Texture gradient effectiveness in the perception of surface slant

To assess the development of monocular slant perception as well as the relative effectiveness of different sources of information, children in first, third, and fifth grades and college adults were asked to make judgments of surface slant on the basis of monocular texture gradient information. Accuracy of judgment increased with increasing age. In addition, differences in gradient effectiveness were found. Compression gradients were relatively ineffective sources of information, whereas perspective and multiple gradients resulted in greater accuracy. The results suggest limitations on the specificity of certain forms of gradients.     

Texture gradient registration and the development of slant perception.

The processes underlying the development of slant perception were investigated by manipulating the degree of texture element variability. Subjects at four grade levels were required to make judgments of physical slant of surfaces with three levels of variability. Absolute error of judgment decreased with age, but texture variability had no effect at any grade level. The results suggest that there is no improvement in the ability to extract gradient information. Rather, improvement in the consistency of judgment reflects a developmental change in the relationship between stimulus information and judgment.     

Encoding specificity in the recall of pictures and words in children and adults

In this study, the modality of the retrieval cues (pictures or words) was varied in a cued recall task to determine how second and fourth grade children and college adults encode words (Experiment 1) and pictures (Experiment 2). According to the assumptions of the encoding specificity principle, cue modality should affect recall only to the degree to which subjects focus on modality specific (sensory) rather than nonmodality specific (semantic) information in stimuli. In both experiments, the results showed progressively smaller encoding specificity effects with increasing age. To ensure that differences in encoding activity were responsible for these effects, comparisons were made of recall patterns under intentional learn conditions, and under incidental conceptual and sensory orienting conditions. The recall patterns of the children in the conceptual orienting condition were similar to the adult patterns in the learn condition, and the adult recall patterns in the sensory orienting conditions were similar to those of the children in the learn conditions. These results suggest that there are developmental differences in encoding the sensory and semantic information in stimuli that may result from differences in the efficiency with which the semantic information in stimuli is processed. The results suggest that young children typically encode stimuli in a fashion that stresses the sensory aspects of the stimuli, and that recall suffers as a result.     

Developmental changes in the internal structure of semantic categories

The present experiment was designed to examine the development of the cognitive representation of semantic categories. Response latencies on a classification task were compared for second, fourth, and sixth graders (8, 10, and 12 years of age, respectively) and college students. On each trial the subjects were presented with two pictures that represented either typical or atypical category exemplars. The two pictures were physically identical, nonidentical pictures from the same category, or pictures from different categories. One half of the trials were primed by presenting a category name in advance of the stimuli. In addition, stimulus degradation was manipulated in order to assess the locus of priming effects. A significant interaction of age × priming × typicality was found for physically identical stimuli. This interaction indicated that the nature of the internal representation of categories changed from the second graders to the adults. It was suggested that the second graders might weigh features inappropriately in generating semantic prototypes. The fact that stimulus degradation and priming did not interact at any age level for any of the match types indicates that priming affected a conceptual encoding stage rather than a perceptual encoding stage.     

Acquisition of representation-mediated conditioned food aversions

Food aversions were established in rats by administering lithium chloride (LiCl) immediately after the presentation of an exteroceptive conditioned stimulus (CS) which previously had been paired with a food substance. In Experiment 1, rats which received first tone-food and then tone-LiCl pairings showed less food consumption in subsequent testing than rats which received only tone-food or tone-LiCl pairings. Experiments 2 and 3 demonstrated the stimulus specificity of aversions established in this manner. Rats which first received pairings of light and tone CSs with two different food substances and then received pairings of one of those CSs with LiCl showed greater aversion to the food previously associated with the LiCl-paired CS than to the other food substance. Experiment 3 also showed that specific aversions were not acquired if rats received CS-shock rather than CS-LiCl pairings. These results suggest that CS-evoked representations of events can substitute for those events themselves in the formation of new associations.     

Exposure effects in person perception: Familiarity,similarity, and attraction

Two experiments explored the relationship between familiarity, similarity, and attraction. In the first experiment, subjects viewed photographs of faces at various exposure frequencies and then rated them for likeableness and similarity. Familiar people were regarded by the subjects as both more likeable and more similar to themselves. The effects of familiarity on perceived similarity were primarily mediated by changes in attraction, although some evidence of a direct link between familiarity and perceived similarity was also found. In the second experiment, subjects viewed the same stimuli at a single exposure frequency, and received bogus information regarding the similarity of the people shown therein. Subsequent ratings of likeableness and perceived familiarity revealed that people who seemed similar to the subjects were regarded as both more likeable and more familiar. The effects of similarity on perceived familiarity were almost entirely mediated by changes in attraction. Some of the theoretical implications of these findings are discussed.     

Developmental changes in children's use of semantic information in recall

Third and seventh graders (age 9 and 13 years) were randomly assigned to three instructional groups and engaged in a sort/recall task. The instructions emphasized either (a) recall of the items, (b) meaningful organization of the items, or (c) meaningful organization and recall of the items. Regardless of instruction, seventh graders sorted 20 unrelated items into semantically-based groupings and exhibited elevated levels of recall. Third graders instructed to group items to facilitate recall formed seemingly random groupings and recalled significantly fewer items than third graders instructed to make semantically-based groupings, even when some of these latter subjects were unaware of a subsequent recall trial. The results indicated that young children are capable of adult-like organizational strategies but are unaware of their relevance to recall performance or conditions under which organization might be an appropriate strategy.     

A test of parallel versus serial processing applied to memory retrieval

Townsend has identified necessary and sufficient conditions that reaction time distributions meet if they are produced by two underlying processes that are parallel and within-stage independent. This paper describes an attempt to use one of these conditions to assess the assumption of independent parallel memory retrieval in Anderson's ACT theory. In the experimental test, subjects studied profession-location pairs, with each profession and location included in two pairs. One pair had a high frequency of presentation and the other had low. When cued with a profession (or location), subjects responded with the first of the two studied locations (or professions) that came to mind. The reaction times to these responses were used to test the ACT assumption of independent parallel search. The problems encountered in trying to apply Townsend's abstract test to a concrete situation included the need to consider mixtures and convolutions of distributions and empirical, rather than theoretical, distributions. These difficulties are discussed at length and some formal analyses concerning their effect on the test are given. Despite these problems, we were able to use Townsend's test and the results of the experiment support the within-stage independent parallel assumption of ACT.     

Developmental changes in memory: The effects of processing time and rehearsal instructions

An overt rehearsal procedure was used to investigate the relationship between children's rehearsal strategies and free recall performance. Previous work has shown that developmental differences in rehearsal content, rather than rehearsal frequency, affect recall performance. This experiment investigated the effects of increased processing time and rehearsal training upon recall. Third-grade girls (age 8) were able to use additional processing time to increase the activity of their rehearsal, and they showed corresponding improvement in recall. In contrast, third-grade boys (age 8) and sixth-grade boys and girls (age 12) did not take advantage of a slower presentation rate to rehearse more actively, and their recall did not change. Further, even without additional processing time, both the third-grade boys and girls were able to use an instructed active rehearsal strategy to facilitate their recall. The direct manipulation of rehearsal activity and the resulting improvement in recall provide experimental support for the proposed relationship between rehearsal content and recall from long-term memory store.     

Categorization and representation of physics problems by experts and novices

The representation of physics problems in relation to the organization of physics knowledge is investigated in experts and novices. Four experiments examine (a) the existence of problem categories as a basis for representation; (b) differences in the categories used by experts and novices; (c) differences in the knowledge associated with the categories; and (d) features in the problems that contribute to problem categorization and representation. Results from sorting tasks and protocols reveal that experts and novices begin their problem representations with specifiably different problem categories, and completion of the representations depends on the knowledge associated with the categories. For, the experts initially abstract physics principles to approach and solve a problem representation, whereas novices base their representation and approaches on the problem's literal features.     

Developmental changes in units of processing in reading

A visual search task was used to investigate the development of word processing skills used in reading meaningful prose. Children from the second and fourth grades and college students were asked to locate a prespecified letter, syllable, word, or category exemplar as they read through sentences. Target detection time, sentence reading time, and sentence comprehension were measured. The results provide converging evidence that whole words were the preferred units of processing during reading for all three grade levels. Reading rates for sentences in the word search condition were comparable to normal reading rates. The search for smaller units required additional processing time, but word and category search times differed only for the youngest subjects.     

Transfer of the signaling properties of aversive CSs to an instrumental appetitive discrimination

Rats received Pavlovian conditioning in which, based on a shock US, white noise was established for different groups as an aversive CS+, CSo, or CS?. Then, half of each group received the CS contingent upon either the food-reinforced or nonreinforced response in an easy, choice discrimination. Correct responses, i.e., number of reinforcements, to criterion showed that a CS+ for the reinforced response facilitated learning, whereas a CS? retarded learning; conversely, a CS+ for the nonreinforced response retarded learning, whereas a CS? facilitated learning. The same contingency difference occurred with errors to criterion for CS? subjects but was obscured for CS+ subjects apparently by an avoidance-producing effect of the CS+. In support of the generality of the transfer effect, Z-score transforms of the correct-response data showed that the magnitude of transfer was comparable to that obtained in more difficult discriminations. Collectively, the findings indicate that an aversive CS can function as a transformed signal for the presence (CS+) or absence (CS?) of an appetitive reinforcer and that the signal's control of behavior is via a within-chain mediational process.     

Developmental changes in free recall: The interaction of task structure and age

Free-recall learning and organization were measured for 3rd, 7th, and 11th graders under conditions which varied the type and amount of task structure. Task structure for the input or list-presentation phase was manipulated by using a random, constant, or alphabetic item sequence across trials. Task structure for the output or recall phase was manipulated by providing standard instructions or instructions which suggested the possible use of an alphabetic ordering scheme. Recall performance and organization showed an interaction between age and both manipulations of task structure. The 3rd graders required the maximal amount of task structure (alphabetic order with alphabetic instructions) to demonstrate recall facilitation relative to the completely unstructured control condition. The 7th graders showed recall facilitation for intermediate and high levels of task structure, and the 11th graders showed recall facilitation for low, intermediate, and high levels of task structure. The results are related to current hypotheses about developmental changes in recall performance and their relationship to changes in the systematic use of organizational strategies.     

The effect of imagining an event on expectations for the event: An interpretation in terms of the availability heuristic

Previous studies have indicated that explaining a hypothetical event makes the event seem more likely through the creation of causal connections. However, such effects could arise through the use of the availability heuristic; that is, subjective likelihood is increased by an event becoming easier to imagine. Two experiments were designed to demonstrate this principle. In Experiment 1, subjects asked to imagine Jimmy Carter winning the presidential election (prior to the election) predicted that he was more likely to win than subjects asked to imagine Gerald Ford winning. In Experiment 2, subjects asked to imagine a good college football season for the previous championship team were more likely to predict a major bowl bid than subjects asked to imagine a bad season, although the effect did not appear in predictions of the season record. In both studies, subjects who were also asked to explain the imaginary event were no different from subjects who only imagined. Several other attributional distortions are interpreted in terms of the availability heuristic.     

Comparison of two oddity tasks with pigeons

Two oddity tasks were compared: one in which the odd stimulus could appear on any of the three stimulus positions (true oddity); the other in which the odd stimulus could only appear on the left or right but not the center (oddity-from-sample). A stimulus-configuration theory predicts faster oddity-from-sample learning, whereas a theory, based on shifts in observing over trials, predicts faster learning of true oddity. Pigeons learned the oddity-from-sample task faster, thus supporting configuration theory. Performance on the oddity-from-sample task but not the true oddity task was facilitated by increasing the number of responses required to terminate a trial. When the oddity-from-sample pigeons were shifted to the true oddity task, no evidence of positive transfer was found, suggesting that a configuration theory alone is insufficient to explain differences in acquisition. Only when a correction procedure was introduced did the true oddity pigeons perform above 50%.     

Primary and secondary reinforcers as distinctive cues which acquire information value in partial-reinforcement discrimination training

To assess the cue as opposed to incentive effect of reward, rats were trained on an easy visual discrimination with food contingent on 50 or 100% of the correct responses, and white-noise contingent on 0, 50 or 100% of these responses. Additionally, the 50% food and noise schedules were structured for different groups to produce positive, zero, or negative correlations of the two events. Although the addition of noise did not affect learning with 100% food, the slower learning observed with 50% food was increasingly offset by greater percentages of noise, with the 50% groups showing faster learning under the negative than zero correlation and faster under the zero than positive correlation. Together with supporting speed data, these results indicate that a “neutral” stimulus can be substituted for food with little loss in performance. Consequently, the reinforcing effect of food is attributed in part to its function as a cue which, like noise, can increase the discriminability of the alternatives and provide information about the correctness of the response.     

The use of the cumulative rehearsal strategy: A developmental study

This study was designed to address two issues: (1) At what age do children spontaneously use a cumulative rehearsal strategy; and (2) What effect does the use of the strategy have on their performance?Twenty-eight children at each of five grade levels (nursery, kindergarten, 1, 3, and 5) were tested in a serial-position recall task. Stimuli were pictures of common objects and animals whose labels were one or two syllables in length. Following testing, the children were asked to report the memory strategy they had used.The assumption was made that children who were using a cumulative rehearsal strategy would perform better on series of one-syllable items than on series of two-syllable items. As predicted, nursery, kindergarten, and first-grade subjects correctly recalled as many two-syllable as one-syllable items: Both third- and fifth-graders recalled significantly more one-syllable than two-syllable items. Results indicated that (1) young children do not spontaneously use a cumulative rehearsal strategy until after first grade, and (2) the use of rehearsal did not facilitate overall performance of the rehearsers relative to the nonrehearsers at any grade level. Results are discussed in terms of their theoretical implications for the study of memory development.     

A functional measurement analysis of the development of dimensional coordination in children

The development of children's dimensional coordination was investigated using kindergarten, second, fourth, and sixth grade subjects (Ages 5, 7, 9, and 11 years, respectively), and an adult sample, by means of a perceptual estimation task requiring the subjects to match in total area a stimulus rectangle to an adjustable square stimulus. The problem was formulated using information integration theory, and the procedures and techniques of functional measurement were used in the analysis. Dimensional coordination was found to develop from a stage of total centration on one dimension to a stage of total decentration with equal weighting applied to both dimensions.Contrary to extant hypotheses, the vertical dimension was not the salient dimension for single dimension centerers. Rather, the spatial axis on which the compared-objects were placed determined the displacement of attention. When this frame of reference effect was controlled, the longer of the two dimensions was the salient dimension for centering subjects.     

Factors affecting developmental changes in the speed of processing

Although many studies have found developmental changes in the speed of various processes, they have potentially confounded the subject's age with his knowledge of the task domain and use of strategies. In this study, the strategies used by the subject and his domain knowledge were independently assessed by a number of tasks. Subsequently, processing rate measures were obtained for a task (the “same/different” judgment task of simultaneously presented stimuli) in which domain knowledge was manipulated independently of age while controlling for strategy usage. It was found that the usual adult superiority in speed of processing could be markedly reduced if children possessed equivalent amounts of domain knowledge and this effect was domain specific. Further, it was found that differences in knowledge affected processing rates in both knowledgeable adults and children and to about the same extent. It was concluded that some part of the typical adult superiority in processing rate was due to knowledge differences.     

Developmental differences in cognitive scanning and encoding of visual information

Report accuracy of horizontally arranged letter sequences was measured for second-grade children and adults using a tachistoscopic single report procedure. Results indicated age differences in both the amount of information encoded out of visual sensory store and in the magnitude of left-right visual field differences. However, large age differences in amount of encoded information were also present under conditions which served to reduce left-right visual-field asymmetries in report accuracy. These findings are discussed in terms of their implications for using a left-to-right cognitive trace scanning explanation to account for age differences in encoding efficiency.