Writing in the journal Neuron, Timothy Keller and Marcel Just reported that they have found changes in children’s neural anatomy that appear to be a consequence of improved reading performance. Whereas previous studies, many of which I’ve mentioned in these posts, have shown changes in the blood flow in children’s brains as a consequence of reading instruction, the findings from Keller and Marcel showed that there are changes in the physical tissue in the brain following remedial reading instruction.
Neuroimaging studies using diffusion tensor imaging (DTI) have revealed regions of cerebral white matter with decreased microstructural organization (lower- fractional anisotropy or FA) among poor readers. We examined whether 100 hr of intensive remedial instruction affected the white matter of 8- to 10-year-old poor readers. Prior to instruction, poor readers had signiﬁcantly lower FA than good readers in a region of the left anterior centrum semiovale. The instruction resulted in a change in white matter (signiﬁcantly increased FA), and in the very same region. The FA increase was correlated with a decrease in radial diffusivity (but not with a change in axial diffusivity), suggesting that myelination had increased. Furthermore, the FA increase was correlated with improvement in phonological decoding ability, clarifying the cognitive locus of the effect. The results demonstrate the capability of a behavioral intervention to bring about a positive change in cortico-cortical white matter tracts.
The researchers studied children who had been randomly assigned to either a control condition or a remedial reading condition. The instruction was provided as a part of a larger study of remedial reading, the Power4Kids study; that study compared Corrective Reading, Wilson Learning System, Spell Read Phonological Auditory Training, and Failure Free Reading. In this study, the different programs did not produce differences in the neurological structure of the children (see this earlier post from LD Blog about another study predicated on the Power4Kids project).
Keller, T. A., & Just, M. A. (2009). Altering cortical connectivity: Remediation-induced changes in the white matter of poor readers. Neuron, 64, 624–631. DOI 10.1016/j.neuron.2009.10.018
Read the abstract of Altering cortical connectivity: Remediation-induced changes in the white matter of poor readers. Visit the Web site for the lab maintained by Professor Just. Read Shilo Raube’s press release about the study from Carnegie Melon University, where the research was conducted and see a press release at Behavioral Training Improves Connectivity and Function in the Brain” from the US National Institutes for Mental Health (one of the study’s funding sources). The folks from Silvia Bunge’s lab covered this on their blog, too. See, also, the study in Nature by Manuel Carreiras and colleagues who reported differences in the white matter of the brains of adults who learned to read as adults and peers who were still illiterate as adults.
In June of 2008 I posted a note about a companion study from Professor Just’s lab showing that “remediation affects brain functioning.”
The following image, from CMU’s press release, shows and explains the changes. The caption is from the press release.