Sentence processing strategies in healthy seniors with poor comprehension: an fMRI study

We used fMRI to examine patterns of brain recruitment in 22 healthy seniors, half of whom had selective comprehension difficulty for grammatically complex sentences. We found significantly reduced recruitment of left posterolateral temporal [Brodmann area (BA) 22/21] and left inferior frontal (BA 44/6) cortex in poor comprehenders compared to the healthy seniors with good sentence comprehension, cortical regions previously associated with language comprehension and verbal working memory, respectively. The poor comprehenders demonstrated increased activation of left prefrontal (BA 9/46), right dorsal inferior frontal (BA 44/6), and left posterior cingulate (BA 31/23) cortices for the grammatically simpler sentences that they understood. We hypothesize that these brain regions support an alternate, nongrammatical strategy for processing complex configurations of symbolic information. Moreover, these observations emphasize the crucial role of the left perisylvian network for grammatically guided sentence processing in subjects with good comprehension.     

Derivation by prefixation in Slovenian: two aphasia case studies

The present study is concerned with two Slovenian-speaking patients who were asked to produce, in various tasks, verbs, nouns, and adjectives derived by prefixation with prepositions. Despite differences due to their specific linguistic difficulties, both patients' performance was characterized by the differential processing of prefixes and remaining components of complex words. Prepositions in prefixation were mostly preserved, and less frequently substituted, regardless of the numerous errors produced in the remaining portion of the words. These errors seem clearly determined by the morphological structure of the words and therefore appear to be authentic morphological errors. These findings contribute to the theoretical debate on mental lexical representation, speaking in favor of a morphological decomposition in processing of prefixed complex words at different processing levels.     

Do orthographic cues aid language recognition? A laterality study with French-English bilinguals

Sixteen French-English late bilinguals performed a speeded language recognition task on lateralized words that were either marked or unmarked for language on the basis of digram frequency. Response latencies were faster to orthographically marked than unmarked words, particularly in the second language (English). Furthermore, L2 marked words were responded to faster than L1 marked words. These effects were especially prominent for words presented in the left visual field. It is suggested that subjects made use of different strategies in performing the task of language recognition task, with a perceptual search strategy deployed to identify orthographically marked words, resulting in an L2 advantage for such words, and a lexical search strategy deployed for unmarked words, resulting in an L1 advantage for such words.     

Diurnal time courses in psychomotor performance and waking EEG frequencies

The present study examined the similarities between the diurnal time courses in the waking EEG activity and the psychomotor performance. The aim was to verify if some ongoing changes in the excitability of the cortical nerve cells across the daytime could facilitate the sensorimotor processing. EEG recordings and performance results for the Four Choice Reaction Time Test (FCRTT) were obtained every two hours, from morning to late evening period, in 8 young normal subjects (21.3 +/- 0.5 years). ANOVAs were used to verify the presence of diurnal variations in the two measures. Nonparametric correlations were obtained to test the similarity between the changes across the day in the two measures. Three EEG frequency bands (delta, sigma, and beta1) and the reaction time measures varied across the daytime. The changes in the sigma (12.00-13.75 Hz) and the beta1 (14.00-19.75 Hz) bands were similar to the diurnal variations in the reaction time measures. It is suggested that the changes in the sigma and the beta1 bands may facilitate the processing of the sensorimotor treatment.     

Detection performance in pop-out tasks: nonmonotonic changes with display size and eccentricity

We carried out three experiments to investigate detection performance in pop-out tasks and analysed how performance varied as a function of display size (number of elements) and retinal eccentricity of the target. Results showed that when display size was increased from 2 to 81 elements performance first decreased and then increased (replicating Sagi and Julesz, 1987 Spatial Vision 2 39-49). Performance variations differed as a function of eccentricity and often were more pronounced in the periphery than in the foveal area. This retinal-eccentricity influence suggests that processes underlying detection performance in small display sizes are different from those in large display sizes. One should be careful when using the variation of display size as an instrument to analyse visual-search processes because this analysis could be based on a comparison between non-equivalent conditions.     

Processing of temporal duration information in working memory after frontodorsal tumour excisions

This study aimed to test the hypothesis that impairments of temporal duration processing after frontal lobe lesions reflect deficits in executive monitoring functions rather than a domain-specific deficit in the maintenance of duration information in working memory. Patients with frontodorsal lesions, clinical controls with post-central lesions, and healthy controls performed recognition and classification tasks, which should allow for testing maintenance and monitoring functions, respectively. Results showed mild non-selective impairments of the frontal patients on both temporal and spatial recognition tasks, but a marked selective degradation on temporal classification while performance on spatial classification was unimpaired. This suggests that maintenance of duration information in working memory after frontal lesions is basically preserved but that, depending on executive task characteristics, there is a specific deficit in the strategic organization of this type of information.     

Adaptation to disability: applying selective optimization with compensation to the behaviors of older adults with osteoarthritis

This research extends the use of P. B. Baltes and M. M. Baltes's (1990) theory of selective optimization with compensation (SOC) in an effort to conceptually integrate the adaptational behaviors of 248 older adults with disability arising from osteoarthritis. The authors also studied the relationship of SOC to age, illness variables, disability, illness perceptions, and support. The results highlight the variability and plasticity of older adults' efforts to manage disability, with most efforts aimed at compensation and optimization rather than selection. The benefit of using SOC to study adaptation to chronic illness and disability is discussed.