Gescheider G A, Hughson B A
Department of Psychology, Hamilton College, Clinton, NY 13323.
Percept Psychophys. 1991 Jul;50(1):45-57. doi: 10.3758/bf03212204.
The effect of stimulus context on absolute-magnitude-estimation (AME) judgments was examined by determining whether the loudness judgment of a tone is influenced by the intensities of other tones presented within the session. A group of 18 subjects was tested in separate sessions in which they judged stimuli within either a low (10-60 dB SL) or a high (40-90 dB SL) range of intensities. Examination of the results of individual subjects revealed that judgments of stimuli common to the two ranges were, in most subjects, unaffected or only slightly affected by the position of the range. The judgments of 2 subjects who failed to follow the instructions, however, showed very large context effects due to changing the stimulus range. The results of a second experiment, in which 22 subjects judged the loudness of tones within either a narrow (35-65 dB SL) or a wide (20-80 dB SL) range, revealed that, in all but 1 subject, the width of the range had no systematic effect on the loudness judgments of stimuli common to both ranges. This was also true 1 month later when 16 of the subjects returned to the laboratory to judge the loudness of tones within an even wider range of 10-90 dB SL. It was concluded that AME judgments are relatively insensitive to the potential biasing influences of stimulus context.
通过确定一个时段内呈现的其他音调的强度是否会影响音调的响度判断，来检验刺激背景对绝对大小估计（AME）判断的影响。一组18名受试者在不同的时段接受测试，他们在低强度范围（10 - 60 dB SL）或高强度范围（40 - 90 dB SL）内判断刺激。对个体受试者结果的检查表明，在大多数受试者中，两个强度范围共有的刺激判断不受该范围位置的影响或仅受到轻微影响。然而，2名未遵循指示的受试者的判断，由于改变了刺激范围，显示出非常大的背景效应。在第二个实验中，22名受试者在窄强度范围（35 - 65 dB SL）或宽强度范围（20 - 80 dB SL）内判断音调的响度，结果显示，除1名受试者外，强度范围的宽度对两个范围共有的刺激的响度判断没有系统影响。1个月后，当16名受试者回到实验室在更宽的10 - 90 dB SL强度范围内判断音调的响度时，情况也是如此。得出的结论是，AME判断对刺激背景的潜在偏差影响相对不敏感。
