RECOVERY FROM PRIOR STIMULATION .2. EFFECTS UPON INTENSITY DISCRIMINATION
RECOVERY FROM PRIOR STIMULATION .2. EFFECTS UPON INTENSITY DISCRIMINATION
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DOI：
10.1016/0378-5955(91)90107-k
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发表时间：
1991-10-01
期刊：
影响因子：
2.8
通讯作者：
RELKIN, EM
中科院分区：
文献类型：
--
作者：
ZENG, FG;TURNER, CW;RELKIN, EM
我们得到了刚可察觉的差异（jnds）的纯音强度后，向前掩蔽。 掩蔽声是以90 dB SPL呈现的以1000 Hz为中心的100 ms窄带噪声突发;纯音信号为1000 Hz，持续时间为25 ms。 掩蔽信号延迟为100 ms。在这些条件下，对于检测前向掩蔽之后的纯音信号没有阈值偏移。 与没有前掩蔽效应对检测阈值的影响相反，观察到异常大的中间电平（40-60 dB SPL）jnds。 这些大的中级jnds被测量为信号延迟的函数，揭示了它们在400 ms时没有完全恢复到正常（未掩蔽）值。我们将这些数据解释为先前刺激后低自发率、高阈值神经元恢复较慢的结果（Relkin和Doucet，1990）。 因此，这些实验可以提供心理物理学证据，低自发率，高阈值神经元是一个必要的生理组成部分，在编码的大动态范围的强度。 此外，目前的数据提供的证据表明，假设前向掩蔽的影响限于100-200毫秒是不合适的，因为这个恢复时间不一定适用于阈上任务。
We obtained just-noticeable differences (jnds) for the intensity of pure tones following a forward masker. The masker was a 100-ms burst of narrow-band noise centered at 1000 Hz presented at 90 dB SPL; the pure-tone signal was at 1000 Hz and was 25 ms in duration. The masker-signal delay was 100 ms. Under these conditions, there is no threshold shift for the detection of the pure-tone signal following the forward masker. In contrast with the absence of a forward-masker effect upon detection thresholds, unusually large midlevel (40-60 dB SPL) jnds were observed. These large midlevel jnds were measured as a function of signal delay, revealing that they are not completely recovered to the normal (unmasked) values by 400 ms. We interpret these data as a consequence of the slower recovery of low-spontaneous rate, high-threshold neurons following prior stimulation (Relkin and Doucet, 1990). These experiments may therefore provide psychophysical evidence that the low-spontaneous rate, high-threshold neurons are a necessary physiological component in the coding of the large dynamic range for intensity. In addition, the present data provide evidence that the assumption that the effect of forward masking is limited to 100-200 ms is inappropriate, as this recovery time does not necessarily apply to suprathreshold tasks.