Hockenbury Discovering Psychology 5th txtbk

The Search for the Biological Basis of Memory267in solving the puzzle. But if you asked Henry if he had ever seen the puzzle before,he would answer “no” because he could not consciously (or explicitly) rememberhaving learned how to solve the puzzle. This suggests that the hippocampus is lesscrucial to the formation of new implicit memories, such as procedural memories,than it is to the formation of new explicit memories.Were Henry’s memory anomalies an exception? Not at all. Studies conductedwith other people who have sustained damage to the hippocampus and relatedbrain structures showed the same anterograde amnesia (e.g., Bayley & Squire,2002). Like Henry, these patients are unable to form new explicit memories, buttheir performances on implicit memory tasks, which do not require conscious recollectionof the new information, are much closer to normal. Such findings indicatethat implicit and explicit memory processes involve different brain structuresand pathways.Brain Structures Involved in MemoryAlong with the hippocampus, several other brain regions involved in memoryinclude the cerebellum, the amygdala, and the frontal cortex (see Figure 6.11). Asyou saw earlier, the cerebellum is involved in classically conditioning simple reflexes,such as the eye-blink reflex. The cerebellum is also involved in procedural memoriesand other motor skill memories.The amygdala, which is situated very close to the hippocampus, is involved inencoding and storing the emotional qualities associated with particular memories,such as fear or anger (McGaugh, 2004). For example, normal monkeys are afraid ofsnakes. But if the amygdala is damaged, a monkey loses its fear of snakes and othernatural predators.The frontal lobes are involved in retrieving and organizing information that isassociated with autobiographical and episodic memories (Greenberg & Rubin,2003). The prefrontal cortex seems to play an important role in working memory(McNab & Klingberg, 2008).The medial temporal lobes, like the frontal lobes, do not actually store theinformation that comprises our autobiographical memories. Rather, they areinvolved in encoding complex memories, by forming links among the informationstored in multiple brain regions (Greenberg & Rubin, 2003). As we described inthe Focus on Neuroscience, “Assembling Memories,” on page 262, retrieving amemory activates the same brain regions that were involved in initially encodingthe memory.Prefrontal cortexMemory involving thesequence of events, butnot the events themselvesAmygdalaEncodes emotionalaspects of memoriesMedial temporal lobe(not visible) Encodes and transfersnew explicit memories to long-termmemoryHippocampusEncodes and transfersnew explicit memories tolong-term memoryCerebellumMemories involvingmovementFigure 6.11 Brain Structures Involvedin Human Memory Shown here are someof the key brain structures involved inencoding and storing memories.