Donna M. Gasparro

Near-Infrared Spectroscopy Study of Language Activated Hyper- and Hypo-Oxygenation in Human Prefrontal Cortex

Oxygenation changes in the left prefrontal cortex during language processing were assessed with near-infrared spectroscopy (NIRS). Oxyhemoglobin and deoxyhemoglobin concentrations at the Fp1 site during 5 min of resting with eyes closed (control), followed by 5 min of reading aloud, were monitored. A statistically significant change in the oxyhemoglobin concentration was observed by NIRS in all the subjects after execution of the experimental task. The observations of hyper-oxygenation as well as hypo-oxygenation in the present investigation extend past studies and suggest a complex phenomenon of activation that may be the result of a vascular steal mechanism, attenuated activation baselines, or active cortical deactivation.

An ab initio and DFT conformational analysis of unsubstituted and ω-substituted ethyl-benzene: (Ph-CH2-CH2-Z; Z = -H, -F, -NH3+, -CH3)

Abstract A series of compounds of Ph–CH 2 –CH 2 –Z, with substituents Z=–H, –F, –NH 3 + , and –CH 3 , were subjected to conformational analysis. Conformational potential energy surfaces were generated and their minima were geometrically optimized at three levels of theory. The relative stabilities of the minima correlated with the electron withdrawing nature of the substituents (Z).