Brain Activation Modulated by Sentence Comprehension

Abstract

The comprehension of visually presented sentences produces brain activation that increases with the linguistic complexity of the sentence. The volume of neural tissue activated (number of voxels) during sentence comprehension was measured with echo-planar functional magnetic resonance imaging. The modulation of the volume of activation by sentence complexity was observed in a network of four areas: the classical left-hemisphere language areas (the left laterosuperior temporal cortex, or Wernicke's area, and the left inferior frontal gyrus, or Broca's area) and their homologous right-hemisphere areas, although the right areas had much smaller volumes of activation than did the left areas. These findings generally indicate that the amount of neural activity that a given cognitive process engenders is dependent on the computational demand that the task imposes.

Interactions of the hippocampal system and the prefrontal cortex in learning language-like rules

“…Broca's area was shown to be involved in syntactic processes in a number of neuropsychological studies, in particular in that patients with lesions including Broca's area clearly suffering from syntactic deficits (Grodzinski, 2000;Caplan and Waters, 1999). In addition, some recent brain imaging studies have demonstrated increased hemodynamic activity in Broca's area during the processing of syntactic aspects during language comprehension (Dapretto and Bookheimer, 1999;Embick et al, 2000;Friederici et al, 2000a;Just et al, 1996;Moro et al, 2001;Tettamanti et al, 2002). Some of these fMRI studies report the activation to be focused in BA44.…”

Semantic disturbance in schizophrenia and its relationship to the cognitive neuroscience of attention

“…As cognition become more intensive or demanding, attention is called to help drive the computational machinery. For example in a functional MRI study of sentence comprehension, Just et al (1996) demonstrated that the increasing linguistic complexity of sentences produced a proportionate increase of activation of the classical left hemisphere language system in healthy controls. By the same token, processes that are presumed automatic and involuntary may also be effected, with attention disregulation perhaps leading to states of hyper-automaticity (Callaway and Naghdi, 1982).…”

Differential effects of syntactic and semantic processing on the subregions of Broca’s area

“…These findings were generexamined through lesion studies and recently with the use ally replicated in another study by the same group with of functional neuroimaging. Evidence from these studies auditory presentation in which subjects judged the suggests that syntactic processes are supported, at least in plausibility of cleft-subject and more complex cleft-object part, by the left inferior frontal gyrus, or Broca's area sentences, except that the activation was in pars trian-[7-10, 13,17,19,22,23,41]. (Note that the posterior left gularis rather than pars opercularis [8].…”

“…[8, 13,17,19,23,41]. For example, in one of the studies mentioned above [39], patients with lesions confined to the frontal operculum and extending posteriorly had significant 2 .…”