The Effect of Stimulus Distribution Form on the Acquisition and Rate of Conditioned Responding: Implications for Theory
The Effect of Stimulus Distribution Form on the Acquisition and Rate of Conditioned Responding: Implications for Theory
复制标题
DOI：
10.1037/a0032151
复制
发表时间：
2013-07-01
期刊：
影响因子：
--
通讯作者：
Bonardi, Charlotte
中科院分区：
文献类型：
--
作者：
Jennings, Domhnall J.;Alonso, Eduardo;Bonardi, Charlotte
在四个实验中，大鼠习惯于与食物配对的听觉条件刺激（条件刺激；CS），并在CS的平均持续时间相等的两种条件下比较对CS的学习。在一种情况下，CS在每次试验中都是单一的、固定的持续时间，而在另一种情况下，CS持续时间是从指数分布中得出的，因此每次试验都是不同的。在实验1和实验2和3中，对固定刺激的条件反应率高于对可变刺激的条件反应率。此外，当用固定或可变持续时间训练的刺激在相同的条件下进行测试时（即，用相同数量的固定和可变持续时间试验），这种差异仍然存在，这表明这种差异不能归因于表现效应（实验3）。为了估计条件反应的习得速度，将威布尔函数的尺度累积分布拟合到每只大鼠的逐次反应率中。在受试者内实验中，对固定和可变CS的习得模式显示出特定的差异；当调整试验间隔（ITI）时，结果略有不同（实验4）。讨论了这些发现对条件作用和时间理论的启示。
In four experiments rats were conditioned to an auditory conditioned stimulus (conditioned stimulus; CS) that was paired with food, and learning about the CS was compared across two conditions in which the mean duration of the CS was equated. In one, the CS was of a single, fixed duration on every trial, and in the other the CS duration was drawn from an exponential distribution, and hence changed from trial to trial. Higher rates of conditioned responding to the fixed than to the variable stimulus were observed, in both between- (Experiment 1) and within-subject designs (Experiments 2 and 3). Moreover, this difference was maintained when stimuli trained with fixed or variable durations were tested under identical conditions (i.e., with equal numbers of fixed and variable duration trials)-suggesting that the difference could not be attributed to performance effects (Experiment 3). In order to estimate the speed of acquisition of conditioned responding, the scaled cumulative distribution of a Weibull function was fitted to the trial-by-trial response rates for each rat. In the within-subject experiments specific differences in the pattern of acquisition to fixed and variable CS were shown; a somewhat different pattern was found when intertrial interval (ITI) was manipulated (Experiment 4). The implications of these findings for theories of conditioning and timing are discussed.