Scientists have known for decades that the thalamus faithfully transmits information about the visual world from the retina to the cortex, leading to the impression that it is largely a messenger of sensory information.
In rodents, humans and other mammals, [neuroscientist Michael] Halassa says, the thalamus is much more than just a passive gatekeeper for sensory input. Instead, it plays an active role in orchestrating cortical activity, telling the cortex what tasks it should carry out in different contexts.
Knowable Magazine asked Halassa to discuss how work in his and other labs is changing the traditional view of the thalamus.
…[Knowable:] What evidence suggests that the thalamus is doing something more interesting than previously thought? [Halassa:] The prefrontal cortex is thought to be one of the most complicated cognitive areas of the cortex — it performs tasks that are even more complicated than face recognition. In humans, for example, it enables our ability to draw parallels, to imagine things that we’ve never seen, and to innovate. Based on our animal studies, we think that the mediodorsal thalamus is helping the brain narrow down its search for the correct behavior or response, so that it can quickly adapt as the environment or situation changes. It takes incomplete data from the cortex, then uses that information to determine which tasks the cortex should perform.
Read full, original post: A long-overlooked brain region may be key to complex thought