This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.

Passage: The latest study using magnetic resonance imaging (MRI) to humans and dogs together proved that dogs have same response to voices and use the same parts of the brain as humans to do so. This gives dogs the ability to recognize emotional human sounds, making them friendly social pets to humans. Question: An MRI study on dogs proved that dogs have the same response as humans to what?
voices