Q: Read the following article and answer the question. Article: Having a child may improve a woman's memory, a new study suggests. In the study, women who were new mothers scored better on tests of visuospatial memory - the ability to understand and remember information about their surroundings--compared with women who didn't have children. The findings contradicts the old belief that women develop"baby brain" or a decline in memory and cognitive function, after they have kids, said study researcher Melissa Santiago, a doctoral student at Carlos Albizu University in Miami. "You don't have to feel that because you have kids, your memory isn't the same," Santiago said. The study was small, and the findings will have to be tested in larger groups of people, Santiago said. Previous studies on the topic have had mixed results--some showed motherhood hurts cognition, and others showed the opposite. Studies on rats show those with pups have better memory than those without offspring. Santiago analyzed information from 35 first-time mothers whose children were ages 10 to 24 months, and 35 women who had never been pregnant. Both groups scored similarly on intelligence tests. The average age of mothers was 29 and the average age of never-pregnant women was 27. To test visuospatial memory, the women were shown a paper containing six symbols for 10 seconds, and then asked to draw what they remembered. This task was repeated several times. The first time women were shown the paper, both groups remembered about the same amount. But on the second and third pass, mothers performed better than those without children, indicating that the mothers collected more information each time than the other women. Later, the women were shown a variety of different symbols, and asked to remember which ones were presented on the earlier task. Mothers did not make a mistake in this task--they remembered every symbol correctly--but those without children made one or two errors, Santiago said. Question: How did Santiago lead to the findings? Answer:
The answer is:
By comparison.