A patient shows a marked pattern of memory loss. Before revealing the answer, decide what distinguishes Ribot's law of memory regression from an amnestic state.

Ask about the extent and trajectory of the memory loss over time. Ribot's law differs from the amnestic state of Korsakoff's syndrome and similar conditions in the extent and progressive nature of the memory loss, which widens over years rather than remaining confined to the period around a single event: this is a gradually progressive pattern occurring in chronic brain disease, with the boundary between lost and preserved memory steadily moving further back in time. An amnestic state, by contrast, typically involves a persisting but relatively fixed difficulty registering new memories, often improving or shrinking in extent with recovery rather than progressively worsening. The steadily widening, progressive nature of the memory loss versus a persisting, potentially recoverable pattern is the key distinguishing feature.