Study Identifies Why Stroke Impairs Ability To Use Word Meanings In Reading

A cardinal find astir nan effect of changeable connected a person's expertise to publication reveals why a shortage occurs – a uncovering that presents a imaginable opportunity for caller therapeutic strategies to thief group retrieve 1 of nan astir important life skills.

It's agelong been known that group who acquisition a changeable tin struggle pinch reading, but researchers weren't clear precisely why. Now, a caller study, led by researchers astatine Georgetown University, reveals that strokes tin rob a person's expertise to usage nan meaning of words to thief them admit nan words erstwhile reading. 

We usually deliberation of reference successful our regular lives arsenic a measurement to summation meaning, but nan other is besides true: we trust connected a word's meanings to thief america admit it erstwhile reading. Some group recovering from changeable can't usage nan meanings of words to thief admit them, making it harder to read." 

Peter E. Turkeltaub, MD, PhD, head of nan Cognitive Recovery Lab astatine Georgetown University and elder writer of nan study

It's agelong been known that group who acquisition a changeable tin struggle pinch reading, but researchers weren't clear precisely why. So, nan scientists looked astatine scanned images of brains damaged by changeable while study participants publication aloud. The researchers were past capable to pinpoint a portion of nan encephalon and related connections that impact really deciphering nan meanings of words facilitates reading.

The National Institutes of Health (NIH)-funded study appears August 13 successful nan diary Brain.

In their study, nan researchers recovered that nan logic immoderate changeable survivors can't usage meanings of words to publication is because they can't representation nan words they are trying to pronounce backmost to nan ideas down nan words.

Annually, astir 800,000 group successful nan U.S. person strokes, which disproportionately impact marginalized and minoritized people. In this study of 56 left-hemisphere changeable survivors and 68 group who had not had a stroke, processing nan meaning of words was overmuch little communal and milder than phonological impairment, aliases nan expertise to sound retired words, which is emblematic of astir changeable patients. The study examined individuals pinch strokes connected nan near broadside of nan encephalon because that is wherever connection processing is located.

The researchers utilized imageability arsenic a marker of really rich | nan meaning of a connection was, and tested if occurrence astatine reference words aloud related to their imageability. High imageability words tin beryllium easy pictured, specified arsenic 'hammer' aliases 'cow'. Low imageability words are difficult to picture: 'justice' whitethorn evoke an image of nan statue of Lady Justice holding equilibrium scales, but nan conception of justness can't really beryllium pictured.

To amended understand nan effect of imageability, nan researchers mapped nan grade of nan strokes pinch MRI imaging. The images revealed that harm on nan superior temporal sulcus, a encephalon region that plays a important domiciled successful reside processing and auditory short-term memory, reduced nan advantage of being capable to publication precocious imageability complete debased imageability words, reflecting an inability to usage meaning to support reading. They besides recovered an overlapping encephalon region that was related to impairments successful connecting meanings of words to their sounds, aliases phonology. Together, these results show that immoderate reference deficits hap successful left-hemisphere changeable survivors arsenic a consequence of an impaired integration of meaning and phonology.

"Our findings explain nan neurobiology of reference and supply nan strongest grounds to day for a shape of reference disorders that tin hap aft a near hemisphere stroke," says nan study's co-first writer Ryan Staples, Ph.D., a postdoctoral chap successful Turkeltaub's lab.

For their adjacent steps, a caller 5-year assistance from nan NIH to study reference successful normal aging compared to group who person had a left-hemisphere changeable should further heighten nan knowing of nan effect of strokes.

In summation to Turkeltaub and Staples, authors astatine Georgetown see Sara M. Dyslin, Andrew T. DeMarco, Sarah F. Snider, Rhonda and B. Friedman. Co-first writer J. Vivian Dickens, MD, PhD, completed his postgraduate activity successful Turkeltaub's laboratory and is now a resident neurologist astatine nan Hospital of nan University of Pennsylvania successful Philadelphia.

Turkeltaub and his co-authors study having nary individual financial interests related to nan study.

This activity was supported by NIH NIDCD grants R01DC020446 and R01DC014960.