The acquisition of conditioned responding.

Abstract

This report analyzes the acquisition of conditioned responses in rats trained in a magazine approach paradigm. Following the suggestion by Gallistel, Fairhurst and Balsam (2004), Weibull functions were fitted to the trial-by-trial response rates of individual rats. These showed that the emergence of responding was often delayed, after which the response rate would increase relatively gradually across trials. The fit of the Weibull function to the behavioral data of each rat was equaled by that of a cumulative exponential function incorporating a response threshold. Thus the growth in conditioning strength on each trial can be modeled by the derivative of the exponential -a difference term of the form used in many models of associative learning (e.g., Rescorla & Wagner, 1972). Further analyses, comparing the acquisition of responding to a continuously reinforced stimulus (CRf) and a partially reinforced stimulus (PRf), provided further evidence in support of the difference term. In conclusion, the results are consistent with conventional models that describe learning as the growth of associative strength, incremented on each trial by an error-correction process.

Duration of the unconditioned stimulus in appetitive conditioning of honeybees differentially impacts learning, long-term memory strength, and the underlying protein synthesis

“…Because the CR during acquisition and extinction 24 h later does not differ between groups that were trained with different US durations we conclude that these parameters were sufficient for the CS to become a predictor for the US. Indeed, several studies in honeybees and vertebrates indicate that timing variables such as the duration of the CS, the interval between CS and US onset, the intertrial interval and the number of trials are directly correlated with the strength of the CR during learning and memory retention (Menzel et al 1993Friedrich et al 2004;Harris 2011;Kirkpatrick 2014).…”

The effect of stimulus distribution form on the acquisition and rate of conditioned responding: Implications for theory.

“…These data were then smoothed by calculating response rates over a 5-trial moving average (i.e. trials 1-5, 2-6, 3-7 etc), to avoid trial-by-trial variability in responding obscuring meaningful differences (Harris, 2011). A scaled Weibull cumulative function (Equation 1) was then fitted to these data.…”

“…This method has been argued to be theoretically unbiased (cf. Gallistel, Fairhurst & Balsam, 2004;Harris, 2011), and yields optimal fit parameters which allow interpretation of different features of the acquisition function. It also gives other estimates of the speed of acquisition, such as the number of trials it takes for responding to reach 10% (onset latencywhich can be seen as the start of acquisition), and the dynamic interval -the number of trials required to go from 10% to 90% of the individual's asymptotic rate of responding.…”

Information Theory, Memory, Prediction, and Timing in Associative Learning

“…The number of reinforced trials to acquisition-trials on which the US predicted by the CS actually occurs-is invariant under partial reinforcement. Interpolating, for example, an average of 9 unreinforced trials between each reinforced trial does not increase the number of reinforced trials required for the conditioned response to appear , Williams 1981, Gottlieb 2005, Harris 2011). Because the interpolation of unreinforced CS presentations weakens net excitatory strength in associative theories of associative learning, this invariance also constitutes a strong explanatory challenge for such theories.…”