Biology subjects

Dalski, A.

Publications and source records attributed to Dalski, A..

3 recordsLinked to original sources

bioRxiv2022

Characterizing the shared signals of face familiarity: long-term acquaintance, voluntary control, and concealed knowledge

Using cross-experiment multivariate classification of EEG patterns, in a recent study we found evidence for a shared familiarity signal for faces, patterns of neural activity that successfully separate trials for familiar and unfamiliar faces across participants and modes of familiarization. Here, our aim was to expand upon this research to further characterize the spatio-temporal properties of this signal. By utilizing the information content present for incidental exposure to personally familiar and unfamiliar faces, we tested how the information content in the neural signal unfolds over time under different task demands - giving truthful or deceptive responses to photographs of genuinely familiar and unfamiliar individuals. For this goal, we re-analyzed data from two previously published experiments using within-experiment leave-one-subject-out and cross-experiment classification of face familiarity. We observed that the general face familiarity signal, consistent with its previously described spatio-temporal properties, is present for long-term personally familiar faces under passive viewing, as well as for acknowledged and concealed familiarity responses. Also, central-posterior regions contain information related to deception. We propose that signals in the 200-400 ms window are modulated by top-down task-related anticipation, while the patterns in the 400-600 ms window are influenced by conscious effort to deceive. To our knowledge, this is the first report describing the representational dynamics of concealed knowledge for faces. HighlightsO_LIPrevious studies found a robust EEG effect for face-familiarity in the 200-600 ms post-stimulus range. C_LIO_LIThis neural pattern was found to be shared across participants and modes of familiarization. C_LIO_LIWe used incidental exposure as a template to probe information content for acknowledged and concealed familiarity C_LIO_LIThe shared familiarity signal is modulated differentially in early (200-400 ms) and late (post-400 ms) windows C_LIO_LICross-experiment classification is a promising tool to investigate how cognitive processes unfold under different conditions C_LI

neuroscience↗

bioRxiv2022

No Semantic Information is Necessary to Evoke General Neural Signatures of Face Familiarity - Evidence from Cross-Experiment Classification

Recent theories on the neural correlates of face identification stressed the importance of the available identity-specific semantic and affective information. However, whether such information is essential for the emergence of neural signal of familiarity has not yet been studied in detail. Here, we explored the shared representation of face familiarity between perceptually and personally familiarized identities. We applied a cross-experiment multivariate pattern classification analysis (MVPA), to test if EEG patterns for passive viewing of personally familiar and unfamiliar faces are useful in decoding familiarity in a matching task where familiarity was attained thorough a short perceptual task. Importantly, no additional semantic, contextual, or affective information was provided for the familiarized identities during perceptual familiarization. Although the two datasets originate from different sets of participants who were engaged in two different tasks, familiarity was still decodable in the sorted, same identity matching trials. This finding indicates that the visual processing of the faces of personally familiar and purely perceptually familiarized identities involve similar mechanisms, leading to cross-classifiable neural patterns.

neuroscience↗

bioRxiv2021

Evidence for a general neural signature of face familiarity

We explored the neural signatures of face familiarity using cross-participant and cross-experiment decoding of event-related potentials, evoked by unknown and experimentally familiarized faces from a set of experiments with different participants, stimuli, and familiarization-types. Participants were either familiarized perceptually, via media exposure, or by personal interaction. We observed significant cross-experiment familiarity decoding involving all three experiments, predominantly over posterior and central regions of the right hemisphere in the 270 - 630 ms time window. This shared face familiarity effect was most prominent between the Media and Personal, as well as between the Perceptual and Personal experiments. Cross-experiment decodability makes this signal a strong candidate for a general neural indicator of face familiarity, independent of familiarization methods and stimuli. Furthermore, the sustained pattern of temporal generalization suggests that it reflects a single automatic processing cascade that is maintained over time. HighlightsO_LIWe investigated if a general neural signature of face familiarity exist C_LIO_LIA cross-experiment decoding analysis of EEG data was used C_LIO_LIThe analysis involved perceptual, media and personal familiarization methods C_LIO_LIWe found a preserved pattern of familiarity decoding across experiments between 270 and 630 ms post-stimulus C_LIO_LIThis signature is consistent with previous reports on face familiarity effects C_LI

neuroscience↗