Abstract
Detection of elongated objects in the visual scene can be improved by additional elements flanking the object on the collinear axis. This is the collinear context effect (CE) and is represented in the long-range horizontal connection plexus in V1. The aim of this study was to test whether the visual collinear motion can improve the CE. In the three experiments of this study, the flank was presented with different types of motion. In particular, the collinear motion aligned with the longitudinal axis of the to-be-detected object: toward or away from it, and the orthogonal motion with a direction perpendicular to the collinear axis. Only collinear motion toward the target showed a robust and replicable empowerment of the CE. This dynamic modulation of the CE likely is implemented in the long-range horizontal connection plexus in V1, but, given that in addition it conveys the time information of motion, there must be a direct feedback in V1 from higher visual areas where motion perception is implemented, such as Middle Temporal (MT). Elongated visual objects moving along their longitudinal axis favor a propagation of activation in front of them via a network of interconnected units that allows the visual system to predict future positions of relevant items in the visual scene.
Highlights
Detection of elongated objects in the visual scene can be improved by additional elements flanking the object on the collinear axis
The presence of the flank collinearly aligned to the target lowered the detection threshold in all conditions for the three observers (Figure 4A) as it was expected from previous studies (Kapadia et al, 1995; Polat & Sagi, 1993, 1994)
The novel result of the present study was that the collinear motion (CM) condition showed, in all observers, the largest change in detection due to the presence of the collinearly moving flank with respect to the Orthogonal Motion (OM) and ST conditions
Summary
Detection of elongated objects in the visual scene can be improved by additional elements flanking the object on the collinear axis This is the collinear context effect (CE) and is represented in the long-range horizontal connection plexus in V1. Neurophysiological evidence supports the idea that the CE is represented in primary visual cortex of primates where the response elicited by a simple bar, falling into the V1 neuron’s receptive field, was potentiated by the presence of a collinear flank outside the receptive field (Kapadia et al, 1995) When this flank presented small deviations from the collinear axis of the target or it was not close enough to the target or, it was replaced by a T-shaped flank that interrupted the good continuation of the border, the CE disappeared.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
