Neuroscientists have no credible explanations for the most important mental phenomena such as consciousness and memory. All that scientists have in this regard are some far-fetched speculations or weak theories that don't hold up to scrutiny. Supposedly the two most popular theories of consciousness proposed by scientists are one theory called integrated information theory and another theory called global workspace theory. You can read here why integrated information theory does not work as a credible theory of consciousness. Global workspace theory isn't any better.
The wikipedia article on global workspace theory starts out by explaining it this way:
"GWT can be explained in terms of a 'theater metaphor.' In the 'theater of consciousness' a 'spotlight of selective attention' shines a bright spot on stage. The bright spot reveals the contents of consciousness, actors moving in and out, making speeches or interacting with each other. The audience is not lit up—it is in the dark (i.e., unconscious) watching the play. Behind the scenes, also in the dark, are the director (executive processes), stage hands, script writers, scene designers and the like. They shape the visible activities in the bright spot, but are themselves invisible."
As a causal explanation for why a brain might be able to produce understanding or consciousness, this is a complete failure, as it does not refer to anything in the brain, but refers to some theater. At most it is some metaphor merely describing selective attention, but selective attention (or mental focus) is merely an aspect of understanding once it exists, not an explanation of consciousness or understanding. You can't spotlight your way to consciousness. Also, there's nothing in the brain that actually corresponds physically to a spotlight. When you're thinking about something, it is not at all true that some particular region of your brain lights up like some area under a spotlight, contrary to the misleading statements and misleading visuals often given on this. Actual signal strength differences (typically far less than 1%) are no greater than we would expect from random variations.
In an interview in Scientific American, Bernard Baars attempts to explain global workspace theory, but fails rather miserably to give a coherent explanation of how global workspace theory is anything like a theory explaining consciousness. He is asked by the interviewer, "What is global workspace theory?" What we then get from Baars is an answer that kind of wanders around all over the place for 11 paragraphs without giving much of any answer that anyone will be able to grasp.
There is some mention of some swarm computing setup: "If you put a hundred crummy algorithms together and let them share hypotheses and vote on the most popular one, it turns out that very inadequate algorithms could jointly solve problems that no single one could solve." There is entirely irrelevant for any explanation of consciousness or understanding, because particular areas of the brain are not like little micro-processors running software code. There is nothing like software code that runs anywhere in the brain.
Baar's rambling and muddled answer to the question ends like this:
"Part IV of my latest book develops GW dynamics, suggesting that conscious experiences reflect a flexible 'binding and broadcasting' function in the brain, which is able to mobilize a large, distributed collection of specialized cortical networks and processes that are not conscious by themselves. Note that the 'broadcast' phase proposed by the theory should evoke widespread adaptation, for the same reason that a fire alarm should evoke widespread responding, because the specific needs for task-relevant responders cannot be completely known ahead of time. General alarms are interpreted according to local conditions. A brain-based GW interacts with an 'audience' of highly distributed, specialized knowledge sources, which interpret the global signal in terms of local knowledge (Baars, 1988). The global signal triggers reentrant signaling, resonance is the typical activity of the cortex."