Daniel Salzman, MD, PhD
Professor of Psychiatry
Professor of Neuroscience
We study the neural mechanisms that give particular sensory stimuli emotional value, leading to emotional behavior. Using the primate visual system as an experimental platform, our basic approach is to conduct neurophysiological experiments in rhesus monkeys performing a variety of tasks involving emotional learning. We generally use conditioning techniques to give otherwise neutral stimuli emotional significance.
We are investigating the physiological responses of amygdala neurons during emotional learning. The amygdala is a limbic brain structure likely to be critical to the process of associating sensory stimuli with emotional values. Simultaneously, we employ quantitative measurements of emotional learning and behavior in the monkey. We are testing the hypothesis that modulations in amygdala neural activity are correlated with the monkeys' emotional learning, behavior, and decision making.
Future studies are planned in three general directions. First, we plan to study how orbitofrontal cortex contributes to emotional learning and behavior on the tasks we employ. Parts of orbitofrontal cortex are intimately connected to the amygdala, and our goal is to understand the distinct processing in these brain areas. Second, we plan to investigate how stimuli in other sensory modalities become associated with emotional value in the amygdala. The amygdala receives input from multiple sensory modalities, and therefore representations of emotional value in the amygdala may exist across sensory modalities, perhaps even in the same cells. Finally, we plan to use pharmacological manipulations to try to understand the critical synaptic mechanisms underlying emotional learning. These experiments may deepen our understanding of psychopharmacology by linking synaptic mechanisms to both neurophysiology and to emotional behavior.
Baruni JK, Lau B, and Salzman CD. Reward expectation differentially modulates attentional behavior and activity in visual area V4. Nature Neuroscience 2015 Nov;18(11):1656-63. doi: 10.1038/nn.4141. Epub 2015 Oct 19.
Saez A, Rigotti M, Ostojic S, Fusi S, Salzman CD. Abstract Context Representations in Primate Amygdala and Prefrontal Cortex. Neuron 2015 Aug 19; 87(4): 869-81. PMCID: PMC4574873.
Gore F, Schwartz EC, Brangers BC, Aladi S, Stujenske JM, Likhtik E, Russo MJ, Gordon JA, Salzman CD*, Axel R*. Neural Representations of Unconditioned Stimuli in Basolateral Amygdala Mediate Innate and Learned Responses. Cell 2015 Jul 2; 162(1): 134-45. PMCID: PMC4526462. *co-senior/corresponding author.
Gore F, Schwartz EC, Salzman CD. Manipulating neural activity in physiologically classified neurons: triumphs and challenges. Philosophical Transactions of the Royal Society London B: Biological Sciences. 2015 Sep 19; 370(1677). Review. PMCID: PMC4528828.
Peck CJ and Salzman CD. Amygdala neural activity reflects spatial attention towards stimuli promising reward or threatening punishment. eLife 2014 Oct 30; 3. 10.7554/eLife.04478. PMCID: PMC4238057.
Peck, CJ, Lau, B, and Salzman CD. The primate amygdala combines information about space and value. Nature Neuroscience 2013 16: 340-348.
Morrison, SE, Saez A, Lau B and Salzman CD. Different time courses for learning-related changes in amygdala and orbitofrontal cortex. Neuron 2011 Sep 22, 71(6): 1127-40.
Morrison SE, Salzman CD. The convergence of information about rewarding and aversive stimuli in single neurons. Journal of Neuroscience 2009, 29(37): 11471-11483.
Belova MA, Paton JJ, Salzman CD. (2008). Moment-to-moment tracking of state value in the amygdala. J Neurosci, 28, 10023-10030.
Belova MA, Paton JJ, Morrison SE, Salzman CD. Expectation modulates neural responses to pleasant and aversive stimuli in primate amygdala. Neuron. 2007 Sep 20;55(6):970-84.
Paton J.J., Belova M.A., Morrison S.E., Salzman C.D. (2006). The primate amygdala represents the positive and negative value of visual stimuli during learning. Nature, 439: 865-870.