Human and animal memory are similar

BRAIN GAMES: A gazelle remembers the person who picked him up when his parent died. Photo/STEVE KINUTHIA
BRAIN GAMES: A gazelle remembers the person who picked him up when his parent died. Photo/STEVE KINUTHIA

When I was in secondary school, there was this teacher who was loved by all his students. He was harsh, as most teachers were, but he was special in that he was genuinely concerned about students who were not very bright. He made sure the slow learners got his personal attention, and this made his students do very well in the subjects he taught. He was our geography teacher, and this subject required us to memorise geographical names and definitions. Remember gully erosion, sheet erosion, names of rocks and their formation, contours and how to interpret them on contour maps?

Whenever we were about to sit examinations, he would ask us to go and play instead of studying for the paper. That used to worry me a lot. Most of the teachers would literally rally us to classrooms and even join us for evening preps to help us prepare for the exams. But this geography teacher would ensure we did not study for his subject a day before exams. Sometimes he would even take away the text books and our notebooks and lock them in his desk until the exams were over. Asked why he did it, he told us it is all about feats of memory. If we studied hard the night before exams, or few hours before sitting exams, we were bound to forget what we had read. Though most of us did not understand his methods of teaching, they worked. We used to pass the geography examination papers almost en mass. Years later, while studying zoology, I bumped into the subject of memory again, which explained in details why our teacher forbade us from studying a day before exams.

Sitting in an exam room faced with questions designed to get you to regurgitate the facts you have been striving to assimilate over recent weeks, you curse your memory. Memory enables you to give a police officer a detailed description of the guy who snatched your phone, even if you saw him in a flash. In general, memory plays a far bigger role in our lives than we usually appreciate.

It is not just the ability to recall facts, telephone numbers, and names of our guests from last year’s itineraries or further back. We also store in our brains smells and tastes together with an enormous variety of other kinds of data including the words that make up the language we speak, read or write. Indeed, psychologists believe that the storage capacity of the human brain with its astronomical number of interconnected nerve cells is so huge that we remember literally everything that we experience. Although we say, and it is a fact that animals lower than humans have a smaller brain mass, they also depend on memory in running their lives.

Evidence of similarity between the working of human and animal memory comes from investigations done by a professor of sensory science, Dr Antony Wright. He devised memory tasks that are identical for both humans and animals. This was not easy because, as the professor noted, humans have a long history of testing themselves and also game playing and they continually develop tricks to improve their performance. He used a particular phenomenon in human memory called "serial position function".

Using specially trained pigeons and monkeys, and of course humans, he showed them four series of slides with images of travel pictures which the animals could identify easily. Then he flashed on a big screen a single slide with travel pictures. Humans and animals were supposed to indicate whether the slide had been part of the four slides shown earlier. Monkeys were trained to answer by gestures. Pigeons by pecking a green disc for ‘yes’ and a red disc for ‘no’.

When the test was done immediately, both animals and humans remembered only the last slides among the four shown. Tested after a long period had elapsed, both animals and humans remembered both the first slide and the last slide. At even longer intervals, they were able to remember slide one and four perfectly, and most of slide two and three. Now I know why the teacher told us not to study the night before exams.

Steve Kinuthia is a veteran professional safari guide and the proprietor of Bushman Adventures Limited.