The Biology of the Engram and the Material Memory Trace

The article analyzes the evolution of the understanding of memory: from philosophical metaphors of wax tablets to modern neuroscience. A key point is the transition from perceiving memory as a static archive to a dynamic biological process. The author invokes Richard Wolfgang Semon's concept of the engram, defining it as a permanent modification of the organism resulting from a stimulus, and the process of ekphory, which is the reactivation of this trace. The text emphasizes the importance of Cajal's neuron doctrine in overcoming Golgi's reticular model, which paved the way for the search for the physical carrier of memories. Overall, it presents memory as a plastic biological mechanism that not only stores the past but allows the organism to adapt to a changing environment through material changes in neuronal structure.