But the hardship of being the Rodney Dangerfield of Psych 101 goes deeper than the wrinkles setting you apart from your classmates. Behind that “non-traditional-student” face is a brain that might not be up for college-course work — not the way it used to be.

As you enter your late 20s and early 30s, you may start noticing that your reaction time is a little slower. Your vision is a little fuzzier; your hearing is a little less sharp. You may not be grasping for nouns or griping about senior moments — that’s still a couple of decades down the line — but is your brain already headed toward its inevitable decline? Can you really keep up with those feisty undergrads and their still-supple minds?

Getting back into the swing of full-time academics may be tough, but you can take solace in knowing that, unless you’re already qualifying for senior-citizen discounts, your brain is still working with you, not against you. Even if your senses are diminishing ever so slightly, and even if you are losing a handful of brain cells every day, your brain is a remarkable organ that finds ways to compensate for most losses — especially in early adulthood.

Everything at once
The brain is constantly engaged in a sort of spring cleaning, pruning away the neurons and connections that are not being used. That, in turn, allows us to be faster and more efficient at tasks that we do a lot, explains Kurt W. Fischer, director of the Mind, Brain, and Education program at the Harvard Graduate School of Education. It also means we have a harder time learning new things, or doing things we haven’t done in years.

“At any point in life, if you don’t do something for a long time, you get rusty,” Fischer says. For older returning students, that rustiness can be frustrating, especially when faced with math or foreign-language requirements, which call on skills that may have been dormant for more than a decade.

Another potential weakness among older students is their declining ability to multitask. That’s a particular liability in college, when you need to be able to write a paper while tuning out the background noise of a rowdy dorm, or take notes while listening to a lecture and looking at a Powerpoint slide.

Trouble with multitasking can begin as early as age 30, according to a study conducted by Allison B. Sekuler, a professor of cognitive neuroscience at McMaster University, in Canada.

Sekuler recruited 176 subjects between the ages of 15 and 84 and asked them to complete two separate tasks. First, she had them identify a letter that flashed in the middle of a video screen. Then she asked them to point to a circle after it briefly appeared somewhere near the edge of the screen. Then, Sekuler had them do both tasks simultaneously — which was the older subjects’ undoing.

In Sekuler’s study, the difficulty with paying attention to two things at once showed up at surprisingly young ages. “On some tasks if you’re 25, 35, 45, it doesn’t really make much of a difference,” she says. But when looking at the ability to multitask, “it was a gradual, linear loss across the age ranges.” People in their 30s, she says, had significantly more trouble with multitasking than people in their 20s.

The results are particularly striking given the simplicity of the tasks involved. “Chances are, as you make the tasks more and more complex, you will see bigger and bigger effects,” Sekuler speculates. For the type of complex multitasking required of a college undergraduate or grad student, then, the difference between a 35-year-old and an 18-year-old can be quite pronounced.

Hope for tired intellects
There is good news, though: whether you’re trying to do eight things at once or pulling out a dusty solar calculator for your first math course since the ’90s, the brain is incredibly flexible and can be trained. Sekuler found, for example, that when subjects repeated divided-attention tasks for an hour a day for multiple days in a row, the age-based differences in ability virtually disappeared.

So even if a 30-year-old student is entering school at a slight disadvantage, chances are that by the end of the semester she’ll be writing her final paper while instant messaging, listening to music, checking the latest news online, and eavesdropping on the couple at the next carrel — just like her multitasking-proficient peers.