Buhusi C V, Schmajuk N A
Department of Psychology: Experimental, Duke University, Box 90086, Durham, NC 27708-0086, USA.
Behav Processes. 1999 Apr;45(1-3):33-57. doi: 10.1016/s0376-6357(99)00008-x.
We present a neural network model of Pavlovian conditioning in which a timing mechanism, by which a CS can predict when the US is presented, activates an architecture in which a stimulus acts as a simple CS and/or as an occasion setter. In the model, stimuli evoke multiple traces of different duration and amplitude, peaking at different times after CS presentation [Grossberg and Schmajuk, 1989. Neural Netw. 2, 79-102]. These traces compete to become associated directly and indirectly (through hidden units) with the US [Schmajuk and DiCarlo, 1992. Psychol. Rev. 99, 268-305]. The output of the system predicts the value, moment, and duration of presentation of reinforcement. Importantly, in contrast to the model by Schmajuk and DiCarlo [Schmajuk and DiCarlo, 1992. Psychol. Rev. 99, 268-305], in the present model a stimulus may assume different roles (simple CS, occasion setter, or both) at different time moments. Moreover, while in the Schmajuk and DiCarlo model [Schmajuk and DiCarlo, 1992. Psychol. Rev. 99, 268-305], competition between CSs is purely associative, in the present model competition between CSs is both associative and temporal. CSs compete to predict not only the presence and the intensity of the US, but also its temporal characteristics: time of presentation and duration. The model is able to address both the temporal and associative properties of simple conditioning, compound conditioning, and occasion setting.
我们提出了一种巴甫洛夫条件作用的神经网络模型，其中一种计时机制（通过该机制条件刺激可以预测无条件刺激何时出现）激活了一种架构，在该架构中，一个刺激既可以充当简单的条件刺激，也可以充当情境设定者。在该模型中，刺激会引发不同持续时间和幅度的多种痕迹，在条件刺激呈现后的不同时间达到峰值[格罗斯伯格和施马尤克，1989年。《神经网络》2，79 - 102]。这些痕迹相互竞争，以直接和间接（通过隐藏单元）与无条件刺激建立联系[施马尤克和迪卡洛，1992年。《心理学评论》99，268 - 305]。系统的输出预测强化呈现的价值、时刻和持续时间。重要的是，与施马尤克和迪卡洛的模型[施马尤克和迪卡洛，1992年。《心理学评论》99，268 - 305]不同，在当前模型中，一个刺激在不同时刻可能承担不同的角色（简单条件刺激、情境设定者或两者皆是）。此外，虽然在施马尤克和迪卡洛的模型[施马尤克和迪卡洛，1992年。《心理学评论》99，268 - 305]中，条件刺激之间的竞争纯粹是联想性的，但在当前模型中，条件刺激之间的竞争既是联想性的也是时间性的。条件刺激不仅竞争预测无条件刺激的存在和强度，还竞争预测其时间特征：呈现时间和持续时间。该模型能够处理简单条件作用、复合条件作用和情境设定的时间和联想特性。
