翻译成英文：萌生了研究心理学的想法

start to become interested in psychology
begin to have the idea of learning psychology

Have germinated the psychological idea of studying

Initiation of the study of psychology, the idea of

It formed the thoughts of studying pcychology in one's mind.

It arose a strong desire in doing sth.(studing pcychology)

One suddenly developed an idea of studying pcychology.

It planted one's idea of studying pcychology.

你也可以改成第三单数形式.

Initiation of the study of the idea of psychology.