The Effects of Feature Identity in Operant Serial Feature-Negative Discriminations

The effects of feature identity in an operant serial feature-negative discrimination (F1 T1−, T1+) were examined in two experiments with rats. In Experiment 1, rats were trained with two operant serial feature-negative discriminations in which different operants were reinforced during two auditory target cues (T1 and T2). The features (F1 and F2) were two neutral cues (visual or auditory stimuli), two motivationally significant cues (flavored sucrose solutions, also used as the operant reinforcers), or one neutral and one motivationally significant cue. Experiment 1 showed that discrimination acquisition, transfer performance, and feature–target interval testing were facilitated with a flavored sucrose feature. Experiment 2 showed that flavored sucrose-alone presentations, more than flavored sucrose trained in a pseudodiscrimination (F1 T1+, T1+), shared several similarities with a standard flavored sucrose feature. The results suggest flavored sucrose rapidly acquires inhibitory properties, which facilitates operant serial feature-negative discrimination performance.     

Flipping and spinning: Spatial transformation procedures in the identification of rotated natural objects

The proposal that identification of inverted objects is accomplished by either a relatively slow rotation in the picture plane or a faster rotation in the depth plane about the horizontal axis was tested. In Experiment 1, subjects decided whether objects at 0° or 180° corresponded to previously learned normal views of the upright objects, or were mirror images. Instructions to mentally flip an inverted object in the depth plane to the upright produced faster decision times than did instructions to mentally spin the object in the picture plane. In Experiment 2, the effects of orientation were compared across an object-naming task and a normal-mirror task for six orientations from 0° to 300°. In the normal-mirror task, objects at 180° were cued for rotation in the picture plane or in the depth plane in equal numbers. The naming function for one group of subjects did not differ from the normalmirror function where inverted objects had been mentally rotated to the upright. For both functions, response time (RT) increased linearly from 0° to 180° and the slopes did not differ. The naming function for a second group of subjects did not differ from the normal-mirror function where inverted objects had been mentally flipped to the upright. For both functions, RT increased linearly at a similar rate from 0° to 120°, but decreased from 120° to 180°. The results are discussed in terms of theories of orientation-specific identification.     

Connectives and narrative text: The role of continuity

Connectives are text devices that signal the relation between adjacent sentences. Recently there has been a surge of research interest in the role played by connectives in on-line processing. The present research tested the hypothesis that connectives will impact on-line processing to the extent that they signal a text event that represents a departure from the continuity of the events stated in the text. In Experiment 1, participants generated sentences to follow a stimulus sentence. An additive, causal, or adversative connective (or no connective) was provided to serve as the first word of the participants’ sentence. Results showed that sentences generated in response to additive or causal connectives depicted text events that were continuous with the stimulus text. In contrast, sentences generated in response to adversative connectives depicted discontinuous text events. In Experiments 2 and 3, participants read coherent sentence pairs containing inappropriately placed additive, causal, or adversative connectives. Support for the continuity hypothesis was found when it was shown that adversative connectives led to the greatest amount of processing disruption, as measured by longer reading time on the postconnective sentence (Experiment 2) and lower ratings of coherence (Experiment 3). Future research in this area is discussed.     

Grouping students for instruction: effects of learning style on achievement and attitudes

The present study examined the effects of matching and mismatching American middle-school students with a preference for learning alone or learning with peers with selected instructional treatments in order to determine the impact upon their attitudes and achievement in social studies. Analysis revealed that the learning-alone preference performed significantly better in the learning-alone condition and that the learning-with-peers preference performed significantly better in the learning-with-peers condition. However, no-preference students also performed significantly better in the learning-alone condition than with peers. In addition, data revealed that the learning-alone and the learning-with-peers students had significantly more positive attitudes when matched with their preferred learning style; the nopreference students had more positive attitudes in the learning-alone condition.     

An examination of the continuous distractor task and the “long-term recency effect”

The continuous distractor task has yielded a so-called "long-term recency effect" that appears to call into question the dual-storage explanation of serial position effects in free recall. In this study, we show that the "long-term recency effect" is really a short-term storage effect, resulting from adaptation to the repeated presentation of a particular type of distractor throughout the list. This adaptation, a time-sharing process, permits short-term storage to carry out its normal functions. Experiment 1 shows that an appropriate postlist distractor task does in fact eliminate the "long-term recency effect." This finding supports the assertion that the effect is a product of short-term storage. Experiment 2 demonstrates the benefits and costs of the time-sharing process, relative to standard free recall, for both long-term and short-term storage. The findings support the time-sharing hypothesis. Experiment 3 replicates Experiment 2, with a change in procedure that rules out output interference as a mechanism responsible for the results of Experiment 2. Data are also presented on the development of the adaptation over trials. It is concluded that the adaptation and time-sharing processes need to be included in the dual-storage model of short-term storage.     

Interactive effects of item content and ethnic group membership on performance on the McCarthy scales

The study investigated cultural bias in the 46 verbal items of the McCarthy Scales of Children's Abilities (MSCA). The verbal items of the MSCA were administered to 59 Anglo and 59 Mexican-American subjects matched for age and sex. The responses of two groups of subjects on these items were analyzed by log-linear technique using the likelihood ratio chi-square statistic. The analysis of the data revealed that the majority of the verbal items of the MSCA are free from cultural bias. Only three items of the MSCA V-scale reflected systematic cultural bias. Two of these items are from the Word Knowledge II Subtest and the third one is from the Opposite Analogies Subtest. Suggestions for the use of the MSCA with children from minority cultures are made.     

Spielberger's State-Trait Anxiety Inventory: Measuring anxiety with and without an audience during performance on a stabilometer

Half of the 56 subjects (n = 28) performed 15 pre-treatment trials on a stabilometer, then six more with an audience of three faculty (Group 1), the other half performed the same task with no audience (Group 2). Subjects completed the State-Trait Anxiety Inventory prior to and after the treatments. Orthogonal contrasts indicated that Group 1 (audience) post State-anxiety was significantly different from its own pre-State-anxiety and significantly different from Group 2 (no audience) on post-State-anxiety. It was concluded that the State-Trait Anxiety Inventory is an appropriate measure of trait and state anxiety in studies of motor performance.     

An analysis of interference in recognition memory

A stimulus-sampling model of recognition memory is presented that predicts both proactive and retroactive interference. To test the predictions of the model, a recognition memory experiment was carried out using a standard proactive-retroactive design with a forced-choice task. Both accuracy and latency were measured. The data showed, as predicted, equal proactive and retroactive effects on accuracy, providing solid support for the model. The interference effects are interpreted in terms of the model as arising from an increase in indirect marking, the marking of shared stimulus elements in words other than the study word. The model has two parameters representing the rate of indirect marking for high-frequency and low-frequency words and two parameters reflecting the efficiency of direct marking. The latency results completely paralleled the accuracy findings, showing proactive and retroactive effects. A possible extension of the model to handle latencies is considered.