Sensory Gating is a process that the brain uses to adjust to stimuli. Our brain has a direct connection to filter out distracting stimuli and performance. Negative emotions like stress, anxiety, and depression can switch the chemistry of the brain and limits the effectiveness of sensory gating. So, to prevent this imbalance, Re-Gating is important.
Creativity is not an entity you can command at will. It is very environment dependent and can be summoned only under the proper stimulation and with proper co-workers. So, the myth that creativity can be summoned as per requirement is bogus. It should depend on the proper grooming and encouragement of the management.