Biomedical subjects

Jyotsna Vaid

Publications and source records attributed to Jyotsna Vaid.

7 recordsLinked to original sources

PubMed2006

Laterality and language experience.

A meta-analysis was conducted on studies that examined hemispheric functional asymmetry for language in brain-intact monolingual and bilingual adults. Data from 23 laterality studies that directly compared bilingual and monolingual speakers on the same language were analysed (n = 1234). Variables examined were language experience (monolingual, bilingual), experimental paradigm (dichotic listening, visual hemifield presentation, and dual task) and, among bilinguals, the influence of second language proficiency (proficient vs nonproficient) and onset of bilingualism (early, or before age 6; and late, or after age 6). Overall, monolinguals and late bilinguals showed reliable left hemisphere dominance, while early bilinguals showed reliable bilateral hemispheric involvement. Within bilinguals, there was no reliable effect of language proficiency when age of L2 acquisition was controlled. The findings indicate that early learning of one vs. two languages predicts divergent patterns of cerebral language lateralisation in adulthood.

Adult↗

PubMed2006

Proverb preferences across cultures: dialecticality or poeticality?

Peng and Nisbett (1999) claimed that members of Asian cultures show a greater preference than Euro-Americans for proverbs expressing paradox (so-called dialectical proverbs; e.g., Too humble is half proud). The present research sought to replicate this claim with the same set of stimuli used in Peng and Nisbett's Experiment 2 and a new set of dialectical and nondialectical proverbs that were screened to be comparably pleasing in phrasing. Whereas the proverbs were rated as more familiar and (in Set 1) more poetic by Chinese than by American participants, no group differences were found in relation to proverb dialecticality. Both the Chinese and Americans in our study rated the dialectical proverbs from Peng and Nisbett's study as more likable, higher in wisdom, and higher in poeticality than the nondialectical proverbs. For Set 2, both groups found the dialectical proverbs to be as likable, wise, and poetic as the nondialectical proverbs. When poeticality was covaried out, dialectical proverbs were liked better than nondialectical proverbs across both stimulus sets by the Chinese and the Americans alike, and when wisdom was covaried out, the effect of dialecticality was reduced in both sets and groups. Our findings indicate that caution should be taken in ascribing differences in proverb preferences solely to cultural differences in reasoning.

Adolescent↗

PubMed2005

Articulation in early and late bilinguals' two languages: evidence from functional magnetic resonance imaging.

The network of cortical and subcortical regions that contribute to articulation was examined in bilinguals using functional magnetic resonance imaging. Participants were all fluent in French and English: half were bilingual from birth and half were 'late bilinguals' who had learned French after the age of 12. Overt articulation resulted in the bilateral activation of the motor cortex, basal ganglia and cerebellum, and also the supplementary motor area, independent of the language spoken. Furthermore, the threshold and extent of the network involved in articulation was identical for the two bilingual groups with the exception of greater variation in the left putamen for the late bilinguals. These data challenge claims that age of acquisition results in fundamental differences in the neural substrates that subserve language in bilinguals.

Adult↗

PubMed2002

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.

Brain↗

PubMedDate not supplied

Exploring word recognition in a semi-alphabetic script: the case of Devanagari.

Unlike other writing systems that are readily classifiable as alphabetic or syllabic in their structure, the Indic Devanagari script (of which Hindi is an example) has properties of both syllabic and alphabetic writing systems. Whereas Devanagari consonants are written in a linear left-to-right order, vowel signs are positioned nonlinearly above, below, or to either side of the consonants. This fact results in certain words in Hindi for which, in a given syllable, the vowel precedes the consonant in writing but follows it in speech. The current research exploited this property of the script to examine when the disparity between spatial and temporal sequencing would incur a processing cost and the implications of the findings from naming speed, accuracy, and writing order for the level at which words in Devanagari are segmented. The results support a partly phonemic and partly syllabic level of segmentation, consistent with the structural hybridity of the script.

Adolescent↗

PubMedDate not supplied

Directional scanning effect and strength of reading habit in picture naming and recall.

The present research examined directional scanning effects (DSE) as a function of reading habit strength among right handers. A picture array naming and recall task was administered to three groups of child readers--unidirectional right-to-left readers of Arabic, unidirectional left-to-right readers of Kannada, and bidirectional readers of Urdu and English--and one group of Urdu illiterate adults. The results showed a right-to-left DSE in the Arabic and Urdu readers. In the latter group the strength of the scanning effect decreased with greater schooling in English. No R-L effect was observed in the Kannada readers or in the Urdu illiterates. These results extend prior research in documenting an "invasion" of culturally acquired reading scan habits onto a nonlinguistic domain. It is suggested that directional scanning effects be controlled or else directly examined in future laterality research involving nonlinguistic stimuli.

Adolescent↗

PubMedDate not supplied

Stroke direction asymmetry in figure drawing: influence of handedness and reading/writing habits.

Recent studies suggest that asymmetries noted in certain nonlinguistic tasks used in laterality research (e.g., facial affect judgment, line bisection) may in part be influenced by prior reading/writing habits. The present study examined the relative influence of reading/writing direction and handedness on the direction of stroke movement in free-hand figure drawing. One hundred twenty right and left handed brain-intact adult readers of scripts with opposing directionality (Hindi vs Urdu) and illiterate controls were observed while drawing a tree, a hand, a house, an arrow, a pencil, and a fish. Right-handers (including right-handed illiterates) and left-to-right readers drew most figures in a left-to-right direction, whereas left handers (including left handed illiterates) and right-to-left readers more often drew the figures from right to left. These results extend previous findings and contribute to a growing body of evidence demonstrating reading scan biases in nonlinguistic perception and production tasks. It would appear that reading/writing habits cannot be ignored as a potential artifact in studies of hemisphere functional asymmetry employing nonlinguistic stimuli.

Adolescent↗