A few of the most fascinating things about humans are thoughts, the subjective experience of emotions and our subjective perception of time intervals. Let’s try to understand the question of whether our subjective experiences can be reduced to neural connections and electrochemical signals.

Localization of functions in neuroscience is studied when a part of the brain gets damaged and impairs abilities or causes changes in personality, behavior, intelligence, decision-making or memory. From this, we try to pinpoint which regions are responsible for which functions. Still, we are uncertain about the exact mechanisms behind many of the functions of different brain regions.

In the future, when we have mapped every single neuron, every synapse and every molecular mechanism inside of each neuron. Will we be able to explain every single aspect of human psychology?

Take the example of the amygdala. It is involved in behaviors, emotional responses and olfaction (smell), particularly the emotional responses to smell. It is, in fact, the key region of the limbic system in behaviors and emotional responses. The Posterior association cortex receives information from three different areas of cortex and sends this information to the amygdala. These areas include the somatosensory association cortex, the visual association cortex, and the auditory association cortex. The amygdala then sends signals to different brain regions to produce emotional and behavioral responses. The two main regions are the septal area and the hypothalamus.

Let’s take the example of fear. The hypothalamus sends signals via sympathetic nerves to particular organs, including the liver to increase glucose production, the heart to pump blood faster and increase blood pressure and the lungs to increase the rate and depth of each breath. These are all autonomic responses. At the same time, the hypothalamus also stimulates the production of cortisol in the adrenal cortex via the HPA-axis (Hypothalamic-Pituitary-Adrenal axis).

All of this is the physical response to fear. Nothing that I have mentioned creates the subjective experience of fear. Then what is it that creates this experience?