Nav: Home

What bats reveal about how humans focus attention

February 23, 2016

RELATED VIDEO: https://youtu.be/OusnottPI7Y

You're at a crowded party, noisy with multiple conversations, music and clinking glasses. But when someone behind you says your name, you hear it and quickly turn in that direction.

The same sort of thing happens with bats, leading Johns Hopkins University researchers to discover how a bat's brain determines what's worth paying attention to. The findings, which have implications across animal systems, were this month published online by the Proceedings of the National Academy of Sciences.

"With so many stimuli in the world, the brain needs a filter to determine what's important," said Melville J. Wohlgemuth, the lead author and a postdoctoral fellow in the Krieger School of Arts and Sciences' Department of Psychological and Brain Sciences. "The bat brain has developed special sensitivities that allow it to pick out sounds from the environment that are pertinent to the animal. We were able to uncover these sensitivities because we used the perfect stimulus -- the bat's own vocalizations."

To navigate as they hunt in the dark, bats use echolocation. This means that bats make certain high frequency sounds as they fly and then listen for echoes bouncing off objects in front of them to orient themselves. The bat pays attention to some of these echo sounds, but not all of them, researchers say.

Wohlgemuth and co-author Cynthia F. Moss, a Johns Hopkins professor and neuroscientist, wanted to figure out which sounds would be deemed "important" enough to evoke responses from neurons that are involved in orienting behaviors, such as turning towards a sound.

The researchers experimented with five big brown bats, playing them a variety of sounds while monitoring their midbrain activity. They played recordings of natural chirps, the actual sounds bats made as they hunt. They also played artificial white noise and sounds between the two extremes. All of the sounds were identical in amplitude, duration and bandwidth.

Although sensorimotor neurons in the bat midbrain reacted to all of the sounds, the neurons involved in stimulus selection, those that guide orienting behaviors, responded selectively to a subset of the natural chirps.

"That's really important because it showed that if a neuron reacts to all stimuli, any sound in the environment, it doesn't do an animal any good," Wohlgemuth said. "You need the selectivity."

Because all mammals share a basic brain organization, these findings suggest for the first time how mammals, including humans, likely choose which stimuli deserve attention.

"Bats produce the sounds that guide their behaviors, and consequently, we know what signals are important to them," Moss said. "By comparing activity patterns of neurons to biologically natural and artificial sounds, we learn general principles of sensory processing that apply to a broad range of species."
-end-
This work was supported by a fellowship from the NIDCD Training Grant in Comparative and Evolutionary Biology of Hearing (T32-DC00046) and research grants from the National Science Foundation (IOS-1010193) and Human Frontiers Science Program (RGP0040).

CONTACT:

Jill Rosen
Office: 443-997-9906 / Cell: 443-547-8805
jrosen@jhu.edu

Johns Hopkins University

Related Neurons Articles:

A molecule that directs neurons
A research team coordinated by the University of Trento studied a mass of brain cells, the habenula, linked to disorders like autism, schizophrenia and depression.
Shaping the social networks of neurons
Identification of a protein complex that attracts or repels nerve cells during development.
With these neurons, extinguishing fear is its own reward
The same neurons responsible for encoding reward also form new memories to suppress fearful ones, according to new research by scientists at The Picower Institute for Learning and Memory at MIT.
How do we get so many different types of neurons in our brain?
SMU (Southern Methodist University) researchers have discovered another layer of complexity in gene expression, which could help explain how we're able to have so many billions of neurons in our brain.
These neurons affect how much you do, or don't, want to eat
University of Arizona researchers have identified a network of neurons that coordinate with other brain regions to influence eating behaviors.
Mood neurons mature during adolescence
Researchers have discovered a mysterious group of neurons in the amygdala -- a key center for emotional processing in the brain -- that stay in an immature, prenatal developmental state throughout childhood.
Connecting neurons in the brain
Leuven researchers uncover new mechanisms of brain development that determine when, where and how strongly distinct brain cells interconnect.
The salt-craving neurons
Pass the potato chips, please! New research discovers neural circuits that regulate craving and satiation for salty tastes.
When neurons are out of shape, antidepressants may not work
Selective serotonin reuptake inhibitors (SSRIs) are the most commonly prescribed medication for major depressive disorder (MDD), yet scientists still do not understand why the treatment does not work in nearly thirty percent of patients with MDD.
Losing neurons can sometimes not be that bad
Current thinking about Alzheimer's disease is that neuronal cell death in the brain is to blame for the cognitive havoc caused by the disease.
More Neurons News and Neurons Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Clint Smith
The killing of George Floyd by a police officer has sparked massive protests nationwide. This hour, writer and scholar Clint Smith reflects on this moment, through conversation, letters, and poetry.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Dispatch 6: Strange Times
Covid has disrupted the most basic routines of our days and nights. But in the middle of a conversation about how to fight the virus, we find a place impervious to the stalled plans and frenetic demands of the outside world. It's a very different kind of front line, where urgent work means moving slow, and time is marked out in tiny pre-planned steps. Then, on a walk through the woods, we consider how the tempo of our lives affects our minds and discover how the beats of biology shape our bodies. This episode was produced with help from Molly Webster and Tracie Hunte. Support Radiolab today at Radiolab.org/donate.