Neural Correlates of Language Control in Bilinguals. Functional MRI and Stimulation Mapping Data in Awake Surgery.

University Hospital, Toulouse24 enrolled

Overview

For bilingual and multilingual patients, brain activation and Electric Stimulation Mapping studies have shown that different languages may be localized, at least partially, in distinct microanatomical systems located within the same gross anatomical areas. The present investigation involves both types of healthy bilinguals with carefully controlled proficiency levels, as well as bilingual patients suffering from low-grade glioma. Functional magnetic resonance imaging data will be collected while the participants perform a picture naming task in blocked conditions for both languages (either English or French) or in switch condition (English and French). A stimulation mapping study will be conducted in the patients during awake surgery with the same tasks.

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

NONE

Enrollment

Conditions

Bilingualism

Interventions

Stimuli will be presented in 3 language conditions, French, English and "switch" in which the participant alternates between English and French every trial. A block design will be used, with 7 line drawings per language condition. Four 9-minute runs will be performed, there being 2 action runs and 2 object runs. In each run, there are 6 blocks of each language condition, presented in a fixed random order. No drawings are repeated. Each stimulus is preceded either by an English or a French prompt word ("to" or "faire" for actions and, "say" or "dire" for objects) for 450 msec; stimuli are presented for 1.5 seconds and followed by a blank screen for 1 second. Language blocks are separated by a variable duration (from 8 to 10 seconds).

Eligibility

Sex: ALLMin age: 18 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: Patients: * Bilingual patients with a pathology indicating an intervention in awake surgery (e.g. low-grade glioma) * At least C1-level of the CECR in both languages * At least 12 years of schooling (French BAC) * Right-handed (Edinburgh test, 1971) * Performance indicator Eastern Cooperative Oncology Group 0-2 (cf. annexe) * Life expectation \> 6 month * Affiliated to social insurance * Having given informed consent Healthy volunteers: * French-English or English-French bilinguals with at least a C1 level (CECR) in both languages * At least 12 years of schooling (French BAC) * Right-handed (Edinburgh test, 1971) * Early bilinguals: age of acquisition of both languages \< 3 years * Late bilinguals: age of acquisition of the L2 \> 10 years Exclusion Criteria: Patients: * Contra-indication for MRI * Left-handed or ambidexter (less than +80 at the Edinburgh test - 1971) * Mini-Mental State Examination \<26 * Patient who cannot respect the procedures, visits, exams described in the protocol * Any other medical or psychiatric affection which renders inclusion of the patient to the study inappropriate as judged by the principal investigator Healthy volunteers: * Contra-indication for MRI * Mini-Mental State Examination \< 26 * Age of acquisition of one of the language between 3 and 10 years

Outcomes

Primary Outcomes

Brain activity

The primary judgment criteria is brain activity as measured by functional magnetic resonance imaging : * In blocked vs. switched naming in control subjects * In switched naming in early vs. late bilingual subjects * In blocked vs. switched naming in early vs. late bilingual subjects

Time frame: 24 hours

Secondary Outcomes