Pauses and syntax in American sign language

Research on spoken languages has shown that the durations of silent pauses in a sentence are strongly related to the syntactic structure of the sentence. A similar analysis of the pauses (holds) in a passage in American Sign Language reveals that sequences of signs are also interspersed with holds of different lengths: long holds appear to indicate the ends of sentences; shorter holds, the break between two conjoined sentences; and the shortest holds, breaks between internal constituents. Thus, pausal analysis is a guide to parsing sentences in ASL.     

Individual differences in immediate serial recall: A matter of mnemonics?

Normal adults differ in a fairly general immediate serial recall ability which is commonly assessed on individual IQ tests. Two experiments tested the role of rehearsal, grouping, and chunking strategies in producing such individual differences. The general approach was to limit interindividual variation in the application of these mnemonics and observe the effects on individual differences in recall. This was accomplished by (1) presenting items too fast to allow variation in rehearsal strategy and (2) requiring all subjects to group and chunk items in the same way. Both manipulations affected average recall, but neither one affected the size or order of individual differences. It was concluded that immediate serial recall differences between normal adults are largely a consequence of something other than differences in rehearsal, grouping, or chunking strategies.     

Categorized and uncategorized attributes as recall cues: The phenomenon of limited access

Our most general proposition is that access to a memory unit is limited to those cues which specify the identifying property of the unit. In our first experiment we had subjects categorize a colored shape by either its shape or color property. Recall for the other member of a unit was faster and better when the cue was the categorized rather than the uncategorized property. In a subsequent experiment evidence was presented which suggested that the asymmetry of the two types of cues was an access rather than an associative asymmetry. Finally, we found that retrieval latency to the uncategorized cue decreased sharply as list length was decreased, while very little effect was evident for the categorized cue, suggesting different retrieval processes for the two types of cues. We are led to infer that when a unit is stored it is also classified and that direct access to that unit is only possible via cues which are specified in the classification system.     

A follow-up developmental study of hypothesis behavior among mentally retarded and nonretarded children

To clarify the roles of IQ and mental age (MA) in hypothesis behavior, MA-matched subjects at three levels of IQ (70, 100, and 130) and three levels of MA ($\text{5}\text{1}\text{2}\text{, 7}\text{1}\text{2}\text{,}\text{and}\text{9}\text{1}\text{2}\text{years}$) received blank-trial discrimination learning problems using procedures designed to discourage position-oriented responding. With position responding discouraged, earlier findings were contradicted in that no hypothesis measure showed a main effect of IQ. This suggest that previously reported IQ group differences in hypothesis behavior may not reflect cognitive deficits inherently linked to low IQ, but instead may reflect the influence of specific methodological factors. The finding and interpretation are consistent with Zigler's (American Journal of Mental Deficiency, 1969, 73, 536–556) “developmental” theory of retardation and inconsistent with the general “difference” position. In additional findings, the predictions that subjects at all three MA levels would use hypotheses, and that retarded children from special-education classes would use hypotheses more often than retarded children “mainstreamed” in classes for the nonretarded were confirmed.     

Teaching autistic children to respond to simultaneous multiple cues

A number of studies have shown that autistic children tend to learn new discriminations by responding to only a restricted number of available cues and that this may be responsible for some of their abnormal behavior. Therefore, this investigation assessed the feasibility of teaching autistic children to respond to multiple cues. The results showed that four autistic children could learn a conditional discrimination requiring them to discriminate a multiple-cue complex from each of its two component cues. However, the autistic children did not learn this discrimination in the same manner as normal children. In the early trials, the autistics responded at a higher level to one of the two component cues. Only after many trials did the autistics respond equally on the basis of both component cues. The results of an initial attempt to teach a general set to respond to multiple cues showed that, when an autistic child was taught a series of successive conditional discriminations, the child eventually learned a set to approach new discriminations by responding equally on the basis of both component cues. The results are discussed in terms of understanding and treating autistic children's abnormal development.     

The differential effect of three auditory stimuli on the frequency of stuttering behaviors

In view of the frequent clinical use of external auditory stimuli in fluency building programs, the purpose of the present experiment was to compare the effects of rhythmic pacing, delayed auditory feedback, and high intensity masking noise on the frequency of stuttering by dysfluency type. Twelve normal hearing young adult stutterers completed an oral reading (approximately 250 syllables) and conversational speech task (3 min) while listening to the three auditory stimuli and during a control condition presented in random order. The results demonstrated that during oral reading all three auditory stimuli were associated with significant reductions in stuttering frequency. However, during conversational speech, only the metronome produced a significant reduction in total stuttering frequency. Individual dysfluency types were not differentially affected by the three auditory stimuli.