Rule learning in children: Multiple-set training and intermediate-size transposition

Two experiments were conducted in which the subjects were trained to choose the middle-size stimulus in either a single stimulus set or in each of two nonoverlapping stimulus sets. Following criterion, each subject was presented with a series of 12 test trials involving a new stimulus set. In Experiment 1, kindergarten children tended to choose the middle-size test stimulus if the test set consisted of stimuli intermediate in size to the stimuli in the smaller and larger training sets. When the test stimuli were all larger than any of the training stimuli, the probability of choosing the middle-size stimulus increased as the distance between the two training sets increased. Three groups of children participated in Experiment 2: a kindergarten group, a first-grade group, and a first-grade group that experienced middle-size training a year earlier. The distance between training sets and two training procedures affected the three groups in a similar manner during acquisition, but several interactions were obtained during the test. The findings were discussed in terms of the Lane and Rabinowitz (D. M. Lane & F. M. Rabinowitz, Child Development, 1977, 48, 412–426) rule based theory of intermediate-size transposition and suggestions were made as to how children acquire the concept of middle.     

Odor as a conditioned inhibitor: Applicability of the Rescorla-Wagner model to feeding behavior

Hooded rats were given conditioned inhibition training in which the taste of saccharin alone was always followed by induced illness, but the taste of saccharin plus the odor of amyl acetate was not. In a series of three subsequent tests—summation, enhancement of conditioning, and retardation—it was demonstrated that the odor had acquired active inhibitory properties. The results paralleled those obtained with more traditionally studied stimuli and techniques and hence were found to be readily predictable from a recent model of conditioning set forth by Rescorla and Wagner (1972).     

Delayed reward learning: Disproof of the traditional theory

Without the aid of secondary rewards to bridge the temporal gap, each of 15 rats learned to select the rewarded side of a T-maze although the reward was delayed until 1 min after the response was emitted. Similar results were obtained from another group of eight rats for which the length of the delay was 5 min. In a final experiment using the same basic procedure, five groups of rats were trained for 25 days with delays of 0.5, 1.0, 2.0, 4.0, or 8.0 min. The percentage of correct responses did not significantly differ among groups. According to prevailing psychological theory, these results are impossible.     

Quasi-statistical inference in rating behavior I. Preliminary investigations

Bem and Allen (1974) have suggested that trait consistency-ratings can function as a moderator variable, with regard to the cross-situational validity of trait position-ratings. The present study attempts to consider the relationship between these two types of self-ratings. A model of “man the quasi-statistician” was proposed which yields the predictions that (a) consistency-ratings will vary positively with the polarization-estimate from position-ratings and (b) the extent of correlation will be a function of the degree of polarization associated with a given class of trait.In two experiments, position-ratings and consistency-ratings were obtained over a series of dimensions. The predictions were confirmed in both studies. In addition, Experiment II provided evidence for a correspondence between intuitive and formal estimates of central tendency polarization, although this was not the case for dispersion. The results were discussed as bearing on the model and as relating to the findings of Bem and Allen (1974).     

Visual discrimination learning with a 1-min delay of reward

Eight rats were successfully trained in a black-white discrimination with a 1-min delay of reward. The procedure was unusual in that the rat spent the delay outside the apparatus in its home cage. Immediately after the rat responded, whether correctly or incorrectly, it was removed from the choice compartment and placed in its home cage. When the delay ended, it was returned to the startbox. If the preceding response had been correct, the rat received a reward of sugar water; otherwise, it was allowed to make another choice response. Mediation by external cues was excluded because there was no difference in the way the rats were treated after a correct or an incorrect response until the delay interval ended. Mediation by proprioceptive stimuli was excluded because position was an irrelevant cue.     

Risky decision: Attention effects or masking effects?

The Marshak bid procedure shows that more money is required to induce a S to exchange gamble a for gamble e and then e for b if e differs from a only in the winning amount and differs from b only in the probability of winning, rather than if e differs from a only in the probability of winning. This is contrary to most theories of risky decision making which imply that the amount of money necessary to effect a 2-step exchange between a and b should be independent of the intermediary gamble. One might attempt to explain the effect by saying that the S attends to the dimension which is different between gambles. But the explanation is untenable if one assumes that states of attention are defined as weightings of the dimensions. An alternative explanation is put forward which basically assumes that winning amounts mask differences in probability of winning more than vice versa. The formalization of the theory is given in terms of Fechnerian integration over imperfect differentials.     

Risky decision: Attention and path dependency as a function of response mode

It was previously shown and was here replicated that the amount of money required to induce a subject to exchange one gamble for a second and then the second for a third depends on the second (intermediate) gamble. This path dependency cannot be explained by any of the algebraic models (including SEU), nor can it be explained as a simple attention effect. A model was put forward which explains the effect in terms of differential masking depending on a kind of stimulus—response compatibility. The effect of response mode on path dependency was examined in this study; similarity judgements showed no consistent path dependency nor did difference in rated attractiveness of gambles presented in pairs, but rated attractiveness was different for gambles presented singly. Since it might be that monetary response emphasises the monetary aspects, that is, the winning amount of the gamble, it was thought that a probability response would emphasise the probability of winning. However, when subjects were asked to set the probability of winning $ 12 which would induce them to exchange one gamble for another, not only was no path dependency observed, but the subjects' responses seemed to depend only on the difference in expected value of the gambles. This suggests the possibility of developing response-display modes which would eliminate or at least attenuate the inconsistencies observed in risky decision processes.     

Cross-modal transfer and intermediate-size transposition

Kindergarten and third grade boys learned an intermediate-size problem either visually or tactually. They were then tested either visually or tactually. The test sets were separated from the training set by either 1, 2, or 4 steps. The data supported predictions derived from the D. M. Lane and F. M. Rabinowitz (Child Development 1977,48, 412–426) transposition theory on choice and consistency measures. Of greatest interest were the markedly different transposition gradients exhibited by the boys in the visual-visual and visual-tactual groups.     

The role of reference in children's acquisition of a miniature artificial language

Nursery school children were presented with a simple miniature artificial language in one of three conditions. In the first, the stimuli to which the words referred contained an inherent lawful relationship and the language syntax reflected this relationship. In the second, the stimuli contained an inherent lawful relationship but the language syntax did not reflect this relationship. In the third, no lawful relationship existed among the stimuli to which the words referred so the language syntax imposed an arbitrary relationship among stimuli. Subjects in the first group were able to produce more correct utterances than those in the other two groups when the stimuli to which the words referred were not present, suggesting that some form of semantic mediation mechanism was being used. Evidence from novel constructions indicates that for both groups using stimuli containing an inherent lawful relation there were interactions between semantic learning mechanisms and syntax learning mechanisms.     

Trace decay and the priming of short-term memory in long-delay taste aversion learning: Disruptive effects of novel exteroceptive stimulation

A variation of Kalat and Rozin's two-presentation paradigm was used to test the hypothesis that the first, as opposed to the second, presentation of a flavor conditioned stimulus (CS) constitutes the functional CS in two-presentation experiments involving moderate interflavor intervals (IFIs), and results in flavor aversions that are a function of the primary, as opposed to the secondary, conditioned stimulus-unconditioned stimulus (CS-US) interval. Contrary to the hypothesis, it was shown in Experiment 1 that holding the primary CS-US interval constant at 4 hr for each of three groups, while decreasing the secondary CS-US interval (i.e., the interval between the second flavor presentation and the illness) from 3.75 hr to 2.5 hr to .5 hr, resulted in the flavor aversion increasing as the secondary CS-US interval decreased. However, the aversion acquired by the group with a 0.5 hr secondary CS-US interval was also found to be significantly weaker than that acquired by a single-presentation 0.5 hr control group. In Experiment 2 it was demonstrated that animals exposed to novel exteroceptive stimulation (NES) immediately prior to a second flavor presentation that preceded the US by 0.5 hr acquired an aversion as strong as that acquired by a 0.5-hr control group. In Experiment 3 it was demonstrated that, in the absence of a second flavor presentation, animals exposed to novel exteroceptive stimulation 0.5 hr prior to the US acquired a weaker flavor aversion than did animals not exposed to novel exteroceptive stimulation during the 4-hr flavor CS-illness US interval. The contrasting effects of novel exteroceptive stimulation observed in Experiments 2 and 3 were replicated in Experiment 4. The results suggest, consistent with the trace-decay hypothesis and Wagner's (1976) general model of stimulus processing, that exposure to novel exteroceptive stimulation disrupts continued processing of the short-term memory (STM) trace of the initial presentation of a flavor CS, and hence minimizes stimulus preexposure effects attributable to the priming of STM.     

The influence of flavor preexposure and test interval on conditioned taste aversions in the rat

The effects of flavor preexposure and test interval on conditioned taste aversions were examined in four experiments. In the first three experiments, prior experience with a flavor different from that used as a conditioned-stimulus (CS) produced attenuated aversions when testing occurred after a 1-day interval but not after a 21-day interval. Preexposure to the same stimulus used as a CS produced attenuated aversions at both 1- and 21-day intervals. In Experiment 4, a delay interval between flavor preexposure and conditioning eliminated the attenuating effect of preexposure, but only when different stimuli were used for preexposure and conditioning. These data could not be easily accounted for by contemporary interpretations of preexposure as an event that interferes with subsequent acquisition of a conditioned aversion. An alternative retrieval interference hypothesis was outlined.     

Visual processing of multielement arrays and selective backward masking

In the first of two selective masking experiments, 7-letter rows were followed at several ISIs by a mask or no-mask and a bar-marker partial report cue. The results suggest that the arrays were processed ends-first and then, in general, from both ends towards the middle. In the second experiment, bar-marker partial report cues were presented at the onset or offset of 6-letter/1-digit or 7-letter rows. The subjects could not anticipate the category of the to-be-reported item with the alphanumeric displays. With a delayed cue, selective masking was obtained with both mixed category and pure letter arrays, but with simultaneous cuing, masking was always distributed across all serial positions. The results suggest that the subjects: (a) abstracted some information about category from the mixed arrays during an initial parallel stage of processing, (b) selectively attended to mainly the cued item with simultaneous probes with homeogeneous and mixed category displays, and (c) employed an ends-first processing strategy with both types of arrays when the bar-marker partial report cue was delayed.     

Blocking of a taste aversion by prior pairings of exteroceptive stimuli with illness

Although rats preferentially associate gustatory stimuli with illness, this does not imply that other types of stimuli cannot be associated with illness. In Experiment 1, rats consuming tap water in a distinctive environment prior to illness subsequently suppressed ingestion in that environment, whereas rats poisoned or injected with saline 10 hr later did not. It was also found that rats poisoned after drinking saccharin in the environment paired with illness developed weaker saccharin aversions than identically trained rats which drank saccharin in a different location. In Experiment 2, degrading the correlation between injection-related cues and illness by interpolating saline injections between LiCl preexposures attenuated the decremental effects of illness preexposure. The strength of the exteroceptive cue-illness associations observed in these studies suggests that theories based on evolutionary arguments are not the most appropriate frame of reference for analyzing stimulus selection in poison-induced avoidance.     

Interference with ingestional aversion learning produced by preexposure to the unconditioned stimulus: Associative and nonassociative aspects

Preconditioning exposure to a lithium chloride unconditioned stimulus (US) interferes with the subsequent conditioning of a taste aversion. Multiple US preexposures produce a long-lasting or durable interference with aversion learning, whereas a single US exposure produces a transient interference effect. The present experiments demonstrate that the durable US preexposure effect is substantially reduced if the method of drug treatment (infusion versus injection of the drug into the peritoneal cavity) or the spatial cues present during drug treatment (home cage versus a distinctive environment) are changed between the preexposure and taste conditioning phases of the experiment. In contrast, these manipulations do not attenuate the proximal/transient US preexposure effect. These findings indicate that different mechanisms are responsible for the two US preexposure effects. The results are consistent with previous suggestions that the durable effects of lithium preexposure are due to associative interference produced by the exteroceptive stimuli that accompany drug administrations and indicate that the proximal/transient US preexposure effect is mediated by nonassociative mechanisms.     

Remembrance of places lasts: Proactive inhibition and patterns of choice in rat spatial memory

A series of experiments was carried out to evaluate the notion that rats given a sequence of massed daily trials on the radial maze reset working memory at the end of each trial by deleting its contents. Although curves presented by D. S. Olton [Scientific American, 1977, 236, 82–98; In S. H. Hulse, H. Fowler, & W. K. Honig (Eds.), Cognitive processes in animal behavior, Hillsdale, N.J.: Erlbaum, 1978] show that rats return to errorless performance at the beginning of each trial after the first, the fact that accuracy falls less rapidly over choices on Trial 1 than on subsequent trials suggests a proactive inhibition (PI) effect. In Experiment 1, Olton's findings were replicated, and a PI effect was observed on Days 1–2 of testing. On Days 3–5, overall accuracy improved significantly and was associated with the development of a strong tendency for rats to enter adjacent alleys, which became particularly marked on the final trials of a day's testing. In order to prevent rats from achieving accurate performance by using an adjacent alleys pattern, a procedure was used in Experiment 2 which involved initial forced random choices followed by a retention test consisting of free choices. Repeated daily trials with this procedure yielded a significant PI effect, which was more marked at a 60-sec delay than at a 0-sec delay. Experiments 3 and 4 showed this PI effect to be robust and resistant to manipulations designed to produce release from PI. Both the PI effect and a strong tendency found in Experiment 1 for animals to avoid on the initial choices of Trial n those alleys most recently entered on Trial n?1 argue that rats do not reset working memory between trials.     

Verbal reports of stimulus effects on learning: Introspection revisited

The accuracy of subjects' verbal reports on the respective causal roles of relevant and irrelevant stimulus factors on learning was investigated. In two experiments, university undergraduates learned strings of letters that were either grammatically structured or unstructured (a causal variable) and either color coded or black (a salient but irrelevant variable). Results indicated that subjects reported more causal impact of color than structure on the learnability of lists, despite the fact that the latter variable and not color had an actual effect on learning. It was proposed that verbal reports of stimulus effects on one's own behavior can be regarded as a task in estimates of covariation rather than direct retrieval of memory traces.