Reading Response to 3/4/2007

I notice a common thread that runs through all three of the readings for this week. The authors attempt to determine the involvement of certain brain regions and structures on the creation, retention, and retrieval of memory. However, each author uses a different method in their examination of brain regions and structures involved in memory. The paper “Cognitive Neuroscience of Emotional Memory” examines the brain systems involved in forming, keeping, and retrieving memories using emotional arousal. LeDoux uses anxiety disorders to help explain brain systems and their involvement in memory. McGaugh uses drugs to show how activation occurs in certain regions of the brain in memory. Although each author attacks the issue of memory differently, all of them add something new to our limited knowledge of memory and the brain regions involved.

In “Cognitive neuroscience of emotional memory”, LeBar and Cabeza found evidence that “emotional arousal benefits memory in part by facilitating consolidation processes”(LeBar & Cabeza 55). This means that arousal is important in molding and consolidating new memories. Using PET and fMRI studies, the researchers traced the impact of emotion events at various stages of memory. They discovered that specific brain regions are involved in various aspects of memory; from initial formation, to retaining and to retrieving. LeBar and Cabeza found the most important of these structures is the amygdala which is involved in encoding memories, retrieving memories, and fear conditioning.

LeDoux investigates the effects of anxiety on various aspects of memory. He shows how anxiety and stress cause problems in brain structures involved in memory. “Stressful events can cause malfunctions in the hippocampus… the failure to recall an instigating trauma may be due to a stress-induced breakdown in hippocampal memory function”(LeDoux 240). Stress interferes with the hippocampus and blocks the formation of new memories by shriveling up the dendrites involved in memory formation in the hippocampus. In survivors of severe trauma, the person’s hippocampus has permanently shrunken causing significant memory defects. Anxiety inhibits brain structures that contribute to the memory process.

McGaugh investigates what effect drugs have on memory. He states that “drugs are highly useful as tools in determining the involvement and role(s) of different brain regions in memory consolidation” (McGaugh 71). McGaugh tests the effects of strychnine on a rat’s performance in a maze test. After successfully completing the maze test, half of the rats were injected with saline and the other half were injected with strychnine. The saline rats performed the maze test successfully after a three hour delay. The strychnine rats performed the maze test successfully after a nine hour delay. The strychnine enhanced the memory of the rats. McGaugh goes on to test other drugs and their effects on brain structures. McGaugh injects various drugs into the amygdale, hippocampus, and other related brain regions and observes the results. He discovers that the amygdala is crucial in the involvement of consolidating memories. The hippocampus and caudate nucleus selectively affect place learning and cue learning. Norepinephrine actions in the amygdala play an important role in the creation of memories. His discoveries increase our understanding of how certain regions and structures in the brain affect memory formation and function.

All three readings help to shed light on our limited understanding of memory and how it is created, retained, and retrieved. The authors approach the study of memory with different tools and from different perspectives. However, each author makes new discoveries or confirms previous findings about the nature of memory. They share the common goal of broadening the field of memory research.



LaBar, K.S. & Cabeza, R. (2006). Cognitive neuroscience of emotional memory. Nature Neuroscience Reviews, 7, 54-64.

LeDoux, J. (1996). The Emotional Brain. Simon & Schuster: New York. Chapter 8

McGaugh, J.L. (2003). Memory and Emotion. New York: Columbia. Chapter 4