Dai H, Nguyen Q, Green D M
Department of Psychology, University of Florida, Gainesville 32611, USA.
J Acoust Soc Am. 1996 Apr;99(4 Pt 1):2298-306. doi: 10.1121/1.415417.
A correlation technique was used to assess the decision rules of three listeners in two cases of spectral-shape discrimination tasks. In one case the signal frequency was fixed, and in the other it was randomly varied within each block of trials. In order to estimate the decision rule of the listeners, the experimenter superimposed random level perturbations on each frequency component upon each stimulus presentation. Over many trials, correlation coefficients were computed between the random perturbations and the binary responses of the listeners, and were expressed as a function of signal level. For both the fixed- and random-signal cases, the measured correlation functions were in reasonably good agreement with those predicted based on the likelihood-ratio decision rules. Thus the listeners appeared to use information nearly optimally in discriminating spectral shapes. This investigation demonstrated that the correlation technique can be used to reveal the decision rules for cases where the decision statistics are nonlinear functions of the observations.
采用一种相关技术来评估三名听众在两种频谱形状辨别任务中的决策规则。一种情况是信号频率固定，另一种情况是在每个试验块内信号频率随机变化。为了估计听众的决策规则，实验者在每次呈现刺激时对每个频率成分叠加随机电平扰动。在多次试验中，计算随机扰动与听众二元反应之间的相关系数，并将其表示为信号电平的函数。对于固定信号和随机信号情况，测量得到的相关函数与基于似然比决策规则预测的函数相当吻合。因此，听众在辨别频谱形状时似乎近乎最优地利用了信息。这项研究表明，相关技术可用于揭示决策统计量是观测值非线性函数的情况下的决策规则。
