Sex and hand-preference effects in the simultaneous and consecutive discrimination of lifted weight

Abstract

Differential thresholds (DLs) for lifted weight were measured in one-handed consecutive and two-handed simultaneous discrimination paradigms using 1eft-and right-handed, male and female subjects. In one-handed discrimination, no preferred-hand advantage was found for either 1eft-or right-handed subjects. Left-handed subjects were found to perform better than right-handed subjects with both left and right hand. A constant error was found in two-handed simultaneous discrimination, in which the subjects reported that weights felt heavier in one hand than in the other. Neither hand preference nor hand sensitivity was found to correlate with the direction of the error. A sex difference was found in two-handed simultaneous weight discrimination: DLs for male subjects differed between left and right, whereas DLs for female subjects did not. The results are discussed in terms of hemispheric specialization and recent theories of motor control.

Can shape be perceived by dynamic touch?

“…Sensitivity to inertial qualities may vary in subtle ways with the parameters of the exploratory activity-the manner in which the objects are hefted or wielded. If so, then Guiard's (1987) argument that the two hands operate on different spatial and temporal scales in bimanual motor tasks could have some bearing on Brodie's (1988) observation, and on that summarized in point (2) <J subjects were allowed to pick up the objects in any order and to shake them in the same ways as had been allowed in Experiment 1. The subjects were also permitted to return to any or all of the three shapes as often as desired.…”

“…Differences between the two hands with respect to sensitivity to inertial properties has been noted. Brodie (1988) reports that, in some experimental conditions, perceived heaviness of an object varies systematically with the hand that does the lifting. Sensitivity to inertial qualities may vary in subtle ways with the parameters of the exploratory activity-the manner in which the objects are hefted or wielded.…”

Hemispheric Asymmetries in Price Estimation: Do Brain Hemispheres Attribute Different Monetary Values?

“…For example, the weight perception seems to be processed by a system which integrates visual cues (object’s features) into an appropriate motor planning necessary for acting in relation to an object ( Gallivan et al, 2014 ). Moreover, unlike price, there is no evidence, to the best of our knowledge, neither of a link between weight estimation and valence attribution nor a clear lateralization of this dimension at a perceptual level ( Shen, 1936 ; Brodie, 1988 ).…”

“…One interpretation for the lack of laterality in the weight condition might be that the SNARC effect was not sufficient to drive a horizontal bias in our task. However, as stated in the Introduction, the perception of weight does not seem to be influenced by perceptual and brain asymmetries ( Brodie, 1988 ). Therefore, had the effect of numerical magnitude been involved, it should have easily biased the weight estimations, which do not seem to have other sources of asymmetry.…”