Human Brain Language Areas Identified by Functional Magnetic Resonance Imaging

Abstract

Functional magnetic resonance imaging (FMRI) was used to identify candidate language processing areas in the intact human brain. Language was defined broadly to include both phonological and lexical-semantic functions and to exclude sensory, motor, and general executive functions. The language activation task required phonetic and semantic analysis of aurally presented words and was compared with a control task involving perceptual analysis of nonlinguistic sounds. Functional maps of the entire brain were obtained from 30 right-handed subjects. These maps were averaged in standard stereotaxic space to produce a robust "average activation map" that proved reliable in a split-half analysis. As predicted from classical models of language organization based on lesion data, cortical activation associated with language processing was strongly lateralized to the left cerebral hemisphere and involved a network of regions in the frontal, temporal, and parietal lobes. Less consistent with classical models were (1) the existence of left hemisphere temporoparietal language areas outside the traditional "Wernicke area," namely, in the middle temporal, inferior temporal, fusiform, and angular gyri; (2) extensive left prefrontal language areas outside the classical "Broca area"; and (3) clear participation of these left frontal areas in a task emphasizing "receptive" language functions. Although partly in conflict with the classical model of language localization, these findings are generally compatible with reported lesion data and provide additional support for ongoing efforts to refine and extend the classical model.

An fMRI Study of the Effect of Amphetamine on Brain Activity,

“…Figure 3 shows the "group-average" activation maps for the TD task superimposed upon an "average" image of brain structure for both the amphetamine and placebo conditions. The areas of activation closely replicate those observed by Binder et al (1997). The ROIs defined from these functional images corresponded to the following regions according to the Talairach atlas: left primary auditory cortex (LPAC), right primary auditory cortex (RPAC), supplemental (right and left) motor cortex (SMA), thalamus (THAL), left cerebellum (LCB), right superior parietal area (RSP), right middle frontal area (RMF), left middle frontal area (LMF), left superior temporal area (LST), right inferior frontal cortex (RIF), left inferior frontal cortex (LIF), left superior temporal gyrus (LSTG), and left inferior parietal area (LIP).…”

“…The TD paradigm followed the procedure of Binder et al (1997). During the 50-second task period, the subject was presented with multiple short series of randomly distributed high (750 Hz) and low (500 Hz) tones.…”

Comprehensive presurgical functional MRI language evaluation in adult patients with epilepsy

“…This shift is likely related to the semantic nature of the SDTD task and to subtracting from the active paradigm the tone decision component, which allows for control of attention/working memory, auditory processing, and motor responses with this task [43]. This LI difference is also likely related, in part, to the differences in the activation patterns between the tasks that are due to various language components involved in the SDTD task versus the VG task.…”

“…language fMRI paradigm consists of two intervening (block design) conditions: the control condition (tone recognition, performed eight times) and the active condition (semantic recognition, performed seven times) [14,43]. Presentation of each condition lasted 30 seconds (15 seconds for the first tone recognition), with stimuli presented every 3.75 seconds.…”

Time‐resolved detection of stimulus/task‐related networks, via clustering of transient intersubject synchronization

“…Both tasks involved visual stimuli and motor responses, and should therefore activate common regions in visual and motor cortex. In addition, the language task should activate frontotemporal regions in the left hemisphere [Binder et al, 1997]; while the spatial task should activate frontoparietal regions in the right hemisphere [Fink et al, 2001; see also Pugh et al, 1996]. The two tasks were presented in different blocks.…”