Whorf hypothesis is supported in the right visual field but not the left

doi:10.1073/pnas.0509868103

Whorf hypothesis is supported in the right visual field but not the left

^*Helen Wills Neuroscience Institute and Departments of ^†Psychology and ^∥Linguistics, University of California, Berkeley, CA 94720; ^§Department of Psychology, University of Chicago, Chicago, IL 60637; and ^¶International Computer Science Institute, 1947 Center Street, Berkeley, CA 94704

Contributed by Paul Kay, November 16, 2005

Abstract

The question of whether language affects perception has been debated largely on the basis of cross-language data, without considering the functional organization of the brain. The nature of this neural organization predicts that, if language affects perception, it should do so more in the right visual field than in the left visual field, an idea unexamined in the debate. Here, we find support for this proposal in lateralized color discrimination tasks. Reaction times to targets in the right visual field were faster when the target and distractor colors had different names; in contrast, reaction times to targets in the left visual field were not affected by the names of the target and distractor colors. Moreover, this pattern was disrupted when participants performed a secondary task that engaged verbal working memory but not a task making comparable demands on spatial working memory. It appears that people view the right (but not the left) half of their visual world through the lens of their native language, providing an unexpected resolution to the language-and-thought debate.

Footnotes

↵ ^‡To whom correspondence may be addressed at: Helen Wills Neuroscience Institute and Department of Psychology, 3210 Tolman Hall #1650, University of California, Berkeley, CA 94720-1650. E-mail: mayfly{at}berkeley.edu. ^**To whom correspondence may be addressed. E-mail: kay{at}icsi.berkeley.edu.
Author contributions: A.L.G., P.K., and R.B.I. designed research; A.L.G. performed research; A.L.G. and R.B.I. analyzed data; A.L.G., T.R., P.K., and R.B.I. wrote the paper; A.L.G. programmed experiments, ran subjects, and contributed significantly to all other phases of research; T.R. provided the original idea for the study and contributed significantly to the analysis and write-up; P.K. contributed to design of research, analysis, and write-up; P.K. provided the impetus for the study with earlier work that lacked the cerebral lateralization variable on which this study is based; R.B.I. collaborated on all portions of the experiment with one or more coauthors; R.B.I. supervised A.L.G. throughout; and R.B.I. provided laboratory facilities.
Conflict of interest statement: No conflicts declared.
Abbreviations: LH, left hemisphere; LVF, left visual field; RT, reaction time; RVF, right visual field.
↵ †† We use the term “perception” throughout this paper in the broad sense in which it is commonly employed in the language-and-thought literature; however, a more restricted concept of perception is also examined in General Discussion.
↵ ‡‡ Behavioral methods may not prove sufficient to distinguish between these alternatives. Physiological procedures might identify both the location and timing at which the two hemispheres diverge in their response to stimuli such as those used in our color discrimination task (24, 25).
↵ §§ After the experiment, we determined the coordinates of the color stimuli in the CIEL^*a^*b^* and CIEL^*u^*v^* color spaces by using the conversion software at www.easyrgb.com, with parameters set to illuminant “daylight” and observer “2 degrees.” For the CIEL^*a^*b^* space, the interstimulus distances were: AB, 12.3; BC,12.5; and CD, 15.7. For the CIEL^*u^*v^* space, the interstimulus distances were: AB, 16.3; BC, 17.5; and CD, 19.5. In both spaces, the within-green (AB) distance is slightly less than the between-category (BC) distance, and the within-blue differences is larger. In both cases, the average of the within-distances (AB and CD) exceeds the between-distance (BC). Whereas we collapse across the within-category pairs in the analyses reported in the main text, these differences led us to perform secondary analyses in which we treated the data for the within-green and within-blue conditions separately, rather than pooled. In no case did the outcome of these secondary analyses deviate from that reported in the main text.