scholarly journals Discrimination of rippled spectra at various frequencies: Contribution of excitation-pattern and temporal-processing mechanisms

2019 ◽  
Author(s):  
Alexander Y. Supin ◽  
Olga Milekhina ◽  
Dmitry Nechaev ◽  
Evgenia Sysueva
Keyword(s):  
Temporal Processing ◽  
Excitation Pattern ◽  
Processing Mechanisms ◽  
Rippled Spectra

Rippled Depth Thresholds: Estimates Obtained by Discrimination From Rippled and Nonrippled Reference Signals

2019 ◽  
Vol 105 (6) ◽  
pp. 1198-1205
Author(s):  
Alexander Ya. Supin ◽  
Olga N. Milekhina ◽  
Dmitry I. Nechaev
Keyword(s):  
Frequency Analysis ◽  
Temporal Processing ◽  
Complex Spectrum ◽  
Pattern Processing ◽  
Reference Signals ◽  
Excitation Pattern ◽  
Processing Mechanisms ◽  
Processing Mechanism

The objective of the study was to better understand of contribution of excitation-pattern and temporal-processing mechanisms of frequency analysis to discrimination of complex-spectrum signals in various discrimination tasks. Using rippled-spectrum signals, the ripple depth thresholds were measured as functions of ripple density under conditions of rippled or non-rippled reference signals. With rippled reference signals, the ripple depth thresholds were as low as 0.11 at low ripple densities (2–3 cycles/oct) and rose to 1.0 at a ripple density of 8.9 cycles/oct. For non-rippled reference signals, ripple depth thresholds were nearly the same as for rippled reference signals at ripple densities of up to 7 cycles/oct; at ripple densities of 10 cycles/oct and higher, ripple depth thresholds rose slowly and reached 1.0 at a ripple density of 26 cycles/oct. The results hypothetically suggest contributions of the excitation-pattern processing and temporal-processing mechanisms of frequency analysis to discrimination of rippled signals. The excitation-pattern mechanism featured low depth thresholds at low ripple densities but could not function at ripple densities above 10 cycles/oct. The temporal-processing mechanism manifested at higher ripple densities and non-rippled reference stimuli.

An instrument to investigate temporal processing mechanisms with the multifocal ERG

2002 ◽  
Vol 26 (4) ◽  
pp. 147-151 ◽  
Author(s):  
D. C. Smith ◽  
D. Keating ◽  
S. Parks ◽  
A.L. Evans
Keyword(s):  
Temporal Processing ◽  
Multifocal Erg ◽  
Processing Mechanisms

scholarly journals A Critical Role of Inhibition in Temporal Processing Maturation in the Primary Auditory Cortex

2017 ◽  
Vol 28 (5) ◽  
pp. 1610-1624 ◽  
Author(s):  
Dongqin Cai ◽  
Rongrong Han ◽  
Miaomiao Liu ◽  
Fenghua Xie ◽  
Ling You ◽  
...  
Keyword(s):  
Auditory Cortex ◽  
Temporal Processing ◽  
Critical Role ◽  
Primary Auditory Cortex ◽  
Cortical Inhibition ◽  
Fast Spiking ◽  
Processing Mechanisms

Abstract Faithful representation of sound envelopes in primary auditory cortex (A1) is vital for temporal processing and perception of natural sounds. However, the emergence of cortical temporal processing mechanisms during development remains poorly understood. Although cortical inhibition has been proposed to play an important role in this process, direct in-vivo evidence has been lacking. Using loose-patch recordings in rat A1 immediately after hearing onset, we found that stimulus-following ability in fast-spiking neurons was significantly better than in regular-spiking (RS) neurons. In-vivo whole-cell recordings of RS neurons revealed that inhibition in the developing A1 demonstrated much weaker adaptation to repetitive stimuli than in adult A1. Furthermore, inhibitory synaptic inputs were of longer duration than observed in vitro and in adults. Early in development, overlap of the prolonged inhibition evoked by 2 closely following stimuli disrupted the classical temporal sequence between excitation and inhibition, resulting in slower following capacity. During maturation, inhibitory duration gradually shortened accompanied by an improving temporal following ability of RS neurons. Both inhibitory duration and stimulus-following ability demonstrated exposure-based plasticity. These results demonstrate the role of inhibition in setting the pace for experience-dependent maturation of temporal processing in the auditory cortex.

scholarly journals Estimates of Ripple-Density Resolution Based on the Discrimination From Rippled and Nonrippled Reference Signals

2019 ◽  
Vol 23 ◽  
pp. 233121651882443 ◽  
Author(s):  
Dmitry I. Nechaev ◽  
Olga N. Milekhina ◽  
Alexander Ya Supin
Keyword(s):  
Test Stimulus ◽  
Temporal Processing ◽  
Temporal Structure ◽  
Reference Stimulus ◽  
Resolution Limits ◽  
The Mean ◽  
Excitation Pattern ◽  
Ripple Phase ◽  
Pattern Resolution ◽  
Density Resolution

Rippled-spectrum stimuli are used to evaluate the resolution of the spectro-temporal structure of sounds. Measurements of spectrum-pattern resolution imply the discrimination between the test and reference stimuli. Therefore, estimates of rippled-pattern resolution could depend on both the test stimulus and the reference stimulus type. In this study, the ripple-density resolution was measured using combinations of two test stimuli and two reference stimuli. The test stimuli were rippled-spectrum signals with constant phase or rippled-spectrum signals with ripple-phase reversals. The reference stimuli were rippled-spectrum signals with opposite ripple phase to the test or nonrippled signals. The spectra were centered at 2 kHz and had an equivalent rectangular bandwidth of 1 oct and a level of 70 dB sound pressure level. A three-alternative forced-choice procedure was combined with an adaptive procedure. With rippled reference stimuli, the mean ripple-density resolution limits were 8.9 ripples/oct (phase-reversals test stimulus) or 7.7 ripples/oct (constant-phase test stimulus). With nonrippled reference stimuli, the mean resolution limits were 26.1 ripples/oct (phase-reversals test stimulus) or 22.2 ripples/oct (constant-phase test stimulus). Different contributions of excitation-pattern and temporal-processing mechanisms are assumed for measurements with rippled and nonrippled reference stimuli: The excitation-pattern mechanism is more effective for the discrimination of rippled stimuli that differ in their ripple-phase patterns, whereas the temporal-processing mechanism is more effective for the discrimination of rippled and nonrippled stimuli.

Pspan: A New Tool for Assessing Pitch Temporal Processing and Patterning Capacity

2019 ◽  
Vol 28 (2) ◽  
pp. 322-332 ◽  
Author(s):  
Aurora J. Weaver ◽  
Jeffrey J. DiGiovanni ◽  
Dennis T. Ries
Keyword(s):  
Temporal Processing

Top-Down Processing and Visual Reorientation Illusions in a Virtual Reality Environment

2004 ◽  
Vol 63 (3) ◽  
pp. 143-149 ◽  
Author(s):  
Fred W. Mast ◽  
Charles M. Oman
Keyword(s):  
Virtual Reality ◽  
Visual Processing ◽  
Line Length ◽  
Perceptual Cues ◽  
Virtual Reality Environment ◽  
Top Down ◽  
Test Conditions ◽  
The Subject ◽  
Processing Mechanisms

The role of top-down processing on the horizontal-vertical line length illusion was examined by means of an ambiguous room with dual visual verticals. In one of the test conditions, the subjects were cued to one of the two verticals and were instructed to cognitively reassign the apparent vertical to the cued orientation. When they have mentally adjusted their perception, two lines in a plus sign configuration appeared and the subjects had to evaluate which line was longer. The results showed that the line length appeared longer when it was aligned with the direction of the vertical currently perceived by the subject. This study provides a demonstration that top-down processing influences lower level visual processing mechanisms. In another test condition, the subjects had all perceptual cues available and the influence was even stronger.

Do Event-Related Brain Potentials Reflect Mental (Cognitive) Operations?

2002 ◽  
Vol 16 (3) ◽  
pp. 129-149 ◽  
Author(s):  
Boris Kotchoubey
Keyword(s):  
Cognitive Processes ◽  
Point Of View ◽  
Internal Variables ◽  
Brain Potentials ◽  
Cognitive Operations ◽  
External Variables ◽  
Series Of Experiments ◽  
Mental Operations ◽  
A Chain ◽  
Processing Mechanisms

Abstract Most cognitive psychophysiological studies assume (1) that there is a chain of (partially overlapping) cognitive processes (processing stages, mechanisms, operators) leading from stimulus to response, and (2) that components of event-related brain potentials (ERPs) may be regarded as manifestations of these processing stages. What is usually discussed is which particular processing mechanisms are related to some particular component, but not whether such a relationship exists at all. Alternatively, from the point of view of noncognitive (e. g., “naturalistic”) theories of perception ERP components might be conceived of as correlates of extraction of the information from the experimental environment. In a series of experiments, the author attempted to separate these two accounts, i. e., internal variables like mental operations or cognitive parameters versus external variables like information content of stimulation. Whenever this separation could be performed, the latter factor proved to significantly affect ERP amplitudes, whereas the former did not. These data indicate that ERPs cannot be unequivocally linked to processing mechanisms postulated by cognitive models of perception. Therefore, they cannot be regarded as support for these models.

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