In Neuroscience, the Reticular Activating System refers to a set of connected nuclei in the brain that monitors and filters information being taken in by the senses. When the brain becomes familiar with certain stimuli or patterns of stimuli, the Reticular Activation System becomes more sensitive to that information. It is what allows a person to pick up on an interesting conversation across a noisy room when he/she hears a key word, or to spot every 1978 Pontiac on the road because it brings back the memory of a first car. Much like a media search engine attempts to predict and recommend what a user would like to hear next, the Reticular Activation System tailors the information that breaks through from the subconscious to the conscious based upon the person’s previous interests and attention.
Similarly, reading Scripture through the illumination of the Holy Spirit increases the brain’s sensitivity and alertness toward more Scripture and situations addressed by Scripture. The more a person studies Scripture under the ministry of the Holy Spirit, the more equipped and apt a person is to apply it effectively.
For instance, the Pharisees missed the simplicity of the law, whereas Jesus summarized it (at the request of a lawyer) in Matthew 22:36-40 by quoting Deuteronomy 6:4 and Leviticus 19:18. Further, Jesus, on more than one occasion, began answering the charges of the Pharisees with the phrase, “have you not read?” (Luke 6:3, Matthew 19:4). Their minds had not been transformed to properly apply Scripture.
In contrast, when Jesus asked, “Who do you say that I am?” Peter answered, “You are the Christ” (Matt. 16:16). Peter was able to recognize Christ as the promised messiah from the Old Testament. Jesus explained Peter’s insight by saying, “Flesh and blood has not revealed this to you, but my Father who is in heaven” (Matt. 16:17)
Was Jesus demeaning Peter by saying, “you didn’t come up with that on your own?” No, He was giving Peter the hope and encouragement that all believers have: The Holy Spirit illuminates Scripture to us and trains us to process life experiences through the Word. What a wonderful gift!
The work of the Holy Spirit is more powerful than human memory because it is completely divine in origin. In other words, our brains, in and of themselves, will fail –often. But the work of the Holy Spirit never fails.
However, it is not that simple of a dichotomy. Instead, the Holy Spirit chooses to work by training our brains –not superseding them (Ps. 119:98-100). In other words, we cannot sit back and lazily expect the Holy Spirit to bring to mind things we have never studied. After all, we are called to be students of the Word (2 Timothy 2:15, Psalm 119:97).
So, approach the Word passionately, asking the Holy Spirit to illuminate the Word, train your brain, and conform your thinking to His. The results are even more powerful than a mere Reticular Activating System!
 Rita Carter, Mapping the Mind (Berkeley, CA: University of California Press, 1998), 186-187.