A PRELIMINARY PROCEDURE FOR PREDICTING THE POSITIVE AND NEGATIVE EFFECTS OF REINFORCEMENT-BASED PROCEDURES

In the current investigation, a modification was made to the preference assessment described by Pace, Ivancic, Edwards, Iwata, and Page (1985) to predict the effects of stimuli when used in a differential-reinforcement-of-other-behavior (DRO) schedule for 2 clients with severe self-injurious behavior (SIB) and profound mental retardation. Based on the results of the preference assessment, three types of stimuli were identified: (a) high-preference stimuli associated with high rates of SIB (HP/HS), (b) high-preference stimuli associated with relatively lower rates of SIB (HP/LS), and (c) low-preference stimuli associated with low rates of SIB (LP/LS). Consistent with the results of the preference assessment, the DRO schedule with HP/HS stimuli resulted in increased SIB, and the DRO schedule with LP/LS stimuli resulted in no changes in SIB. HP/LS stimuli were demonstrated reinforcers but did not result in a change in SIB when used in a DRO schedule. Thus, the stimulus preference assessment may be useful clinically in some situations for predicting both the beneficial and the negative side effects of stimuli in DRO procedures.     

Procedural dependence in action memory: Effects of verb form and individual vs group conditions

Two experiments explored whether the magnitude of the enactment effect in action memory (i. e., higher recall with motor than with non-motor encoding) may depend upon the use of individual or group testing procedures. Nonmotor encoding instructions, requiring the subjects to listen to orally presented action items, were compared to instructions which also required enactment. With encoding treated as a within-subject factor, the observations failed to reveal any significant difference between individual and group testing. With encoding treated as a between-subject factor, the results showed an interaction between test and encoding conditions, such that an enactment effect was found only with group testing. Different support value for auditory cues in group and individual test situations was assumed to account for this difference. In a third experiment the indicative and imperative verb forms were compared. An interaction was observed, showing that in Norwegian, enacted verbs were remembered better when presented in the indicative than in the imperative. No corresponding difference was found under non-enactment conditions. For this finding, a social interaction interpretation was offered.     

Can we learn from the clinically significant face processing deficits,prosopagnosia and capgras delusion?

This review describes two clinically significant face processing deficits, prosopagnosia and Capgras delusion, and provides new knowledge about the face recognition process by a convergence of empirical findings. These empirical findings are structured around two questions that are viewed from the perspectives of the two deficits. First is the question of hemispheric specificity, which inquires into the degree of each hemisphere's contribution to the face recognition process. Second is the question of dual neural pathways, which addresses the possibility that the face recognition process proceeds along two parallel pathways in the brain. Findings from the hemispheric specificity studies reinforce the current view that right hemisphere involvement is necessary for face recognition while left hemisphere involvement is minimal. Findings from the dual neural pathways studies reinforce the plausible but yet unproven hypothesis that two neural pathways pass information from the visual association cortex in the occipital lobe toward the temporal lobes and limbic system when faces are seen and recognized. These findings, which also indicate that each of the dual neural pathways carries different, nonredundant information, could be instrumental in showing that the pathways play different roles in the manifestations of the clinically significant face processing deficits, prosopagnosia and Capgras delusion.     

Competing interests: The need to control conflict of interests in biomedical research

Individual and institutional conflict of interests in biomedical research have becomes matters of increasing concern in recent years. In the United States, the growth in relationships — sponsored research agreements, consultancies, memberships on boards, licensing agreements, and equity ownership — between for-profit corporations and research universities and their scientists has made the problem of conflicts, particularly financial conflicts, more acute. Conflicts can interfere with or compromise important principles and obligations of researchers and their institutions, e.g., adherence to accepted research norms, duty of care to patients, and open exchange of information. Disclosure is a key component of a successful conflict policy. Commitments which conflict with a faculty member's primary obligations to teaching, research, administrative responsibilities, or patient care also need attention. Institutional conflict of interests present different problems, some of which are discussed in an analysis of an actual problem posed by two proposed clinical trials. This paper is adapted from a lecture presented to a Symposium on Scientific Integrity, Warsaw, Poland, 23 November 1995. Daniel Steiner was Vice-President and General Counsel of Harvard University (1972–92) and in that capacity became familiar with conflict of interest issues. He is currently Counsel to the Boston law firm. Ropes and Gray, and is Adjunct Lecturer in Public Policy at the John F. Kennedy School of Government. Harvard University.     

A new measure for determining children's subjective organization of speech

A new technique for determining children's subjective organization of speech is described. The technique consists of teaching a child a sentence and then repeatedly (1) reading the sentence up to a selected point, (2) sounding a tone, and (3) having the child supply the next word. The time from the tone to the onset of the child's voice is the dependent variable. In the first study 6- and 8-year-old children memorized the following sentence: “John likes to feed the little puppies in the barn.” Their response times suggested that the dominant segmentation pattern consisted of four phrases: a subject phrase, a verb phrase, an object phrase and a modifier phrase. Within each phrase differences between reaction times were on the order of 30 msec. Across phrases they were on the order of 120 msec. The same trend emerged for subsamples of the children with various short-term memory sizes, and for adults. It also appeared for subsamples of the total scores (e.g., first six trials and last six trials). In order to provide further evidence of the technique's validity, different sentences of the same general type were presented to children with short-term memory spans of either 3, 4, or 5. As predicted, it was found that when children's spans corresponded to the number of hypothesized chunks (i.e., 4), they could repeat the sentences verbatim on the first exposure. They could not do so, however, when their spans were lower than that value or when the number of phrases was increased. It was concluded that the new technique is a promising one for assessing young children's patterns of speech segmentation.     

Effects of neutral and positive stimuli on stuttering: “Calling attention to stuttering” revisited

This study investigated the effects of presumably positive and neutral response-contingent stimuli on the occurence of stuttering. Eight adult stutterers spoke spontaneously during a 60-min experimental session, which was divided into three 20-min periods. During Condition I no stimuli were delivered. During Condition II a digital counter and a pair of yellow lights were activated each time the subject stuttered. During Condition III these same response-contingent stimuli were delivered, but with the additional factor that the subject would earn 5¢ each time the counter moved forward and the lights were illuminated. Conditions II and III were counterbalanced across subjects. The experimenter was unaware of which of the two contingencies were operative during Conditions II and III. Results showed no significant changes in occurence of stuttering due to either response-contingent stimulus. A discussion of theoretical and experimental implications is given.     

The use of averaged electroencephalic response techniques in the study of auditory processing related to speech and language

This paper reviews a number of studies done by the authors and others, who have utilized various averaged electroencephalic response (AER) techniques to study speech and language processing. Pertinent studies are described in detail. A relatively new AER technique, auditory brainstem responses (ABR), is described and its usefulness in studying auditory processing activity related to speech and language is outlined. In addition, a series of ABR studies, that have demonstrated significant male—female differences in ABR auditory processing abilities, is presented and the relevance of these data to already established differences in male—female language, hearing, and cognitive abilities is discussed.     

Are there constraints on childhood disfluency?

Analysis of the spontaneous speech of eight stuttering and eight normally fluent children reveals that (a) the location of both stuttering and normal disfluent moments is constrained by sentential constituent structure, and (b) stuttering children experience fluency breakdown with a particular type of constituent (verb phrase) not usually disfluently produced by normals. A view of early stuttering as a sentence planning and integration disorder is present.     

Stuttering and fluency: Exclusive events or points on a continuum?

In recent years, several studies have been conducted in which the fluency of stutterers was compared with that of normal speakers. These investigations have been of two basic types, some involving objective measures of physiologic, aerodynamic, or acoustic features of the subjects' fluent speech signal, and others involving experiments performed in which listeners attempted to distinguish the fluency produced by stutterers from that generated by normal speakers. The body of literature pertaining to each of these two types of investigations is reviewed and interpreted. The interpretations offered are then developed in an effort to shed further light on both fluency and stuttering. Implications for further research, as well as for the evaluation, treatment, and post-therapy assessment of stutterers are drawn.