Sinnott J M, Brown C H
Psychology Department, University of South Alabama, Mobile 36688.
J Acoust Soc Am. 1993 Mar;93(3):1541-6. doi: 10.1121/1.406812.
This study examined the effects of varying signal duration and pulse repetition rate on pure tone frequency difference limens (FDLs) at 500 Hz and 4 kHz in humans and monkeys. Two experiments examined FDLs as a function of tone duration from 12-400 ms, using stimuli presented either with a constant pulse rate, or with a constant interstimulus interval. In both cases, at 500 Hz, human FDLs increased more than monkey FDLs as duration decreased from 400 to 12 ms. This effect resulted in monkey FDLs that were about 14 times larger than human FDLs at 400 ms, but only about 4 times larger at 12 ms. At 4 kHz, human and monkey FDLs showed more similar rates of increase as duration decreased. A third experiment examined FDLs at 500 Hz for a 100-ms tone as a function of pulse rate (1 per 250-2000 ms). Here, FDLs for humans and monkeys varied in a similar fashion, indicating that both species' sensitivity was similarly affected by manipulating temporal variables relating to memory load, rather than sensory coding. These data provide evidence that, at 500 Hz, humans have a qualitatively different pure tone frequency analyzing mechanism from monkeys, possibly based on better access to phase-locking mechanisms.
本研究考察了不同信号持续时间和脉冲重复率对人类和猴子在500赫兹和4千赫兹时纯音频率辨别阈限（FDLs）的影响。两项实验考察了FDLs作为音调持续时间（12 - 400毫秒）的函数，使用以恒定脉冲率或恒定刺激间隔呈现的刺激。在这两种情况下，在500赫兹时，当持续时间从400毫秒减少到12毫秒时，人类的FDLs比猴子的FDLs增加得更多。这种效应导致在400毫秒时猴子的FDLs比人类的FDLs大约大14倍，但在12毫秒时仅大约大4倍。在4千赫兹时，随着持续时间的减少，人类和猴子的FDLs显示出更相似的增加速率。第三个实验考察了在500赫兹时100毫秒音调的FDLs作为脉冲率（每250 - 2000毫秒1次）的函数。在这里，人类和猴子的FDLs以相似的方式变化，表明通过操纵与记忆负荷相关的时间变量，而不是感觉编码，两个物种的敏感性受到相似的影响。这些数据提供了证据，即在500赫兹时，人类与猴子在纯音频率分析机制上存在质的差异，这可能基于对锁相机制更好的利用。
