VERTICAL SNARC WITH POSITIVE AND NEGATIVE NUMBERS
Participants compared the magnitudes of pairs of vertically presented digits, viewed as temperatures, ranging from (-7,-6) through to (6,7 ). On half the trials the larger digit was selected and the smaller on the other half. Taken together, the findings show: 1) SNARC occurs in the vertical dimension for both positive and negative numbers; 2) the direction of the SNARC effect is not fixed but depends on the instruction; 3) the mental number line extends past zero to include negative numbers, and 4) SNARC was more robust when a thermometer was included. As well, semantic congruity effects were obtained: selection of the smaller of a pair of negative digits was faster than with the instruction â€œlargerâ€ and selection of the larger of a pair of positive digits was faster than with the instruction â€œsmallerâ€. These findings did not depend on whether the positive and negative pairs were intermixed or whether they were presented in separate blocks.