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PjThe anterior portion of the prefrontal
cortex was bilaterally activated during bipedal walking to a goal.
T. Harada1*, K. Ebe2, A. Kozato2,
K. Shimizu3, T. Amita3 and K .Kubota1 1. Nihon Fukusi University,
Handa, Japan 475-0012; 2. Human safety Div., Toyota Central R&D
Labs., Nagakute, Japan; 3. Medical Systems Div, Shimazu Corp., Kyoto,
Japan.
Previous study showed that the lowerlimb motor and premotor areas were activated
during walking on the treadmill. To further find frontal areas involved in walking
on the road, we measured hemodynamic activities, using near-infrared spectroscopy
technique (NIRS) during walking to a goal. Nine subjects (41}8, 7 male, 2 female)
were participated. Initially the subject was waiting the traffic signal change
while standing at the start line. Walking was started when the traffic signal
was turned to blue and then, stopped when the signal turned to red. The subjects
walked for 15 s along a short road (18.6}0.7m) at a speed of 4.2}1.0 km/h to
a goal. When walking was started, concentration of the oxygenated hemoglobin
in the anterior portion of the prefrontal cortex (APFC), involving in BAs 10
and 46, were increased and increased activities were sustained until the walking
was stopped, and those of activities in motor related areas were changed slightly.
Activities changes were bilaterally induced. Changes in the deoxygenated hemoglobin
were not clear. When these hemodynamic changes were compared with those during
car driving to a goal on the same road (25.8}0.8 m) at a speed of 5.9}0.3 km/h.
The APFC did not show changes of the oxyHb concentration during a car driving
while the motor areas showed an increase of the oxyHb and a decrease of the deoxyHb.
It appears that the APFC is involved in an initiation and continuation of the
walking.
QjWorking memory in car driving and
the dorsolateral prefrontal cortex
K.Ebe1, A.Kozato1, Y.Hashimoto2, K.Kimura3, K.Shimizu4, T.Amita4, I.Oda5, I.
Konishi5, K.Kubota2*
1.Human Safety Div., Toyota Central R&D Labs., Inc., Nagakute, Japan; 2.Graduate School of Management Information Systems, Nihon Fukushi University, Handa, Japan; 3.Vehicle Engineering Div., Toyota Motor Corp., Toyota, Japan; 4.Medical Systems Div., Shimadzu@Corp., Nishinokyo-Kuwabaracho, Japan. 5Technol. Res. Lab., Shimadzu Corp., Seika-cho, Japan
As a hypothesis, we consider that the dorsolateral prefrontal cortex
(DLPF) plays an important role as the spatial working memory in car driving.
To prove our hypothesis, hemodynamic activities of the frontal lobe were
recorded with a near infrared spectroscopic imaging system installed
within the car. Subjects were instructed a destination on a three-forked
road before stating the car, and then they started driving, after having
memorized their final destination. As experimental results, we found
that the concentrations of deoxyhemoglobin in the DLPF and in the anterior
part of the prefrontal cortex were significantly decreased when subjects
kept the spatial information of the destination in mind before steering
the car toward the instructed direction. We concluded that the DLPF and
the anterior prefrontal cortex play important roles as the spatial working
memory in car driving.
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