Behavioural and MEG studies of perception of low spatial frequency faces

A pivotal issue in the field of cognitive neuroscience of face perception has centered on the extraction and processing of relevant information from the visual environment. Previous research has documented distinct spatial frequency (SF) channels that process incoming visual information with selective properties. Low spatial frequency (LSF) is reported to support configural (global) processing while high spatial frequency (HSF) information aids fine-grained, featural (local) processing. While most research addresses individual roles of the SF scales (using just one SF band at a time), issues regarding the integration of these scales have remained unexplored. In order to better understand how faces are processed by the visual system, it is necessary to determine the relative contribution of LSF and HSF scales in the perception of faces. Recently, through a series of categorisation experiments, we demonstrated interference by LSF information while reaching for HSF targets. We also established the LSF supports stronger, faster and lateralised perception of faces. Magnetoencephalography (MEG) was then used to further probe the temporal and neural markers of LSF and HSF information processing the faces. Collated findings from the behavioural and MEG studies will be discussed in the context of the role of LSF in face processing.