Word-finding abilities of three types of aphasic subjects

Word-finding difficulties are often observed among different types of aphasic patients. This investigation analyzed the word-finding abilities of 30 aphasic subjects (10 Broca's, 10 Wernicke's, and 10 anomic). Forty nouns counterbalanced according to word length and frequency of occurrence in English language usage were used as stimuli and presented through four modalities (oral expression, writing, auditory comprehension, and reading comprehension). It was expected that patterns of word finding abilities would help in the classification of the different types of aphasia. In addition, long words and less frequently occurring words in English language usage should prove more difficult in word-finding ability, regardless of modality. The results of this study found long words and less frequent words were more difficult for aphasic subjects. Among the modalities, long words were significantly harder than short words for the writing modality only. It was also found that semantic errors were the most common errors for all types of aphasic subjects. Broca's subjects produced significantly moreno response errors in oral expression; Wernicke's subjects produced significantly more semantic and phonemic errors in reading comprehension; and, Wernicke's subjects produced significantly more unrelated errors in both oral expression and reading comprehension. Clinical implications were also discussed.The present study was based on a doctoral dissertation completed at the City University of New York in partial fulfillment of the requirements of the doctoral degree in Speech and Hearing Sciences by the first author under the direction of the second author. The authors wish to thank Dr. Louis J. Gerstman for his assistance with the statistical analysis of this research and Dr. Robert Goldfarb for all his helpful suggestions and editorial comments.     

Rhythmic motor behavior of preambulatory motor impaired,down syndrome and nondisabled children: A comparative analysis

The developmental course of rhythmic motor behavior was followed longitudinally for three groups of preambulatory children — normally developing, Down syndrome, and those with profound motor impairment. The groups differed in chronological age but were comparable with respect to motor age. The motor impaired subjects displayed significantly less rhythmic motor behavior than the nondisabled and Down syndrome groups. In comparing particular subtypes of rhythmic motor behavior, differences were found in both the average number of bouts and duration of subtypes among the groups. Longitudinal analyses of the data over the entire observation period revealed that the rhythmic motor behavior of the children with Down syndrome was more similar to that exhibited by the nondisabled children than was the rhythmic motor behavior of the children with motor impairment. However, there was considerable variability among the groups in several particular subtypes.This research was supported by grants from the National Institute of Child Health and Human Development (HD 17650 and HD 07226).The authors acknowledge the assistance of Robert E. Arendt, Grant Youngquist, Michael Hohn, and Charles Lowitzer in obtaining the observational data and thank the families of the subjects for their enthusiasm and dedication to the project.This study was presented at the 23rd Annual Gatlinburg Conference on Research and Theory in Mental Retardation and Developmental Disabilities, April 21, 1990.     

Adults' difficulties in identifying concealment among children interviewed with the putative confession instructions

The putative confession (PC) instructions (“[suspect] told me everything that happened and wants you to tell the truth”) increases children's honesty. However, research has shown that children who maintain secrecy despite the PC are more convincing. We examined whether (a) the PC undermines adults' deception detection abilities or (b) children who conceal despite the PC are better deceivers. Adults evaluated truthful and deceptive children interviewed with the PC where the PC portion of the interview was either present or absent. Adults' deception detection was no worse when the PC was present; in fact, it was slightly better. Rather than negatively affecting adults' ability to detect deception, the PC selects an unusually convincing group of concealers.     

Detecting children's true and false denials of wrongdoing: Effects of question type and base rate knowledge

One common and unfortunately overlooked obstacle to the detection of sexual abuse is non-disclosure by children. Non-disclosure in forensic interviews may be expressed via concealment in response to recall questions or via active denials in response to recognition (e.g., yes/no) questions. In two studies, we evaluated whether adults' ability to discern true and false denials of wrongdoing by children varied as a function of the types of interview question the children were asked. Results suggest that adults are not good at detecting deceptive denials of wrongdoing by children, even when the adults view children narrate their experiences in response to recall questions rather than provide one word answers to recognition questions. In Study 1, adults exhibited a consistent “truth bias,” leading them toward believing children, regardless of whether the children's denials were true or false. In Study 2, adults were given base-rate information about the occurrence of true and false denials (50% of each). The information eliminated the adults' truth bias but did not improve their overall detection accuracy, which still hovered near chance. Adults did, however, perceive children's denials as slightly more credible when they emerged in response to recall rather than recognition questions, especially when children were honestly denying wrongdoing. Results suggest the need for caution when evaluating adults' judgments of children's veracity when the children fail to disclose abuse.     

The locus of semantic priming in RSVP target search

At what stage does semantic priming affect accuracy in target search? In two experiments, participants viewed two streams of stimuli, each including a target word among distractors. Stimulus onset asynchronies (SOAs) between the targets (T1 and T2) ranged from 53 to 213 msec. A word semantically related to one or neither of the targets preceded each trial. In Experiment 1, participants were instructed to report both targets. Although more primed than unprimed targets were reported, there was no cost for unprimed words. A strong interaction between SOA and T1 versus T2 was found, but priming did not interact with either variable. In Experiment 2, only related targets were reported. Performance was similar to that for primed targets in Experiment 1. Semantic priming does not seem to modulate how attentional resources are initially allocated between targets, but instead affects a later stage of processing, the point at which a target word reaches lexical identification.     

Feedback specificity, exploration, and learning

Greater feedback specificity is generally considered to be beneficial for performance and learning, but the evidence for this generalization is limited. The authors argue that increasing the specificity of feedback is beneficial for initial performance but discourages exploration and undermines the learning needed for later, more independent performance. The results of their transfer experiment demonstrate that increasing the specificity of feedback positively affected practice performance, but its benefits did not endure over time or modification of the task. In addition, feedback specificity negatively affected levels of exploration during practice and interacted with exploration strategies to affect learning. The results suggest that those who received feedback of varying specificity may have learned through different but equally beneficial mechanisms.     

Feedback specificity, learning opportunities, and learning

Although increasing feedback specificity is generally beneficial for immediate performance, it can undermine certain aspects of the learning needed for later, more independent performance. The results of the present transfer experiment demonstrate that the effects of increasing feedback specificity on learning depended on what was to be learned, and these effects were partially mediated through the opportunities to learn how to respond to different task conditions during practice. More specific feedback was beneficial for learning how to respond to good performance and detrimental for learning how to respond to poor performance. The former relationship was partially mediated by feedback specificity's effect on learning opportunities during practice. The results have implications for designing feedback interventions and training to maximize the learning of various aspects of a task.     

Verbal mediation of number knowledge: evidence from semantic dementia and corticobasal degeneration

Patients with corticobasal degeneration (CBD) appear to have impaired number knowledge. We examined the nature of their number deficit while we tested the hypothesis that comprehension of larger numbers depends in part on verbal mediation. We evaluated magnitude judgments and performance on number conservation measures rooted in Piagetian theory in nonaphasic patients with CBD (n=13) and patients with a fluent form of progressive aphasia known as semantic dementia (SD; n=15). We manipulated the numbers of the arrays and the visual-spatial properties of the stimuli being compared during magnitude judgments and Piagetian conservation measures. CBD patients were consistently impaired judging the magnitudes of larger numbers (4-9), while they had minimal difficulty with smaller numbers (magnitudes < or = 3). By comparison, SD patients performed all measures of number knowledge at a ceiling level regardless of number magnitude. Neither patient group was significantly impacted by manipulations of the spatial properties of the stimuli. CBD patients' impairment with larger numbers despite minimal aphasia, and SD patients' intact performance despite an aphasia, challenge the proposal that understanding larger numbers depends on verbal mediation.