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.     

Shift of visual field preference for English words in native Hebrew speakers.

Lateralization for visual verbal material was tested with Hebrew and English stimuli presented to Israeli adolescents in their second, fourth, and sixth years of study of English as a second language. Seventy-two children, 12 male and 12 female subjects in each class, were tested by means of a target-word recognition task. Laterality scores derived from reaction-time measures resulted in: (1) a left visual field preference for the English stimuli in the youngest group which decreased with increasing age, becoming a right visual field preference in the oldest group, and (2) a significant and equal right visual field preference for Hebrew stimuli for all groups. The data suggest right hemisphere involvement in acquiring the reading skills of a new language.     

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.     

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.     

Impact of emotional content on discourse production in patients with unilateral brain damage.

A picture story task was developed to examine expression of emotion via the verbal/lexical channel. The task elicited discourse with either emotional, visual-spatial, or neutral content and was administered to right brain-damaged (RBD), left brain-damaged (LBD), and normal control (NC) right-handed adults. Subjects were matched for gender, age, education, and occupational status. The brain-damaged groups were matched for months post-CVA onset and were similar with respect to intrahemispheric site of lesion. While the number of words produced was equivalent for each of the subject groups, the RBDs and LBDs expressed quantitatively less content than did the NCs. When content differences were examined within each subject group, there were no differences for LBDs and NCs, but the RBDs showed a selective deficit when producing emotional content. This finding suggests a special role for the right hemisphere in the production of emotional content in verbal discourse.     

Cerebral lateralization in bilinguals: Methodological issues

The literature on lateralization for language in bilinguals manifests two apparent contradictions. Some papers demonstrate differences in lateralization between bilinguals and monolinguals; others demonstrate none. In studies with exclusively bilingual subjects, some papers demonstrate differences between the lateralization for the two languages, while others demonstrate none. This paper discusses the range of methodological parameters which must be borne in mind when conducting or evaluating studies of lateralization for language in bilinguals. These include issues of subject selection, language and stimulus selection, testing procedures, data analysis, and interpretation of results.     

The phonology-morphosyntax interface: affixed words in agrammatism.

In three experiments with nondysarthric agrammatics, we explored the association between phonology and morphosyntax. (1) Contrasting phonological and nonphonological factors on inflectional-affix production of English verbs across three tasks in eight agrammatics, longer stem-syllabic length and stem-final-CC status resulted in poorer affix-production. (2) Studying verb inflections in six agrammatic Spanish-speakers, affix-length and affix-stress correlated with poorer repetition, as did low affix frequency. (3) Four English-speaking agrammatics read aloud and repeated derived words varying in syllable-length and stem-stress reassignment; both contributed independently to word-production difficulty. Phonological complexity of affixes and stems appears to reduce resources for morphological processing in nondysarthric agrammatics.     

Concurrent validity of the wide range assessment of visual motor abilities in typically developing children ages 4 to 11 years

Pediatric clinicians working with school-age children use the Wide Range Assessment of Visual Motor Abilities (WRAVMA) as a method for evaluating visual perception and motor skills in children despite limited information on concurrent validity. Whether it may be substituted for the Beery-Buktenica Developmental Test of Visual-Motor Integration (VMI) and has suitable estimates of concurrent validity were examined with a convenience sample of 91 typically developing children ages 4 to 11 years. No systematic concurrent validity between the WRAVMA and the VMI emerged. Only two subtests of the WRAVMA (Matching with Visual Perception, and Pegboard with Motor Coordination) gave scores statistically significantly correlated with those on the VMI, and these correlations were weak, accounting for very small amounts of the shared variance. As such, they have low clinical relevance. These findings do not provide evidence of concurrent validity to support the use of WRAVMA as an alternative method for the VMI for assessing children's visual perception and motor skills.     

Cross-language lexical connections in the mental lexicon: evidence from a case of trilingual aphasia

Despite anecdotal data on lexical interference among the languages of multilingual speakers, little research evidence about the lexical connections among multilinguals' languages exists to date. In the present paper, two experiments with a multilingual speaker who had suffered aphasia are reported. The first experiment provides data about inter-language activation during natural conversations; the second experiment examines performance on a word-translation task. Asymmetric patterns of inter-language interference and translation are evident. These patterns are influenced by age of language learning, degree of language recovery and use, and prevalence of shared lexical items. We conclude that whereas age of language learning plays a role in language recovery following aphasia, the degrees of language use prior to the aphasia onset and of shared vocabulary determine the ease with which words are accessed. The findings emphasize the importance of patterns of language use and the relations between the language pair under investigation in understanding lexical connections among languages in bilinguals and multilinguals.