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.     

Procedures for synthesizing ratio judgements

Requirements which seem reasonable for functions synthesizing judgements (quantities or their ratios), in particular separability, associativity or bisymmetry, cancellativity, consensus, reciprocal or homogeneity properties are investigated and all functions satisfying them are determined.     

Right hemisphere comprehension of verbs in patients with complete forebrain commissurotomy: Use of the dichotic method and manual performance

The paradigm of dichotic listening was used to investigate verbal comprehension in the right, so-called “nonverbal,” hemisphere. Verbal commands were presented to the right and left ears in the simultaneous (dichotic) paradigm. There were striking instances, especially when the left hemisphere was occupied with some extraneous task, in which the right hemisphere understood the verbal command and executed the appropriate motor responses. In those instances the left hemisphere gave no overt response. Although the left hemisphere was usually dominant, it can be nevertheless concluded that not only can the right hemisphere understand verbal commands but can also express itself manually by executing actions more complex than object retrieval or pointing. As has been known for some time, the blockage of the ipsilateral pathway seems so complete during dichotic listening in the commissurotomy patient that there is no report of the words in the left ear—only of those presented to the right. At the same time there is normal report when words are presented to the left ear alone. It was found in the present study, however, that this model is too simple and only applies to the verbal response paradigm of dichotic listening. Under circumstances of dichotic presentation where the stimulus in the left ear (ipsilateral pathway) is necessary or important to the left hemisphere for completing a task, words from both pathways are reported. One may conclude that there exists a gating mechanism in each hemisphere that controls the monitoring of each auditory pathway and the degree of ipsilateral suppression.     

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%.     

Across-reinforcement blocking effects in a mediational test of the CS's general signaling property

Rats received Pavlovian aversive (shock) conditioning in which white noise was established for independent groups as a CS+, CSo, or CS−. Then, in an easy (light-dark) T-maze discrimination, the CS was presented either immediately following choice (Locus 1) or at the food cup in the goal (Locus 3), contingent upon either a food-reinforced (right) or nonreinforced (wrong) response. When presented at Locus 3, the CS+ facilitated and the CS− retarded learning for CS/right subjects, with these effects being exactly reversed but somewhat less pronounced for CS/wrong subjects. However, when the CS was presented at Locus 1, the CS+ and CS− effects for both response contingencies were attenuated. These findings oppose an interpretation of the CS's function as a general cue or transformed signal for the presence or absence of the new appetitive reinforcer and argue instead for across-reinforcement blocking effects: By signaling in the presence of food reinforcement an outcome (safety or shock) which is consonant with or discrepant from the “good” outcome obtained, the CS− blocks (retards) and the CS+ counterblocks (enhances) the association of food reinforcement and the S^D; conversely, in the presence of nonreinforcement (a “bad” outcome), the CS− counterblocks and the CS+ blocks inhibitory conditioning to the S^Δ. As in Kamin's (1968) original research, such effects are attenuated when the CS is presented early in the compound, distal to the reinforcer.     

Variations in explicitly unpaired training are differentially effective in producing conditioned inhibition

To evaluate a contingency interpretation of conditioned inhibition (CI), rats were given “explicity unpaired” training in which the locus and duration of a CS within the inter-US (shock) interval were systematically manipulated for different groups. Summation and retardation tests in Experiment 1 indicated that stronger CI resulted from both a backward and a trace CS than from a midlocus CS of equal or greater duration. Complementing these findings, the same tests in Experiment 2 showed that, by comparison with novel-stimulus controls, CI developed to a trace CS but not to a mid-locus CS, nor to a trace CS that was accompanied by an immediate signal for the US. These findings argue against a contingency interpretation of CI and favor a contiguity interpretation stressing the short-term rehearsal of stimulus events. Such rehearsal of the US allows a backward CS, but not a mid-locus CS with an extended US-CS interval, to be discriminated as a signal for nonreinforcement, and thus to develop as a conditioned inhibitor. Similarly, excitatory conditioning to the memory trace of a CS allows the nominal trace CS to develop as a signal for nonreinforcement, and thus as a conditioned inhibitor, but not when its memory trace is overshadowed by another CS that immediately precedes the US. In short, the development of CI is facilitated when excitation is mediated by the memorial processing of either the US or a discrete CS for the US rather than by contextual cues.     

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.     

Sex differences in retention of verbal and spatial characteristics of stimuli

Males and females from Grades 3, 6, and college viewed sets of five or seven letters in a 4 × 4 matrix, and remembered either (a) names of the letters, (b) positions of the letters within the matrix, or (c) both letters and positions. At all grade levels females remembered letters more accurately than positions, while males remembered letters and positions equally well. However, there was also evidence that verbal and spatial information was processed independently by both males and females. Results are discussed in terms of neurological development and sex differences in specific abilities.     

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.     

Developmental changes in the semantic processing of pictures and words

Second- and fifth-graders' semantic decision times for pictures and words were analyzed relative to the predictions derived from unitary- and dual-memory models. At both grade levels, word-word response latencies were greater than picture-word latencies which, in turn, were greater than picture-picture latencies. An interaction between Grade and Condition indicated that verbal access times decreased more than pictorial access times. The data fit the predictions of a memory model postulating category storage in a single memory system as opposed to simultaneous representation in verbal and nonverbal memory systems. It was concluded that with increasing experience verbal access to this single semantic system is more rapid.     

Changes with age in two components of visual search speed

Subjects aged 8, 10, 12, and 18 years participated in two visual search tasks. In one task the rate of visual search reflected the speed of preattentive localization processes, and in the other task it additionally reflected letter identification process speeds. The data revealed that localization processes become faster from ages 8 to 12 and remain stable thereafter, and that identification processes increase in speed primarily from ages 8 to 10. Performance on a subsequent recognition task indicated that subjects of all ages were employing a similar encoding strategy during visual search. Furthermore, subjects retained general information about the features of irrelevant background letters even though recognition accuracy for more specific information about letter names was not high. The finding that localization and identification processes have different rates of development confirms the hypothesized distinction between the two and implies that developmental studies of visual scanning speed must focus upon changes in the relationships among various processes or component skills throughout development.     

Causal attributions and information seeking to explain success and failure

Previous studies of attributions for success and failure have relied upon a theoretically derived set of causal attributions, either luck versus skill (derived from Rotter, 1966) or ability, effort, luck, and task difficulty (Weiner et al., 1971; Weiner, 1972). The same tendency of relying upon a set of logically derived cues has been evident in investigations of information-processing in making attributional judgments for success and failure (e.g., Fontaine, 1972; Frieze & Weiner, 1971). Two studies were conducted which employed an open-ended format to determine the relevance of the causal categories and information which have been utilized in previous studies. Results of these studies supported the validity of previously employed causal categories and information cues as well as establishing other important but previously ignored causes and sources of information.     

Generalization effects of social skills training in chronic schizophrenics: An experimental analysis

Social skills training was administered to three (one male and two female) chronic schizophrenic patients in a Partial Hospitalization Service. Treatment consisted of instructions. feedback and modeling, and was administered in 25. 26 and 31 sessions, respectively, for the three patients. Target behaviors were identified for each patient based on his/her responses to role-played interactions involving male and female partners in situations requiring commendatory or hostile assertion. Five to seven target behaviors were selected for each subject and were treated sequentially in a multiple baseline format. Skills training was highly successful for the two female patients but was only partially effective for the male patient. Two forms of generalization measures were included, indicating that the effects of training generalized from trained to untrained, and trained to novel role-played interactions. Follow-up assessments for the two female patients indicated that most of the effects persisted over 8–10-week post-treatment periods.     

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.     

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.     

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.     

Development of relational learning: Effects of instruction and delay of transfer

Preschool children were trained on a color relevant oddity problem by one of three methods: increased salience of the oddity relationship, instruction on the solution rule, or a combination of increased salience and rule instruction. The youngest Ss solved the training problem when the solution rule was provided but not under the salience procedure. The two older groups solved in all conditions and errors decreased with age. The generality of the solution was determined by performance on a form relevant transfer task. The youngest Ss made fewer errors on the transfer problem following rule instruction training than following training in the combined procedure. The intermediate age group made fewer errors when the transfer task was administered one week after training than one minute after training. The transfer problem was easily solved by the oldest Ss and performance was independent of training procedure and amount of delay. These results were interpreted as reflecting developmental differences in relational concept learning.