Memory devices and methods for read disturb mitigation involving word line scans to detect localized read disturb effects and to determine error count in tracked sub sets of memory addresses

A memory device, comprising:

• a main memory comprising a plurality of memory addresses, each memory address corresponding to a single one of a plurality of word lines and being included in a tracked subset of the plurality of memory addresses, each tracked subset including memory addresses corresponding to more than one of the plurality of word lines;
• and
• a controller operably connected to the main memory and configured to:
• track, for each tracked subset, a number of read operations,
• scan, in response to the number of read operations for a first tracked subset exceeding a threshold value as scaled by a first threshold scaling factor corresponding to the first tracked subset, a portion of data corresponding to each word line of the first tracked subset to determine an error count corresponding to each word line of the first tracked subset, and
• update the first threshold scaling factor by an amount corresponding to the determined error count.