Human memory is very subtle. For example, revisiting the hometown often reminds people of many past events naturally. Therefore, many people will go to places where they have grown up, studied, worked and romantic, look for the footprints of that year and experience the feelings of the past. Why is it easy to remind people of the past? Can we examine this problem by experiment? The answer is yes. Psychologist Bauer has done this for a long time, and has obtained enlightening and valuable results.

Gordon Howard Bower (1932-2020) was born in the small town of Theo, Ohio. His father opened a grocery store and his mother was a substitute teacher in primary school. In 1954, Bauer received a Bachelor of Arts from Case Western Reserve University. Then, he went to the University of Minnesota and Yale University for graduate studies. In 1956, he received a master's degree from Yale University. In 1959, Bauer received a doctorate in psychology from Yale University. After that, he taught at Stanford University. In 1973, Bauer was elected as an academician of the National Academy of Sciences. In 2005, he won the National Science Award.

Bauer started thinking from common memory experiments. In the experiment, the word list that the subjects learn is usually not the meaningless syllable learned by Ebbinghaus, but the materials that the subjects are familiar with, such as numbers, letters and words. Taking the word list composed of learning words as an example, the subjects did not learn the words themselves, because the words were familiar to them; What they really need to learn is that these specific words appear in this specific experiment. In other words, the subjects need to form a connection between each word and the experimental situation, remember that they are the words presented in this time, this place and this word list, that is, remember that they are the words related to the experiment.

If so, the connection formed by the subjects is actually the connection between these words and the whole situation of the experiment. This situation includes the experimental site and everything in the site, as well as the internal state of the subjects. If the word is related to all these clues, the memory performance of the subjects should be the best when they are tested in the same situation. The same situation here is that the subjects have the same internal and external conditions during testing and learning. Under this condition, the subjects had the largest number of clues related to the materials to be recalled.

Based on this, Bauer can carry out experimental test. He chose to manipulate one of the subjects' internal states - emotions. Through hypnosis, Bauer made half of the subjects in a happy mood when learning the word list, and half of the subjects in a sad mood when learning the word list. Then, half of the subjects in each group were asked to recall the learned words in a happy mood and the other half were asked to recall the learned words in a sad mood.

The results showed that if the subjects were in a sad mood when learning materials, they scored better in a sad mood; If the subjects were in a happy mood when learning materials, they scored better in a happy mood. In other words, how subjects remember materials depends on whether they are in the same state as they were in when they were tested. If the status is the same, the result is good; Different states, poor grades. Therefore, this phenomenon that the memory effect depends on the test and learning state is called state dependent memory.

In order to improve the external validity of the study, other methods and indicators can be used to continue to investigate the relationship between internal state and memory effect. For example, some subjects were asked to learn materials in a slightly drunk state, while others were asked to learn materials in a conscious state. During the test, half of the subjects in each group were slightly drunk and the other half were awake. The results show that when the test conditions are the same as the original learning conditions, the memory performance is better. Of course, those who are sober in learning and testing have the best results.

The above research involves the internal state of subjects. What about the external state? In one experiment, the subjects were divers equipped with scuba. The researchers arranged for some subjects to learn a word list at 10 feet underwater, and some subjects to learn the word list on land. All subjects were equipped with scuba and listened to words through headphones. Then, half of the subjects in each group were tested underwater and half were tested on land. The results show that if the test conditions are the same as the learning conditions, the memory performance is better, that is, the subjects who study underwater remember better; Subjects who study on land remember better on land.

Psychological research has application value, even important application value. The same is true of the kind of state dependent memory Bauer found. For example, in 1968, US presidential candidate Robert Kennedy was shot by Sirhan. After being brought to justice, Saihan had no memory of the actual shooting. However, under hypnosis, when Saihan gradually became excited and excited, he also gradually recalled more content, including his shooting.

Now, Saihan recalled that he shot Kennedy. It may also be a false memory. However, according to the analysis of the researchers, Saihan's recollection of the shooting plot is more likely to be state dependent memory, that is, the events he made when he woke up at high call can be better recalled when he returned to the same state.

Revisit the old place. There are some things that are the same or close to the original place, which become clues to memories. Therefore, it can make it easier for people to remember the plot of that year. If great changes have taken place in the hometown and people can't find memory clues, it will be difficult to remember the past. Therefore, they will not only sigh more about the vicissitudes of life, but also probably won't have the idea of returning to the hometown.