Spatiotemporal Dynamics Underlying Object Completion in Human Ventral Visual Cortex

• Published in: Neuron (Cambridge, Mass.) Mass.), 2014-08, Vol.83 (3), p.736-748
• Main Authors: Tang, Hanlin, Buia, Calin, Madhavan, Radhika, Crone, Nathan E., Madsen, Joseph R., Anderson, William S., Kreiman, Gabriel
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Brain Mapping; Bubbles; Child; Electrodes; Evoked Potentials, Visual - physiology; Experiments; Female; Humans; Male; Medical imaging; Pattern Recognition, Visual - physiology; Photic Stimulation - methods; Reaction Time - physiology; Studies; Visual Cortex - physiology; Visual Fields - physiology; Visual Pathways - physiology; Young Adult
• ISSN: 0896-6273; 1097-4199
• DOI: 10.1016/j.neuron.2014.06.017

Natural vision often involves recognizing objects from partial information. Recognition of objects from parts presents a significant challenge for theories of vision because it requires spatial integration and extrapolation from prior knowledge. Here we recorded intracranial field potentials of 113 visually selective electrodes from epilepsy patients in response to whole and partial objects. Responses along the ventral visual stream, particularly the inferior occipital and fusiform gyri, remained selective despite showing only 9%–25% of the object areas. However, these visually selective signals emerged ∼100 ms later for partial versus whole objects. These processing delays were particularly pronounced in higher visual areas within the ventral stream. This latency difference persisted when controlling for changes in contrast, signal amplitude, and the strength of selectivity. These results argue against a purely feedforward explanation of recognition from partial information, and provide spatiotemporal constraints on theories of object recognition that involve recurrent processing. •Selectivity retained in high-level visual cortex despite incomplete information•Object completion required an additional ∼100 ms for robust responses to emerge•Processing delays were feature dependent and increased along the visual hierarchy•Physiological observations support role for recurrent signals in object completion Tang et al. investigate object completion by recording intracranial field potentials from human cortex. When only a fraction of an object is visible, responses in higher visual cortex remain selective but emerge later, suggesting that recurrent processing could orchestrate object completion.