TY - JOUR
T1 - Different signal enhancement pathways of attention and consciousness underlie perception in humans
AU - van Boxtel, Jeroen J.A.
PY - 2017/6/14
Y1 - 2017/6/14
N2 - It is not yet known whether attention and consciousness operate through similar or largely different mechanisms. Visual processing mechanisms are routinely characterized by measuring contrast response functions (CRFs). In this report, behavioral CRFs were obtained in humans (both males and females) by measuring afterimage durations over the entire range of inducer stimulus contrasts to reveal visual mechanisms behind attention and consciousness. Deviations relative to the standard CRF, i.e., gain functions, describe the strength of signal enhancement, which were assessed for both changes due to attentional task and conscious perception. It was found that attention displayed a response-gain function, whereas consciousness displayed a contrast-gain function. Through model comparisons, which only included contrast-gain modulations, both contrast-gain and response-gain effects can be explained with a two-level normalization model, in which consciousness affects only the first level and attention affects only the second level. These results demonstrate that attention and consciousness can effectively show different gain functions because they operate through different signal enhancement mechanisms.
AB - It is not yet known whether attention and consciousness operate through similar or largely different mechanisms. Visual processing mechanisms are routinely characterized by measuring contrast response functions (CRFs). In this report, behavioral CRFs were obtained in humans (both males and females) by measuring afterimage durations over the entire range of inducer stimulus contrasts to reveal visual mechanisms behind attention and consciousness. Deviations relative to the standard CRF, i.e., gain functions, describe the strength of signal enhancement, which were assessed for both changes due to attentional task and conscious perception. It was found that attention displayed a response-gain function, whereas consciousness displayed a contrast-gain function. Through model comparisons, which only included contrast-gain modulations, both contrast-gain and response-gain effects can be explained with a two-level normalization model, in which consciousness affects only the first level and attention affects only the second level. These results demonstrate that attention and consciousness can effectively show different gain functions because they operate through different signal enhancement mechanisms.
KW - Afterimages
KW - Attention
KW - Consciousness
KW - Contrast response function
UR - http://www.scopus.com/inward/record.url?scp=85020543339&partnerID=8YFLogxK
U2 - 10.1523/JNEUROSCI.1908-16.2017
DO - 10.1523/JNEUROSCI.1908-16.2017
M3 - Article
AN - SCOPUS:85020543339
SN - 0270-6474
VL - 37
SP - 5912
EP - 5922
JO - The Journal of Neuroscience
JF - The Journal of Neuroscience
IS - 24
ER -