The brethren here have been asking about the mind and heart in reference to salvation. When one believes from the heart, is it the same thing as the mind doing it? Some passages say the heart does something and other passages say the mind does them.
"Jesus said to him," 'You shall love the LORD your God with all your heart, with all your soul, and with all your mind'" (Matthew 22:37).
"Mind" translates the Greek word dianoia, which refers to your mind, your thoughts, your reasoning or your intellect. By extension it also refer to your emotions or your desires that are produced as a result of your thoughts, as seen in: "among whom also we all once conducted ourselves in the lusts of our flesh, fulfilling the desires of the flesh and of the mind, and were by nature children of wrath, just as the others" (Ephesians 2:3).
"Heart" translates the Greek word kardia, which refers to your physical heart. But since your heart responds to your emotional state, this word also refers to your emotions, your feelings, and your desires. Since our emotions impact our thoughts, by extension this word can refer to our thoughts. Since the heart is hidden from sight, it can figuratively refer to the thoughts we hide from others. "You have neither part nor portion in this matter, for your heart is not right in the sight of God. Repent therefore of this your wickedness, and pray God if perhaps the thought of your heart may be forgiven you. For I see that you are poisoned by bitterness and bound by iniquity" (Acts 8:21-23).
Because of this overlap in meaning, you may find heart and mind being used interchangablely. However, "heart" leans toward our emotions and "mind" leans toward our intellect.