Thousand Steps
Ethan Petersen
Personal Thoughts, stories, and discussion.

Along the western coast of Bonaire lies one of my favorite dive sites: Thousand Steps. It’s really only 67, but feels like a thousand when you’re lugging all of the dive gear down under the blistering sun. But further north in the national park hides the most incredible dive. On a high school marine biology trip, myself and other students rode for several hours through the park to this site on another typical, hot day in the island’s summer. When we finally arrived, myself and a friend quickly donned our gear and got in the water. We swam south, following the reef wall at a 30-40 meter depth. Stunningly colorful and full of life, the wall captivated us until I turned and saw only blue. The wall ended, the dazzling, vibrant reef ended, and only a deep blue remained. We swam towards this surprise and realized that the wall actually turned sharply inwards towards the coast, and revealed an underwater cathedral of color and life. Turning the corner, the reef curled towards the coast and back to the ocean, surrounding and impressing us with radiance and creation. I kid you not, just a few feet above us floated a green turtle grazing happily along the reef. Swimming along, the wall continued to weave again inwards and outwards along the coast. We stayed as long as we could, and that dive will forever remain as a treasured memory, one that I hope to revisit again!

One of the greatest research pursuits is the understanding of how our brains work. Towards this goal, a landmark discovery by Dr. John O’Keefe revealed that information flowing into the brain is not processed independently, but understood by relationships between the stimuli. He observed that hippocampal neurons fired based on where the organism was in its environment. Dr. O’Keefe termed these neurons as place cells, and the location causing their firing as a place field. Similar phenomenons have been observed with other sensory inputs, forming the more general idea of a receptive field. A neuron’s receptive field is the subset of the stimulus space that causes the neuron to fire. In Dr. O’Keefe’s studies, the stimulus space would be the visual and physical characteristics of a maze and an example receptive field could be a specific corner. But these results beg the question: