Wednesday, December 9, 2015

Time to Cram for that Final!... or Not?

         

          
           Many research studies in the recent years have been interested in the process of learning and memory within the brain.  To understand memory formation and consolidation researchers have been studying both neuronal synapses through neurobiology methods and behavioral methods.  It is one thing to see the formation of strong synapses, but quite another to see the behavioral implications.  Researcher Barbara Knowlton is a member of the Psychology Department at the University of California, Los Angeles.  Recently, she gave a talk about neural substrates of desirable difficulties in motor sequence learning.  According to the study, Knowlton found statistical significance in the implementation of interleaved learning in terms of memory consolidation.  Knowlton’s results suggest that cramming for an exam is not as effective of a study method as studying throughout a longer period of time.  The concept of interleaved practice comes into play in the sense that actually studying many different things over a period of time shows greater memory retention.  Therefore, the most effective form of studying would not just include spreading the material across a period of time, but also involves incorporating different subjects into every study period.  Retrieval practice is seen to be beneficial to long-term learning.  Doing different things in between learning actually forces information retrieval at a later time. 
In a simple example and one of Knowlton’s early studies, a group of participants underwent “blocked practice” while another group underwent “interleaved practice”.  Blocked practice refers to learning information one group at a time.  For example, it would be like memorizing the list AAA, BBB, CCC, etc.  Interleaved practice is similar to memorizing the list ABC, BCA, CAB, etc.  Each letter refers to a separate group or subject.  According to Knowlton’s results, after a delay of even ten minutes post memorization, the second group actually did much better.  At first, the performance of the second group looked much worse, but after a longer period of time, the second group seemed to have the best results.  An example involving a motor skill would be like playing the piano.  It is better to learn three songs at the same time in different parts than to learn one song fully and then move on to another song. 
Similarly, Knowlton and researchers conducted an fMRI study on subjects who experienced both blocked and interleaved practice.  The fMRI results showed that interleaved practice leads to better results than repetitive practice. The disadvantage to interleaved practice is that constant retrieval of information is very difficult; however, it does pay off in the long run!  According to Knowlton, “The extra pain during practice gives you more of a gain during retention” (quoted during talk).  Results also showed that increased activation in the superior frontal gyrus during interleaved practice was significantly correlated with a subsequent behavioral benefit.  When cerebellar function was manipulated with tDCS, cerebellar activity was seen to be positively correlated with individual transfer ability scores.  The general trend showed that cerebellar structure was beautifully suited to learning in that plasticity at the synapses facilitate in the formation of strong connections. The overall conclusions of this study demonstrate that interleaved practice is beneficial for both retention and transfer of motor sequence learning. 
A related study at Carnegie Mellon University in the summer of 2013 analyzed synaptic formation and synaptic strength in mice. This study was also published in the Journal of Neuroscience.  Mice with one whisker were studied in different environments in order to analyze one brain region at a time.  (In mice, each brain region controls the opposite whisker as a form of environmental perception. I find it similar to how the right side of the brain controls the left side of the human body and vice versa.)  This method is based off a specialized transgenic mouse model.  Previous research has shown that learning is best incorporated when it is cumulative over a long period of time.  Many studies have also shown that synapses in the brain become much stronger when exposed to a stimuli multiple times.  However, this may not be the only case.  According to neuroscientist Alison L. Barth, synapses that are recently strengthened due to intense memorization or learning are actually very fragile and vulnerable to increased stimulation.  This activity could actually wipe out the effects of learning.  Data from Barth’s study shows that synapses do strengthen with increased stimuli in the short term; however, after a transitional phase predicted to involve consolidation of the new information, the synapses quickly weaken!  
Both Knowlton and Barth have similarities in their studies in that they are looking beyond the effects of long-term, cumulative practice in terms of memory and learning.  Knowlton focuses on the behavioral aspects while Barth studies the same phenomenon from a neuronal perspective.  Even with the efforts of both Knowlton and Barth, there is still so much to be learned in terms of memory formation.  When looking at future endeavors, I would love to see a combinatorial study using the skill sets of both researchers.  This study could implement interleaved learning in terms of analyzing memory retrieval ability as a whole and the same data could be analyzed for cues of synaptic strength at varying periods of time.  Overall, both studies exemplify the importance of pushing beyond what previous research shows in order to understand if there is more to the picture than what we may actually see.  Plus more research on memory formation and consolidation means better exam scores, and I’m sure we could all use a lot more of that!

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