Preference and discrimination between response-dependent and response-independent schedules of reinforcement

Four Asian quail (Coturnix coturnix japonica) were exposed to concurrent-chain schedules, the terminal links of which were either variable-interval 30 sec and variable-time 30 sec, or fixed-interval 30 sec and fixed-time 30 sec. Except for one bird that exhibited a preference for the variable-interval schedule over the variable-time schedule, no consistent preferences were demonstrated for response-dependent or response-independent schedules. However, response rates were three times greater on response-dependent than on response-independent schedules. The discrimination between terminal-link schedules was rapidly recovered after the schedule positions were reversed. Casual observations revealed that the birds engaged in stereotypic circling and pecking while the response-independent schedules were operative.     

The analysis of slalom-ski type movement using a ski-simulator apparatus

The research reported in this paper was designed to assess the feasibility of using a novel apparatus (a so-called ski-movement simulator) in the study of the acquisition of gross cyclical motor skills and further to develop analytic techniques appropriate to the movements involved. Three such methods are discussed: (1) the mean absolute deviation from the middle position as a measure of the ‘amplitude’ of the movement; (2) an auto-correlation coefficient as a measure of the ‘timing’ of the movement; (3) a cross-correlation coefficient as a measure of the ‘smoothness’ of the movement.Progress in learning - as shown by the measures of amplitude and smoothness- showed the expected trend, in that performance improved throughout the whole of the duration of the experiment (four consecutive days), but the rate of improvement gradually decreased. The largest effects were found for the ‘amplitude’ measure, which had the drawback that the ultimate level of performance was constrained by the body weight of the subject. The ‘smoothness’ measure did not suffer from this disadvantage and its suitability as a measure designed to evaluate gross skill acquisition in a laboratory situation is discussed.The ‘timing’ measure did not follow the same trend and reasons for this finding are proposed. Overall, it would seem that the different measures have varying usefulness in the study of skill acquisition and it is therefore advisable to study them separately.     

Validation of ratio scales of opinion by multimodality matching

Ss adjusted loudness and force of handgrip (and in one experiment apparent duration) to match the strength of their opinions regarding racism, occupational desirability, and pronunciability of trigrams. For each stimulus item, median settings of one continuum were plotted as a function of median settings of the other. The resulting power-function exponents agree with previous cross-modality matches and with the results of a cross-modality match of loudness and duration produced by Ss in the present experiments. The results provide validation of ratio scales of opinion and further establish the direct scalingmethods used to obtain them.     

Preferred tempo in the learning of a gross cyclical action

Seventy-five subjects, randomly assigned to one of five training conditions, were required to learn to make large-amplitude, high-tempo, fluent movements on a so-called ski-simulator over a period of four days. Subjects trained under different tempo conditions. In four of the conditions the tempo was prescribed (“preferred”, high, low, or increasing), augmented feedback being provided to enable subjects to stay on “target”. “Preferred” tempo was based on the weight of the subject and was derived from a regression equation based on previous empirical research. In a fifth condition, subjects trained on “discovery learning” principles, i.e. without the tempo being prescribed. The results obtained on the three parameters (amplitude, frequency, and fluency) during the daily test sessions (in which the tempo was not prescribed) formed the data for the analyses.

A learning effect was apparent on all three parameters over the four-day training period. Subjects who trained under the high or the low prescribed tempos, however, were shown to produce significantly smaller amplitude movements than subjects who trained under the other three conditions. Training under the low-tempo condition was also shown to have disadvantageous effects on the parameters tempo and fluency. It was concluded that, for these kinds of action, training at a high or a low tempo—and particularly the latter—has undesirable effects. Such disadvantageous effects, however, were shown to be avoidable if training is begun with the “preferred” tempo of the subject and increased successively by 7% over days.     

The effect of the availability of a dynamic model on the acquisition of a complex cyclical action

This study examines the effect of the availability of a dynamic model on the acquisition of a complex cyclical action: slalom-type ski movements on a ski-simulator. A two-condition design was used, with N = 20 subjects per condition. In the experimental condition subjects had, during training trials, the benefit of the availability of a dynamic (video) model of an expert performer, while subjects in the control condition were left entirely to “discovery learning”. The dependent variables were the amplitude, frequency and fluency of the movement of the ski-simulator platform on which subjects were required to stand in operating the simulator. Movement characteristics of the platform were recorded by means of a microcomputer (Apple II+) coupled to a Selcom 403 camera (SELSPOT system). Subjects having the benefit of a dynamic model during training were shown, at the end of the five-day training period, to produce more fluent movements (of the platform) and to show greater consistency of fluency and of tempo than subjects left entirely to discovery learning. The results are discussed in the context of theories of perception and of motor learning.