最新發表在PNAS的研究顯示, 除了傳統已知的語意, 字形, 字音等. 最近發現兩側的
anterior temporal lobe也參與了語意的歷程. 因為之前在使用fMRI造影時, 這個腦區經
常有扭曲或型變無法正確造影. 這個團對解決了這個問題之後, 發現ATL也參與在語言歷程
之中, 特別是理解非常規拼法的單字或需要靠語意來認的字.
是說中文不知道是否也會有這種歷程就是了.
--
(Medical Xpress)—The Triangle Model is a widely accepted theoretical
framework that comprises the basis for a number of cognitive models of word
reading. It is built around three primary cognitive units that encode
different types of information: semantics, orthography and phonology.
Neuroscientists seek to map such cognitive models to actual neural
architecture, an endeavor made possible in the last several decades by MRI
technologies.
Researchers in the United Kingdom recently studied the neurocomputational
architecture that underpins reading aloud, which was hitherto complicated by
the difficulties inherent in scanning the lateral anterior temporal lobe
(ATL) with standard fMRI. Using distortion-corrected fMRI and dynamic causal
modeling, they were able to associate several brain regions including the ATL
with reading aloud. This area had not previously been considered a part of
the brain's reading network, likely because the region is affected by signal
dropout using standard fMRI.
Despite the lack of imaging evidence in previous work, this study, published
in the Proceedings of the National Academy of Sciences, focused on the ATL as
a site for the representation of semantic knowledge because the Triangle
Model predicts that the semantic representations supported by the ATL are
critically involved in the process of reading.
The study involved 27 subjects who were asked to read aloud 180 words chosen
from the Cambridge surface reading list. This is a diagnostic tool effective
in identifying surface dyslexia, therefore providing ideal stimuli for
studying the effects of difficult-to-pronounce words. Words were presented on
a screen and participants in an fMRI scanner were instructed to read them
aloud as quickly and accurately as possible. The researchers also recorded
the verbal responses. All of the word reading was later compared with a
baseline task in order to identify the regions that activated during reading
aloud.
The researchers found that the ATL is particularly active in subjects who
were reading aloud words with exceptional spelling-to-sound mappings and
subjects who rely heavily on semantic knowledge to read those words. Areas of
the premotor cortex involved with processing phonology exhibited the reverse
pattern, and the authors believe this demonstrates a division of labor
between direct and semantically mediated pathways for the conversion of words
to speech sounds.
Though the study considers a number of brain structures activated during
reading aloud activity, the main focus was the ATL. The authors found robust
activation in the ventral ATL (vATL) during the reading of both regular and
exception words. Previous studies have associated the region with the
representation of conceptual knowledge. "Because the great majority of
experience with written words involves reading for meaning, it is likely that
this core semantic knowledge is activated automatically whenever written
words are processed," the authors write.
The second ATL region studied is on the lateral surface of the temporal lobe.
A previous study found that this region activates when subjects read
exception words, but does not activate for pseudowords. The current study
also finds that the region responds more strongly to exception words than to
regular words. The authors suggest that it plays an intermediary role in
mapping word meaning and speech sounds.
The researchers suggest that future studies should adopt a developmental
perspective to study the origins of individual neurocognitive variations they
observed in the subjects.
Explore further: Hear Jane read: Researcher gives new meaning to semantics
More information: "Triangulation of the neurocomputational architecture
underpinning reading aloud." PNAS 2015 ; published ahead of print June 29,
2015, DOI: 10.1073/pnas.1502032112
網址:
http://medicalxpress.com/news/2015-07-scientists-previously-unknown-neural-cul
prit.html ( http://0rz.tw/MEnCD )
--
※ 發信站: 批踢踢實業坊(ptt.cc), 來自: 134.58.253.57
※ 文章網址: https://www.ptt.cc/bbs/Cognitive/M.1436885247.A.FC5.html