Loraine K. Obler

Lexical retrieval in healthy aging

Lexical retrieval for common nouns and verbs was measured using 2 picture naming tests in 162 healthy female and male subjects aged 30 to 79 years. Responses were scored for correctness, responsivity to cueing, and response type. The ability to name both word types declined with age, especially after age 70 in healthy subjects. More errors were made on object names than action names, especially for older subjects. Subjects of all ages were equally able to utilize phonemic cues. With increasing age subjects produced more circumlocutions and fewer semantic errors. Response type difference need not reflect qualitative differences in lexical retrieval; rather, they reflect the quantitatively greater difficulty of the task for healthy older people as compared to younger adults. The naming difficulty for healthy aging, we conclude, is at the label retrieval stage.

Right hemisphere specialization for the identification of emotional words and sentences; evidence from stroke patients

This study examines the contribution of the lexical/verbal channel to emotional processing in 16 right brain-damaged (RBD), 16 left brain-damaged (LBD) and 16 normal control (NC) right-handed adults. Emotional lexical perception tasks were developed; analogous nonemotional tasks were created to control for cognitive and linguistic factors. The three subject groups were matched for gender, age and education. The brain-damaged groups were similar with respect to cerebrovascular etiology, months post-onset, sensory-motor status and lesion location. Parallel emotional and nonemotional tasks included word identification, sentence identification and word discrimination. For both word tasks, RBDs were significantly more impaired than LBDs and NCs in the emotional condition. For all three tasks, RBDs showed a significantly greater performance discrepancy between emotional and nonemotional conditions than did LBDs or NCs. Results were not affected by the valence (i.e. positive/negative) of the stimuli. These findings suggest a dominant role for the right hemisphere in the perception of lexically-based emotional stimuli.

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.

Naming errors in healthy aging and dementia of the Alzheimer type.

Naming errors were analyzed for healthy younger and older adults and patients with a diagnosis of senile dementia of the Alzheimer type (SDAT). Three types of errors were identified, varying in relatedness to the target word: near synonyms; semantically related naming errors; and unrelated naming errors. Older adults made relatively more related errors than did younger adults. SDAT patients were distinguished by the number of unrelated responses given. In addition, SDAT patients who scored within the normal range were identified by the high number of response attempts relative to the number of initial errors. We suggest that error patterns on naming tasks may potentially serve as clinical markers to distinguish healthy older persons with mild naming disorders from patients with SDAT.

Aphasia type and aging

Abstract 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 Brocas, Wernickes, anomic, conduction, and global aphasics were considered. The median age of the Brocas group (51 years old) was significantly lower than that of the total group (55.8 years old), while the median age of the Wernickes group was significantly higher (63 years old). Moreover the incidence of Wernickes aphasia increased steadily with age, while incidence of the other types of aphasia peaked in the sixth decade and then diminished with increasing age.

Auditory comprehension and aging: Decline in syntactic processing

Comprehension of six syntactic structures was tested across four age groups. Each structure was presented with both plausible and implausible content. The contribution of cognitive nonlinguistic factors important for comprehension (attention, short-term memory, and mental control) was tested via standard neuropsychological tasks. Sixty-six women aged 30–79 were tested. Both errors and reaction times increased with age, especially for more complex syntactic types and implausible sentences. The neuropsychological factors tested contributed minimally to an age-related decline in comprehension, suggesting that the subtle breakdown seen in syntactic processing may be a language-specific impairment.

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

Abstract 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.

Relationships among Facial, Prosodic, and Lexical Channels of Emotional Perceptual Processing

This study was designed to address the issue of whether there is a general processor for the perception of emotion or whether there are separate processors. We examined the relationships among three channels of emotional communication in 100 healthy right-handed adult males and females. The channels were facial, prosodic/intonational, and lexical/verbal; both identification and discrimination tasks of emotional perception were utilised. Statistical analyses controlled for nonemotional perceptual factors and subject characteristics (i.e. demographic and general cognitive). For identification, multiple significant correlations were found among the channels. For discrimination, fewer correlations were significant. Overall, these results provide support for the notion of a general processor for emotional perceptual identification in normal adult subjects.

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.

On the Nature of Naming Errors in Aging and Dementia: A Study of Semantic Relatedness

This study investigated the nature of naming errors produced on the Boston Naming Test by patients with mild and moderate Alzheimers disease (AD) and elderly and young controls, using a newly devised scoring system. This new approach involved ratings of error responses on a scale of semantic relatedness to the target name. Error responses of both mild and moderate AD subjects were no less semantically related to target names than were responses of age- and education-matched controls. We conclude that some available evidence of semantic loss in AD may be an artifact of the methodology chosen for evaluating naming errors.