Searching for the functional locus of the SNARC effect: evidence for a response-related origin.

Dehaene, Bossini, and Giraux (1993) showed that when participants make parity judgments, responses to numerically small numbers are made faster with the left hand, whereas responses to large numbers are made faster with the right hand (the SNARC [spatial-numerical association of response codes] effect). According to one view, the SNARC effect arises at an early processing stage due to (in)congruencies between the digit's side of presentation and its representation on the mental number line, independently of response effector(s). Alternatively, the SNARC effect might arise at a later response-related stage due to (in)congruencies between the digit's representation on the mental number line and the side of response, independently of the side of presentation.

Psychophysiological evidence that the SNARC effect has its functional locus in a response selection stage.

When participants judge the parity of visually presented digits, left-hand responses are faster for numerically small numbers, whereas right-hand responses are faster for large numbers. The present study aimed to find more direct evidence for the functional locus of this effect by recording brain waves while participants performed speeded parity judgments giving manual responses. Our results show clear and robust SNARC effects in the response-locked event-related potentials (ERPs) compared to the stimulus-locked ERPs, confirming that the SNARC effect arises during response-related rather than stimulus-related processing stages.

Moving the eyes along the mental number line: comparing SNARC effects with saccadic and manual responses.

Bimanual parityjudgments about numerically small (large) digits are faster with the left (right) hand, even though parity is unrelated to numerical magnitude per se (the SNARC effect; Dehaene, Bossini, & Giraux, 1993). According to one model, this effect reflects a space-related representation of numerical magnitudes (mental number line) with a genuine left-to-right orientation. Alternatively, it may simply reflect an overlearned motor association between numbers and manual responses--as, for example, on typewriters or computer keyboards--in which case it should be weaker or absent with effectors whose horizontal response component is less systematically associated with individual numbers.

Perceptions of cardiovascular risk among patients with hypertension or diabetes.

We aimed to examine risk perceptions among patients at moderate to high cardiovascular risk. A questionnaire about perceived absolute risk of myocardial infarction and stroke was sent to 2424 patients with hypertension or diabetes. Response rate was 86.