Frontal lobe role in simple arithmetic calculations: an fNIR study.

This study aimed to affirm the use of functional near-infrared spectroscopy (fNIR) in examining frontal lobe role during automatic (i.e., requires retrieval from long-term memory) and method-based (i.e., requires calculation) arithmetic processing. Adult university students (math difficulties [MD] and control) performed simple arithmetic calculations while monitored using an fNIR system designed to image regions within the frontal cortices. Addition and subtraction problems presented on a computer screen belonged to one of three categories: triples "under 10" (e.g., 2+3=?, 5-3=?), triples that "break 10" (e.g., 5+8=?, 13-5=?), or triples "including 10" (e.g., 10+7=?, 17-10=?). fNIR recordings indicated significant interactions between type of triple, operation, and group over left frontal lobe, and between type of triple and group over right frontal lobe. Within-group differences among controls were found in the "break 10" triples with higher DeOxyHb level recorded during subtraction processing. Between-group differences were found in the "break 10" and "including 10" triples for subtraction with higher levels of DeOxyHb recorded among controls. Results imply that among adults frontal lobe is still involved during simple mathematical processing and fNIR recordings can differentiate its role in adults of varying mathematical ability.

Implicit learning processes of compensated dyslexic and skilled adult readers.

This article presents preliminary results from two implicit learning tasks (linguistic and nonlinguistic) aimed at ascertaining whether or not compensated adult dyslexic readers have a deficit in implicit learning. The dyslexic readers and a control group were compared on measures of accuracy and reaction time. In addition, EEG measures were obtained. Initial results suggest that dyslexic readers do in fact have a deficit in implicit learning, evidenced by differences in accuracy and the P300 component, and that this deficit is more pronounced when the task at hand is linguistic.