Long Ding, Ph.D.

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Research Assistant Professor of Neuroscience
Department: Neuroscience
Graduate Group Affiliations

Contact information
111 Johnson Pavilion
Dept. of Neuroscience
University of Pennsylvania
3610 Hamilton Walk
Philadelphia, PA 19104
Office: 215-898-9656
Fax: 215-573-9050
BS (Telecommunications)
Xidian University, 1994.
MS (Biomedical Engineering)
University of Northern California, 1997.
Ph.D. (Neuroscience)
University of Pennsylvania, 2003.
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Description of Research Expertise

Electrophysiology; psychophysics; basal ganglia; frontal cortex; perceptual decisions

How does the brain combine information gathered from the external world and internal preferences to reach an appropriate decision? How do different brain regions contribute to decision making and coordinate their actions?

Psychophysics; electrophysiology in awake, behaving monkeys; computational modeling.

When we make decisions, we consider not only external sensory information but also internal factors like prior experience, internal bias and evolving goals. The ability to properly incorporate internal factors is crucial for our well-being: solely relying on external sensory information leads to rigid, machine-like behavior; excessively relying on internal factors leads to compulsive decisions, as is often seen in addiction. An important step in developing effective treatments for patients with impaired cognitive and executive functions, especially for those patients without apparent sensory deficits, is to understand the neural mechanisms underlying this incorporation.

Our research focuses on the systems level question of how the brain, especially the basal ganglia pathway, incorporates reward information in decisions. To address this question, we use a combination of behavioral, electrophysiological and computational techniques in awake, behaving monkeys.

Our current efforts focus on identifying the computational roles of the basal ganglia way in transformation of noisy sensory information into a perceptual decision. We train monkeys to perform a demanding random-dot motion direction discrimination task, which allows us to probe the perceptual process by manipulating the signal-to-noise ratio and/or duration of visual inputs. We record single-neuron activity in the basal ganglia to examine decision-related signals; we interfere with the decision-related activity to test for its causal relationship to monkey’s behavior; we combine these results, in conjunction with computational modeling, to assess how the basal ganglia pathway contributes to perceptual decisions.

Building upon these new knowledge, we will introduce additional manipulations of internal preferences to the basic random-dot task in order to directly assess how different information are combined to drive the most beneficial behavior.

Selected Publications

Niu Jingwen, Ding Long, Li Jian J, Kim Hyukmin, Liu Jiakun, Li Haipeng, Moberly Andrew, Badea Tudor C, Duncan Ian D, Son Young-Jin, Scherer Steven S, Luo Wenqin: Modality-based organization of ascending somatosensory axons in the direct dorsal column pathway. The Journal of neuroscience : the official journal of the Society for Neuroscience 33(45): 17691-709, Nov 2013.

Ding, L., Gold, J. I.: Separate, causal roles of the caudate in saccadic choice and execution in a perceptual decision task. Neuron 75(5): 865-74, Sep 2012.

Ding, L., Gold, J. I.: Neural Correlates of Perceptual Decision Making before, during, and after Decision Commitment in Monkey Frontal Eye Field. Cereb Cortex 22(5): 1052-67, May 2012.

Ding, L., Gold, J. I.: Caudate encodes multiple computations for perceptual decisions. J Neurosci 30(47): 15747-59, Nov 2010.

Ding, L., Hikosaka, O.: Temporal development of asymmetric reward-induced bias in macaques. J Neurophysiol 97(1): 57-61, 2007.

Ding, L., Hikosaka, O.: Comparison of reward modulation in the frontal eye field and caudate of the macaque. J Neurosci 26(25): 6695-703, 2006.

Farries, M. A., Ding, L., Perkel, D. J.: Evidence for "direct" and "indirect" pathways through the song system basal ganglia. J Comp Neurol 484(1): 93-104, 2005.

Ding, L., Perkel, D. J.: Long-term potentiation in an avian basal ganglia nucleus essential for vocal learning. J Neurosci 24(2): 488-94, 2004.

Ding, L., Perkel, D. J., Farries, M. A.: Presynaptic depression of glutamatergic synaptic transmission by D1-like dopamine receptor activation in the avian basal ganglia. J Neurosci 23(14): 6086-95, 2003.

Ding, L., Perkel, D. J.: Dopamine modulates excitability of spiny neurons in the avian basal ganglia. J Neurosci 22(12): 5210-8, 2002.

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Last updated: 10/23/2014
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