Writing Direction

The relationship between reading direction and the “left brain/right brain” concept is often misunderstood. Let’s break down the implications, first by addressing the popular myth and then by explaining what actually happens.

1. The Popular Myth (Which is Mostly Incorrect)

The Myth: “Left-to-right readers use their left brain more, and right-to-left readers use their right brain more.”

• Why it’s intuitive: The left brain is often (over-simplistically) associated with logic and language, while the right is associated with spatial awareness and creativity. Since reading direction is a spatial process, it’s tempting to assign different directions to different hemispheres.

• Why it’s wrong: This is a major oversimplification. The core language centers (Broca’s area for speech production, Wernicke’s area for comprehension) are predominantly in the left hemisphere for about 90% of people, regardless of their native language’s reading direction.

2. The Scientific Reality (A More Nuanced View)

The real implication isn’t about which hemisphere is used for language, but how the reading direction trains specific spatial attention networks within each hemisphere.

The key players are the two brain hemispheres’ parietal lobes, which are crucial for visual attention and spatial processing.

Here’s how it works:

For Left-to-Right (LTR) Readers (e.g., English, Spanish):

• The right parietal lobe is specialized for broadly monitoring the entire surrounding space (“global attention”), but with a slight bias toward attending to the left side of space. (This is why damage to the right parietal lobe can cause a patient to completely neglect the left side of their world).

• The left parietal lobe is specialized for focusing on fine details (“local attention”) with a bias toward the right side.

• The Implication: Reading LTR fits perfectly with this natural asymmetry. The task of reading—focusing on details (letters and words) while moving rightward—engages the left hemisphere’s detail-oriented, rightward-biased system. The right hemisphere provides the broader context of the page and line.

For Right-to-Left (RTL) Readers (e.g., Arabic, Hebrew):

• The underlying hemispheric specializations are the same. The right parietal lobe still has a bias for global/left attention, and the left parietal lobe for local/right attention.

• The Implication: Reading RTL requires the brain to overcome its innate spatial biases. To read from right to left, the reader must use their left hemisphere’s detail-oriented system to scan leftward, which goes against its natural rightward tendency.

• This acts as a constant training exercise for the attentional systems. Studies suggest this may lead to a more balanced engagement of both hemispheres during reading in RTL readers compared to LTR readers. It doesn’t mean they use the “right brain for language,” but that the spatial attention networks in both hemispheres are recruited more equally to perform the task.

Summary: The Actual Left/Right Brain Implications

The Bottom Line:

The difference isn’t about which side of the brain “does the reading.” Language remains primarily left-hemispheric.

The difference is in how the brain’s spatial attention networks are trained:

• LTR reading reinforces the brain’s pre-existing attentional biases.

• RTL reading acts as a form of constant cognitive training, forcing the brain to exercise greater control over its spatial attention and likely leading to a more balanced use of both hemispheres’ parietal lobes for the task of reading.

This is a powerful example of how a cultural practice (writing direction) can shape and train fundamental cognitive processes in the brain.