scholarly journals Temporal integration near threshold fine structure–The role of cochlear processing

2013 ◽  
Vol 133 (5) ◽  
pp. 3428-3428
Author(s):  
Bastian Epp ◽  
Manfred Mauermann ◽  
Jesko L. Verhey
Author(s):  
Alan N. Hodgson

The hermaphrodite duct of pulmonate snails connects the ovotestis to the fertilization pouch. The duct is typically divided into three zones; aproximal duct which leaves the ovotestis, the middle duct (seminal vesicle) and the distal ovotestis duct. The seminal vesicle forms the major portion of the duct and is thought to store sperm prior to copulation. In addition the duct may also play a role in sperm maturation and degredation. Although the structure of the seminal vesicle has been described for a number of snails at the light microscope level there appear to be only two descriptions of the ultrastructure of this tissue. Clearly if the role of the hermaphrodite duct in the reproductive biology of pulmonatesis to be understood, knowledge of its fine structure is required.Hermaphrodite ducts, both containing and lacking sperm, of species of the terrestrial pulmonate genera Sphincterochila, Levantina, and Helix and the marine pulmonate genus Siphonaria were prepared for transmission electron microscopy by standard techniques.


1996 ◽  
Vol 13 (10) ◽  
pp. 1960 ◽  
Author(s):  
Miguel P. Eckstein ◽  
James S. Whiting ◽  
James P. Thomas

2021 ◽  
Author(s):  
jacky even ◽  
philippe tamarat ◽  
philipe bourges ◽  
guido roma ◽  
claudine katan ◽  
...  

1971 ◽  
Vol 9 (3) ◽  
pp. 581-601
Author(s):  
D. G. ROBINSON ◽  
R. D. PRESTON

Naked swarmers of both Cladophora rupestris and Chaetomorpha melagonium have been examined by the freeze-etching technique. The swarmers of Cladophora, collected just after settling, reveal several layers of granules external to the plasmalemma and internal to the so-called ‘fibrous-layer’. Chaetomorpha swarmers collected just before settling show extrusion of vesicles through the plasmalemma. The structures associated with the membranes are discussed in relation to known features of these swarmers already observed by sectioning. The role of granules in the synthesis of cell wall microfibrils is strengthened though the spatial arrangement of the granules seen in this investigation does not completely fulfil the ‘ordered granule’ hypothesis. Description of, and comments on, features related to cell wall synthesis, particularly the Golgi and vacuolar systems, are given.


2012 ◽  
Vol 25 (0) ◽  
pp. 188
Author(s):  
Helena Sgouramani ◽  
Chris Muller ◽  
Leon van Noorden ◽  
Marc Leman ◽  
Argiro Vatakis

We report two experiments aiming to define how experience and stimulus enactment affect multisensory temporal integration for ecologically-valid stimuli. In both experiments, a number of different dance steps were used as audiovisual displays at a range of stimulus onset asynchronies using the method of constant stimuli. Participants were either professional dancers or non-dancers. In Experiment 1, using a simultaneity judgment (SJ) task, we aimed at defining — for the first time — the temporal window of integration (TWI) for dancers and non-dancers and the role of experience in SJ performance. Preliminary results showed that dancers had smaller TWI in comparison to non-dancers for all stimuli tested, with higher complexity (participant rated) dance steps requiring larger auditory leads for both participant groups. In Experiment 2, we adapted a more embodied point of view by examining how enactment of the stimulus modulates the TWIs. Participants were presented with simple audiovisual dance steps that could be synchronous or asynchronous and were asked to synchronize with the audiovisual display by actually performing the step indicated. A motion capture system recorded their performance at a millisecond level of accuracy. Based on the optimal integration hypothesis, we are currently looking at the data in terms of which modality will be dominant, considering that dance is a spatially (visual) and temporally (audio) coordinated action. Any corrective adjustments, accelerations–decelerations, hesitations will be interpreted as indicators of the perception of ambiguity in comparison to their performance at the synchronous condition, thus, for the first time, an implicit SJ response will be measured.


2021 ◽  
Author(s):  
Vibha Viswanathan ◽  
Barbara G. Shinn-Cunningham ◽  
Michael G. Heinz

To understand the mechanisms of speech perception in everyday listening environments, it is important to elucidate the relative contributions of different acoustics cues in transmitting phonetic content. Previous studies suggest that the energy envelopes of speech convey most speech content, while the temporal fine structure (TFS) can aid in segregating target speech from background noise. Despite the vast literature on TFS and speech intelligibility, the role of TFS in conveying additional speech content over what envelopes convey in complex acoustic scenes is poorly understood. The present study addresses this question using online psychophysical experiments to measure consonant identification in multi-talker babble for intelligibility-matched intact and 64-channel envelope-vocoded stimuli. Consonant confusion patterns revealed that listeners had a greater tendency in the vocoded (versus intact) condition to be biased towards reporting that they heard an unvoiced consonant, despite envelope and place cues being largely preserved. This result was replicated when babble instances were varied across independent experiments, suggesting that TFS conveys important voicing cues over what envelopes convey in multi-talker babble, a masker that is ubiquitous in everyday environments. This finding has implications for assistive listening devices that do not currently provide TFS cues, such as cochlear implants.


2014 ◽  
Vol 136 (2) ◽  
pp. 877-882 ◽  
Author(s):  
Laurianne Cabrera ◽  
Feng-Ming Tsao ◽  
Dan Gnansia ◽  
Josiane Bertoncini ◽  
Christian Lorenzi

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