This review article (NRN Jan 2005) has a nice summary of cross-modal neuroplasticity in humans, mostly dealing with how occipital cortex (primarily visual for normals) takes over tactile and auditory processing duties in blind patients. The authors go on to speculate that these neuroplasticity insights could be applied to neural prothestic users to speed adaptation to their new sensory apparati, like combining tactile/auditory information with the prosthetic based stimulation. There’s also a nice comparison of visual implants at several levels, including retina, optic nerve, and cortex.
Neat article in this month’s Nature Neuroscience on how gap junctions (ie. direct, non-synaptic coupling) between neurons in the superchiasmatic nucleus might be responsible for their millisecond-scale synchrony and time-keeping abilities. Also, a variation in the amount of coupling (eg. number of gap junctions) was observed that followed a night-day cycle. Read on below for the news and views.
Stanislas Dehaene postulates that spindle cells, a type of neuron found in the anterior cingulate of humans and great apes, but not other primates, is fundamental to higher-order processing and consciousness. He postulates that these cells, which form connections through the cortex, fundamentally increase long-distance connectivity in the cortical network, which allows different brain areas to better intercommunicate.
One way that I think about this is that it allows consciousness to access information within a variety of brain areas. His way of putting this is, “we can mobilize, in a top-down manner, essentially any brain area and bring it into consciousness”.
He also believes that this increased long-distance connectivity leads to a qualitatively greater amout of spontaineous, reverberating activity in the cortical network, which corresponds to our ability to sustain a conscious narrative independent of external sensory and motor events, or, as he puts it, “the autonomy of consciousness”.
I noticed that AAAI maintains a blog of AI links to articles in the news. I added it to our “Must Read” list.