VTE in rats: overlearning and difficulty of discrimination.

Abstract

Previous experiments (1,3) on VTE 1 and visual discrimination learning in rats have indicated that the VTE starts to increase just before (or just as) learning begins, and after that it tends to decrease somewhat. VTE curves have not hitherto, however, ever been carried to a state of definite overlearning to see if, perhaps, when learning is complete, they may not then drop to a very low level.It has also been shown previously (3) that in initial learning rats do more VTE for an easy white-black discrimination than for a difficult white-grey discrimination. It has also been pointed out, however (4) that, in psychophysical experiments with human beings where the instruction as to the stimulus dimension to which they are to respond is already known, the more difficult discrimination tends to induce more rather than less VTE. As a possible explanation of this difference between rats and human beings it was suggested that whereas the data on VTE for rats has thus far been obtained only for the first part of learning (where essentially the animal is still learning what he is to pay attention to), the data for human beings in the psychophysical experiment are obtained after the instructions are already known. Therefore it appeared to us possible that, if rats were first brought to a condition of overlearning on an easy discrimination and then switched to a more difficult discrimination, they might, like human beings, do more rather than less VTE for the more difficult discrimination.The present experiment was an attempt, therefore, to investigate the following questions: (1) What, in general, is the course of the VTE curve for rats after learning has reached a stable maximum and overlearning has set in; (2) what will happen to VTE in rats when, after overlearning has been established on an easy discrimination, the animals are switched to a more difficult discrimination; and(3) how will the final level of VTE for rats on a relatively difficult discrimination compare with its final level on a previous easier discrimination? THE EXPERIMENT

Human vicarious trial and error is predictive of spatial navigation performance

“…Therefore, it not only suggests that participants adapt their strategies to the experimental contingency but also rejects the hypothesis that participants relied on a memory of action sequences in the low-frequency condition. Our results are congruent with the assumption that humans take advantage of head-orientation during spatial-decision making, a component observed in both VTE and head-scanning behaviors 2,9 . In previous studies, the head-orientation variability at given location served to identify the cognitive processes underlying spatial decision-making and spatial representation.…”

“…Evidence for the relationship between VTE behavior and spatial learning have been previously shown 2,6 . In a review of the VTE behavior in rodents, David Redish showed indications that VTE occurs mostly in early stages of spatial learning 6 .…”

“…We hypothesized that humans benefit from behavioral correlates of spatial decision-making, specifically from VTE behaviors, as has been previously shown in rodents 1, 2,5,16 In order to measure whether humans do benefit from these back and forth head-scanning behaviors, we quantified navigational variables in both high and low-frequency conditions. Because highfrequency conditions have, by definition, a greater probability of occurring, we expected that trajectory length and duration of trials with high-frequency start-target combinations would be shorter when compared with low-frequency conditions.…”

Response strategies after overtraining in the jumping stand

“…2 shows that over the last 5 days of overtraining,·Ss made an average of about five VTEs a day (per 10 trials). Tolman and Minuim (1942) have reported a similar decline in VTE for rats overtrained on a black against white discrimination in the jumping stand. During acquisition, most of the Ss took up position habits before they solved the problem.…”

Eye movements of stumptailed monkeys during discrimination learning: VTE revisited

“…Tolman (1938Tolman ( , 1948 reported that, in general, frequency of VTE increases during the learning of visual discrimination problems. Following abrief period at maximum levels, a decline in VTE was usually reported if the problem was not difficult (Tolman & Minium, 1942). Muenzinger (1938) also concluded that VTE was most likely to occur on the trials near the point that learning was complete.…”