In 1848, a 43-inch-long tamping iron pierced Phineas Gage’s left cheek, ripped into his brain and exited through the top of his skull

To the amazement of witnesses, Gage remained conscious and aware of his surroundings. To the surprise of physicians, Gage lived.

Phineas Gage
Photo of Phineas Gage

But not everything was the same. People who were close with Gage described a profound personality change: Gage was unable to stick to plans, uttered the “grossest profanity” and showed “little deference for his fellows.”

His case was one of the first examples of the impact of trauma to the frontal lobe, which is the primary region responsible for executive functioning.

Parts of the human brain

What is executive function?

Executive function describes the ability to organize, plan and carry out a set of tasks in an efficient manner. It also includes the ability to self-monitor and control our behaviors and other cognitive functions.

Executive function can be thought of as high-level thinking skills that control and direct lower levels of cognitive functioning. The frontal lobe is the area of the brain we now know was responsible for Phineas Gage’s personality change.

Most of us won’t experience serious head trauma like Gage, but research has shown executive function decreases as people age, especially in those with Alzheimer’s disease or frontotemporal dementia.

Signs of decreased executive functioning

Individuals experiencing a decline in executive functioning may experience memory problems, and may have difficulty holding back spontaneous actions or comments even though they may be harmful, rude, or untimely.

People with frontal lobe problems may have difficulty:

  • Keeping up with a conversation
  • Making decisions
  • Respecting personal boundaries
  • Planning new actions when there is an unexpected change

To learn more about executive function and how it affects everyday tasks, watch the video below.