Rama Ratnam received his bachelor's degree in Chemical Engineering in 1985 from the Indian Institute of Technology, Delhi (IIT-D). He received his doctoral degree in Biophysics in 1998 from the University of Illinois at Urbana-Champaign (UIUC).
After receiving his bachelor's degree, he was a design engineer with the Process Heat Division of Thermax Limited, Pune (India), and then a research scientist (Scientist B) in the Process Design Group, Division of Chemical Engineering, the National Chemical Laboratory, Pune (India). His interest in control theory, specifically the control of multi-echelon hierarchical systems, led him to neuroscience. The brain is perhaps the best known example of a hierarchical control system. Hence, his switch to biology and neuroscience.
His doctoral research, with Albert S. Feng, was on the neural basis of the cocktail-party effect in the auditory midbrain of the frog. This led to his abiding interest in single-neuron coding. After receiving his doctoral degree, he was a postdoctoral research associate in the Department of Molecular & Integrative Physiology (1998-2001) and the Beckman Institute for Advanced Science and Technology at UIUC. His postdoctoral research, with Mark E. Nelson, was on neural coding in the electrosensory periphery of the weakly electric fish and its influence on weak signal detection. From 2001-2004 he was a research scientist with the Intelligent Hearing Aid Project at the Beckman Institute, UIUC, where he worked on the blind determination of acoustic reverberation time.
From 2004-2013 he was an assistant professor of neuroscience in the department of biology at the University of Texas at San Antonio (UTSA). He also held an affiliate appointment as a Core Faculty Member in the joint Biomedical Engineering Program between UTSA and the University of Texas Health Science Center at San Antonio (UTHSCSA), and was an adjunct scientist at the Texas Biomedical Research Institute (TBRI), San Antonio. At TBRI he maintained a colony of common marmosets (Callithrix jacchus), a New World primate, for the study of the effects of aging on marmoset hearing.
In 2013 he moved to the University of Illinois at Urbana-Champaign as Senior Scientist in the Coordinated Science Laboratory (CSL). He also held a joint appointment as a Principal Scientist with the university's Advanced Digital Sciences Center (ADSC) in Singapore (until 2017). In 2017 he resumed his full-time appointment in CSL. He maintains an animal neurophysiology lab in the Beckman Institute for Advanced Science and Technology, and a human neurophysiology lab in CSL.
Ratnam's (RR's) doctoral advisor Albert S Feng was a doctoral student of Robert Capranica, one of the founders of Neuroethology. Bob Capranica's work on the evoked calling behavior in the bullfrog (Rana catesbeiana) deeply influenced Al Feng who passed on his passion for both neuroethology and field biology (in vocal communication behavior of frogs) to RR. Al Feng also did a postdoc with Ted Bullock, a giant in the field of neuroethology, and also one of its founders. Al worked on object discrimination in weakly electric fish with Bullock (which RR revisited many years later as a signal detection problem in spike trains). Al then went on to do one more postdoc with Jim Simmons in echolocation in bats before joining the University of Illinois (in what was then the Department of Physiology & Biophysics). RR's postdoctoral advisor Mark Nelson was formerly a particle physicist who did his postdoctoral training in neuroscience with Jim Bower at Caltech before joining the Beckman Institute in Illinois. At Caltech, Jim Bower had encouraged Brian Rasnow and Chris Assad (who were then his graduate students) to study the electric field generated by weakly electric fish. This inspired Mark to dive into electrosensory processing in these wonderful and fascinating animals when he moved to Illinois. A scientist who is a part of RR's lineage is Peter Narins. Peter, like Al Feng, was a student of Capranica and a colleague and contemporary of Al Feng. Besides being an inspiration, Peter has had a major influence on RR's research and his intellectual development. Peter's work on the use of multiple microphones to study male-male interactions in Coqui frogs (Eleutherodactylus coqui) was ahead of its time, and it directly inspired RR's work on the Green treefrog (Hyla cinerea). This led to RR's work with Doug Jones on the development of microphone arrays and adaptive beamforming for source localization and source separation in anuran choruses. RR worked with Al on frogs and bats, and with Mark on electric fish. When RR was leaving Illinois to take up a position at the University of Texas at San Antonio, Al presented him a copy of one of the well-known Springer ("Green") books on mammalian auditory neurophysiology. In it he inscribed "Dear Rama, This book is for the world's second bat, frog, and electric fish person. All the best, AlF".