University of Florida, USA.
J Exp Anal Behav. 2010 Jul;94(1):57-68. doi: 10.1901/jeab.2010.94-57.
Previous reports using stimulus intensity changes to disrupt temporal discrimination have shown shifts in the psychophysical curve for time, while studies using other disruptors have shown a flattening of the curve. The current study investigated the impact of increases and decreases in stimulus intensity on temporal discrimination in pigeons, to determine if a flattening of the curve could be extended to this disruptor. The brightness of the sample to be timed was manipulated under two procedural variations, in which the response alternatives were differentiated by color or location. Results showed that all subjects in the color procedure, and one in the location procedure, showed a flattening of the psychophysical curve when they experienced increased stimulus intensity in descending order. No subjects exposed to an ascending order of stimulus intensities, and none of the other subjects in the location procedure, showed any impact of changed stimulus intensity. Minimal disruption was found when test sessions presented decreased stimulus intensity levels in a second series. These results, together with those using other types of disruptors, add to the evidence of a flattening of the psychophysical curve when temporal discrimination is disrupted.
先前使用刺激强度变化来干扰时间辨别能力的报告显示，时间的心理物理曲线发生了转移，而使用其他干扰物的研究则显示曲线变平。本研究调查了刺激强度增加和减少对鸽子时间辨别能力的影响，以确定这种曲线变平是否可以扩展到这种干扰物。在两种程序变化下，操纵样本的亮度，其中响应选择通过颜色或位置区分。结果表明，在颜色程序中的所有受试者，以及在位置程序中的一个受试者，当他们经历下降顺序的增加刺激强度时，心理物理曲线变平。没有受试者经历上升顺序的刺激强度，也没有位置程序中的其他受试者受到改变刺激强度的影响。当在第二系列中呈现降低的刺激强度水平时，发现最小的干扰。这些结果与使用其他类型的干扰物的结果一起，增加了时间辨别受到干扰时心理物理曲线变平的证据。
