Task and exposure time modulate laterality of spatial frequency for faces.

Abstract

The present study psychophysically investigated the laterality of low spatial frequencies (LSFs) and high spatial frequencies (HSFs) during face recognition at different exposure times. Spatial frequency–filtered faces were presented in a divided visual field at high and low temporal constraints in 2 tasks: face recognition (Experiment 1) and face gender recognition (Experiment 2). Both experiments revealed general primacy in the recognition of LSF over HSF faces. In Experiment 1, LSF and HSF facial information was more efficiently processed in the right and left hemispheres, respectively, and exposure time had no effect. Experiment 2 showed right hemisphere asymmetry for LSF faces at a low temporal constraint. These results suggest that the spatial frequency processing for face recognition is lateralized in the brain hemispheres. However, the contributions of LSFs and HSFs depend on the task and exposure time.

Increased sensitivity for happy faces in depressed patients following 15 Hz repetitive transcranial magnetic stimulation (rTMS) over the left dorsolateral prefrontal cortex.

“…The increased sensitivity for happy faces observed following rTMS can also be discussed in terms of functional brain asymmetry. Studies show laterality effects in a variety of face processing tasks, for example, spatial frequency sensitivity, configural/featural encoding, and emotional processing (e.g., de Moraes, Faubert, Vasques, Cravo, & Fukusima, 2017;Renzi et al, 2013;Torro-Alves, Fukusima, & Aznar-Casanova, 2008). According to the valence hypothesis proposed by Davidson (1995), the left hemisphere is dominant for positive emotions processing (happiness and surprise) and the right hemispheres is dominant for negative emotions processing (anger, disgust, fear, and sadness).…”