Psychometric Aspects of Verbal Pragmatic Ratings

This study examined the psychometric aspects of a verbal pragmatic rating scale. The scale contained six pragmatic features (i.e., Conciseness, Lexical Selection, Quantity, Relevancy, Specificity, and Topic Maintenance) based on Grice's cooperative principles. Fifteen right brain-damaged (RBD), 15 left brain-damaged (LBD), and 16 healthy normal control (NC) right-handed adult participants produced narratives while recollecting emotional and nonemotional experiences. Naive raters evaluated each pragmatic feature for appropriateness on a 5-point Likert scale. When reliability was examined, the overall internal consistency of the pragmatic scale was extremely high (alpha =.96). Factor analysis was conducted to examine the theoretical relations among the six pragmatic features. Three meaningful factors involving discourse content, conceptual unity, and parsimony were identified. Findings are discussed in light of Grice's model and the construct validity of the scale.     

Dual Processing of Open- and Closed-Class Words

A series of articles in the past two decades has suggested differential processing of open- and closed-class lexical items by normal adults. Difficulties in replicating a crucial study (Bradley, 1978), however, have weakened the dual route hypothesis. We matched 16 French open-class items to 16 closed-class items for phonological structure, word length, and relative word frequency. Three agrammatic aphasics were asked to read each word in isolation and in a sentence context. Error analysis revealed strikingly more phonological errors on closed-class than open-class items. Dysfluencies were greater on closed-class items and contributed to greater overall reading time for the closed-class words, consistent with a two-route model for the production of closed- and open-class lexical items in Broca's aphasics and, thus, normals.     

Aphasia type and aging

We analyzed the relationship between age and clinical type of aphasia in 167 right-handed men who had suffered cerebrovascular accidents. Patients with unequivocal diagnoses as Broca's, Wernicke's, anomic, conduction, and global aphasics were considered. The median age of the Broca's group (51 years old) was significantly lower than that of the total group (55.8 years old), while the median age of the Wernicke's group was significantly higher (63 years old). Moreover the incidence of Wernicke's aphasia increased steadily with age, while incidence of the other types of aphasia peaked in the sixth decade and then diminished with increasing age.     

Bias in visual attention behavior in a normal school-aged population

Hemi-field visual-spatial attention was studied on a timed letter cancellation task in proficient readers from 7th to 9th grades. Participants maintained greater accuracy in identifying targets in the left quadrants (top/bottom) when compared with the right quadrants (top/bottom), revealing a leftward bias in their responses. Effects of gender and age were evident on performance; females scored significantly higher than males, and 9th graders scored significantly higher than 7th and 8th graders. Thus, a substantial shift in brain maturation may take place from 8th to 9th grades or from the ages of 13.0 to 14.11. Discriminative characteristics of the task are analyzed by assigning greater value to targets located in the top left quadrant. The 9th graders, as compared to the younger students, and the girls, as compared to the boys, evidenced a reading-direction-related bias toward systematic preference for the upper-left to lower-right quadrants.     

Intentions to Care for Children Orphaned by HIV/AIDS: A Test of the Theory of Planned Behavior

HIV/AIDS has added an unparalleled number of children to South Africa's orphan population. The theory of planned behavior (TPB) was used to investigate the decision-making processes of potential substitute caregivers of children orphaned by AIDS. Existing foster and adoptive parents ( n  = 175) completed a self-report postal survey. Of the sample, 76.0% reported willingness to care for an HIV-negative child and 62.2% an HIV-positive child. Analyses of the theory's components reveal contradictory and disappointing results. While the theory is most useful in conceptualizing the factors that bear on fostering and adoption, the current study suggests that the TPB is limited in its ability to address the complexity of decisions that attend fostering and adoption of children orphaned by HIV/AIDS.     

Semantic Degradation and Lexical Access in Age-Related Naming Failures

This study investigated the impaired lexical access and semantic degradation hypotheses as two potential explanations of naming failures in normal aging. Naming responses on the Boston Naming Test (BNT) and Action Naming Test (ANT) were analyzed across three test sessions for 39 adults from three age groups (50s, 60s, and 70s). Failures to name before and after cues were classified as either impaired access if failures occurred at an earlier test session followed by successful naming at a later test session or semantic degradation if naming was successful at an earlier test session followed by failures at a later test session. The results indicated that on both the BNT and ANT all age groups produced more naming failures attributed to impaired access than to semantic degradation. However, for object naming, the failures showed significantly more semantic degradation for people in their 70s compared to the younger age groups. By contrast, for action naming, semantic degradation was negligible, possibly masked by a ceiling effect, and the only age-difference result that approached significance indicated that adults in their 70s produced more naming failures attributed to impaired access than adults in their 50s.     

Naming ability across the adult life span

Abstract

Longitudinal performance on the Boston Naming Test (BNT) was evaluated in 53 normal subjects aged 30 to 79 who were each tested three times over a 7-year span. Naming performance showed a significant decline over time that was greatest for the oldest subjects. These results confirm that decline in naming is a real phenomenon in normal aging that cannot be attributable primarily to cohort effects. We conclude that the changes in naming ability across the life span reflect more than simply a breakdown in lexical retrieval and that perceptual and semantic processing may be implicated.