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Work Lazy to Work Crazy: Can Gene Therapy 'Cure' Laziness?

Image adapted from: U.S. Department of Energy Human Genome Program

INTRODUCTION:

The popular press misleads us in its report of a recent scientific by Zheng et al. (2004). A popular press article by Richard Black of BBC invites the inference that gene therapies to cure laziness and depression are close on the horizon.

BASICS OF THE RECENT SCIENTIFIC STUDY:

DNA targeting of the rhinal cortex D2 receptor protein reversibly blocks learning of cues that predict reward by Zheng et. al. 2004

Monkeys given a particular gene therapy were not able to perform visual cue related associative learning tasks. The associateive learning tasks tested was as follows: monkeys pulled a lever when a light turned from red to green. The monkeys were rewarded with food and water if they pulled the lever at the exact time the light changed, not before and not after. When the monkey performed the task correctly the light turned blue. The catch is that monkeys were only rewarded with food and water after the third trial, regardless of how they performed on the first two trials. We would expect that under normal curcumstances a monkey would 'learn' to be less vigilant during the first two trials and more vigilant in the third trial. This is precisely what researchers found in the control condition of the experiment. In the untreated, or control condition of the experiment monkeys committed fewer errors on the first two trials than on the third. The monkeys treated with gene therapy (i.e. antisense-DNA for the D2-dopamine receptors) in their rhinal cortexes were equally vigilant regardless of whether it was the third, second or first trial. Their error rate remained constant regardless of trial number and they committed fewer errors on average than the control group. Thus, the researchers concluded that the monkeys treated with D2-receptor targetted gene therapy were unable to associate the visual cues (i.e. light change) with reward (i.e. food and water) because these monkeys did not demonstrate contingency scheduling.

MEDIA REPORT OF THE SCIENTIFIC STUDY COMMITS TYPICAL FLAWS. A LENS FOR EVALUATION OF PRESS WRITING:

In his August 2004 article, 'Monkey's test hardworking gene', Richard Black commits sterotypical flaws of science reporting. The common flaws in science reporting include: ommision of qualifiying statements; lack of discussion of the methodology followed; a change of emphasis; and an overstatement of the generalizability of the data (Kuo et. al., 2004).

NO REPORTING OF METHODS OR CONTEXT:

Black does not report on the methods at all. He mentions a single phrase regarding the methodology: "the treatment consists of blocking an important chemical-dopamine" (Black, 2004). He also mentions that the experiement employed a 'genetic treatment.' This reporting is inadequate because the methods and the context of the experiment are necessary to make informed judgements about the meaning of the results (Kuo et al, 2004). He does not provide us the tools to understand where the investigation is, based on where it has been and where it needs to go (Kuo et. al., 2004).

The actual methods included injection of an anti-sense DNA construct into both sides of the rhinal cortex of monkeys. This anti-sense DNA interfered with the translation of a single receptor (the D2 Dopamine receptor) in this region of the brain. This receptor was chosen as a target because it is abundant in this region of the brain. This region of the brain is thought to be involved in the visually cued associative learning processes. These associations take weeks to develop. Thus, the researchers could not use older methods of receptor interference because biochemical methods (i.e. injections of D2 receptor competitive inhibitors ) wear off in a few hours. If researchers injected a monkey's brain every few hours for 9 weeks the monkey would get brain damage.

LACK OF QUALIFIERS AND OVERSTATEMENT OF THE GENERALIZABILITY OF THE DATA:

Black overgeneralizes the conclusions that we can draw from the data. Black suggests that we can use this study will apply to humans. In bold print, the first sentence of his BBC article states: "scientists in the United States have found a way of turning lazy monkeys into workaholics using gene therapy" (Black, 2004). The choice of words makes us think that humans could benefit from the gene therapy because laziness prevents us from working effectively. The study by Zheng, et. al. (2004) was not designed to test laziness, so barring any unusual findings or changes in research direction we cannot conclude anything about laziness or workaholism. The study was designed to test learning. The fact that monkeys treated with a particualr gene therapy cannot perform visual associative learning does not demonstrate that monkeys became workaholics. It does demonstrate that monkeys will be more vigilant during all tasks because the monkeys cannot learn that they only receive rewards after the third trial. The study does help localize visual cue associative learning to the D2 receptors in the rhinal cortex of monkeys.

The news article would be more accurate if i helped people understand that monkeys appear to be 'workaholics' when treated with the D2 receptor targetted antisense DNA because these monkeys cannot learn to associate visual cues with rewards. The key qualifiers here are: 'visual' learning, and 'appear to be' workaholics.

CHANGE OF EMPHASIS AND OVERSTATEMENT OF THE GENERALIZABILITY OF THE DATA:

The author overemphasized quotes that supported generalizing the data to humans. He quotes one of the researchers Dr. Richmond as follows: 'Normal monkeys and people procrastinate - tend not to work very well when they have a lot of time to get the job done, and work better when the reward is nearer in time" (Black, 2004). If Dr. Richmond did in fact say this he did not do so in the written paper. It is likely that Dr. Richmond used this phrase 'procrastinate' in a context where it was appropriate, such as to attract the attention of the PNAS audience at the annual meeting or to help people understand the possible research directions that could be taken. Teleological explanations and anthropomorphosis are agreed upon expository devices at scientific conferences because they prevent us from falling asleep (Sapolsky, 1990). Black makes Richmond's quote the centerpiece of Black's article. The emphasis should be placed on the conclusions reached by the the authors of the study: that we can identify and localize an integral part of visual cue associative learning (i.e. the D2 receptor in the rhinal cortex) in monkeys; the genomic method employed, antisense-DNA targetted at the D2 receptor, gained support as being a reliable method of translation prevention of the D2 receptor.

Black overgeneralized the conclusions that can be drawn from the study in the following sentence: "Dr. Richmond believes treatments based on this concept [gene therapy targetted at the D2 receptors presumabley] could one day benefit people with conditions like depression, where motivation has largely disappeared from their lives" (Black, 2004). In the paper Richmond and the other researchers 'speculate' that the targetted gene therapy in question could have such curative effects on human ailments. To say that Richmond believes that such cures could exists leapfrogs many steps in the scientific puzzle-solving process. Black's writing prevents us from seeing that many otheer experiments would have to be done before Black could reasonabley believe the above statement. Kua beliives that such reporting perpetuaes the public inability to evaluate scientific findings in a historical context.

 

CONCLUSION:

Black's BBC article exemplifies the problems rife wthin scientific writing today. At first glance his errors seemed small. At first glance it appeared that he said 'basically' the same thing that the NIMH press release said. However, once I read the article by Kuo et. al. (2004) the flaws in Black's article became evident. The press does not give the public the tools to evaluate the results of scientific research. We need methodological and historical context in order to understand not only which 'conclusions' are speculations for further research directions, but also the meaning and significance of the results obtained.

 

OTHER PRESS ARTICLES DESCRIBING THE STUDY:

Press Report in Nature
Press Release in NIMH - We would expect this one to be very accurate because it is by NIMH; however, its terminology includes 'procrastinating primates'.
Discussion in Medical News Today - In a rant titled 'Bad Science and Zombie Monkeys Face Procrastination' a concerned citizen that blames not the media, but the reseachers themselves for perpetrating misunderstanding.

REFERENCES:

Black, R. 2004. Monkeys test hardworking gene. BBC News UK Edition. Aug., 12 2004. <http://news.bbc.co.uk/1/hi/sci/tech/3557310.stm> Accessed 2004 1Sept.

Kua et. al. 2004. Science in the news: a study of reporting genomics. Public Understand. Sci. 13: 309-322

McCord, Rachel. 2003 5-HTT: The Gene for Susceptibility to Depression. <http://www.bio.davidson.edu/Courses/genomics/2003/mccord/5-HTT.html >. Accessed 2004 11 Sept.

Sapolsky, R. 1999. The War Between Men and Women (tales told by genomic imprinting). Discover. 20: 56-61.

Zheng, L et. al. 2004. DNA targetting of rhinal cortex D2 receptor protein blocks learning cues that predict reward. PNAS 101: 12336-12341.

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