The effects of stimulus type,training, and chronological age on children's identification and recoding of multidimensional stimuli

Kindergarten and second-grade children (75 and 99 months of age, respectively) were first taught that the two stimuli within each of four pairs of multidimentional stimuli differed with respect to their values on every one of three bivalued dimensions: color, size, and form. Each of the eight stimuli was then presented twice, one at a time, and the child was asked either to find its duplicate (eight encoding trials) or to find its complementary mate (eight recoding trials) among the complete set of eight stimuli. Next, each of the eight stimulus compounds was presented twice as a display stimulus for 5 sec and, after a delay of 10 to 15 sec, the child was asked to find the display stimulus (eight trials of encoding plus memory) or its complement (eight trials of recoding plus memory) among the complete set. The stimuli for half the children in each age group were standard unitary compounds (e.g., a large red circle, a small blue square, etc.) and for the other half they were partitioned stimuli with their dimensional values spatially separated (e.g., large arrow, circle outline, and patch of color). Half of the children in each of these subgroups were given a basic pretraining, and the other half received extended pretraining, in recoding the stimulus attributes. The results indicated that unitary stimuli were easier to encode but the partitioned stimuli were easier to recode, that recoding was much more difficult than encoding, that extended training improved recoding performance, and that second graders were slightly better at encoding and much better at recoding than the kindergarten children. The patterns of performance on the tasks involving memory were similar to those just described. The results were discussed in terms of children's abilities to analyze multidimensional stimuli into their dimensional components.     

Factors affecting hypothesis testing in kindergarten children

In a previous experiment, the authors demonstrated that kindergarten and first-grade children can be trained to test hypotheses sequentially within the context of a discrimination learning task. The present experiment is concerned with delineating various aspects of the pretraining that contribute to the improved hypothesis-testing strategies of kindergarten children (mean CA = 71.6 months). It was found that children who have learned to anticipate an invariant cue-reward relation in such tasks manifest improved hypothesis-testing behavior, as well as improved discrimination performance, whereas children who have been trained to identify and name the various stimulus components of the discriminanda do not perform better than those without such training. It was also found that children who have had practice in shifting from an irrelevant to a relevant dimension perform better than those who have not had such experience. Moreover, children who have been given explicit instruction and training in the use of win-stay and lose-shift rules, as well as in the use of valid hypotheses, manifest strategies superior to those without such training. Finally, extensive pretraining over two sessions, administered on separate days, resulted in a marked reduction in the proportion of children who were dimensionally fixated while solving discrimination problems with two genuine dimensions.     

Effects of associatively significant posttrial stimuli on learning and memory

Pigeons were trained on a delayed conditional discrimination in which the choice between two simultaneously presented stimuli depended on how the trial started. Choice of one of the stimuli was reinforced if the trial had been initiated by presentation of a food sample and choice of the other was reinforced if no sample had been presented. Subsequently, test trials were administered on which an associatively significant stimulus was presented during the retention interval. This manipulation was intended to modulate the short-term retention of information about the food sample. It was found that performance on food sample test trials was enhanced by presentation of an excitor for food, disrupted by presentation of an inhibitor for food and unaffected by presentation of an associatively neutral stimulus. The impact of these posttrial stimuli was also assessed on the ability of the food sample to serve as a reinforcer. This was done by recording the development of responding to a keylight that signalled the food sample on these test trials. Compared to the associatively neutral stimulus, both the excitor and the inhibitor interfered with the development of keypecking. These results are discussed with regard to the issue of how posttrial events modulate associative learning.     

Avoidance conditioning as a function of appetitive stimulus pretraining: Response and stimulus transfer effects

Pretrained appetitive discriminative stimuli were used as warning signals in subsequent avoidance learning. In Expt 1 identical responses were required in pretraining and in avoidance learning. An appetitive S+ facilitated avoidance learning in rats in comparison to S? or a stimulus previously uncorrelated with food. In Expt 2, the type of response in pretraining and in avoidance learning was varied. Groups with homogeneous responses in the two situations replicated Expt 1 results, whereas groups with different responses in pretraining and avoidance learning failed to show an advantage when S+ served as warning; in the heterogeneous response groups, S? was as effective as S+. Inhibitory factors in the heterogeneous groups were discussed as an explanation for these results.     

The problem-solving strategies of kindergarten and first-grade children during discrimination learning

Kindergarten and first-grade children (6 and 7 years of age, respectively) were given specially designed discrimination tasks with introtact probes preceding each trial. One group (CON) was given the criterion task without prior training. A second group (LTL) received three pretraining tasks of the same type as the criterion task. A third group (HYP) received the same pretraining tasks, but with explicit instructions designed to teach a simple hypothesis-testing strategy. Several indices, designed to reflect the use of win-stay and lose-shift rules, as well as memory for disconfirmed hypotheses, were computed from the protocols of the criterion task. The indices for Group CON suggested that most of these children were using a guessing strategy that involved quite frequent changes in hypotheses. Moreover, many of these children restricted their hypotheses to the irrelevant cues. The indices for Group LTL revealed a spontaneous use of the hypothesis-testing strategy by nearly half of the children. The results for Group HYP indicated that over four-fifths of these children became highly efficient in the use of the problem-solving strategy.     

Transfer in discrimination learning: Do children mediate more than adults?

A series of four-dimensional, discrimination-learning problems were presented to second-, sixth-, eighth-, and twelfth-grade students (ages 7, 11, 13, and 17 years, respectively). One pretraining problem, using different dimensions, preceded the four experimental problems; these employed identical dimensions and stimulus values. Solutions were selected without dimensional replacement.Blank-trial probes enabled detection of initial predictions. Results clearly indicated that (1) older subjects made dramatically fewer intradimensional predictions (utilizing the solution dimension from the preceding problem) than did younger subjects, (2) all age groups demonstrated systematic changes over problems; these reflected the specific solution sequence experienced, and (3) there were consistent developmental differences in the speed with which subjects noted and utilized regularities across problems.The pattern of data is not congruent with the expectations of mediation theory. However, it is in accord with the transfer hypothesis, which is a recent extension of hypothesis theory. The transfer hypothesis provides a theoretical framework which suggests when we should observe “mediational” behavior (i.e., intradimensional transfer) and when to expect the inverse.     

Scopolamine amnesia of passive avoidance: a deficit of information acquisition

Despite its increasing use as an animal model of memory deficit in human dementia, relatively few studies have attempted to assess the memory processes involved in the anticholinergic-induced impairment of passive avoidance retention. In the present experiments, the influence of scopolamine administered prior to or immediately following training on 24-h retention of step-through passive avoidance was studied in NMRI mice. In low doses (0.3-3.0 mg/kg ip) pretraining administration (-5 min) of scopolamine induced a very strong amnesia. Post-training scopolamine induced a significant effect only at the highest dose tested (30 mg/kg). In a retention test of longer than normal duration (600 vs 180 s), which resulted in a more favorable comparison value in the control group, an intermediate post-training dose (10 mg/kg) induced a small effect which approached significance; a finding which may account for conflicting reports in the literature concerning the ability of scopolamine to induce a post-training deficit. The pretraining effect does not appear to have been solely the result of state-dependent learning; scopolamine (3 mg/kg) administered before both the training and test sessions induced a deficit of approximately the same magnitude as that found when administered before training or before testing only. The results indicate that scopolamine can induce a small post-trial effect, presumably through an influence on consolidation processes. The much larger effect of pretrial scopolamine, however, indicates a primary influence on processes related to information acquisition. Together with findings from the literature, the present experiments suggest that scopolamine-induced amnesia partially, but not completely, models the memory deficits of human dementia.     

BASIC PREMISES OF MULTIDIMENSIONAL ATTITUDE CHANGE THEORY: AN EXPERIMENTAL ANALYSIS

Multidimensional attitude change models propose that (1) stimuli defining the domain of attitudes may consist of a multidimensional rather than unidimensional pattern; (2) stimuli associated with each other in the persuasion process will converge with each other in the multidimensional attitude domain. These two propositions receive clear support from three of the hypotheses tested in four-panel cohort data, which analyses show to be multidimensional. The sources of a persuasive message converge on the position they advocate. Multiple sources converge on each other. The findings provided partial support for two other hypotheses on the convergence of self-concept with advocated position and with sources of a persuasive message. A final, somewhat tangential hypothesis also receives clear support: existential associations of concepts are more effective than hortatory associations. These results support further development of multidimensional attitude change models.     

The value of being imitated

Theories and research on the topics of attraction, conformity, and imitation support the view that the relational stimulus arising from being imitated serves a reinforcing function. To examine this possibility, 48 preschool children performed a task in which some neutral stimuli were repeatedly associated with an adult's matching the behavior of the subject, and other neutral stimuli were associated with the same adult's mismatching the behavior of the subject. Preference for the stimuli associated with being matched was greater at the end of training than earlier, and the overall preference for the matched stimuli exceeded chance. The results are considered in terms of the thesis that similarity arising from being imitated served a reinforcing function and the thesis that response strategies were adopted by the children.     

Control of children's observing responses by information feedback during visual discrimination learning

Four experiments examined the control of observing responses by information feedback during visual discrimination learning. Second-grade children participated in Experiment 1; kindergarten, second-, and fifth-grade children were subjects in Experiments 2 and 3, and grade 5 and adult subjects were tested in Experiment 4. In order to view the stimuli, subjects in Experiments 1, 2, and 3 activated lights in viewing boxes; in Experiment 4, stimulus fixations were measured using a corneal reflection technique. Fifth graders and adults observed the discriminative stimuli for longer times on trials following negative feedback than on trials following positive feedback; in contrast, kindergartener's observing was not affected by type of feedback. Second graders showed smaller and less reliable reactions to type of feedback than did older subjects. These results support the view that visual observing is controlled by cognitive processes associated with hypothesis testing.     

Influence of temporal context on value in the multiple-chains and successive-encounters procedures

This set of studies explored the influence of temporal context across multiple-chain and multiple-successive-encounters procedures. Following training with different temporal contexts, the value of stimuli sharing similar reinforcement schedules was assessed by presenting these stimuli in concurrent probes. The results for the multiple-chain schedule indicate that temporal context does impact the value of a conditioned reinforcer consistent with delay-reduction theory, such that a stimulus signaling a greater reduction in delay until reinforcement has greater value. Further, nonreinforced stimuli that are concurrently presented with the preferred terminal link also have greater value, consistent with value transfer. The effects of context on value for conditions with the multiple-successive-encounters procedure, however, appear to depend on whether the search schedule or alternate handling schedule was manipulated, as well as on whether the tested stimuli were the rich or lean schedules in their components. Overall, the results help delineate the conditions under which temporal context affects conditioned-reinforcement value (acting as a learning variable) and the conditions under which it does not (acting as a performance variable), an issue of relevance to theories of choice.     

Extradimensional transfer in the easy-to-hard effect

In three experiments analyzing determinants of the easy-to-hard effect, pigeons acquired a hard discrimination after training on other problems. Intradimensional pretraining resulted in immediate transfer to the hard discrimination. Extradimensional pretraining consistently did not produce immediate transfer but did facilitate learning rate. In Experiment 1, the compounding of cues from an easy extradimentsional discrimination with those from the hard discrimination resulted in the former overshadowing the latter. When different types of extradimensional discriminations were introduced in Experiments 2 and 3, the degree of transfer was not proportional to the similarity in incidental background cues across problems. The findings indicate that in the easy-to-hard effect: (a) intra- and extradimensional mechanisms jointly contribute to the development of stimulus control, (b) intradimensional transfer is more consistent with the gradient-interaction model than the selective attention model, and (c) extradimensional transfer is better accounted for by the construct of general attentiveness rather than by the neutralization of background cues.     

On the dominance of unidimensional rules in unsupervised categorization.

In several experiments, observers tried to categorize stimuli constructed from two separable stimulus dimensions in the absence of any trial-by-trial feedback. In all of the experiments, the observers were told the number of categories (i.e., two), they were told that perfect accuracy was possible, and they were given extensive experience in the task (i.e., 800 trials). When the boundary separating the contrasting categories was unidimensional, the accuracy of all observers improved significantly over blocks (i.e., learning occurred), and all observers eventually responded optimally. When the optimal boundary was diagonal, none of the observers responded optimally. Instead they all used some sort of suboptimal unidimensional rule. In a separate feedback experiment, all observers responded optimally in the diagonal condition. These results contrast with those for supervised category learning; they support the hypothesis that in the absence of feedback, people are constrained to use unidimensional rules.     

Retardation of autoshaping following pretraining with unpredictable food: Effects of changing the context between pretraining and testing

In Experiment 1, pigeons exposed to US ONLY pretraining were observed to be retarded in the acquisition of autoshaping relative to naive controls; however, gross changes in contextual stimuli between pretraining and testing alleviated the retardation effect. In Experiment 2, groups of pigeons exposed to CS ONLY, US ONLY, or random CS-US presentations (TRC) were tested for the acquisition of autoshaping. The US ONLY and TRC groups were retarded relative to naive controls. The context change manipulation eliminated the US ONLY retardation effect and attenuated, but did not eliminate, the TRC retardation effect. Context blocking accounts for the US ONLY effect and contributes to the TRC effect; however, context-independent retardation following TRC pretraining suggests the operation of the learned irrelevance cognition.     

Attending and processing broadened within children's concept learning

In a reviewed series of spontaneous and learning-set studies of adults and children, we have monitored active-touch overt attending during concept learning. Adults solved the problems even if they attended to four dimensions in the same trial; however, young children failed when attending so broadly but solved when attending to a single dimension. In the present training study, 18 6-year-olds solved all problems when restricted to attend to anly one dimension. After a special pretraining program proceeding through the subprocesses of stimulus familiarization, discrimination, labeling, “attentional broadening,” and memorization, 13 of the children managed to attend to all four dimensions in one trial and solve faster than adults. Findings suggest a developmental hypothesis that learning grows with spontaneous “tailoring” of attention to memory capacity.     

Establishing discriminative stimulus control within generalized oddity performance,without reinforcement

In two oddity learning studies with children, subjects were reinforced for oddity (or nonoddity) responding on line-tilt or dot numerosity problems. Interposed form and color problems were not reinforced. No instructions to make oddity choices were given. In Experiment I it was found that reinforcement for oddity or nonoddity responding on tilt and numerosity problems produced the corresponding tendency toward oddity or nonoddity performance on these problems and also on the nonreinforced form and color problems. These results show a generalized oddity phenomenon similar to generalized imitation. In Experiment II a third type of nonreinforced problem was presented in this same format: compound stimuli permitting either a color or a form solution. It was found that immediate prior training with nonreinforced form problems, interpolated among the reinforced tilt and numerosity problems, led to form-oddity choices in the compound problems. Similarily, color pretraining produced color-oddity choices. These results show that selective discriminative stimulus control can be obtained in oddity learning, without reinforcement for choices on either of the two dimensions involved.     

Normative Scoring of Multidimensional Pairwise Preference Personality Scales Using IRT: Empirical Comparisons With Other Formats

In this article, we offer some suggestions as to why tetrads and pentads have become the dominant formats for administering multidimensional forced choice (MFC) items but, in turn, raise questions regarding the underlying psychometric model and means of addressing item quality and scoring accuracy. We then focus our attention on multidimensional pairwise preference (MDPP) items and present an item response theory–based approach to constructing and modeling MDPP responses directly, assessing information at the item and scale levels, and a way of computing standard errors for trait scores and estimating scale reliability. To demonstrate the viability of this method for applied use, we show that the correspondence between MDPP scores derived from direct modeling with those obtained using single statement and unidimensional pairwise preference measures administered in a laboratory setting. Trait score correlations and criterion related validities are compared across testing formats and rating sources (i.e., self and other), and the usefulness of our model-based approach is further demonstrated by some illustrative results involving computerized adaptive tests (CAT).     

A Multidimensional and Multilevel Extension of a Random-Effect Approach to Subjective Judgment in Rating Scales

In responding to rating scale items, respondents may hold different perspectives on the given categories. The random-effect rating scale model (RERSM), developed to account for variations in the category thresholds across respondents, is unidimensional and unilevel. It becomes statistically inefficient when multiple unidimensional tests have to be analyzed and inapplicable when data have a multilevel structure (e.g., respondents nested within organizations, students nested within schools). To resolve these problems, this study develops a multidimensional and multilevel version of the RERSM. The parameters can be estimated with existing computer software. Thus, there is no need to develop estimation procedures or corresponding computer programs. Simulation studies were conducted to evaluate the parameter recovery of the multidimensional RERSM, the multilevel RERSM, and the multidimensional and multilevel RERSM using WinBUGS. The results showed that the parameter recovery was generally satisfactory. An empirical example of the application of the multidimensional and multilevel RERSM to 2006 Program for International Student Assessment inventories about attitudes toward learning sciences is provided.     

Value of conditioned reinforcers as a function of temporal context

In two experiments, pigeons were trained on a multiple-chain schedule, in which the initial link for one chain was a variable-interval (VI) 100 s schedule and for the other chain a VI 10 s schedule. The terminal links were both fixed-time 30 s schedules signaled by differently colored stimuli. Following training, the pigeons had their preference for the terminal-link stimuli tested either by presenting these stimuli in concurrent probes or by presenting these stimuli as reinforcement for completing novel initial links. In Experiment 1, pigeons significantly preferred the terminal-link stimulus that followed the long initial link in three of the five conditions. This preference was observed across all three testing procedures (concurrent chains, concurrent chains probes, and concurrent probes). Experiment 2 was a replication of this effect in one of the conditions from Experiment 1. The results demonstrate that temporal context does impact the value of a conditioned reinforcer in a manner consistent with delay-reduction theory, and inconsistent with other choice theories, such as the contextual choice model and scalar expectancy theory.     

The effects of perceptual pretraining on concept identification and preference

The effects of perceptual pretraining on preferences and concept identification performance in five- and eight-year-old Ss were investigated. The results indicated that perceptual pretraining facilitated performance on a concept identification task with a non-preferred relevant cue for the five-year-olds, but not for the eight-year-olds. However, perceptual pretraining did not affect preference in either age group and Ss were as consistent in their preference responding before and after perceptual pretraining as was a control group that had not received perceptual pretraining. Preferences were highly consistent in both age groups over a one week period. Perceptual pretraining was interpreted to increase the usability of the less preferred dimensions for the younger Ss, and to leave the affective preference response unaltered in both groups.