Neural mechanisms underlying visual pareidolia processing: An fMRI study

Abstract

Objectives: Pareidolia is the interpretation of previously unseen and unrelated objects as familiar due to previous learning. The present study aimed to determine the specific brain areas that exhibited activation during real-face and face-pareidolia processing.

Methods: Functional Magnetic Resonance Imaging (fMRI) scans were performed on 20 healthy subjects under real-face and face-pareidolia conditions in National Magnetic Resonance Research Center (UMRAM), Ankara, Turkey from April 2016 to January 2017. FSL software was used to conduct a FEAT higher level (group) analysis to identify the brain areas activated during real-face and face-pareidolia processing.

Results: Under both the real-face and face-pareidolia conditions, activation was observed in the Prefrontal Cortex (PFCX), occipital cortex V1, occipital cortex V2, and inferior temporal regions. Also under both conditions, the same degree of activation was observed in the right Fusiform Face Area (FFA) and the right PFCX. On the other hand, PFCX activation was not evident under the real-face versus face scrambled or face-pareidolia versus pareidolia scrambled conditions.

Conclusions: The present findings suggest that, as in real-face perception, face-pareidolia requires interaction between top-down and bottom-up brain regions including the FFA and frontal and occipitotemporal areas. Additionally, whole-brain analyses revealed that the right PFCX played an important role in processing real faces and in face pareidolia (illusory face perception), as did the FFA.

Keywords: Face processing; Fusiform face area; Pareidolia; Prefrontal cortex; fMRI.

Fig.1

This block represents the real-face condition (upper row) and the face-pareidolia condition (lower row).

Fig.2

Representative set of brain images showing brain activation under the a) real-face condition and b) face-pareidolia condition; results are based on group analysis FFA: Fusiform face area, V1: Occipital cortex V1,V2: Occipital cortex V2, PFCX: Prefrontal cortex.

Fig.3

Representative set of brain images showing brain activation under the a) scrambled-face condition and b) scrambled-pareidolia condition; results are based on group analysis.

Fig.4

Representative set of brain images showing brain activation under the a) scrambled-face condition > face and b) scrambled-pareidolia > pareidolia condition; results are based on group analysis.