SNARC EFFECT

According to a study conducted by Dehaene and his colleagues, they found that people respond faster to small numbers with their left hand and to large numbers with their right hand (Dehaene, Bossini, & Giraux, 1993). Interestingly, they found that these responses were not related to whether the person was right-handed or left-handed, but that the culture of writing was significant in this context. In other words, for those who grew up in a culture where the writing direction was from left to right and wrote in this way, it was observed that when smaller numbers were responded with left hand, reaction times decreased; and also when larger numbers were responded with right hand, reaction times decreased. Conversely, when people wrote from right to left, as in Arabic, responding larger numbers with left hand and smaller numbers with right was associated with the reaction times’ being shorter.

“If words such as fifty-six be spoken, I most clearly, easily and instantly visualise the figures. I do so almost automatically. I perceive that when I speak the word "thousand" or hear it spoken, the figures at once group themselves together. I find it quite impossible to think of the date of a year without remem- bering and visualising the figures, though I express myself in words. The figures are always printed; in type and size they resemble those commonly used for the headings of newspapers. I cannot, however, appreciate a back-ground, the figures appear simply in space. I think that by practice and concentration I conld hold fast many figures.” (Galton, 1880).

Galton, who laid the first stone with his words in 1880, as he himself stated, when numbers were conceptualized, he placed them in a spatial plane and visualized them. When he asked his friends, whom he considered talented, of different ages, genders and status, he received feedbacks that they made visualizations like him; however, one of his friends stated that the numbers were reflected in his mind as sounds. In addition, he suggested that this experiment can be conducted simultaneously with larger groups in order to obtain more "average" answers, thus contributing to the science of psychology.

About 100 years later, the studies of Deheane and his colleagues, which were the basis for many experiments to be done after him, were mostly about numbers and their responses to written words. On the other hand, Nuerk and his colleagues wanted to test whether auditory input could also be related to the representation of this magnitude perception, since SNARC is related to abstract meaning and magnitude perception (Nuerk, Wood & Willmes, 2005). According to the results of this study, in which 3 visual and 1 auditory (number, number written in words, dice dots and numbers spoken by a man) variables were used, the SNARC effect is not only a visual effect but also an auditory effect.

The SNARC effect is a relatively new subject and open to broadening areas of study. For example, Baldassi and his colleagues, who studied the existence of such an effect in music tempo, found a significant difference between the left and right hand responses to slow and fast tempos in a spatial context (Prpic, Fumarola, De Tommaso, Baldassi, Agostini, 2013). This effect was named as Spatial Music Tempo Association of Response Codes (SMTARC).

Another study examined how SNARC effect relates to numerical and visual-spatial abilities (Viarouge, Hubbard, McCandliss, 2014). One of the tasks presented to the participants in this study was to decide whether letters straight or mirrored on a 2-dimensional plane. If the letter shown on the screen was straight, they would respond with their left hand, and if it was a mirrored letter, they would respond with their right hand. The results showed that those who were successful in this task showed less SNARC effect. According to the results, it was concluded that people with lower visual-spatial skills pay less attention to the number line in their minds. In addition, it was found in this study that the SNARC effect can be reduced with training.

                         The last study I mentioned is a step towards revealing the cognitive infrastructure of the SNARC effect. So what does the existence of the SNARC effect or its ability to be reduced mean? I believe that examining the cognitive infrastructure or conducting research that can be put into practice will contribute more to science rather than examining where the SNARC effect manifests itself, which can be adapted to different variables like the other studies above.

REFERENCES

Deheane, S., Bossini, S., Giraux, P. (1993). The mental representation of parity and             number magnitude. Journal of Experimental Psychology: General, 122(3), 371–396.         https://doi.org/10.1037/0096-3445.122.3.371

Galton, F. (1880). Visualized numerals. Nature, 252-256.

Nuerk HC, Wood G, Willmes K. (2005). The universal SNARC effect: the association             between number magnitude and space is amodal. Experimental Psychology. 52(3), 187-94. doi: 10.1027/1618-3169.52.3.187

Prpic, V., Fumarola, A., De Tommaso, M., Baldassi, G., Agostini, T. (2013). A SNARC-like   effect for music tempo. Review of Psychology, 20(1-2), 47-51.

Viarouge, A., Hubbard, E. M., McCandliss, B. D. (2014) The cognitive mechanisms of the   SNARC effect: an individual differences approach. PLoS ONE 9(4): e95756.             doi:10.1371/journal.pone.0095756