Episode 48 of the Brain Science Podcast is an interview with Gary Lynch, PhD, co-author (with Richard Granger) of Big Brain: The Origins and Future of Human Intelligence.  Dr. Lynch has spent decades studying memory at the level of the synapse.  His work with computer simulations based on how the brain really works led him to a fascination with the question of how our brains got so large.  Are humans smart because we have big brains or because are brains are different?

Dr. Lynch argues that the unique features of the human brain are a natural result of increased brain size.  He also argues against the conventional view that increasing brain size resulted from selection pressures during the millions of years of primate evolution that proceeded the emergence of homo sapiens.  We talk about the evidence supporting this radical position during the interview.

We also talk about another radical theory that Dr. Lynch has proposed, which is the idea that the olfactory cortex formed the template for the evolution of the cortex in mammals and primates.  This intriguing theory brings a new perspective to the fact that the olfactory system has unique access to important brain systems including the frontal lobes, the amygdala (which is involve in emotion), and the hippocampus (which is essential to long-term memory.

In addition to discussing the evidence that led him to his controversial theories, Dr. Lynch discusses the challenges facing scientists interested in pursuing research questions about brain evolution.

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References and Links:

• Big Brain: The Origins and Future of Human Intelligence, by Gary Lynch and Richard Granger.

• Gary Lynch, PhD: Department of Psychiatry, University of California-Irvine.

• Principles of Brain Evolution, by Georg F. Striedter: was discussed in Episode 47.

The figure below is used with the permission of the author and the artist (Cheryl Cotman).

Send email feedback to Ginger Campbell, MD at brainsciencepodcast@gmail.com