Page 1 - LN 4_Human Memory

Class XI

Chapter 7

Human memory

Module 4

(Topic: Nature and causes of forgetting and theories of forgetting and
enhancing memory)

SHORT NOTE

• The first systematic attempt to understand the nature of forgetting was made by

Hermann Ebbinghaus, who memorised lists of nonsense syllables and then
measured the number of trials he took to relearn the same list at varying time

intervals.

• He observed that the course of forgetting follows a certain pattern.

• The rate of forgetting is maximum in the first nine hours, particularly during the

first hour.

• After that the rate slows down and not much is forgotten even after many days.

• Although Ebbinghaus’s experiments constituted initial explorations and were not
very sophisticated yet they have influenced memory research in many important

ways.

• It is now upheld, almost unanimously, that there is always a sharp drop in memory

and thereafter the decline is very gradual.

THEORIES OF FORGETTING
1. TRACE DECAY (ALSO CALLED DISUSE THEORY)

▪ is the earliest theory of forgetting.

▪ The assumption here is that memory leads to modification in the central

nervous system, which is akin to physical changes in the brain called memory

traces.

▪ When these memory traces are not used for a long time, they simply fade away
and become unavailable.

▪ This theory has been proved inadequate on several grounds.