Tag: Oral Session 2SW

Does Seeing Something Old Help Infants Pay Attention to Something New in Object Sequences?

Presenter(s): Allison Zhou − Biology

Faculty Mentor(s): Caitlin Fausey

Oral Session 2SW

Research Area: Developmental Psychology

Funding: UO VPRI, UO WGS

Infants’ first words include the names of objects that appear frequently in their lives. Could these frequent objects also help them learn the names of less common objects? We know from prior research that what people see and hear is largely structured so that there are a small number of ubiquitous items and a large number that are much less prevalent. In the present study, we test the hypothesis that the shape of a frequency distribution matters for how infants pay attention to its instances. In ongoing work, infants (16-30 months old) view pictures of novel objects that vary in both color and size. Infants sample the pictures one-at-a-time from either (a) a uniform distribution, where infants see each unique object an equal number of times, or (b) a non-uniform distribution, where infants see one of the objects six times more often than the others. Specifically, we measure how many object pictures the infant chooses to observe before they stop engaging in our task. Data collection is ongoing. We predict infants to pay significantly more attention to sequences of objects sampled from a non- uniform distribution. The non-uniform distribution has higher rates of repetition and may encourage the learner to compare newly seen objects to the familiar anchor. Learning about objects and their names requires encountering them. Our research will yield new insight into how object distributions potentiate the ways infants attend to their world.

The Role Of Patterned Spontaneous Circuit Activity In Drosophila Neuronal Circuit Assembly

Presenter(s):Nelson Perez − Biology

Faculty Mentor(s): Arnaldo Carreira-Rosario, Chis Doe

Oral Session 2SW

Research Area: Natural sciences, Neuroscience, Biology, Developmental Biology

Funding: HHMI (Howard Hughes Medical Institute), SPUR Program

Neuronal networks become active before they are fully functional. This is known as patterned spontaneous network activity (PaSNA), an event characterized by quiescent periods followed by bursts of activity. Many studies have demonstrated the importance of PaSNA for proper neuronal circuit assembly. Yet, little is known about the mechanisms underlying PaSNA.
In the Drosophila ventral nerve cord (spinal cord for invertebrate counterpart) PaSNA occurs during late embryonic stages. During PaSNA, embryos exhibit intermittent episodes of uncoordinated motor activity that gradually mature into crawling waves. Concomitantly with wave maturation, more neurons become active during PaSNA. The identity of these neurons and function during PaSNA remains unknown. To identify which cells undergo PaSNA and their function during circuit assembly, we are screening for GAL4 lines, which maintain expression in small subsets of neurons from the onset of PaSNA until the circuit is fully assembled. We have identified several GAL4 lines suitable for our experiments. Using in vivo calcium imaging, we identified that the neurons labeled by one of these lines participates in PaSNA. Four other lines have been identified as good candidates for future experiments that involve calcium imaging and tracking of synapsis formation during PaSNA. This represents a unique tool to study PaSNA and its role in circuit formation.

Enhancing Low Frequency Rhythms in the Motor Cortex of Humans

Presenter(s): Ashley Dresen − Psychology

Faculty Mentor(s): Michael Posner, Pascale Voelker

Oral Session 2SW

Research Area: Cognitive Psychology

Funding: ONR Grant N00014-15-1-2148 to the University of Oregon

Theta frequencies are associated with internalized attention and positive emotional states. In our laboratory, mice receiving theta frequency stimulation of the anterior cingulate cortex (ACC) showed increased myelin and improved connectivity as measured by g-ratio (axon diameter/axon diamenter + myelin). To extend these results to humans, we stimulated the
ACC by applying electrical stimulation at a theta frequency (6Hz) to a set of scalp electrodes overlying that area. Following stimulation, we found enhanced low frequency power in ACC sites compared to baseline, and this power increased when a task known to stimulate the ACC was performed. To test whether this method could be applied to other brain areas, we chose a task activating the hand region of the primary motor cortex and electrodes stimulating the motor area. We are testing 12 undergraduates using a generic set of electrodes known to stimulate the motor area, and comparing this with electrodes selected for each person based on structural brain images. We plan to determine if stimulation increases low frequency theta rhythms during non-stimulated periods, and whether the electrodes chosen individually produce superior effects to the generic ones. We are currently summarizing the results from 12 subjects. We expect that intrinsic theta will be increased in the motor area in the minute following electrical stimulation and this will be greater when performing the task. We expect these effects to be larger for individually selected electrodes. If results are as expected, it will suggest that many cortical and subcortical areas show increased theta following stimulation and allow us to test whether long term use of such stimulation can alter white matter connectivity as found in our mouse model.