雅思阅读 188: The Reading Brain and Its Disruptions（阅读的大脑及其紊乱）

改编自 Nature Communications / PMC neuroscience reviews。雅思阅读 Section 3 难度，约 1050 词。 素材来源：https://pmc.ncbi.nlm.nih.gov/articles/PMC10624919/

Reading Passage

A. Reading is such a recent invention — perhaps five thousand years old — that the human brain could not possibly have evolved a dedicated system for it. Yet almost every literate adult reads with extraordinary speed and apparent ease, recognising thousands of words in a fraction of a second. Neuroscientists have concluded that the brain solves this puzzle by repurposing older circuits, originally evolved for object recognition and speech, and wiring them into a new network specialised for written symbols. That network, mapped over three decades of imaging studies, is centred in the left hemisphere of the brain and connects three core regions. The occipito-temporal cortex, including a patch on the fusiform gyrus known as the visual word form area, recognises written strings at a glance. The temporo-parietal cortex maps those visual shapes onto speech sounds. The inferior frontal cortex — Broca's area — articulates and manipulates the sounds. Reading smoothly is the result of all three talking to one another, with no single region acting in isolation. Children who are slow to learn to read are not visually impaired; they are simply slower to wire these three ancient circuits into the new network that written language requires.

B. In developmental dyslexia, a condition affecting somewhere between five and seventeen per cent of children depending on the language and the diagnostic threshold, that conversation goes wrong. For decades dyslexia was described as a problem of reversing letters or seeing words backwards, but modern imaging has shown the real deficit is deeper. Functional MRI studies consistently show underactivation — reduced blood flow — in the very same left-hemisphere regions that typical readers use. The left temporo-parietal cortex is reliably underactive when dyslexic readers try to match letters to sounds, and the occipito-temporal visual word form area fails to develop the automatic, rapid responsiveness it shows in skilled readers. A 2023 network analysis added a further detail: it is not only that these regions are quieter, but that the functional coupling between them is disrupted. The left temporo-parietal and occipito-temporal cortices, which should work as a tightly integrated circuit, fail to communicate efficiently. The child sees the letters but cannot lock them onto the sounds quickly enough.

C. The same study also identified a second, more surprising finding. Adults with dyslexia showed stronger-than-normal interaction between their reading network and the right cerebellum — a structure traditionally associated with motor coordination and balance rather than language. The researchers interpreted this as evidence that dyslexic readers compensate for the weak left-hemisphere circuit by recruiting additional resources, essentially asking the rest of the brain to help where the standard network cannot. This compensatory pattern is not unique to the right cerebellum. Other studies have found that dyslexic readers overactivate right-hemisphere homologues of the left reading areas, as though the brain is trying to perform a left-hemisphere task on the weaker right side. The picture is therefore not simply one of damage; it is one of both under-functioning in the core circuit and over-activity in compensatory regions that are less efficient for reading. It is as though a car with a worn transmission is driven harder on the auxiliary gears to keep moving forward.

D. Crucially, these patterns are not confined to English. A synthesis of studies across alphabetic languages as different as Italian, English and German, and across non-alphabetic scripts such as Chinese, has identified a universal signature: underactivation in the left occipito-temporal, temporo-parietal and inferior frontal cortices appears in dyslexic readers regardless of writing system. But the same review also found language-specific differences. In languages with transparent spelling — where letters correspond predictably to sounds, as in Italian or Spanish — the underactivation is milder and more concentrated in specific sub-regions. In deep, irregular orthographies like English, where a single letter can represent several sounds, the disruption is more widespread. Chinese readers, whose script represents meaning as much as sound, show additional abnormalities in regions associated with visual analysis and stroke order. Dyslexia, in other words, is both a universal neural condition and one shaped by the writing system it encounters. A child learning Chinese faces a different neural challenge from a child learning Italian, even though the underlying deficit in mapping symbols to sounds is the same. Teachers who understand this can tailor their instruction to the writing system rather than applying a single universal method. A one-size-fits-all phonics programme works better in Italy than in English-speaking countries.

E. The practical question is whether the reading brain can be rewired. Intensive phonological training — exercises that teach children to notice and manipulate the sounds in words — has repeatedly been shown to improve reading scores, and imaging studies have tracked corresponding changes in the brain. Some children show "normalisation," meaning their left-hemisphere network begins to look like that of typical readers. Others show "compensation," where reading improves without the left circuit fully normalising, suggesting the brain has found an alternative route. The field has not yet determined which response predicts long-term success, and individual differences are large. What is clear is that dyslexia is not a sign of low intelligence or laziness; it is a specific, measurable difference in how the brain organises itself around written symbols. Recognising that difference early — and matching instruction to the neural reality rather than to the myth of backwards letters — is the closest thing to a treatment the current science offers. Waiting for a child to "grow out of it" wastes the window in which the reading brain is still most plastic. The children who struggle with reading in the first three grades rarely catch up on their own; they are the ones whose brains most need the structured phonological training that the neuroscience recommends.

Questions 1-4

Choose the correct heading for paragraphs B, C, D and E from the list of headings below.

List of Headings i. The three regions of the left-hemisphere reading network ii. What dyslexia looks like in the brain: underactivation and disrupted coupling iii. Compensatory over-activity beyond the standard network iv. Universal patterns across languages — and language-specific variations v. Can the reading brain be rewired? vi. Why dyslexia is caused by poor eyesight vii. The history of teaching phonics in schools

1. Paragraph B: ____
2. Paragraph C: ____
3. Paragraph D: ____
4. Paragraph E: ____

Questions 5-8

Choose the correct letter, A, B, C or D.

5. Why does the brain need to repurpose older circuits for reading? A. Reading is too recent an invention for a dedicated system to have evolved. B. The left hemisphere is not large enough. C. Reading is a purely visual task with no sound component. D. Children cannot learn to read without surgery.

6. What does functional MRI show in dyslexic readers? A. Overactivation in the left temporo-parietal cortex. B. Underactivation in left-hemisphere reading regions and disrupted coupling between them. C. Complete absence of activity in the visual cortex. D. No difference from typical readers.

7. What is unusual about the right cerebellum in adults with dyslexia? A. It is smaller than normal. B. It shows stronger-than-normal interaction with the reading network as a compensation. C. It is completely inactive. D. It controls eye movements only.

8. How does the neural signature of dyslexia differ between Italian and English readers? A. Italian readers show more widespread disruption. B. English readers show milder disruption. C. The underactivation is milder in transparent languages like Italian. D. There is no difference at all between any languages.

Questions 9-13

Do the following statements agree with the claims of the writer?

Write:

• TRUE if the statement agrees with the information
• FALSE if the statement contradicts the information
• NOT GIVEN if there is no information on this

9. The visual word form area is located on the fusiform gyrus.
10. Dyslexia is typically caused by children seeing letters backwards.
11. Dyslexic readers show underactivation in left-hemisphere regions across different writing systems.
12. Phonological training has never been shown to change brain activation patterns.
13. Dyslexia is diagnosed more frequently in boys than in girls.

Questions 14-15

Complete the summary below using NO MORE THAN TWO WORDS from the passage.

Dyslexic readers show both under-functioning in the core left-hemisphere circuit and over-activity in (14) __________ regions; intensive phonological training can lead either to normalisation or to (15) __________ in the brain.

答案与解析

← 上一篇 | 返回雅思焦点 | 下一篇 →