Peripheral preview abolishes N170 face-sensitivity at fixation: Using fixation-related potentials to investigate dynamic face processing

ABSTRACT

The N170 ERP peak has been found to be consistently larger in response to the presentation of faces than to other objects, yet it is not clear whether this face-sensitive N170 is also elicited during fixations made subsequent to the initial presentation. To investigate this question, the current study utilised Event and Fixation-Related Potentials in two experiments, time-locking brain potentials to the presentation of faces and objects (watches) images in participants’ peripheral vision, and to their first fixations on the images. Experiment 1 found that a face-sensitive N170 was elicited by the onset of images but not by a subsequent fixation on the images, and that face inversion did not modulate N170 beyond presentation. Experiment 2 found that disrupting the structure of the peripheral preview (phase-scrambling) led to a face-sensitive N170 at fixation onsets on the intact-images. Interestingly, N170 amplitudes for both faces and objects were significantly enhanced after the peripheral preview was phase-scrambled, suggesting that the N170 in part reflects a category-detection process that is elicited once when an image structure is viewed. These results indicate that neural processing during fixations will be significantly modulated when they are immediately preceded by peripheral previews, and is not specific to faces.

KEYWORDS:

• Faces
• N170
• ERP
• FRP
• fixation

Acknowledgements

Contributions- Original idea: RP, FH, SH, PdL, YM. Protocol development: RP, PdL, YM, FH, SH, GM. Data collection: PdL, YM, FD. Data processing and analyses: PdL. Writing of manuscript: PdL, GM, RP, FH, SH, YM, FD.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Stefan Hawelka http://orcid.org/0000-0002-5304-8521

Romina Palermo http://orcid.org/0000-0002-8678-4592

Federica Degno http://orcid.org/0000-0002-9621-9968

Florian Hutzler http://orcid.org/0000-0001-8195-4911

Additional information

Funding

This work was supported with funding from a Macquarie University MQRES postgraduate grant, the Macquarie University Strategic Infrastructure Scheme, and the Experimental Psychology Society Study Visit Grant.