TY - JOUR
T1 - MT+/V5 activation without conscious motion perception
T2 - A high-field fMRI study
AU - Itoh, Kosuke
AU - Fujii, Yukihiko
AU - Kwee, Ingrid
AU - Nakada, Tsutomu
PY - 2005
Y1 - 2005
N2 - While activity of MT+/V5 neurons is believed to be necessary for the conscious perception of visual motion, whether neural activity in MT+/V5 is a sufficient condition for the conscious perception of motion in vision still remains unanswered. A high-field (3.0 Tesla) functional magnetic resonance imaging (fMRI) study was designed and performed to answer this specific question. Eleven healthy subjects viewed a checkerboard pattern stimulus reversed in contrast at 0.2, 12, 30, and 60 Hz while being probed for activation in MT+/V5. At 0.2 Hz, all viewers perceived pattern-reversal which was stationary in position. However, at 12, 30, and 60 Hz, many subjects perceived apparent motion (e.g., vertical and horizontal flows) in the square pattern. At 12 and 30 Hz reversals, MT+/V5 was activated in all subjects (11/11). Nevertheless, three out of eleven (3/11) subjects denied motion perception in these conditions. At 60 Hz reversal, as many as seven out of eleven (7/11) subjects failed to see motion but activation in MT+/V5 was found in the majority (5/7) of the subjects. The results demonstrated that significant MT+/V5 activation occurs without accompanying subjective awareness of seeing motion in an apparent-motion stimulus, indicating that neural activity in MT+/V5 does not represent a sufficient condition for conscious perception of motion in vision.
AB - While activity of MT+/V5 neurons is believed to be necessary for the conscious perception of visual motion, whether neural activity in MT+/V5 is a sufficient condition for the conscious perception of motion in vision still remains unanswered. A high-field (3.0 Tesla) functional magnetic resonance imaging (fMRI) study was designed and performed to answer this specific question. Eleven healthy subjects viewed a checkerboard pattern stimulus reversed in contrast at 0.2, 12, 30, and 60 Hz while being probed for activation in MT+/V5. At 0.2 Hz, all viewers perceived pattern-reversal which was stationary in position. However, at 12, 30, and 60 Hz, many subjects perceived apparent motion (e.g., vertical and horizontal flows) in the square pattern. At 12 and 30 Hz reversals, MT+/V5 was activated in all subjects (11/11). Nevertheless, three out of eleven (3/11) subjects denied motion perception in these conditions. At 60 Hz reversal, as many as seven out of eleven (7/11) subjects failed to see motion but activation in MT+/V5 was found in the majority (5/7) of the subjects. The results demonstrated that significant MT+/V5 activation occurs without accompanying subjective awareness of seeing motion in an apparent-motion stimulus, indicating that neural activity in MT+/V5 does not represent a sufficient condition for conscious perception of motion in vision.
KW - Apparent motion
KW - Checkerboard pattern reversal
KW - Consciousness
KW - Illusory motion
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U2 - 10.2463/mrms.4.69
DO - 10.2463/mrms.4.69
M3 - Article
C2 - 16340160
AN - SCOPUS:33644873440
VL - 4
SP - 69
EP - 74
JO - Magnetic Resonance in Medical Sciences
JF - Magnetic Resonance in Medical Sciences
SN - 1347-3182
IS - 2
ER -