"while speaking English" and "when I speak English"

[Odessa Dawn]

In a recent study, researcher Katarzyna Ożańska-Ponikwia examined why some people report feeling different while others do not. She asked some 100 bilinguals made up of people who had grown up speaking two languages, immigrants who acquired their second language later on in life, as well as students who had stayed in a foreign country for an extended period of time, to give answers to two personality questionnaires and to give scale values to statements such as, "I feel I'm someone else while speaking English", or "Friends say that I'm a different person when I speak English".
More: Change of Language, Change of Personality? Part II | Psychology Today

According to the information in the below quotation, can I say what has been written in the underlined parts are not interchangeable?

When emphasized the exact moment. While suggests a long duration.

[bhaisahab]

In a recent study, researcher Katarzyna Ożańska-Ponikwia examined why some people report feeling different while others do not. She asked some 100 bilinguals made up of people who had grown up speaking two languages, immigrants who acquired their second language later on in life, as well as students who had stayed in a foreign country for an extended period of time, to give answers to two personality questionnaires and to give scale values to statements such as, "I feel I'm someone else while speaking English", or "Friends say that I'm a different person when I speak English".
More: Change of Language, Change of Personality? Part II | Psychology Today

According to the information in the below quotation, can I say what has been written in the underlined parts are not interchangeable?

I feel that both could work in the first example but not in the second. That's just a personal opinion.

[Odessa Dawn]

In a recent study, researcher Katarzyna Ożańska-Ponikwia examined why some people report feeling different while others do not. She asked some 100 bilinguals made up of people who had grown up speaking two languages, immigrants who acquired their second language later on in life, as well as students who had stayed in a foreign country for an extended period of time, to give answers to two personality questionnaires and to give scale values to statements such as, "I feel I'm someone else while speaking English", or "Friends say that I'm a different person when I speak English".
More: Change of Language, Change of Personality? Part II | Psychology Today

What they found is that the ASL learners, when speaking English, had increased their rate of gestures significantly after one year of language instruction, in particular iconic gestures, i.e. gestures that represent the attributes, actions, or relationships of objects or characters, according to University of Chicago Professor David McNeill.
More: When Sign Language Influences Speech | Psychology Today


Excellent! I am satisfied with your answers. I think when we have a verb being constructed in gerund, when and while are interchangeable. However, while can't precede a verb being formed in bare infinitive. Correct me, please.