Month: February 2017

Do twitter or facebook activity influence scientific impact?

Are scientists smart when they promote their work on social media? Isn’t this a waste of time, time which could otherwise be spent in the lab running experiments? Perhaps not. An analysis of all available articles published by PLoS journals suggests otherwise.

My own twitter activity might best be thought of as learning about science (in the widest sense), while what I do on facebook is really just shameless procrastination. It turns out that this pattern holds more generally and impacts on how to use social media effectively to promote science.

In order to make this claim, I downloaded the twitter and facebook activity associated with every single article published in any journal by the Public Library of Science (PLoS), using this R-script here. PLoS is the open access publisher of the biggest scientific journal PLoS ONE as well as a number of smaller, more high impact journals. The huge amount of data allows me to have a 90% chance of discovering even a small effect (r = .1) if it actually exists.

I should add that I limited my sample to those articles published after May 2012 (which is when PLoS started tracking tweets) and January 2015 (in order to allow for at least two years to aggregate citations). The 87,649 remaining articles published in any of the PLoS journals offer the following picture.


There is a small but non-negligible association between impact on twitter (tweets) and impact in the scientific literature (citations): Pearson r = .12, p < .001; Spearman rho = .18, p < .001. This pattern held for nearly every PLoS journal individually as well (all Pearson r ≥ .10 except for PLoS Computational Biology; all Spearman rho ≥ .12 except for PLoS Pathogens). This result is in line with Peoples et al.’s (2016) analysis of twitter activity and citations in the field of ecology.

So, twitter might indeed help a bit to promote an article. Does this hold for social media in general? A look at facebook reveals a different picture. The relationship between facebook mentions of an article and its scientific impact is so small as to be practically negligible: Pearson r = .03, p < .001; Spearman rho = .06, p < .001. This pattern of only a tiny association between facebook mentions and citations held for every single PLoS journal (Pearson r ≤ .09, Spearman rho ≤ .08).


In conclusion, twitter can be used for promoting your scientific work in an age of increased competition for scientific reading time (Renear & Palmer, 2009). Facebook, on the other hand, can be used for procrastinating.

Wanna explore the data set yourself? I made a web-app which you can use in RStudio or in your web browser. Have fun with it and tell me what you find.

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Peoples BK, Midway SR, Sackett D, Lynch A, & Cooney PB (2016). Twitter Predicts Citation Rates of Ecological Research. PloS one, 11 (11) PMID: 27835703

Renear AH, & Palmer CL (2009). Strategic reading, ontologies, and the future of scientific publishing. Science (New York, N.Y.), 325 (5942), 828-32 PMID: 19679805

Why does music training increase intelligence?

We know that music training causes intelligence to increase, but why? In this post I 1) propose a new theory, and 2) falsify it immediately. Given that this particular combination of activities is unpublishable in any academic journal, I invite you to read the whole story here (in under 500 words).

1) Proposing the ISAML

Incredible but true, music lessons improve the one thing that determines why people who are good on one task tend to be better on another task as well: IQ (Schellenberg, 2004; Kaviani et al., 2013; see coverage in previous blog post). Curiously, I have never seen an explanation for why music training would benefit intelligence.

I propose the Improved Sustained Attention through Music Lessons hypothesis (ISAML). The ISAML hypothesis claims that all tasks related to intelligence are dependent to some degree on people attending to them continuously. This ability is called sustained attention. A lapse of attention, caused by insufficient sustained attention, leads to suboptimal answers on IQ tests. Given that music is related to the structuring of attention (Boltz & Jones, 1989) and removes attentional ‘gaps’ (Olivers & Nieuwenhuis, 2005; see coverage in previous blog post), music training might help in attentional control and, thus, in increasing sustained attention. This in turn might have a positive impact on intelligence, see boxes and arrows in Figure 1.


Figure 1. The Improved Sustained Attention through Music Lessons hypothesis (ISAML) in a nutshell. Arrows represent positive associations.

The ISAML does not predict that intelligence is the same as sustained attention. Instead, it predicts that:

a) music training increases sustained attention

b) sustained attention is associated with intelligence

c) music training increases intelligence

2) Evaluating the ISAML

Prediction c is already supported, see above. Does anyone know something about prediction b? Here, I shall evaluate prediction a: does music training increase sustained attention? So far, the evidence looks inconclusive (Carey et al., 2015). Therefore, I will turn to a data set of my own which I gathered in a project together with Suzanne R. Jongman (Kunert & Jongman, in press).

We used a standard test of sustained attention: the digit discrimination test (Jongman et al., 2015). Participants had the mind-boggingly boring task of clicking a button every time they saw a zero while watching one single digit after another on the screen for ten minutes. A low sustained attention ability is thought to be reflected by worse performance (higher reaction time to the digit zero) at the end of the testing session compared to the beginning, or by overall high reaction times.

Unfortunately for the ISAML, it turns out that there is absolutely no relation between musical training and sustained attention. As you can see in Figure 2A, the reaction time (logged) decrement between the first and last half of reactions to zeroes is not related to musical training years [Pearson r = .03, N = 362, p = .61, 95% CI = [-.076; .129], JZS BF01 with default prior = 7.59; Spearman rho = .05]. Same for mean reaction time (logged), see Figure 2B [Pearson r = .02, N = 362, p = .74, 95% CI = [-0.861; 0.120], JZS BF01 = 8.181; Spearman rho = 0.03].


Figure 2. The correlation between two different measures of sustained attention (vertical axes) and musical training (horizontal axes) in a sample of 362 participants. High values on vertical axes represent low sustained attention, i.e. the ISAML predicts a negative correlation coefficient. Neither correlation is statistically significant. Light grey robust regression lines show an iterated least squares regression which reduces the influence of unusual data points.

3) Conclusion

Why on earth is musical training related to IQ increases? I have no idea. The ISAML is not a good account for the intelligence boost provided by music lessons.

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Carey, D., Rosen, S., Krishnan, S., Pearce, M., Shepherd, A., Aydelott, J., & Dick, F. (2015). Generality and specificity in the effects of musical expertise on perception and cognition Cognition, 137, 81-105 DOI: 10.1016/j.cognition.2014.12.005

Jongman, S., Meyer, A., & Roelofs, A. (2015). The Role of Sustained Attention in the Production of Conjoined Noun Phrases: An Individual Differences Study PLOS ONE, 10 (9) DOI: 10.1371/journal.pone.0137557

Jones, M., & Boltz, M. (1989). Dynamic attending and responses to time. Psychological Review, 96 (3), 459-491 DOI: 10.1037//0033-295X.96.3.459

Kaviani, H., Mirbaha, H., Pournaseh, M., & Sagan, O. (2013). Can music lessons increase the performance of preschool children in IQ tests? Cognitive Processing, 15 (1), 77-84 DOI: 10.1007/s10339-013-0574-0

Kunert R, & Jongman SR (2017). Entrainment to an auditory signal: Is attention involved? Journal of experimental psychology. General, 146 (1), 77-88 PMID: 28054814

Olivers, C., & Nieuwenhuis, S. (2005). The Beneficial Effect of Concurrent Task-Irrelevant Mental Activity on Temporal Attention Psychological Science, 16 (4), 265-269 DOI: 10.1111/j.0956-7976.2005.01526.x

Glenn Schellenberg, E. (2004). Music Lessons Enhance IQ Psychological Science, 15 (8), 511-514 DOI: 10.1111/j.0956-7976.2004.00711.x

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