Slower handwriting may be early warning sign of dementia

By Stephen Beech

Slower handwriting speed may be an early warning sign of dementia, according to new research.

A new accessible digital tool recording writing speed could aid diagnosis of cognitive decline in older people, say scientists.

They explained that handwriting requires a combination of fine motor control and a complex set of mental skills — including selecting, organizing, and interpreting sensory information — making it a "cognitively challenging" task.

Because of handwriting's high demand on the brain, the Portuguese research team say it is a potential marker of cognitive decline, especially as we age.

The team examined if different handwriting features, including speed and stroke organization, differ between older people who show signs of cognitive decline and those who don't and if handwriting features could therefore serve as a diagnostic tool.

Study senior author Dr. Ana Rita Matias said: "Writing is not just a motor activity, it's a window into the brain.

"We found that older adults with cognitive impairment displayed distinct patterns in the timing and organization of their handwriting movements.

"Tasks involving higher cognitive demands showed that cognitive decline is reflected in how efficiently and coherently handwriting movements are organized over time."

The team set out to determine whether the writing process could yield earlier and more sensitive indicators of cognitive decline than test scores or final outputs, which are the measures often analyzed in traditional cognitive assessments.

The study included 58 adults, aged between 62 and 92, living in care homes. A total of 38 had previously been diagnosed with a form of cognitive impairment.

Participants performed two types of tasks using an inking pen on a digitizing tablet.

During pen control tasks, participants were prompted to draw 10 horizontal lines within 20 seconds and make at least 10 dots on the paper during the same time frame.

The handwriting speed task included noting down two sentences of varying complexity that were either shown on a card or dictated, respectively.

The findings, published in the journal Frontiers in Human Neuroscience, showed that neither of the pen control tasks could distinguish cognitive status between groups.

As "simple" tasks, the researchers said they mainly rely on basic motor control and may not be enough to reveal subtle differences that more cognitively taxing tasks can show.

Copying tasks, which are more mentally demanding than pen control but less demanding than dictation, also didn't show group differences but demonstrated a trend towards significance.

But the results of the dictation tasks showed "clear differences" between the two participant groups.

Matias says that could be due to the higher cognitive demand such tasks place on working memory and executive functions.

She said: "Dictation tasks are more sensitive because they require the brain to do multiple things at once: listen, process language, convert sounds into written form, and coordinate movement.

"Even within dictation tasks, differences can emerge. A longer, less predictable, or linguistically demanding sentence places greater strain on cognitive resources."

In the group with cognitive impairment, two predictors — start time and number of strokes — emerged as significant for the shorter sentence of the dictation task.

For the more complex sentence three predictors — vertical size, start time, and duration — were significant.

Matias, an assistant professor at the department of sport and health at the University of Évora, said that could be due to not all handwriting features reflecting cognition in the same way.

She added: "Timing and stroke organization are closely linked to how the brain plans and executes actions, which depends on working memory and executive control.

"As these cognitive systems decline, writing becomes slower, more fragmented, and less coordinated.

"In contrast, other features can remain relatively preserved, especially in the early stages of cognitive decline, making them less sensitive indicators."

The team said their approach, relying only on simple writing tasks and accessible digital tools, could serve as a practical way to monitor cognitive decline in a variety of settings, for example in doctors' offices.

Because it's a non-invasive and relatively low-cost method, they say it could easily be integrated into routine clinical practice.

But the researchers said further research will have to confirm the effects in larger and more diverse groups.

Matias added: "The long-term goal is to develop a tool that is easy to administer, time-efficient, and affordable, allowing integration into everyday healthcare contexts without requiring specialized or expensive equipment."