Serial learning: A multilevel access analysis

In Experiment I the lists were 36 and 48 unrelated words. Each was divided into successive groups of four words and learned to a perfect criterion. In Experiment II the lists were made up of six categorical groups of five exemplars each. Degree of learning was varied. In both experiments serial anticipation learning was followed by ordinary free recall and free recall under speed stress. Analyses of acquisition and of both recall tests indicate that group access is a marked function of serial position but that within-group retrieval given group access is constant over serial position. It is argued that serial learning proceeds simultaneously at different levels of representation.     

Single-trace fragility theory of memory dynamics

In single-trace fragility theory, forgetting is produced by two factors, time and interference. Memory traces are assumed to have two partially coupled dynamic properties, strength and fragility. Strength determines the probability of correct recall and recognition, while fragility determines the susceptibility of the trace to the time-decay process but not to the interference process. Consolidation is assumed to be a continual reduction in the fragility of the memory trace rather than any change in strength or availability. Decreasing fragility accounts for the continually decreasing forgetting rate, the temporal character of retrograde amnesia and recovery therefrom, and the type of internal clock necessary for nonassociative recency judgments. Data are presented to indicate that interference is independent of the interval between original and interpolated learning, that nonassociative recency discriminability approaches a limit at about 30 min, and that the decay rate of long-term retention in amnesic patients is the same as in normal Ss.     

The separate and combined effects of GSR biofeedback and delayed auditory feedback on stuttering: A preliminary study

The separate and combined effects of galvanic skin response biofeedback low wave amplitude self regulation (GSR LW) and amplified delayed auditory feedback (DAF) upon stuttering dysfluency are examined. Two college age male stutterers who were seen on an intensive longitudinal basis were the subjects in this study.Results suggest that GSR LW, when it is accomplished, functions to moderately but significantly reduce stuttering dysfluency compared to no GSR biofeedback. This effect does not noticeably dissipate over time. There occurred a marked and sustained reduction in stuttering dysfluency under DAF compared to no DAF conditions. Without separating accomplished and not accomplished GSR LW, there occurred slightly but not statistically significantly fewer blocks under the combined DAF-GSR LW condition than under DAF alone. Nevertheless, it does seem likely, considering these findings overall, that when GSR LW is accomplished, the fluency facilitating effect of its simultaneous combination with DAF is additive i.e., greater than either alone. Possible theoretical and therapeutic implications are discussed.     

Sequential constraint impairment in aphasia: A case study

Our aphasic subject appeared to demonstrate disorders related to phonological sequential constraint rules. In particular, he seemed to have difficulty in distinguishing between accidental and systematic gaps. Although he had little trouble repeating actual English lexical items, he was unable in the majority of cases to repeat possible but non-existent ones (as well as impossible ones). A reading test was administered in o der to control for errors related to the modality of the repetition test.In order for us to insure that his disorder was related to his aphasia, three normal subjects performed both the repetition test and the reading test. The aphasic's results were significantly different from theirs.We conclude that the aphasic's lexical redundancy system was impaired and that the phonological lexical redundancy rules of generative phonology form a functional neuropsychological unit the proper function of which can be selectively disrupted by brain damage.     

The roles of practice and correction in the categorization of sour and bitter taste qualities

Ten Ss were selected from a group of 40 screened to determine misnaming of stimuli usually called sour (hydrochloric and citric acid) and bitter (quinine sulfate). The 10 Ss were then given 16 trials in which they were asked to match the stimuli to standards, with or without verbal feedback for each stimulus. This was followed by 16 trials without feedback for all Ss and, several days later, by a 16-trial posttest. Final improved performance of the Ss was not affected by having received the feedback. It was concluded that experience with the stimuli leads to a reduction in the degree of misnaming, implying a nonphysiological basis for sour-bitter confusions.     

Factor analysis of the army air forces sheppard field battery of experimental aptitude tests

A factor analysis was made of 39 experimental printed aptitude tests and seven reference tests selected from the Army Air Forces Aircrew Classification Battery. Thirteen factors were extracted and two independent orthogonal rotational solutions were completed. Twelve factors were interpreted. Of these, seven were clearly identifiable with previously known factors: numerical, perceptual-speed, spatial-relations, visualization, visual-memory, paired-associates-memory, and length-estimation factors. A planning factor was not as clearly identifiable. A reasoning factor was probably a composite of two or more factors that failed to separate. A new factor possibly has to do with orientation with respect to the points of the compass. Two factors were doublets, each apparently specific to one kind of test. Better conceptions were gained of the spatial-relations and visualization factors and of the kinds of tests that measure them best. Efforts to improve measures of unique factors were not uniformly successful. The attempt to duplicate a psychomotor test rather directly by analogy in printed form failed almost completely.For support of a large part of the investigation the senior author is indebted to the Social Sciences Research Council for a grant-in-aid. Dr. Fruchter supervised the computational work in the extraction of factors and in one of the rotational solutions. Much of the work was done while he was employed by the Air Training Command Human Resources Research Center. While the opinions and conclusions are those of the authors, they wish to express their appreciation to that organization and especially to Dr. John T. Dailey for making the facilities possible and to Mr. William B. Lecznar for technical and computational assistance.