The activation of visual memory for facial identity is task-dependent: Evidence from human electrophysiology

Serial dependence in facial identity perception and visual working memory

Serial dependence (SD) refers to the effect in which a person's current perceptual judgment is attracted toward recent stimulus history. Perceptual and memory processes, as well as response and decisional biases, are thought to contribute to SD effects. The current study examined the processing stages of SD facial identity effects in the context of task-related decision processes and how such effects may differ from visual working memory (VWM) interactions. In two experiments, participants were shown a series of two sequentially presented face images. In Experiment 1, the two faces were separated by an interstimulus interval (ISI) of 1, 3, 6, or 10 s, and participants were instructed to reproduce the second face after a varying response delay of 0, 1, 3, 6, or 10 s. Results showed that SD effects occurred most consistently at ISI of 1 s and response delays of 1 and 6 s consistent with early and late stages of processing. In Experiment 2, the ISI was held constant at 1 s, and to separate SD from VWM interactions participants were post-cued to reproduce either the first or the second face. When the second face was the target, SD effects again occurred at response delays of 1 and 6 s, but not when the first face was the target. Together, the results demonstrates that SD facial identity effects occur independently of task-related processes in a distinct temporal fashion and suggest that SD and VWM interactions may rely on separate underlying mechanisms.

Early different cognitive processes evoked by carnival vs. general promotions when shopping online: An ERPs study

Introduction

The booming development of online shopping has intensified market competition. In addition to general sales promotions, online shopping has introduced new changes including artificial carnival promotions.

Method

This study aims to investigate cognitive processes to an unknown e-commerce platform after exposure to carnival and general promotion activities using event-related potentials. Thirty-three participants were recruited in this study to probe how consumers perceive carnival and general promotion information using event-related potentials (ERPs). Carnival or general promotion posters were presented first, then an unknown e-commerce platform brand was presented in the second stage, at which time the subjects' cognitive process to the brand were observed in an implicit paradigm.

Results

The results showed that after priming with carnival promotion posters, the unknown e-commerce platform stimuli elicited larger P2 and N2 components than were observed after the presentation of general promotion posters; however, the P3 component did not show a significant difference. These findings indicate that the target identification and cognitive control mechanism with regard to an unknown e-commerce platform are likely influenced by the implicit memory of different promotion activities when shopping online.

Discussion

The results suggest that ERP components may have the potential to be employed as indices to estimate the effectiveness of promotion methods for an unknown brand.

Learning own- and other-race facial identities: Testing implicit recognition with event-related brain potentials

Exposure to varying images of the same person can encourage the formation of a representation that is sufficiently robust to allow recognition of previously unseen images of this person. While behavioural work suggests that face identity learning is harder for other-race faces, the present experiment investigated the neural correlates underlying own- and other-race face learning. Participants sorted own- and other-race identities into separate identity clusters and were further familiarised with these identities in a matching task. Subsequently, we compared event-related brain potentials (ERPs) in an implicit recognition (butterfly detection) task for learnt and previously unseen identities. We observed better sorting and matching for own- than other-race identities, and behavioural learning effects were restricted to own-race identities. Similarly, the N170 ERP component showed clear learning effects for own-race faces only. The N250, a component more closely associated with face learning was more negative for learnt than novel identities. ERP findings thus suggests a processing advantage for own-race identities at an early perceptual level whereas later correlates of identity learning were unaffected by ethnicity. These results suggest learning advantages for own-race identities, which underscores the importance of perceptual expertise in the own-race bias.