Missing left temporal lobe? No problem.

[sue_frantz]

Here’s a question for your students after covering the brain in Intro Psych: “How would you react if you learned, today, that you were missing your left temporal lobe?” 

In 1987 at the age of 25, EG (not her real initials) happened to have an MRI scan, and her physicians—and I imagine, she—were surprised to see a blank spot where her left temporal lobe should be. EG is highly educated with strong language skills. Her missing left temporal lobe does not appear to be affecting her in any way (Tuckute et al., 2022).

Unless we have had an MRI scan of our brain, we have no idea if we have a neurotypical brain or if we, too, are missing an entire cerebral lobe.

In the research article (Tuckute et al., 2022), Figure 2a features MRI scans of EG’s brain from the right, the front, and the top. The images are worth sharing with your students.

In early childhood, language processing is bilateral. It is only later that language specialization—for most of us—moves to the left cerebral hemisphere. EG does not recall any early childhood brain trauma, so it may be that EG’s missing left temporal lobe was congenital. In any case, EG’s brain had no problem turning language specialization over to her right hemisphere. While EG’s left frontal lobe is intact, it is her right frontal lobe that is language dominant, not left. Researchers speculate that it is the language specialization of the temporal lobe that drives the language specialization of the frontal lobe. If that specialization happens in the left temporal lobe, then the left frontal lobe also develops language specialization. Conversely, if that specialization happens in the right temporal lobe—as it did for EG—then the right frontal lobe also develops language specialization.

EG’s experience is a good one to share with Intro Psych students, because it illustrates the remarkable flexibility of the human brain.

The research article featuring EG opens with a statement from EG herself. She opens with how she came into contact with this group of researchers in 2016. Then EG reminds us that the language we use matters. “Though [the research team’s] studies answer some questions about how my brain is wired the same as or differently than a typical brain, it does not tell others who I am. Please do not call my brain abnormal, that creeps me out. My brain is atypical. If not for accidently finding these differences, no one would pick me out of a crowd as likely to have these, or any other differences that make me unique” (Tuckute et al., 2022, p. 1).

With many of our Intro Psych students preparing for careers in healthcare, EG includes an important reminder that each patient is a person, not merely a collection of health conditions who should then fit into a particular health condition box. “In the past, several well-meaning but misguided healthcare professionals have told me that I should not have more than a 5th grade vocabulary, that I should have seizures, or that I should have other deficits and limitations. I do not. They seemed disappointed, even angry, that I did not have the limitations they unilaterally pronounced that I should have, without the benefit of any further investigation” (Tuckute et al., 2022, p. 1).

Reference

Tuckute, G., Paunov, A., Kean, H., Small, H., Mineroff, Z., Blank, I., & Fedorenko, E. (2022). Frontal language areas do not emerge in the absence of temporal language areas: A case study of an individual born without a left temporal lobe. Neuropsychologia, 169, 108184. https://doi.org/10.1016/j.neuropsychologia.2022.108184