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Broca's area, sentence comprehension, and working memory: an fMRI Study.

Rogalsky C, Matchin W, Hickok G - Front Hum Neurosci (2008)

Bottom Line: A second experiment used fMRI to document the brain regions underlying this effect.However, during concurrent speech articulation (but not finger-tapping) this complexity effect was eliminated in the pars opercularis suggesting that this region supports sentence comprehension via its role in articulatory rehearsal.Activity in the pars triangularis was modulated by the finger-tapping task, but not the speech articulation task.

View Article: PubMed Central - PubMed

Affiliation: Center for Cognitive Neuroscience & Department of Cognitive Sciences, University of California Irvine, USA.

ABSTRACT
The role of Broca's area in sentence processing remains controversial. According to one view, Broca's area is involved in processing a subcomponent of syntactic processing. Another view holds that it contributes to sentence processing via verbal working memory. Sub-regions of Broca's area have been identified that are more active during the processing of complex (object-relative clause) sentences compared to simple (subject-relative clause) sentences. The present study aimed to determine if this complexity effect can be accounted for in terms of the articulatory rehearsal component of verbal working memory. In a behavioral experiment, subjects were asked to comprehend sentences during concurrent speech articulation which minimizes articulatory rehearsal as a resource for sentence comprehension. A finger-tapping task was used as a control concurrent task. Only the object-relative clause sentences were more difficult to comprehend during speech articulation than during the manual task, showing that articulatory rehearsal does contribute to sentence processing. A second experiment used fMRI to document the brain regions underlying this effect. Subjects judged the plausibility of sentences during speech articulation, a finger-tapping task, or without a concurrent task. In the absence of a secondary task, Broca's area (pars triangularis and pars opercularis) demonstrated an increase in activity as a function of syntactic complexity. However, during concurrent speech articulation (but not finger-tapping) this complexity effect was eliminated in the pars opercularis suggesting that this region supports sentence comprehension via its role in articulatory rehearsal. Activity in the pars triangularis was modulated by the finger-tapping task, but not the speech articulation task.

No MeSH data available.


Related in: MedlinePlus

Plausibility judgment performance for each sentence type in each concurrent task condition. Mean a′ values across subjects for each sentence type in each task condition are depicted. Error bars represent 95% confidence intervals.
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Figure 3: Plausibility judgment performance for each sentence type in each concurrent task condition. Mean a′ values across subjects for each sentence type in each task condition are depicted. Error bars represent 95% confidence intervals.

Mentions: Behavioral results in the scanner were consistent with behavioral results from Experiment 1. Sentence comprehension performance in the absence of a secondary task was quite good (>90%) and similar for OR and SR sentences. As predicted by the behavioral study reported above, the largest difference between plausibility judgment performance of object-relative clause and subject-relative clause sentences was seen during concurrent speech articulation (Figure 3). Paired-sample one-tailed t-tests were calculated for the difference in performance (as represented by mean a′ values) between sentence types during each task condition. The difference of judgment performance between the two sentence types during concurrent articulation was significant: t(14) = 2.31, p = 0.03. Differences between judgment performance for the two sentence types during the finger-tapping sequence, as well as in the absence of a concurrent task were not significant, although there was a trend for OR sentences to lead to more errors during the finger tapping task than SR sentences, as expected from Experiment 1 (Table 2).


Broca's area, sentence comprehension, and working memory: an fMRI Study.

Rogalsky C, Matchin W, Hickok G - Front Hum Neurosci (2008)

Plausibility judgment performance for each sentence type in each concurrent task condition. Mean a′ values across subjects for each sentence type in each task condition are depicted. Error bars represent 95% confidence intervals.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2572210&req=5

Figure 3: Plausibility judgment performance for each sentence type in each concurrent task condition. Mean a′ values across subjects for each sentence type in each task condition are depicted. Error bars represent 95% confidence intervals.
Mentions: Behavioral results in the scanner were consistent with behavioral results from Experiment 1. Sentence comprehension performance in the absence of a secondary task was quite good (>90%) and similar for OR and SR sentences. As predicted by the behavioral study reported above, the largest difference between plausibility judgment performance of object-relative clause and subject-relative clause sentences was seen during concurrent speech articulation (Figure 3). Paired-sample one-tailed t-tests were calculated for the difference in performance (as represented by mean a′ values) between sentence types during each task condition. The difference of judgment performance between the two sentence types during concurrent articulation was significant: t(14) = 2.31, p = 0.03. Differences between judgment performance for the two sentence types during the finger-tapping sequence, as well as in the absence of a concurrent task were not significant, although there was a trend for OR sentences to lead to more errors during the finger tapping task than SR sentences, as expected from Experiment 1 (Table 2).

Bottom Line: A second experiment used fMRI to document the brain regions underlying this effect.However, during concurrent speech articulation (but not finger-tapping) this complexity effect was eliminated in the pars opercularis suggesting that this region supports sentence comprehension via its role in articulatory rehearsal.Activity in the pars triangularis was modulated by the finger-tapping task, but not the speech articulation task.

View Article: PubMed Central - PubMed

Affiliation: Center for Cognitive Neuroscience & Department of Cognitive Sciences, University of California Irvine, USA.

ABSTRACT
The role of Broca's area in sentence processing remains controversial. According to one view, Broca's area is involved in processing a subcomponent of syntactic processing. Another view holds that it contributes to sentence processing via verbal working memory. Sub-regions of Broca's area have been identified that are more active during the processing of complex (object-relative clause) sentences compared to simple (subject-relative clause) sentences. The present study aimed to determine if this complexity effect can be accounted for in terms of the articulatory rehearsal component of verbal working memory. In a behavioral experiment, subjects were asked to comprehend sentences during concurrent speech articulation which minimizes articulatory rehearsal as a resource for sentence comprehension. A finger-tapping task was used as a control concurrent task. Only the object-relative clause sentences were more difficult to comprehend during speech articulation than during the manual task, showing that articulatory rehearsal does contribute to sentence processing. A second experiment used fMRI to document the brain regions underlying this effect. Subjects judged the plausibility of sentences during speech articulation, a finger-tapping task, or without a concurrent task. In the absence of a secondary task, Broca's area (pars triangularis and pars opercularis) demonstrated an increase in activity as a function of syntactic complexity. However, during concurrent speech articulation (but not finger-tapping) this complexity effect was eliminated in the pars opercularis suggesting that this region supports sentence comprehension via its role in articulatory rehearsal. Activity in the pars triangularis was modulated by the finger-tapping task, but not the speech articulation task.

No MeSH data available.


Related in: MedlinePlus