Nudging the N170 forward with prior stimulation—Bridging the gap between N170 and recognition potential. Issue 4 (17th November 2021)

• Record Type: Journal Article
• Authors: Luo, Canhuang; Chen, Wei; VanRullen, Rufin; Zhang, Ye; Gaspar, Carl Michael
• Is Part Of: Human brain mapping. Volume 43:Issue 4(2022)
• Page Start: 1214
• Page End: 1230
• Publication Date: 2021-11-17
• Subjects: Chinese characters -- ERP -- N170 -- object recognition -- recognition potential -- visual masking; Brain mapping -- Periodicals; 611.81
• DOI: 10.1002/hbm.25716
• Languages: English
• ISSNs: 1065-9471

Abstract

Abstract: Evoked response potentials are often divided up into numerous components, each with their own body of literature. But is there less variety than we might suppose? In this study, we nudge one component into looking like another. Both the N170 and recognition potential (RP) are N1 components in response to familiar objects. However, the RP is often measured with a forward mask that ends at stimulus onset whereas the N170 is often measured with no masking at all. This study investigates how inter‐stimulus interval (ISI) may delay and distort the N170 into an RP by manipulating the temporal gap (ISI) between forward mask and target. The results revealed reverse relationships between the ISI on the one hand, and the N170 latency, single‐trial N1 jitter (an approximation of N1 width) and reaction time on the other hand. Importantly, we find that scalp topographies have a unique signature at the N1 peak across all conditions, from the longest gap (N170) to the shortest (RP). These findings prove that the mask‐delayed N1 is still the same N170, even under conditions that are normally associated with a different component like the RP. In general, our results suggest greater synthesis in the study of event related potential components. Abstract : We use a parametric design of forward masking and a focus on individual‐level event‐related potential (ERP) to show that N170 latency can be gradually pushed forward by as much as 100 ms. We also show that the N170 is indistinguishable from the recognition potential component, which is often treated as completely different and studied in a separate literature. Our results suggest that classifications of ERP component‐based waveform morphology are unreliable, and raises new questions about what causes delays in visual processing.