Voice-onset time as a clue to the nature of Broca speech errors

Blumstein, Cooper, Goodglass, Statlender, and Gottleib (Brain and Language, 9, 153–170 (1980)) attempt to determine by an examination of the VOTs of aphasic speakers whether Broca's aphasics make phonemic substitutions in addition to their well-known phonetic errors. There are a number of problems with this study, mostly due to an apparent failure to fully appreciate the fact that VOT is a cover term for several acoustic features. It is suggested that VOT measurement in any given position in a word cannot solve this problem and that future studies should include glottographic observations as well as VOT measurements made in all positions in the word.     

Fitting longitudinal reduced-rank regression models by alternating least squares

An alternating least squares method for iteratively fitting the longitudinal reduced-rank regression model is proposed. The method uses ordinary least squares and majorization substeps to estimate the unknown parameters in the system and measurement equations of the model. In an example with cross-sectional data, it is shown how the results conform closely to results from eigenanalysis. Optimal scaling of nominal and ordinal variables is added in a third substep, and illustrated with two examples involving cross-sectional and longitudinal data.Financial support by the Institute for Traffic Safety Research (SWOV) in Leidschendam, The Netherlands is gratefully acknowledged.     

Antecedents of fluent and dysfluent oral reading: A descriptive analysis

Utilizing the method of repeated observations of a single subject, 18 oral reading samples were obtained from a fluent male child. Observations were made when the child was 5.6 to 6.1 yr of age. The reading material contained varying amounts of words neither understood nor produced by the child. Taped samples were analyzed for antecedents and consequences of fluent and dysfluent events, and extraneous verbal and nonverbal stimulus-response sequences. The analysis revealed the presence of five antecedents of dysfluencies: (1) poor lexical control, (2) competing stimulus-response sequences, (3) intraverbal break, (4) poor prosodic control, and (5) unusually strong intraverbal control. The results also suggested that fluency may be a function of appropriate, sequential, discriminative, stimulus control, adequate intraverbal and prosodic control in the absence of overbearing intraverbal control and interfering stimulus-response sequences.     

The problem of relapse in stuttering: Some thoughts on what might cause it and how to deal with it

Bloodstein recently wrote that “the most vital part of science is not accurate measurement or the insistence on empiricism. It is an attitude of inquiry into the how and why of things” [Bloodstein, O. Foreword. In: Maintenance of Fluency (E. Boberg ed.). New York: Elsevier, 1981, p. vii]. In the paper below, I present some unsubstantiated and no doubt controversial thoughts on the how and why of relapse in stuttering. The overall thrust of these thoughts is that stutterers have different propensities to stutter because of the inherent variability in their speech production systems. For this reason, for therapy to have long-range success, stutterers must learn to accept and deal with the inherent variability in their speech production mechanisms.     

Scene perception: Detecting and judging objects undergoing relational violations

Five classes of relations between an object and its setting can characterize the organization of objects into real-world scenes. The relations are (1) Interposition (objects interrupt their background), (2) Support (objects tend to rest on surfaces), (3) Probability (objects tend to be found in some scenes but not others), (4) Position (given an object is probable in a scene, it often is found in some positions and not others), and (5) familiar Size (objects have a limited set of size relations with other objects). In two experiments subjects viewed brief (150 msec) presentations of slides of scenes in which an object in a cued location in the scene was either in a normal relation to its background or violated from one to three of the relations. Such objects appear to (1) have the background pass through them, (2) float in air, (3) be unlikely in that particular scene, (4) be in an inappropriate position, and (5) be too large or too small relative to the other objects in the scene. In Experiment I, subjects attempted to determine whether the cued object corresponded to a target object which had been specified in advance by name. With the exception of the Interposition violation, violation costs were incurred in that the detection of objects undergoing violations was less accurate and slower than when those same objects were in normal relations to their setting. However, the detection of objects in normal relations to their setting (innocent bystanders) was unaffected by the presence of another object undergoing a violation in that same setting. This indicates that the violation costs were incurred not because of an unsuccessful elicitation of a frame or schema for the scene but because properly formed frames interfered with (or did not facilitate) the perceptibility of objects undergoing violations. As the number of violations increased, target detectability generally decreased. Thus, the relations were accessed from the results of a single fixation and were available sufficiently early during the time course of scene perception to affect the perception of the objects in the scene. Contrary to expectations from a bottom-up account of scene perception, violations of the pervasive physical relations of Support and Interposition were not more disruptive on object detection than the semantic violations of Probability, Position and Size. These are termed semantic because they require access to the referential meaning of the object. In Experiment II, subjects attempted to detect the presence of the violations themselves. Violations of the semantic relations were detected more accurately than violations of Interposition and at least as accurately as violations of Support. As the number of violations increased, the detectability of the incongruities between an object and its setting increased. These results provide converging evidence that semantic relations can be accessed from the results of a single fixation. In both experiments information about Position was accessed at least as quickly as information on Probability. Thus in Experiment I, the interference that resulted from placing a fire hydrant in a kitchen was not greater than the interference from placing it on top of a mail ? in a street scene. Similarly, violations of Probability in Experiment II were not more detectable than violations of Position. Thus, the semantic relations which were accessed included information about the detailed interactions among the objects—information which is more specific than what can be inferred from the general setting. Access to the semantic relations among the entities in a scene is not deferred until the completion of spatial and depth processing and object identification. Instead, an object's semantic relations are accessed simultaneously with its physical relations as well as with its own identification.     

Memory development in adolescence: Relationships between metamemory,strategy use,and performance

Eighth and tenth grade students were asked to study and recall a list of paired associates. The word pairs were available either throughout an 8 sec per word study period or only at the beginning and were composed of either high frequency or low frequency words. After recall, students were asked to indicate which of several study strategies they had used with each word pair (read pair carefully, rehearsal, visual elaboration, verbal elaboration). In addition, they were asked which of these strategies would have had the best effect on recall. Knowledge of appropriate memory strategies (metamemory) was positively related to strategy use, and strategy use was positively related to recall performance at both ages. Improved performance with materials available throughout study and with high frequency word pairs was explained by increased use of elaborative strategies. Age differences in performance were explained by increased strategy effectiveness. These results are discussed in relation to changing relationships among metamemory, strategy use, and performance with age.     

An application of a biased version of the Bradley-Terry-Luce model to professional basketball results

Some extensions of the Bradley-Terry-Luce model for paired comparisons are presented and used to assess the existence of a home court advantage for professional basketball teams. It is shown how maximum likelihood estimates for these models can be obtained from a simple iterative scaling algorithm. Won-loss records for the regular season are used to make predictions for playoff series. The models are extended to include possible differences among divisions. These models can be applied in many other situations to incorporate group effects and order effects into analysis of paired comparisons.