Category-selective human brain processes elicited in fast periodic visual stimulation streams are immune to temporal predictability

Abstract

Recording direct neural activity when periodically inserting exemplars of a particular category in a rapid visual stream of other objects offers an objective and efficient way to quantify perceptual categorization and characterize its spatiotemporal dynamics. However, since periodicity entails predictability, perceptual categorization processes identified within this framework may be partly generated or modulated by temporal expectations. Here we present a stringent test of the hypothesis that temporal predictability generates or modulates category-selective neural processes. In Experiment 1, we compare neurophysiological responses to periodic and nonperiodic (i.e., unpredictable) variable face stimuli in a fast (12 Hz) visual stream of nonface objects. In Experiment 2, we assess potential responses to rare (10%) omissions of periodic face events (i.e., violations of periodicity) in the same fast visual stream. Overall, our observations indicate that long duration category(face)-selective processes elicited in a fast periodic stream of visual objects are immune to temporal predictability. These observations do not support a predictive coding framework interpretation of category-change detection in the human brain and have important implications for understanding human perceptual categorization in a rapidly changing (i.e., dynamic) visual scene.

Understanding human individuation of unfamiliar faces with oddball fast periodic visual stimulation and electroencephalography

“…A related issue is whether rare “missing oddballs” in a temporally periodic sequence (i.e., AAAABAAAACAAAA A …) would lead to substantial, specific EEG deflections recorded in the frequency and time domains, despite the absence of objective FI. Again, in line with the absence of any “missing oddball” effects for faces inserted in rapid trains of non‐face objects (Quek & Rossion, 2017) and the results of a variant of the present design with only two facial identity discriminations (Feuerriegel et al., 2018), we think it unlikely. Such studies would nevertheless be important to perform with the present paradigm.…”

“…These observations suggest that periodic and non‐periodic temporal changes in facial identity could lead to different responses in the present paradigm. However, given the fast rate of stimulation used here for high‐level visual discrimination, and in line with the absence of any difference between periodic and non‐periodic presentations of natural images of faces in rapid trains of non‐face objects (Quek & Rossion, 2017), we think that it is unlikely. A related issue is whether rare “missing oddballs” in a temporally periodic sequence (i.e., AAAABAAAACAAAA A …) would lead to substantial, specific EEG deflections recorded in the frequency and time domains, despite the absence of objective FI.…”

Mapping face categorization in the human ventral occipitotemporal cortex with direct neural intracranial recordings

“…However, such responses are of much smaller amplitude and are associated with a distinct spatial topography than face‐selective responses . Moreover, the face‐selective response observed on the scalp is identical whether faces appear periodically or not . Future iEEG studies could build upon such paradigms to assess the exclusivity of the responses to faces particularly in the right VATL (ventral anterior temporal lobe).…”

“…Currently, there is a lack of information about the frequency ranges of stimulation that are associated with the most sensitive and specific responses. The paradigm presented in Figure and used in the described study relies on a 6 Hz stimulation rate, which provides similar responses on the scalp as 12–12.5 Hz rates . However, higher frequency rates may be associated with lower face‐selective responses, owing to the limited presentation and duration of (masked) faces.…”

The Decision Decoding ToolBOX (DDTBOX) – A multivariate pattern analysis toolbox for event-related potentials

“…DDTBOX has also been used to investigate perceptual categorisation of faces (Quek and Rossion, 2017) and multi-sensory integration in elderly and younger adults (Chan et al, 2017). Another application of DDTBOX has been the use of SVR to predict postexperimental ratings of affective and abstract stimulus attributes of task-irrelevant images to inform theories of automatic processing of stimulus features during passive exposure .…”