Evaluating the Impact of Spatial Frequencies on the Perception of Gender

Face perception is fundamentally important for judging the characteristics of individuals, such
as identification of their gender, age, ethnicity or expression (Webster, Kaping, Mizokami, &
Duhamel, 2004). It has been hypothesized that gender perception takes place in higher level visual processing areas. Little, DeBruine, & Jones (2005) suggest that distinct neural
populations may code for subcategories of faces for which expertise-derived configural
processing is equivalent (i.e. male and female faces). They suggest that visual after-effects
are thought to reflect changes in the responses of neural mechanisms underlying face
processing and cannot be attributed to retinal (i.e. lower level) adaptations, as the after-effects
are robust to difference in the retinal location and size of faces at exposure and post-exposure
testing (Little, DeBruine, & Jones, 2005). In a study by Webster et al. (2004) categorical
perception of faces was examined based on gender, ethnicity and expression. Observers
made forced choice responses to categorize images along the continuum, for example
responding to whether a face from a gender morph appeared “female” or “male.” The
boundary for gender represents an androgynous image intermediate to the female and male
exemplars and could be set consistently by observers. However, after adapting to a male
face, the previously ambiguous image appeared distinctly feminine. Conversely, adaptation to
the female face induced the opposite changes. This effect is similar to results found in visual
after-effect studies. In a different investigation by Cellarino, Borghetti, and Sartucci (2004), the effect of pixilation on gender identification was conducted. As the photos became more pixilated the male faces were identified correctly more frequently than the female faces. This can be inferred to mean that male faces are composed of more lower frequencies since the pixilation wipes out the higher frequencies. The combination of these findings may suggest that the perception of gender can be influenced by lower level processes such as spatial frequency processing.