The slime mould Physarum polycephalum is a microorganism that possesses a spatial memory. In essence, as it moves it lays down a layer of slime in a complex 2-dimensional network. When it has explored a region of its environment where there is no food or opportunity, it retracts from this area, but leaves its traces of slime behind. If it encounters these abandoned threads of slime again, it will not re-explore this region, as it knows, in a sense, that it has visited this area before and that there is no reward here.
In an attempt to imprint my own memories into the slime mould’s spatial memory I told it the story of my mother’s death from breast cancer and my fond memories of her. I filmed its response using a Differential Interference Contract microscope, and the microvideos above record its reaction to my words. Its reponse to my speech can be seen in its pulse-like intracellular activity, and its memory, and perhaps mine, can be seen in the threads of lifeless slime that it leaves behind.