Attending to Attention
Robert desimone studies the brain mechanisms that allow us to focus our attention on a specific task while filtering out distractions (“A Turning Point,” January/February 2015). Our brains are constantly bombarded with sensory information, so the ability to distinguish contextually relevant from irrelevant information is critical. Perhaps not surprisingly, this ability is impaired in several brain disorders.

In Desimone’s lab, where I am a graduate student, we believe that filtering relevant from irrelevant helps the brain solve the fundamental challenge of information overload. By studying the visual system of humans and animals, we have shown that encoding of task-­relevant information is selectively amplified in the brain while the irrelevant is suppressed, and that neurons whose activity reflects relevant information become rhythmically synchronized with one another while neurons encoding irrelevant information do not.

This rhythmic synchronization can be thought of as a chorus chanting a tune that rises above the background chatter of a crowd, thereby making it “heard” (and processed) more effectively by other “listening” brain regions. We suspect this pattern of rhythmic activity is not just specific to attention but may also represent a general mechanism for communication between different parts of the brain.

Our work also suggests that the prefrontal cortex—a brain region involved in planning and executive control of behavior—most likely serves as the conductor of this neural chorus. It provides a top-down signal that coördinates rhythmic activity across multiple brain regions.

Azriel Ghadooshahy
Cambridge, Massachusetts

Learning to Swim at MIT
Until I read “MIT’s Wettest Test” (January/February 2015), I was unaware that MIT requires every student to pass a swim test to graduate. I entered MIT in 1942 as a civilian freshman. At that time, the Institute did not have the requirement. However, all freshmen were required to enroll in an athletic program. Not being very athletic, I opted for gymnastics. I never became proficient, but the only requirement was to attend the classes (which were held at the YMCA in Boston) and do the best you could.

Beginning July 1, 1943, the Navy V-12 program began at MIT and 130 other U.S. colleges. I became one of 916 Naval Reserve apprentice seamen who were undergraduate students at MIT. Our academic schedule changed from two semesters a calendar year to three. We had a full academic schedule plus requirements for Navy-taught subjects, including swimming. As a nonswimmer, I was assigned to three one-hour beginner classes a week. The classes were held in the Alumni Pool and included breast stroke, side stroke, backstroke, and crawl. The MIT swim coach, who had been an Olympic swimmer, served as our instructor. Once I passed the basic swim test, I was transferred to the weekly Navy swim class, where our goal was to learn survival techniques in a water environment. This included treading water, making water wings out of Navy-issue pants, jumping off the high diving board feet first wearing a full life jacket, simulating swimming in water with burning oil on the surface, swimming with one arm held up in the air as if holding a rifle, and towing a disabled sailor while holding his head above water.

I agree with Carrie Moore, the MIT director of physical education, that the origins of the swim test requirement probably date to “sometime around World War II.” It seems to be a logical extension of the Navy’s V-12 swim requirements.

Marshall Byer ’45, SM ’47
Vista, California

In 1961, my first year at MIT, the swim test was four lengths of the pool, only one of which could be on your back. I used up my backstroke on the third length, failed, and took swimming. So glad I did. Swim three days a week now.
MIT did what living on Long Island near the sound and the ocean on Lake Avenue near Wildwood Lake on Little River near the Peconic River didn’t do.

Gene Chase ’65
Mechanicsburg, Pennsylvania

A Slight Photo Rebellion
The caption to the picture accompanying “Slight Rebellion off Mass. Ave.” (September/October 2014) is incorrect. Instead of being taken on March 4, 1969, the picture was taken on October 15, 1969, at the start of the Moratorium Day protest against the Vietnam War. I was on the far right of the original picture (which was cropped in the magazine).

Matthew Goetz ’73
Los Angeles, California

Another Alumnus Sketcher
The “Sketches of Science” piece in the January/February 2015 Alumni Connection contains an unfortunate error in attributing the Nobel laureates’ MIT connections. The statement “The MIT alumni are all physicists” overlooks molecular biologist Robert Horvitz ’68. Bobby Horvitz served as managing editor of the Tech in 1966 and president of the Undergraduate Association in 1967. He is, as noted, a distinguished member of the MIT faculty, but he was a distinguished MIT student first.

Chuck Kolb ’67
Bedford, Massachusetts