How Inversion Tricks The Brain

Researchers have mapped the neural pathways required for the normal recognition of faces, explaining why orientation makes inversions difficult to spot.

AsianScientist (Apr. 22, 2015) – When presented with an upside down image of a face, the region of the brain responsible for object recognition kicks in, making facial recognition challenging. The study documenting these findings has been published in The Journal of Neuroscience.

First demonstrated with a picture of British prime minister Margaret Thatcher, the so-called Thatcher illusion is where the the flipping of features such as the eyes and mouth is made more difficult to recognize when the face is upside down.

Researchers led by Professors Ryusuke Kakigi and Norihiro Sadato of the National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences (NINS), used functional magnetic resonance imaging (fMRI) to show that suppression of the brain area responsible for object recognition known as the lateral occipital cortex was necessarily for normal face recognition.

The researchers mathematically simulated networks between face-specific regions of the brain and brain areas that had been considered non-essential to face recognition such as the lateral occipital cortex. They found that when faces were shown upright, the lateral occipital cortex was suppressed by the face-specific regions such as the early visual cortex, occipital and fusiform face areas.

In contrast, the lateral occipital cortex was not inhibited when faces were inverted. Instead, the researchers observed increased couplings to the intraparietal sulcus, a region associated with visual working memory.

“In this research, we have found that not only brain areas that execute face recognition but also brain areas that had been considered non-essential to face recognition are important for normal face recognition. It could be that disorders of face recognition such as developmental prosopagnosia may be attributable to the brain networks,” said Kakigi.

The article can be found at: Matsuyoshi et al. (2015) Dissociable Cortical Pathways For Qualitative And Quantitative Mechanisms In The Face Inversion Effect.


Source: National Institutes of National Sciences.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

Asian Scientist Magazine is an award-winning science and technology magazine that highlights R&D news stories from Asia to a global audience. The magazine is published by Singapore-headquartered Wildtype Media Group.

Related Stories from Asian Scientist