Study IDs what brings our senses and thoughts together

The neocortex of our brains is where we get the ability to reason, choose, recall recent events, and do other things. Now, crucial components of the mechanisms behind these functions have been uncovered by neuroscientists at the University of California, Irvine. Their research may eventually lead to better treatments for some neuropsychiatric conditions and brain damage. Their research is published in Neuron.                                                                                                         

Long known to scientists, feedforward and feedback information streams are integrated by the neocortex. The sensory systems of the brain transmit feedforward information to the higher order regions of the neocortex from the periphery (our senses). These higher-order brain areas subsequently transmit feedback data to improve and modify sensory processing. The brain uses this back-and-forth communication to focus attention, hold onto short-term memories, and make decisions.

According to corresponding author Gyorgy Lur, Ph.D., an assistant professor of neurobiology & behavior in the School of Biological Sciences, "a straightforward example is when you wish to cross a busy road." "Trees, people, moving cars, traffic lights, signage, and more are all present. Your sensory system is informed by your higher-level neocortex as to which stimuli warrant attention while determining when to cross."

We are also able to recall the details of what you saw when you looked in both directions to obtain the information thanks to the interaction between higher- and lower-level systems. He claimed that if you didn't have short-term memory, you would simply keep staring back and forth without ever moving. In fact, if our feedforward and feedback streams weren't continually interacting, we wouldn't be able to do much more than react automatically.

Scientists are still unsure of how neurons in the brain contribute to these intricate processes. In the parietal regions of the neocortex, Lur and his colleagues found that feedforward and feedback signals converge into single neurons. The scientists also discovered that certain cortical neuronal types combine the two information streams on noticeably varied time scales and they pinpointed the cellular and circuit architecture that underlies these variations.

Scientists previously understood that combining different senses improves neural responses, according to Lur. "Your reaction time is slower than when you experience something with both of your senses at once if you can just see or hear it. The underlying processes that enable this have been found."

According to the study's data, the same principles still hold true if one input stream is sensory and the other is cognitive, he pointed out.

Future treatments for neuropsychiatric conditions like sensory-processing problems, schizophrenia, and ADHD as well as for strokes and other neocortical lesions must take into account these mechanisms, which must be understood.

The Center for Neural Circuit Mapping, the Center for Hearing Research, and the Center for the Neurobiology of Learning and Memory at UC Irvine are all affiliated with Lur.

The initial author of the study was Daniel Rindner, a Ph.D. candidate, who carried out all neuronal recordings and biological tissue studies. Computational modeling was carried out by second author and postdoctoral researcher Archana Proddutur, Ph.D., to gain a mechanistic understanding of the processes integrating sensory and cognitive information streams. The National Institute of Mental Health, National Institute of Neurological Disorders and Stroke, National Institute on Deafness and Other Communications Disorders, and Whitehall Foundation all provided funding for their study.

University of California - Irvine