The Effects of Signal Rise Time and Duration on the Early Components of the Auditory Evoked Cortical Response

1971 ◽  
Vol 14 (3) ◽  
pp. 552-558 ◽  
Author(s):  
Paul H. Skinner ◽  
Frank Antinoro

The effects of signal rise time and duration on the early components of the auditory evoked cortical response were studied in 20 subjects. Tone bursts were presented at 1000 Hz at various rise times and durations. No consistent effects of signal duration on the latency or amplitude of the early response were observed. The effects of signal rise time yielded no consistent change in peak latency but revealed a dramatic effect on peak amplitude. Amplitude decreased markedly with slower rise times. Stimuli presented with slow rise times resulted in instability of the wave form, while click stimuli produced remarkably stable responses from trial to trial.

1983 ◽  
Vol 105 (1) ◽  
pp. 20-23 ◽  
Author(s):  
T. M. Wright ◽  
J. M. Carr

The soft tissue attenuation of acoustic emission signals was measured by transmitting pulses through volunteers and measuring the decay of the waveform characteristics of the pulse as a function of the thickness of the interposed tissue. Waveform characteristics of the received signal (signal duration, number of counts, peak amplitude, energy, and rise time) demonstrated an exponential decrease with increasing tissue thickness. The decrease appeared insensitive to the frequency of the pulse within the range of 50 to 600 KHz.


1968 ◽  
Vol 11 (2) ◽  
pp. 301-306 ◽  
Author(s):  
Paul H. Skinner ◽  
Howard C. Jones

Summing computer technique was used to study the effects of signal duration and rise time on evoked auditory responses of 40 adult subjects. An additional objective was to determine whether signal duration for short signals up to 150 msec would reflect temporal summation through amplitude and latency changes in the wave form of evoked potentials. In the experiment on signal-duration, 1000 Hz tones were presented at near threshold levels (10 or 15 dB SL) to maximize the probability of observing the possible effects of temporal summation. In the second experiment different rise times with 1000 Hz stimuli were presented at four sensation levels: 30, 50, 70, and 90 dB. No consistent trend was observed in the evoked responses with increments in signal duration. Conversely, a very clear trend of increased peak amplitude in the potentials occurred as signal rise-time was decreased.


PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259653
Author(s):  
Hiroki Nakata ◽  
Miho Takezawa ◽  
Keita Kamijo ◽  
Manabu Shibasaki

We investigated modality differences in the N2 and P3 components of event-related potentials (ERPs) between somatosensory and auditory Go/No-go paradigms in eighteen healthy prepubescent children (mean age: 125.9±4.2 months). We also evaluated the relationship between behavioral responses (reaction time, reaction time variability, and omission and commission error rates) and amplitudes and latencies of N2 and P3 during somatosensory and auditory Go/No-go paradigms. The peak latency of No-go-N2 was significantly shorter than that of Go-N2 during somatosensory paradigms, but not during auditory paradigms. The peak amplitude of P3 was significantly larger during somatosensory than auditory paradigms, and the peak latency of P3 was significantly shorter during somatosensory than auditory paradigms. Correlations between behavioral responses and the P3 component were not found during somatosensory paradigms. On the other hand, in auditory paradigms, correlations were detected between the reaction time and peak amplitude of No-go-P3, and between the reaction time variability and peak latency of No-go-P3. A correlation was noted between commission error and the peak latency of No-go-N2 during somatosensory paradigms. Compared with previous adult studies using both somatosensory and auditory Go/No-go paradigms, the relationships between behavioral responses and ERP components would be weak in prepubescent children. Our data provide findings to advance understanding of the neural development of motor execution and inhibition processing, that is dependent on or independent of the stimulus modality.


2021 ◽  
Vol 15 ◽  
Author(s):  
Lingjing Zeng ◽  
Haijing Wu ◽  
Jialu Li ◽  
Haiteng Wang ◽  
Songyue Xie ◽  
...  

Homeostatic sleep pressure can cause cognitive impairment, in which executive function is the most affected. Previous studies have mainly focused on high homeostatic sleep pressure (long-term sleep deprivation); thus, there is still little related neuro-psycho-physiological evidence based on low homeostatic sleep pressure (12 h of continuous wakefulness) that affects executive function. This study aimed to investigate the impact of lower homeostatic sleep pressure on executive function. Our study included 14 healthy young male participants tested using the Go/NoGo task in normal resting wakefulness (10:00 am) and after low homeostatic sleep pressure (10:00 pm). Behavioral data (response time and accuracy) were collected, and electroencephalogram (EEG) data were recorded simultaneously, using repeated measures analysis of variance for data analysis. Compared with resting wakefulness, the participants’ response time to the Go stimulus was shortened after low homeostatic sleep pressure, and the correct response rate was reduced. Furthermore, the peak amplitude of Go–P2 decreased significantly, and the peak latency did not change significantly. For NoGo stimulation, the peak amplitude of NoGo–P2 decreased significantly (p < 0.05), and the peak latency was significantly extended (p < 0.05). Thus, the P2 wave is likely related to the attention and visual processing and reflects the early judgment of the perceptual process. Therefore, the peak amplitude of Go–P2 and NoGo–P2 decreased, whereas the peak latency of NoGo–P2 increased, indicating that executive function is impaired after low homeostatic sleep pressure. This study has shown that the P2 wave is a sensitive indicator that reflects the effects of low homeostatic sleep pressure on executive function, and that it is also an important window to observe the effect of homeostatic sleep pressure and circadian rhythm on cognitive function.


1993 ◽  
Vol 70 (5) ◽  
pp. 1874-1884 ◽  
Author(s):  
K. Morita ◽  
G. David ◽  
J. N. Barrett ◽  
E. F. Barrett

1. The hyperpolarization that follows tetanic stimulation was recorded intra-axonally from the internodal region of intramuscular myelinated motor axons. 2. The peak amplitude of the posttetanic hyperpolarization (PTH) that followed stimulation at 20-100 Hz for < or = 35 s increased with increasing train duration, reaching a maximum of 22 mV. PTH decayed over a time course that increased from tens to hundreds of seconds with increasing train duration. For a given frequency of stimulation the time integral of PTH was proportional to the number of stimuli in the train, averaging 3-4 mV.s per action potential. 3. Ouabain (0.1-1 mM) and cyanide (1 mM) depolarized the resting potential and abolished PTH. Tetanic stimulation in ouabain was followed by a slowly decaying depolarization (probably due to extra-axonal K+ accumulation) whose magnitude and duration increased as the duration of the train increased. 4. Axonal input resistance showed no consistent change during PTH in normal solution but increased during PTH in the presence of 3 mM Cs+ (which blocks axonal inward rectifier currents). 5. PTH was abolished when bath Na+ was replaced by Li+ or choline. PTH persisted after removal of bath Ca2+ and addition of 2 mM Mn2+. 6. Removal of bath K+ abolished the PTH recorded after brief stimulus trains and greatly reduced the duration of PTH recorded after longer stimulus trains. 7. A brief application of 10 mM K+, which normally depolarizes axons, produced a ouabain-sensitive hyperpolarization in axons bathed in K(+)-free solution. 8. These observations suggest that in these myelinated axons PTH is produced mainly by activation of an electrogenic Na(+)-K(+)-ATPase, rather than by changes in K+ permeability or transmembrane [K+] gradients. This conclusion is supported by calculations showing agreement between estimates of Na+ efflux/impulse based on PTH measurements and estimates of Na+ influx/impulse based on nodal voltage-clamp measurements. Pump activity also appears to contribute to the resting potential. 9. The stimulus intensity required to initiate a propagating action potential increased during PTH but decreased during the posttetanic depolarization recorded in ouabain. Thus changes in axonal excitability after tetanic stimulation correlate with changes in the posttetanic membrane potential. 10. Action potentials that propagated during PTH had a larger peak amplitude and were followed by a larger and longer depolarizing afterpotential than action potentials elicited at the resting potential. This enhancement of the depolarizing afterpotential is consistent with previous reports of an increased superexcitable period after action potentials evoked during PTH.


1991 ◽  
Vol 66 (3) ◽  
pp. 955-973 ◽  
Author(s):  
J. C. Hall ◽  
A. S. Feng

1. Single-unit responses to different temporal acoustic parameters were characterized in the dorsal medullary nucleus (DMN) of the Northern leopard frog, Rana pipiens pipiens. Our goal was to provide both a quantitative and a qualitative assessment of the neural representation of behaviorally relevant temporal acoustic patterns in the frog's DMN. 2. Acoustic stimuli included tone bursts having different durations, rise times, or rates of amplitude modulation (AM). Several metrics were used to compute temporal response functions for each of these, including mean spike count, average firing rate, and/or peak firing rate. Synchronization coefficients were also used to characterize responses to stimuli presented at different AM rates. 3. On the basis of mean spike count, the temporal response functions of DMN neurons with respect to signal rise time could be characterized as 1) all-pass, in which the mean spike count was largely independent of rise time, or 2) fast-pass, in which the mean spike count decreased with increasing rise time. Fast-pass response functions were of two types, those that decayed rapidly and those that decayed gradually from their peak values. 4. The minimum threshold varied with signal rise time for cells showing fast-pass but not all-pass response functions. Minimum response thresholds for fast-pass neurons were typically higher with slower signal rise time. 5. The filtering characteristics of cells displaying fast-pass rise time response functions were dependent on signal level, becoming all-pass when signal levels exceeded 30-40 dB above the minimum threshold. 6. Approximately 44% of DMN neurons exhibiting fast-pass response functions for signal rise time showed all-pass filtering characteristics when broadband noise rather than best frequency tones were used, thereby signifying an influence of signal spectrum on the pass-band characteristics of these cells. 7. All DMN neurons, regardless of discharge pattern, showed maximal instantaneous firing rates to signals having short (less than 25 ms) rise times. Response functions based on instantaneous firing rate were, therefore, fast-pass in nature. These responses were independent of signal level and spectrum. 8. There was an ordinal relationship between signal duration and the duration of tonic but not phasic unit discharges. This relationship was not intensity dependent. 9. On the basis of mean spike count, the temporal response functions of DMN neurons with respect to signal duration were characterized as 1) all-pass, in which the mean spike count was largely independent of signal duration, or 2) long-pass, in which the mean spike count increased with increasing signal duration.(ABSTRACT TRUNCATED AT 400 WORDS)


1987 ◽  
Vol 64 (3_suppl) ◽  
pp. 1251-1260 ◽  
Author(s):  
Y. Nishihira ◽  
H. Araki ◽  
A. Ishihara

The changes within central somatosensory pathways accompanying reaction movements were examined by subtracting the peak latency of the major response from the cervical area (14 msec.) from that of the primary cortical response (20 msec.) and also measuring the CNV which is dependent on the direction of the subject's attention and level of arousal. These parameters were measured before (at rest), during fast and slow reaction movements, and mental readiness to act. Analysis showed that the difference in N20-N14 potential latencies is the shortest during fast reaction movements and is shorter during movement tasks than during mental readiness and intention to act. Moreover, we confirmed that the CNV amplitudes are significantly higher during fast than during slow reaction movements and also that the difference in N20-N14 potential latencies decreases as the CNV amplitude increases. Accordingly, from the present results and a series of studies conducted by others, it may be concluded that not only are the changes in the central motor area confirmed by the movement-associated cerebral potentials but also those in the central somatosensory area occur prior to reaction movements.


Author(s):  
Amarapini Divya and Dr.Prasadarao Bobbili

IMC based PID controllers are being used to speed control of DC motor and DC servomotor in industry. As this controller offer good performance comparitive to conventional controllers like PI, PID and Ziegler Nichols frequency method controllers. This paper presents the speed control of the DC motor and DC servomotor using PI, PID, Ziegler Nichols method and IMC-PID controllers, to realize the optimization of control action. A mathematical calculation of DC motor and DC servomotor has developed and simulations are carried out in MATLAB/ Simulink environment. From the results, it is observed that time domain parameters like rise time 0.6 secs, settling time 2 secs, speed for peak over shoot 1450, peak amplitude 1, with no oscillations using IMC-PID controller on DC motor. And for DC servomotor its rise time is 0.3 seconds, settling time is 1 second, speed for peak overshoot 1450 rpm, peak amplitude 1 with absence of oscillations by using IMC-PID controller


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