Neurons in the lateral prefrontal cortex represent the content of consciousness. The red trace depicts neural activity (neuronal discharges) in the lateral prefrontal cortex when a stimulus is consciously perceived for 1 second while the green trace depicts neural activity when the same stimulus is suppressed from awareness. Credit Max Planck Institute.
People have never been exposed to as many sensory stimuli as they are today. We do not, however, consciously perceive the majority of the sensory impressions that bombard us. Our brain processes these impressions without us noticing. But where does the brain decide which sensory information should reach our consciousness and which should not? Tests on the brains of macaques have shown that neurons in at least two regions of the brain, the temporal and frontal lobes, are responsible for this. Coma patients are among the potential beneficiaries of this research breakthrough.
The cerebral cortex, i.e. the external part of the brain with its grooves and folds, plays a major role in our consciousness. When macaques see something and consciously perceive it, neurons in the temporal lobes of the cerebral cortex are active. This much was already known. However, is this part of the brain really the sole seat of consciousness, or do other areas of the brain also play a role in this process?