Brain activity (<i>ΔCOE</i>) in the PAC (parietal association cortex) during left and right curve driving.

<p>(a) Under driving conditions, <i>ΔCOE</i> showed the greatest increase in right curves in the left PAC. (b) Vector tracks during right and left curves in the left PAC (channels 40, 44 and 45 [average]) plotted every 3 seconds, beginning 30 seconds from the start of the easement curve. At <i>L</i> peak times, the right curve vector is in Phase 4, and the left curve vector is in Phase 1. a.u. = arbitrary unit.</p

Phase classification of hemodynamic responses.

<p>Phase classification of hemodynamic responses.</p

Brain activity (<i>ΔCOE</i>) during left and right curves under non-driving conditions.

<p>(a) Brain activity during left curves: activity in the right FEF (frontal eye field, channels 18 and 24) increased significantly more in the left curves. (b) Brain activity during right curves: activity in the medial PM (premotor area, channel 30) and right PAC (parietal association cortex, channels 37 and 46) increased significantly more in the right curves. a.u. = arbitrary unit.</p

Brain activity (<i>ΔCOE</i>) during left and right curve driving.

<p>Under driving conditions, <i>ΔCOE</i> increased more in left curves than in right curves in four areas of the brain: right PM (premotor area), right FEF (frontal eye field) and bilateral PFC (prefrontal cortex). a.u. = arbitrary unit.</p

Relationship between channel configuration / probe placement and the underlying brain sites.

<p>(a) Probes mounted on the head. (b) Probe arrangement and measurement channel numbers. (c) Relationship between brain regions and measurement channels were confirmed using MRI. PFC: prefrontal cortex (including superior and middle frontal gyrus). PAC = parietal association cortex, M1 = primary motor cortex, PM = premotor cortex, FEF = frontal eye field, and PFC = prefrontal cortex.</p

Comparison of <i>PRI</i> during curve driving in different sites of the brain.

<p><i>PRI</i> (phase-associated response intensity) in the <i>L</i> peak time zones were compared between sites: (a) during left curve driving and (b) during right curve driving. Asterisks (*) indicate significant differences between the sites. PM = premotor area, PFC = prefrontal cortex, FEF = frontal eye field, and PAC = parietal association cortex. During left curve driving, activity was greatest in the right PM, and it was greater in the right frontal lobe than in the left hemisphere. During right curve driving, activity was greatest in the left PAC, followed by the left PFC, and activity was greater in the left frontal lobe than in the right hemisphere. a.u. = arbitrary unit.</p

Time-series waveforms of ΔOxyHb and ΔDeoxyHb, and a <i>ΔO</i>/<i>ΔD</i> vector plane.

<p>(a) Raw waveform data for changes in oxyhemoglobin and deoxyhemoglobin (ΔOxyHb and ΔDeoxyHb) from the right PM (channel 23) and the left PM (channel 27). These channels are symmetrical regions of the cerebral cortex. Frequencies of more than 0.1 Hz were removed from the raw data using a low-pass filter. Straight sections of the course are indicated in black, easement curves in gray, and circular curves in orange. PM = premotor cortex. (b) Vector trajectories on this polar coordinate plane make it possible to visually evaluate relationships between changes in the cerebral blood volume vector component (<b><i>ΔCBV</i></b>) and the cerebral oxygen exchange vector component (<b><i>ΔCOE</i></b>).</p

Characteristic vectors at vector peak time zones under driving conditions.

<p>Characteristic vectors at vector peak time zones under driving conditions.</p

Experimental course.

<p>(a) Starting point. (b) Overview of entire course. (c) Schematic view of a left curve and a right curve. The course comprised 5 of these right/left curve sections.</p