Emotional Hormones and Memory Modulation

Emotionally arousing experiences are generally well remembered. We know that from our own experiences as well as from extensive research findings. Memories of automobile accidents, fires, muggings, rapes, wartime battles, terrorists’ bombings, and other intensely emotional experiences are often reported as being ‘deeply etched in the brain.’ We also remember significant details of special occasions such as birthdays, bar mitzvahs, weddings, graduation ceremonies, and funerals as well as horrific events such as those of 11 September 2001. Milder emotional experiences such as those induced by praises, insults, or embarrassments also tend to be well remembered. There are some obvious and partly correct explanations of why it is that emotional experiences (of either positive or negative valence) create strong memories. We may pay more attention to details during the experiences and we may repeatedly recall the experiences and, thus inadvertently, or purposefully, rehearse them. However, in addition, as discussed below, there is extensive evidence that neurobiological processes initiated by emotionally arousing experiences act automatically to strengthen memories of the experiences. And, it certainly seems highly adaptive to have such automatic processes that enable the significance of events to regulate their remembrance. However, stress and emotional arousal not only induce strong memories of new information but can also impair our remembering. We all have, probably, experienced situations such as stressful examinations or job interviews during which we were simply not able to recall information. The evidence from many animal and human studies now indicates that the mechanisms that enhance the consolidation of new, emotionally arousing experiences are also responsible for the impairment of memory retrieval and working memory.