The role of temporal structure in envelope processing

Abstract Some species of Andean hummingbirds produce high-frequency vocalizations which exceed the vocal range of most birds. They also challenge our understanding of the role of habitat structure in the evolution of vocal signals because these hummingbirds live in strikingly different habitats, ranging from cloud forest to high-altitude grasslands. Although these vocalizations are produced at high frequencies, they exhibit considerable variation in frequency content and temporal structure. The calls of the hummingbirds from the cloud forest are simpler and have a narrow frequency range compared to the complex song of the grasslands hummingbird. We hypothesized that each of the three high-frequency vocalizations is adapted for transmission in their habitat. We characterized the transmission of high-frequency vocal signals in the cloud forest and in the grasslands. All vocalizations attenuated and degraded substantially at short distances, suggesting that they are adapted for short-range communication. The simple vocalizations of the cloud-forest species transmitted better in both environments compared to the complex song of the grasslands hummingbird, probably due to relaxed constraints for high-frequency sounds in open habitats.

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Role of intraglomerular circuits in shaping temporally structured responses to naturalistic inhalation-driven sensory input to the olfactory bulb

Journal of Neurophysiology ◽

10.1152/jn.00394.2014 ◽

2015 ◽

Vol 113 (9) ◽

pp. 3112-3129 ◽

Cited By ~ 11

Author(s):

Ryan M. Carey ◽

William Erik Sherwood ◽

Michael T. Shipley ◽

Alla Borisyuk ◽

Matt Wachowiak

Keyword(s):

Olfactory Bulb ◽

Sensory Neuron ◽

Temporal Structure ◽

Decay Kinetics ◽

Response Dynamics ◽

Output Neurons ◽

Tufted Cells ◽

Slow Onset ◽

Feedforward Inhibition

Olfaction in mammals is a dynamic process driven by the inhalation of air through the nasal cavity. Inhalation determines the temporal structure of sensory neuron responses and shapes the neural dynamics underlying central olfactory processing. Inhalation-linked bursts of activity among olfactory bulb (OB) output neurons [mitral/tufted cells (MCs)] are temporally transformed relative to those of sensory neurons. We investigated how OB circuits shape inhalation-driven dynamics in MCs using a modeling approach that was highly constrained by experimental results. First, we constructed models of canonical OB circuits that included mono- and disynaptic feedforward excitation, recurrent inhibition and feedforward inhibition of the MC. We then used experimental data to drive inputs to the models and to tune parameters; inputs were derived from sensory neuron responses during natural odorant sampling (sniffing) in awake rats, and model output was compared with recordings of MC responses to odorants sampled with the same sniff waveforms. This approach allowed us to identify OB circuit features underlying the temporal transformation of sensory inputs into inhalation-linked patterns of MC spike output. We found that realistic input-output transformations can be achieved independently by multiple circuits, including feedforward inhibition with slow onset and decay kinetics and parallel feedforward MC excitation mediated by external tufted cells. We also found that recurrent and feedforward inhibition had differential impacts on MC firing rates and on inhalation-linked response dynamics. These results highlight the importance of investigating neural circuits in a naturalistic context and provide a framework for further explorations of signal processing by OB networks.

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The Role of Prestin in the Generation of Electrically Evoked Otoacoustic Emissions in Mice

Journal of Neurophysiology ◽

10.1152/jn.01216.2007 ◽

2008 ◽

Vol 99 (4) ◽

pp. 1607-1615 ◽

Cited By ~ 13

Author(s):

Markus Drexl ◽

Marcia M. Mellado Lagarde ◽

Jian Zuo ◽

Andrei N. Lukashkin ◽

Ian J. Russell

Keyword(s):

Hair Cells ◽

Otoacoustic Emissions ◽

Temporal Structure ◽

Organ Of Corti ◽

Outer Hair Cells ◽

Tectorial Membrane ◽

Wild Type ◽

Short Delay ◽

Delay Component

Electrically evoked otoacoustic emissions are sounds emitted from the inner ear when alternating current is injected into the cochlea. Their temporal structure consists of short- and long-delay components and they have been attributed to the motile responses of the sensory-motor outer hair cells of the cochlea. The nature of these motile responses is unresolved and may depend on either somatic motility, hair bundle motility, or both. The short-delay component persists after almost complete elimination of outer hair cells. Outer hair cells are thus not the sole generators of electrically evoked otoacoustic emissions. We used prestin knockout mice, in which the motor protein prestin is absent from the lateral walls of outer hair cells, and Tecta ΔENT/ΔENT mice, in which the tectorial membrane, a structure with which the hair bundles of outer hair cells normally interact, is vestigial and completely detached from the organ of Corti. The amplitudes and delay spectra of electrically evoked otoacoustic emissions from Tecta ΔENT/ΔENT and Tecta +/+ mice are very similar. In comparison with prestin +/+ mice, however, the short-delay component of the emission in prestin −/− mice is dramatically reduced and the long-delay component is completely absent. Emissions are completely suppressed in wild-type and Tecta ΔENT/ΔENT mice at low stimulus levels, when prestin-based motility is blocked by salicylate. We conclude that near threshold, the emissions are generated by prestin-based somatic motility.

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Creation in a Closed Universe Or, Have Physicists Disproved the Existence of God?

Religious Studies ◽

10.1017/s003441250000130x ◽

1991 ◽

Vol 27 (1) ◽

pp. 39-48 ◽

Cited By ~ 2

Author(s):

Robin Le Poidevin

Keyword(s):

Temporal Structure ◽

Closed Surface ◽

Closed Universe ◽

Existence Of God ◽

Space And Time ◽

Stephen Hawking ◽

History Of ◽

The Universe

Could a theory concerning the temporal structure of the universe have any implications for the possibility of a creator? A recent remark by Stephen Hawking suggests that it could. In A Brief History of Time, Hawking writes:The idea that space and time may form a closed surface without boundary … has profound implications for the role of God in the affairs of the universe… So long as the universe had a beginning, we could suppose it had a creator. But if the universe is really completely self-contained, having no boundary or edge, it would have neither beginning nor end: it would simply be. What place, then, for a creator?

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Dynamic facial expressions of emotion decouple emotion category and intensity information over time

10.31234/osf.io/4gpev ◽

2020 ◽

Author(s):

Chaona Chen ◽

Daniel Messinger ◽

Yaocong Duan ◽

Robin A A Ince ◽

Oliver G. B. Garrod ◽

...

Keyword(s):

Facial Expressions ◽

Temporal Structure ◽

Emotion Classification ◽

Information Theoretic ◽

Facial Movements ◽

Communicative Functions ◽

Intensity Information ◽

Dynamic Facial Expressions ◽

Facial Expressions Of Emotion

Facial expressions support effective social communication by dynamically transmitting complex, multi-layered messages, such as emotion categories and their intensity. How facial expressions achieve this signalling task remains unknown. Here, we address this question by identifying the specific facial movements that convey two key components of emotion communication – emotion classification (such as ‘happy,’ ‘sad’) and intensification (such as ‘very strong’) – in the six classic emotions (happy, surprise, fear, disgust, anger and sad). Using a data-driven, reverse correlation approach and an information-theoretic analysis framework, we identified in 60 Western receivers three communicative functions of face movements: those used to classify the emotion (classifiers), to perceive emotional intensity (intensifiers), and those serving the dual role of classifier and intensifier. We then validated the communicative functions of these face movements in a broader set of 18 complex facial expressions of emotion (including excited, shame, anxious, hate). We find that the timing of emotion classifier and intensifier face movements are temporally distinct, in which intensifiers peaked earlier or later than classifiers. Together, these results reveal the complexities of facial expressions as a signalling system, in which individual face movements serve specific communicative functions with a clear temporal structure.

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Seasonal structure of water stages on lakes in Northern Poland

Bulletin of Geography Physical Geography Series ◽

10.2478/bgeo-2018-0019 ◽

2018 ◽

Vol 15 (1) ◽

pp. 101-110 ◽

Cited By ~ 1

Author(s):

Katarzyna Plewa ◽

Dariusz Wrzesiński ◽

Mariusz Ptak

Keyword(s):

Water Level ◽

Annual Cycle ◽

Dominant Role ◽

Temporal Structure ◽

Level Fluctuation ◽

Frequency Distributions ◽

Structure Of Water ◽

Daily Water ◽

Unsupervised Approach

Abstract The paper presents the characteristics of hydrological periods in an average annual cycle in Polish lakes. The types of period and their sequence determine the regime of water stages in lakes. The article applies the unsupervised approach to analysis of water level fluctuation patterns, where the regime is identified by grouping analytical parameters. Hydrological periods were designated by grouping elementary time units of the hydrological year (pentads) based on the similarity of their parameters, namely water level frequency distributions. The analysis covered daily water stages in 33 lakes in Poland from the period from 1984 to 2012. Five types of hydrological period were designated. The studied lakes differ in the number, type and sequence of hydrological periods in an average annual cycle. Most of the lakes (19 lakes) have a 4-period temporal structure of water stages with the course of water stages in a year characteristic of this geographical zone. No spatial patterns occurred in the location of lakes from particular groups. This suggests the dominant role of local factors in determining the seasonality of water stages.

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Reassessing the relationship between elections and democratization

International Political Science Review ◽

10.1177/0192512119846144 ◽

2019 ◽

Vol 41 (3) ◽

pp. 305-320

Author(s):

Nam Kyu Kim

Keyword(s):

Temporal Structure ◽

Negative Relationship ◽

Causal Role ◽

Institutional Changes ◽

Authoritarian Elections ◽

The Relationship

Do elections improve a country’s prospects for democratization? The theory of democratization by elections proposes that reiterated multiparty elections foster gradual institutional changes leading to progress toward democracy. Edgell et al. provide the most systematic evidence for this theory, but substantial disagreements remain among scholars studying the effects of authoritarian elections on democratization. In this study, I reassess the relationship between elections and democratization. In doing so, I account for the temporal structure of democratic qualities that are highly persistent. When I control for the dynamics of democratic qualities by adding a lag (or lags) of the dependent variable, the democratizing effects of repeated elections disappear; indeed, most evidence indicates a negative relationship between elections and democratization. This finding calls into question the causal role of elections in the process of democratization and demonstrates the importance of modeling the persistent nature of democracy in exploring the effect of a variable on democratization.

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Unresolved Futurities: On Hermeneutical Shapes

Oxford Literary Review ◽

10.3366/olr.2015.0150 ◽

2015 ◽

Vol 37 (1) ◽

pp. 45-66

Author(s):

Ammon Allred

Keyword(s):

Da Vinci ◽

Thought Experiment ◽

Temporal Structure ◽

Leonardo Da Vinci ◽

Being And Time ◽

Crucial Importance ◽

Mediating Role

I offer a hermeneutical/deconstructive interpretation of a specific drawing by Leonardo da Vinci and a thought-experiment suggested by that drawing. My reason for turning to this drawing is that it graphically illustrates an ambiguity in Martin Heidegger's notion of the hermeneutical circle. I take this ambiguity to be illustrative of an interpretive problem of crucial importance to mainstream interpretations of Heidegger as well as to the hermeneutical and deconstructive traditions. I explicate this problem through an interpretation of relevant passages in Being and Time and argue 1) that there are two different, irreducible understandings of futurity in Heidegger's thought, and 2) that Heidegger's understanding of the present helps to mediate these different meanings of futurity. The thought experiment with which the article begins raises questions about the role of the imagination in understanding the temporal structure of intentionality. By calling attention to the mediating role that the present plays in Heidegger's understanding of temporality in Part II of Being and Time, I argue for an interpretation of the hermeneutics of understanding that better answers the questions posed by this thought experiment.

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