Thomas James P, Knoblauch Kenneth
Department of Psychology, University of California, Los Angeles 90095-1563, USA.
J Opt Soc Am A Opt Image Sci Vis. 2005 Oct;22(10):2257-61. doi: 10.1364/josaa.22.002257.
Observers detected a temporally modulated luminance pattern embedded in dynamic noise. A Gabor function with a carrier frequency, in separate conditions of 0, 1.56, or 3.12 Hz, modulated signal contrast. Classification images were constructed in the time, temporal frequency, and temporal phase domains. As stimulus frequency increased, amplitudes of the phase images decreased and amplitudes of the frequency images increased, indicating a corresponding shift in the observers' criteria. The reduced use of phase attenuated time-domain images from signal-absent trials, but physical interactions between signal and noise components tended to preserve time-domain images from signal-present trials. The results illustrate a frequency-dependent strategy shift in detection that may reflect a degree of stimulus uncertainty in the time domain.
观察者检测到嵌入动态噪声中的时间调制亮度模式。在载波频率分别为0、1.56或3.12 Hz的不同条件下，一个Gabor函数调制信号对比度。在时间、时间频率和时间相位域中构建分类图像。随着刺激频率增加，相位图像的幅度减小，频率图像的幅度增加，表明观察者的标准发生了相应变化。来自无信号试验的时域图像中相位的减少使用，但信号和噪声成分之间的物理相互作用倾向于保留来自有信号试验的时域图像。结果说明了检测中频率依赖性策略的转变，这可能反映了时域中刺激不确定性的程度。
