A memory board (lukasa) is an object used by experts in the oral retelling of history in the Luba culture of the Democratic Republic of Congo. A master who has the skill and knowledge to read the memory board will use it as a mnemonic device. Made of small wooden planks, usually rectangular or hourglass-shaped, some memory boards are simply carved in relief; others are first carved and then studded with beads and shells. Web resources here and  here. Video here.

Memory board. Luba peoples, Democratic Republic of Congo. Wood, beads and metal. 19th-20th century. Brooklyn Museum.