Timing of repetition suppression of event‐related potentials to unattended objects

• Published in: The European journal of neuroscience Vol. 52; no. 11; pp. 4432 - 4441
• Main Authors: Stefanics, Gabor, Heinzle, Jakob, Czigler, István, Valentini, Elia, Stephan, Klaas E.
• Format: Journal Article
• Language: English
• Published: France Wiley Subscription Services, Inc 01.12.2020; John Wiley and Sons Inc
• Subjects: Brain; Brain Mapping; Event-related potentials; event‐related potential; Evoked Potentials; Functional plasticity; general linear modeling; Humans; Information processing; Neuroimaging; Neuronal Plasticity; Neuroplasticity; object recognition; Pattern recognition; predictive coding; Repetition; repetition enhancement; Scalp; Special Issue; Time Perception; object recognition; repetition enhancement; general linear modeling; event-related potential; predictive coding
• ISSN: 0953-816X; 1460-9568; 1460-9568
• DOI: 10.1111/ejn.13972

Current theories of object perception emphasize the automatic nature of perceptual inference. Repetition suppression (RS), the successive decrease of brain responses to repeated stimuli, is thought to reflect the optimization of perceptual inference through neural plasticity. While functional imaging studies revealed brain regions that show suppressed responses to the repeated presentation of an object, little is known about the intra‐trial time course of repetition effects to everyday objects. Here, we used event‐related potentials (ERPs) to task‐irrelevant line‐drawn objects, while participants engaged in a distractor task. We quantified changes in ERPs over repetitions using three general linear models that modeled RS by an exponential, linear, or categorical “change detection” function in each subject. Our aim was to select the model with highest evidence and determine the within‐trial time‐course and scalp distribution of repetition effects using that model. Model comparison revealed the superiority of the exponential model indicating that repetition effects are observable for trials beyond the first repetition. Model parameter estimates revealed a sequence of RS effects in three time windows (86–140, 322–360, and 400–446 ms) and with occipital, temporoparietal, and frontotemporal distribution, respectively. An interval of repetition enhancement (RE) was also observed (320–340 ms) over occipitotemporal sensors. Our results show that automatic processing of task‐irrelevant objects involves multiple intervals of RS with distinct scalp topographies. These sequential intervals of RS and RE might reflect the short‐term plasticity required for optimization of perceptual inference and the associated changes in prediction errors and predictions, respectively, over stimulus repetitions during automatic object processing. We studied the time course of repetition effects on event related potentials (ERP) to objects. Model comparison favored an exponential model of repetition suppression—compared to linear or categorical “change detection”—indicating that repetition effects are observable in trials beyond the first repetition. We found successive intervals of repetition effects with distinct scalp distribution which might reflect the short‐term plasticity required for optimization of perceptual inference.