yang Anthony Zador Google Scholar Yang Yang Anthony Zador PubMed Yang Yang Anthony Zador 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.

Auditory streaming based on temporal structure in hearing-impaired listeners

The influence of temporal cues on sequential stream segregation was investigated using five elderly hearing-impaired listeners. In experiment 1, an alternating pattern of A and B tones was used. Each tone was a harmonic complex with a 100-Hz fundamental, with one of three passbands (1250–2500, 1768–3636, or 2500–5000 Hz) and one of three component-phase relationships (cosine, alternating, or random). The complexes had an overall level of 96 dB SPL. The detection of a change in relative timing of the A and B tones was measured in a two-interval-forced-choice paradigm. The sequence in one interval remained isochronous while the sequence in the other started isochronously but became increasingly irregular with the addition of a cumulative delay between the A and B tones. Component phase relationship and passband difference both had significant effects on the minimum detectable delay, indicating that temporal structure produced obligatory stream segregation. In experiment 2, subjects continuously reported whether tones presented in a 30-s ABA–ABA– sequence were perceived as segregated or integrated. Differences in component phase between A and B significantly increased perceived segregation, but passband did not. In conclusion, stream segregation due to differences in temporal structure is robust in elderly subjects with cochlear hearing loss and comparable to that found previously in young normally hearing subjects.

Lower hippocampal volume in patients suffering from depression: a meta-analysis.

A number of studies have used magnetic resonance imaging to examine volumetric differences in temporal structures in subjects suffering from major depressive disorder. Studies have reported lower hippocampal and amygdala volume, but results have been inconsistent. The authors were interested, therefore, in examining these studies in the aggregate in order to determine whether hippocampal volume is lower in major depressive disorder. They also examined factors that may contribute to the disparate results in the literature. A meta-analysis was conducted of studies that used magnetic resonance imaging to assess the volume of the hippocampus and related structures in patients with major depressive disorder. Patients were seen to have lower hippocampal volume relative to comparison subjects, detectable if the hippocampus was measured as a discrete structure. Although the effect of major depressive disorder on amygdala volume remains to be conclusively established, inclusion of the amygdala with the hippocampus appears to have decreased the likelihood of detecting volumetric differences in either structure. Slice thickness or other scan parameters did not account for a substantive amount of the variance in results, whereas clinical variables of the populations studied, such as duration of illness or presence of abuse, may account for much of the discrepancy between findings.

Auditory streaming based on temporal structure in hearing-impaired listeners

The influence of temporal cues on sequential stream segregation was investigated using five elderly hearing-impaired listeners. In experiment 1, an alternating pattern of A and B tones was used. Each tone was a harmonic complex with a 100-Hz fundamental, with one of three passbands (1250–2500, 1768–3636, or 2500–5000 Hz) and one of three component-phase relationships (cosine, alternating, or random). The complexes had an overall level of 96 dB SPL. The detection of a change in relative timing of the A and B tones was measured in a two-interval-forced-choice paradigm. The sequence in one interval remained isochronous while the sequence in the other started isochronously but became increasingly irregular with the addition of a cumulative delay between the A and B tones. Component phase relationship and passband difference both had significant effects on the minimum detectable delay, indicating that temporal structure produced obligatory stream segregation. In experiment 2, subjects continuously reported whether tones presented in a 30-s ABA–ABA– sequence were perceived as segregated or integrated. Differences in component phase between A and B significantly increased perceived segregation, but passband did not. In conclusion, stream segregation due to differences in temporal structure is robust in elderly subjects with cochlear hearing loss and comparable to that found previously in young normally hearing subjects.

Perceptual relevance of species-specific differences in acoustic signal structure in Streptopelia doves

Acoustic signal characteristics that differ strongly between vocalizations of closely related species need not necessarily be the perceptually most important ones. In the dove genus Streptopelia, temporal parameters have been identified as the most distinctive species-specific differences between perch-coo vocalizations. Using synthetic coo model stimuli and an operant design, we tested the perceptual relevance of species-specific differences in temporal structure and amplitude modulation structure for two partly sympatric species, S.decaocto and S.chinensis. The majority of birds used both parameters to classify sound stimuli, although overall, amplitude modulation structure appeared somewhat more important. In an additional experiment, we tested the same birds to examine whether they predominantly used the first element in the classification of coo model stimuli. Our results show that the characteristics of the full signal, rather than the first element, determine classification.