Brain games, crosswords and math puzzles are often promoted as tools for sharpening memory and clearing mental fog. But a neurologist says random cognitive exercises may miss the specific mental function causing the problem.

Dr. Rhonda Voskuhl, a professor of neurology at UCLA and one of the founders of Cleopatra RX in Los Angeles, says an exercise must address the exact ability that has slowed. Matching the activity to the problem is crucial.

“You can’t just do random cognitive exercises,” Voskuhl told Fox News Digital at the Livelong Women’s Health Summit in New York City in September. “They’ve got to fit the problem.”

For people struggling with verbal memory, number focused activities may offer little help. “The problem,” Voskuhl said, “is verbal memory. Doing math is not going to help … You need an exercise that will help you with words.”

Mental fog connected to hormone changes during perimenopause and menopause can affect particular areas of mental performance. According to Voskuhl, estrogen loss can influence verbal memory, processing speed and focus.

Overall intelligence and basic logic remain normal when estrogen levels drop, experts say. The more specific difficulties involve recalling names and words, along with thinking quickly when under pressure.

That distinction helps explain why Sudoku and other number puzzles may not improve word recall. Those activities primarily exercise logic and mathematical abilities rather than the verbal functions involved in retrieving a name or finding the right word.

“It’s not a global problem with the brain,” Voskuhl said. “It’s not global brain atrophy, but there are some regions on MRIs and research studies that show that the hippocampus, the memory area, will have some atrophies, some functional connection issues.”

Understanding the difference between encoding and retrieval can also clarify what is happening. Encoding is the process through which the brain takes in and stores new information, while retrieval is how it accesses that stored information when needed.

Brain fog typically interferes with retrieval rather than encoding, according to the source. The name or word remains stored in memory, but the process of finding it becomes slower.

Exercises intended to address this challenge should concentrate on rapidly finding words. “It’s basically processing speed,” Voskuhl said. “So you need an exercise that is going to be something that makes you rush, makes you do it quickly.”

One targeted option is a timed word game using a single category. A person can set a 60 second timer and list as many words as possible within a category, such as animals or foods.

Another exercise combines speed reading with immediate recall. A person reads a short article quickly and then summarizes it aloud in two or three sentences, requiring both rapid processing and active retrieval.

Rapid recall drills offer another focused approach. Flashcards or picture prompts can be used to name objects or people as quickly as possible without pausing, directly exercising the ability to pull words from memory.

These activities differ from generic puzzle apps because they focus on speed and active word recall. Rather than choosing a game simply because it is marketed for the brain, Voskuhl recommends identifying the difficulties that appear during ordinary life.

People can consider what they are currently struggling with or what they previously did well but now find harder. That personal assessment can guide the selection of games that test the relevant ability.

People “know themselves,” Voskuhl said, including “what they are bad at or what they used to be good at and now they’re not as good at ... Once you know those things, you should think about what kind of games [to play]. You can play around with different games. You can see if it pushes you.”

The central principle is specificity. For mental fog involving verbal memory and processing speed, a focused 60 second category drill, rapid reading summary or recall exercise may better match the challenge than an unrelated logic or math puzzle.