Your job can shape your cognitive abilities

The job that you do can change your brain. This has famously been found for London cab drivers but also acupuncturists, typists, musicians and airport security officers. There is also evidence that more intellectually stimulating jobs bring cognitive benefits, which extend into later life.

This past work has found job-related improvements in skills like touch discrimination and emotion regulation. Now a new study finds that a job that challenges a key aspect of cognitive functioning — the updating of information held in working memory — improves this ability too.

Effective updating of the contents of working memory is vital for all kinds of everyday experiences, including having a conversation and reading. It's also linked to greater academic success. So this new work, led by Xin Zhao at Northwest Normal University, China, and colleagues, published in Applied Cognitive Psychology, provides evidence that job choice can affect a fundamentally important aspect of everyday brain function.

In the first of two studies, the team recruited 53 men who worked as restaurant ticket collectors in beef noodle restaurants in China, plus 53 security guards as a control group. (Men typically hold these jobs, they write.)

Ticket collectors in this kind of popular restaurant have a challenging task. After placing an order, a customer is given a ticket that itemises that order. They then take that ticket to a ticket collector at the kitchen area. The ticket collector checks and memorises the order and also notes what that customer looks like. Then they give the order information to the kitchen staff. When an order is ready, the kitchen gives the food to the ticket collector, who must then remember which customer to give it to.

To perform this job well, a ticket collector has to continually monitor incoming information and regularly update their memories of who has ordered what. "Hence this job is assumed to require a strong working memory updating ability," the team writes.

The team gave the ticket collectors, who were recruited from about 30 restaurants, and the security guards a working memory updating task, in which they viewed a sequence of numbers and had to constantly update their memory to hold in their mind just the previous three digits. The team found that the ticket collectors did better on this measure than the security guards, even after controlling for participants' fluid intelligence (the kind of intelligence used in problem-solving) and various demographic variables.

But did working as a ticket collector improve those participants' working memory updating ability, or were they better at this to begin with?

To investigate whether the ticket collectors' job experience could have caused improvements, the team ran a second study. A total of 33 student participants were trained for half an hour a day, for 20 consecutive days, on a computer simulation of the demands placed on a ticket collector.

In each session, these participants saw a series of cartoon characters, each paired with a type of beef noodles. (The team had a total of 30 different characters and six different noodle types to draw on.) In each trial, the participants had to judge whether or not the current person-food pairing was identical to one they had been shown a specified number of times earlier in the series.

A control group of another 33 students spent the same amount of time in a similar university lab room but making sand paintings, a Tibetan Buddhist tradition that requires focused attention.

The team found that the participants in the ticket collector simulation group showed a clear, linear improvement on a few different measures of working memory updating ability: the digit updating task from the first study, and also a numerical n-back test; this is very similar to the task they faced in the training, but with numbers instead of character-food order pairings. The control group did not show these improvements. So, these results support the idea that working as a restaurant ticket collector does improve working memory updating.

However, as the researchers acknowledge, it's also possible that the participants in the second study may have developed a technique, such as a mnemonic technique, to help them keep track of character-food pairings, and that this, rather than a fundamental improvement in working memory updating, led to their improvements. Further research is needed to explore this.

For now, though: "The collective results provide further evidence of environmentally induced cognitive plasticity, in the form of repeated experience with occupation-specific demands affecting specific cognitive abilities," the team concludes.