All in the first glance: first fixation predicts individual differences in valence bias^*

* The underlying research materials for this article can be accessed at http://psychology.unl.edu/can-lab/publications

ABSTRACT

Surprised expressions are interpreted as negative by some people, and as positive by others. When compared to fearful expressions, which are consistently rated as negative, surprise and fear share similar morphological structures (e.g. widened eyes), but these similarities are primarily in the upper part of the face (eyes). We hypothesised, then, that individuals would be more likely to interpret surprise positively when fixating faster to the lower part of the face (mouth). Participants rated surprised and fearful faces as either positive or negative while eye movements were recorded. Positive ratings of surprise were associated with longer fixation on the mouth than negative ratings. There were also individual differences in fixation patterns, with individuals who fixated the mouth earlier exhibiting increased positive ratings. These findings suggest that there are meaningful individual differences in how people process faces.

KEYWORDS:

• Emotional ambiguity
• individual differences
• eye tracking
• surprise
• fear

Acknowledgements

We thank Rebecca L. Brock for help with statistical analyses.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Tien T. Tong http://orcid.org/0000-0002-1940-3198

Notes

* The underlying research materials for this article can be accessed at http://psychology.unl.edu/can-lab/publications

1. The results were the same for DT: significantly longer DT on the mouth for positive trials than negative trials (t(50) = 2.28, p < .03, d = 0.32), and no significant differences for the eyes (t(50)  = 1.56, p > .1, d = 0.22). Also, there was no significant difference between trials in which fear was rated as positive and negative for both DT on the mouth and on the eyes (p’s > .1).

2. When testing the correlations directly against each other, we found a trend difference between correlations for LSFs (eyes vs. mouth, p = .07), where the correlation for the mouth was significant but the correlation for the eyes was not. As expected, there was no difference between the HSF correlations (eyes vs. mouth, p = .18), or between the correlations for the eyes (LSF vs. HSF; p = .50). However, there was also no significant difference between the correlations for the mouth (LSF vs. HSF, p = .29). In other words, it appears that the correlation between the FFT on the mouth and ratings of surprise LSF images was distinct from the non-significant correlations for the eyes, but not distinct from the correlation between the mouth and ratings of surprise HSF images. Finally, we ran the correlations between FFT and ratings also on fear faces (as reported for surprised faces). There was a trend correlation between FFT to the eyes and ratings of HSF images (r(49) = -.27, p = .06), such that faster FFT to the eyes were associated with more negative ratings of fear. All other correlations for the fear faces were not significant (p’s > .2).

Additional information

Funding

M.J.K. was supported by the National Institute of Mental Health [F31 MH090672].