is there any validity in academic testing?

Now that I'm getting ready to apply for jobs and graduate programs, I've have to come into contact with my transcript more than I would have liked to. Over the past four years, I've had my share of abysmal grades. And I'm not being dramatic, some semesters have been just as atrocious as you can get. When I think back to the courses in which I had received such poor grades, I realize that the classes were based almost solely on exam grades. You do poorly on an exam or two, and you don't really have an opportunity to help yourself. Is that really fair? Grades, after all, are supposed to be indications of how well a student is understanding the course material, not punishments for inadequate or misguided study habits.

I get that "intelligence" or "knowledge of a subject" needs to be operationalized somehow in order to make comparisons. While an exam is a way to numerically gauge how much a student has retained about a subject, it almost never truly displays their understanding of it. When you see a student cramming for an exam - whether it be biochemistry or history - you see them hunched over a notebook full of facts and figures, attempting to jam their head full with as much as possible, with the hope that come exam time, they will be able to regurgitate enough to form cohesive answers.

If exams really did a good job of assessing knowledge of a subject, why do students dread cumulative exams so much? If we had truly gained an understanding of material we were previously tested on, we would prefer a cumulative exam, which would allow us to integrate across material of multiple exams. If professors are going to really use testing to assess a student's understanding of material, they should make exams cumulative, because to me, mastery of a subject requires integration, rather than being able to report on bits and pieces of material.

While standardized testing has been continually lambasted for being an inadequate measure of how prepared a student is for college or graduate schools, there is not much more of an option. However, once you're at school, professors have an entire semester to gauge their students' understanding of the course material. By spreading the grade out over a variety of assignments, some of which are subjectively graded by the professor, not only will students who consider themselves "bad test-takers" feel that they have equal opportunity to do "well" in the class, but there will be much less extrinsic motivation and would most likely spur students' interests in the course material itself. Isn't that what college courses are supposed to be about anyway? Spending four years consistently worried about grading and cramming could potentially be a big precursor for giving students a propensity to dislike fields they would otherwise be interested in.

It would be interesting to perform some kind of meta-analysis comparing students who take classes in which grades are overwhelmingly based off of exam grades and those who receive grades more based off of presentations/papers/integrative assignments. Not only would it be cool to see how GPAs differ, but to see which students pursue careers directly correlated with what they studied in college. How satisfied were they with their collegiate experiences? How do they perform on other, non-academic based, integrative and/or memory tasks? Are there really such people as "bad test-takers"?

a spray of DNA keeps the bad guys away?

Some businesses in Holland have been using a new burglary system - one that sprays synthetic DNA on robbers as they walk out the door. The spray is deployed by an employee without the knowledge of the robber - it's odorless and invisible - and alerts the local police department. The synthetic DNA (which doesn't even cost that much to produce) is specific to the store from which it's deployed, and is meant to help cops link burglars to the scene of the crime.  Businesses that have used this system (usually installed by the police departments) have reported declines in crime rate, although there is no current data as of yet.

What could be causing this decline? The synthetic DNA alarm system hasn't been used yet to identify a criminal, but it has been triggered accidentally many times, which would allude to it being used as a scare tactic more than anything else. Businesses that have this system installed are required to have a sign posted outside alerting consumers. Even if it weren't required, it'd be a good move. The appearance of "DNA" on a sign outside of stores definitely deters prospective burglars. I don't see how synthetic DNA spray is any more effective than using UV ink, but fear of the unknown is daunting enough for most people. Even by glancing at readers' comments below the NYTimes article, I'm surprised at how little people actually understand about the use of DNA. Some worry about the prospect of being sprayed by "hybrid-human DNA", without realizing synthetic DNA is completely inactive and would cause no harm to the individual it's been sprayed on. On a more general level, I think criminals tend to associate "DNA" with "getting caught", which is enough to dissuade them.

In this case, the fear of the unknown appears to be effective enough to discourage robbers. It'll be interesting to see raw data pertaining to crime rates though...

is memory reorganization during labile states evolutionarily adaptive?

There are two labile states of fear memories. The first occurs shortly after learning, before the consolidation process, during which short-term memories are vulnerable for disruption whereas long-term memories are impervious. After consolidation, with the exposure to the proper environmental cues, such a memory can be retrieved in the brain. Following this retrieval, the second labile stage occurs. During this stage, the aforementioned memory is susceptible to alterations once again. Evidence (Nader, et al. 2000; Kaang, et al. 2009) has illustrated that protein-synthesis dependent reconsolidation processes are required to maintain the original memory. Administering a protein synthesis inhibitor before or immediately after memory retrieval (not quite sure how they elicited the retrieval, or how they measured when exactly it occurred, which would be interesting to know) disrupted the original memory.

Kaang, et al. (2009) hypothesized that these reconstruction processes induced by memory retrieval provide opportunities for memory update or reorganization. Furthermore, they found that new information (stimuli) must be necessary to trigger the destabilization process after memory retrieval. When I first read this, I automatically figured this made sense evolutionarily. Wouldn't we want the opportunity to modify our memories if our environmental stimuli are changing around us? Especially as humans, who live for a much longer time than do rodents, it would be important for our memories to adapt to new technologies and experiences. No question about it. But then as I thought further - I thought about all the downsides this could potentially have.

Let's say as a child you develop a taste aversion to dairy products because you have gotten sick from them on multiple occasions. If your memory serves you right, hopefully you have learned to stay away from dairy. But what happens if one day you have dairy by accident and you don't happen to get sick? Does that mean that single experience should remodel the existing memory you already have of dairy-induced discomfort? This example could be applied throughout species - especially since taste aversions are much more imperative to survival of rodents and less complex animals than humans. Anyway...my point being - if memory reorganization occurs each time a long-term memory is retrieved, how drastic does the changed stimulus have to be to alter the existing memory? Does it have to occur more than once? Does it matter how long the memory has been encoded for, or how many times it has previously been retrieved (strength of memory)? It just doesn't seem like it would make evolutionary sense to have all long-term memories susceptible to disruption each time it is retrieved, does it? Would it make more sense to just form new memories in response to new stimuli rather than modify pre-existing ones? Or would that just require more (ugh, don't make me say it) neural plasticity/neurogenesis than our brains are capable of?

It's important to take into consideration that the studies i've read largely deal with fear-conditioned memories. It would be compelling to study and determine whether or not there are differences in the appearance of labile states in other types of memories (e.g. olfactory aversions, conditioned taste aversions, object/social recognition memory, spatial memory). Would it make sense for some of these to be more susceptible to disruptions more or less routinely?