Amygdala Stimulation in the Absence of Emotional Experience Enhances Memory for Neutral Objects

Theamygdala is a small structure located within the medial temporal lobes (MTL), consisting of a discrete set of nuclei. It has a reputation as the “fear center” or “emotion center” of the brain, although it performsmultiple functions. One well-known activity of the amygdala, via its connections with otherMTL areas, involves an enhancement of memories that are emotional in nature (compared to neutral). Humans and rodents with damaged or inactivated amygdalae fail to show this emotion-related enhancement, although memory for neutral items is relatively preserved (Adolphs et al., 1997;Phelps& Anderson, 1997;McGaugh, 2013).A new brain stimulation study (Inman et al., 2017) raises interesting questions about thenecessity of subjective emotional experience in the memory enhancement effect. A group of 14 refractory epilepsy patients underwent surgery to implant electrodes in the left or right amygdala (and elsewhere) for the sole purpose of monitoring the source of their seizures. In a boon for affiliated research programs everywhere, patients are able to participate in experiments while waiting around for seizures to occur.The stimulating electrodes were located in or near the basolateral complex of the amygdala (BLA), shown below. The stimulation protocol was developed from similar studies in rats, which demonstrated that direct electrical stimulation of BLA can improve memory for non-emotional events when tested on subsequent days (Bass et al., 2012;2014;2015).Fig. 1...
Source: The Neurocritic - Category: Neuroscience Authors: Source Type: blogs