Effects of Aging and Shock on Memory

It is a matter of common observation that the aged may have great difficulty recalling what happened an hour ago but can discourse fluently about events of 50 years past. This is due to a decline in the memory-span function with encroaching senility. That, in turn, may well depend upon loss of perceptual acuity. An item which was never clearly perceived can hardly produce a sharply defined memory impression and so can never be clearly recalled. Childhood and early adult memories, on the other hand, were clearly formed and moreover have probably been rehearsed many times during life. The wish to be young again may also motivate the older person to direct his attention to his youthful achievements and obtain gratification by talking about them. He may think that this will distract the listener’s attention from the old man’s inadequacy.

The fragility of the memory trace when first established can also be verified by studying the effects of shock. A blow on the head often causes loss of memory for events immediately preceding the blow (“retrograde amnesia”). The opportunity to observe this process at close hand has occurred frequently since psychiatrists have begun to use electroconvulsive shock and insulin shock as forms of therapy for mental disorders. The following account is quite characteristic of these observations:

One patient, immediately after her seventh electro-convulsive treatment, was unable to recall that she was married. Actually she had been so for ten years. She could not remember her three children, the onset of the illness, coming to the hospital, nor could she recognize her physician. Within a few hours she was able to recall her marriage, her children and her illness, but was still unable to remember coming to the hospital or to identify her doctor. By the end of the day these last major defects had vanished. It is of importance to note that this recovery adheres to a chronological order.

According to a long-accepted principle in psychology (Jost’s law), recent memories are more readily lost than those of long standing. This principle is based upon laboratory experiments, but the facts cited with regards to aging and shock suggest that it holds also for real-life occurrences.