Cunningham Paul J, Kuhn Robin, Reilly Mark P
Central Michigan University.
J Exp Anal Behav. 2015 Jul;104(1):20-9. doi: 10.1002/jeab.159. Epub 2015 Jun 15.
Whereas intertemporal choice procedures are a common method for examining impulsive choice in nonhuman subjects, the apparatus used to implement this procedure varies across studies. The purpose of the present study was to compare impulsive choice between a two-lever chamber and a T-maze. In Experiment 1, rats chose between a smaller, immediate reinforcer and a larger, delayed reinforcer, first in a two-lever chamber and then in a T-maze. Delay to the larger reinforcer changed in an ascending and descending order (0-32 s) across sessions. Experiment 2 examined the same between-apparatus comparison but under steady-state conditions with the delay fixed at 32 s. In Experiment 1, choice for the larger, delayed reinforcer was generally higher in the T-maze than in the two-lever chamber. Similarly in Experiment 2, steady-state choice for the larger, delayed reinforcer was higher in the T-maze. Choice for the 32-s delayed reinforcer was also greater in Experiment 2 than in Experiment 1, suggesting that extended exposure to the delay is required for the T-maze to yield reliable impulsive choice data. While the reasons for the between-apparatus discrepancies are at present unknown, results from both experiments clearly demonstrate that the apparatus matters when assessing overall level and reliability of impulsive choice data.
虽然跨期选择程序是研究非人类受试者冲动选择的常用方法，但用于实施该程序的设备在不同研究中有所不同。本研究的目的是比较双杠杆箱和T型迷宫中的冲动选择。在实验1中，大鼠在较小的即时强化物和较大的延迟强化物之间进行选择，首先在双杠杆箱中，然后在T型迷宫中。较大强化物的延迟在各实验环节中按升序和降序（0 - 32秒）变化。实验2在稳态条件下进行了相同的设备间比较，延迟固定为32秒。在实验1中，在T型迷宫中对较大延迟强化物的选择通常高于双杠杆箱。同样在实验2中，在T型迷宫中对较大延迟强化物的稳态选择更高。在实验2中对32秒延迟强化物的选择也比实验1中更大，这表明T型迷宫需要更长时间暴露于延迟条件才能产生可靠的冲动选择数据。虽然目前尚不清楚设备间差异的原因，但两个实验的结果都清楚地表明，在评估冲动选择数据的总体水平和可靠性时，设备很重要。
