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Rony Paz"Perception and Persistence of Emotional memories: mechanisms and implications"

Abstract :

The Amygdala and the dorsal-anterior-cingulate-cortex (dACC) form a 2-way dense projection network that is highly involved in many forms of emotional learning and memory, and is extremely evolved in the primate.
In the first line of studies, I will show how complex schedules of reinforcement can lead to memories that are more resistant to extinction by engaging synchronized activity in this network, how different types of prediction errors that emerge in such learning interact in this network, and how low-frequency deep-brain-stimulation can reduce excitability and prevent the spontaneous recovery of the memories. In the second line of studies, I will show how negative/aversive reinforcement alters perception and discrimination. In line with evolutionary considerations, there is reduced sensitivity for the aversive conditioned stimulus, which results in wider generalization and also affects choice-behavior. Whereas this can be beneficial for risky situations in general, such wide generalization can result in stress in extreme cases, and we show that this is indeed a possible mechanism underlying abnormal behaviors in anxiety patients. We also show that it can result from secondary reinforcers, as monetary loss, suggesting new and different ways by which loss can result in irrational choice-behavior - by compromising early perceptual mechanisms. We identify different characteristics of these behaviors and the underlying network using both imaging in humans and electrophysiology in non-human primates. Finally, if time permits, I will show results from a natural social interaction paradigm, and highlight ways by which the amygdala-dACC is involved in social computations. I will conclude by suggesting how these studies can shed light on our understanding of different psychiatric disorders.

Selected publications

Self-monitoring of social facial expressions in the primate amygdala and cingulate cortex.Livneh U, Resnik J, Shohat Y, Paz R.Proc Natl Acad Sci U S A. 2012 Oct 29. [Epub ahead of print]

Dirnberger G, Hesselmann G, Roiser JP, Preminger S, Jahanshahi M, Paz R Give it Time: Neural Evidence For Distorted Time Perception and Enhanced Memory Encoding in Emotional Situations.
Neuroimage (2012) Html link to full text

Livneh U, Paz R
Aversive-Bias and Stage-Selectivity in Neurons of the Primate Amygdala During Acquisition, Extinction, and Overnight Retention.
Journal of Neuroscience (2012) Html link to full text

Livneh U, Paz R
Amygdala-Prefrontal Synchronization Underlies Resistance to Extinction of Aversive Memories.
Neuron (2012) Html link to full text

Klavir O, Genud-Gabai R, Paz R
Low-Frequency Stimulation Depresses the Primate Anterior-Cingulate-Cortex and Prevents Spontaneous Recovery of Aversive Memories..
Journal of Neuroscience (2012) Html link to full text

Cyril Herry du Neurocentre Magendie