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Congratulate Shraddha when you see her. Her paper, "Attention differentially modulates multiunit activity in the lateral geniculate nucleus and V1 of macaque monkeys" has just been published in the Journal of Comparative Neurology. The work used rigorous data processing & statistical techniques to offer some clues to why the effects of attention differ vastly in magnitude in humans & macaques.

Attention promotes the selection of behaviorally relevant sensory signals from the barrage of sensory information available. Visual attention modulates the gain of neuronal activity in all visual brain areas examined, although magnitudes of gain modulations vary across areas. For example, attention gain magnitudes in the dorsal lateral geniculate nucleus (LGN) and primary visual cortex (V1) vary tremendously across fMRI measurements in humans and electrophysiological recordings in behaving monkeys. We sought to determine whether these discrepancies are due simply to differences in species or measurement, or more nuanced properties unique to each visual brain area. We also explored whether robust and consistent attention effects, comparable to those measured in humans with fMRI, are observable in the LGN or V1 of monkeys. We measured attentional modulation of multiunit activity in the LGN and V1 of macaque monkeys engaged in a contrast change detection task requiring shifts in covert visual spatial attention. Rigorous analyses of LGN and V1 multiunit activity revealed robust and consistent attentional facilitation throughout V1, with magnitudes comparable to those observed with fMRI. Interestingly, attentional modulation in the LGN was consistently negligible. These findings demonstrate that discrepancies in attention effects are not simply due to species or measurement differences. We also examined whether attention effects correlated with the feature selectivity of recorded multiunits. Distinct relationships suggest that attentional modulation of multiunit activity depends upon the unique structure and function of visual brain areas.

The Journal of Neurophysiology highlighted Farran's paper "Dynamic communication of attention signals between the LGN and V1" in their Twitter feed.

They showcased the fact that the authors found that attentional modulation of visual information communication was not static, but dynamic over the time course of trials.

Well done Farran!

Neuroscience Graduate student Allison Murphy co-authored a paper with the Briggs lab while in a rotation with the lab. Allison contributed an extensive amount of work toward the paper during her fall rotation, and the paper was accepted shortly after her joining the lab.

Postdoctoral fellow, Mike Hasse was the first author on the paper, "Morphological heterogeneity among corticogeniculate neurons in ferrets: quantification and comparison with a previous report in macaque monkeys."

Nice work Allison and Mike!!

Our brains are made up of an intricate network of neurons. Understanding the complex neuronal circuits—the connections of these neurons—is important in understanding how our brains process visual information.

Farran Briggs, a new associate professor of neuroscience and of brain and cognitive sciences at the University of Rochester, studies neuronal circuits in the brain's vision system and how attention affects the brain's ability to process visual information.

Previously a professor at the Geisel School of Medicine at Dartmouth, Briggs became interested in neuroscience in high school. "I took a class and just became really fascinated by the brain and how it works," she says. Today, her research on the fundamental levels of vision may provide new insight on impairments associated with attention deficit disorders.

Newly appointed Dept. of Neuroscience faculty member, Farran Briggs, Ph.D. has her research highlighted on Wired.

When ferrets get a rabies shot in a neurobiology lab, they don't get infected with the virus—or even inoculated against it. They get a brain hack that might just explain how your brain handles vision, and maybe even your other senses, too.

In a lab at Dartmouth, scientists are experimenting with targeted injections of a modified rabies virus into the brains of ferrets—essentially allowing them to control how the animal responds to simple visual patterns. The goal is to understand the brain's enormously complex visual processing system. But really? Rabies? Ferrets? Are these guys just screwing around?

Lots of visual research depends on lab mice—the most popular of model organisms in biology. But Dartmouth neuroscientist and lead author Farran Briggs wanted to study an animal that uses its vision the same way humans do, in an evolutionary sense: to prey on tasty snacks. Mice aren’t predators, and their vision falls solidly in the ‘legally blind’ range. So these vision researchers turned to the notoriously vicious ferret and its front-facing eyes. They're color blind, but at the neural level, ferrets’ visual systems have “remarkable similarities to a primate, and a human,” says Briggs. (Ferrets also help avoid the ethical issues of experimenting on primates.)