The potentiation of grasp types during visual object categorization

Abstract

Brain responses to handwritten and printed letters differentially depend on the activation state of the primary motor cortex.

Context effects on the processing of action-relevant object features.

“…So far, object affordance effects have mostly been reported only for button-press responses or simple finger movements that are involved in grasping actions (e.g., Derbyshire et al, 2006;Ellis & Tucker, 2000;Tucker & Ellis, 2001). The major advantage to using natural object-directed grasping action is the possibility of dissociating between effects in reaching and grasping components of motor response.…”

“…This dissociation between small and large objects was possibly driven by the fact that small objects were more difficult for the participants to discriminate, and as a result, they were not strongly associated with a particular motor representation. The idea of object affordances and the observation of response compatibility effects in object perception has led many researchers to conclude that the processing and representation of action-relevant visual information in object perception takes place in a rather automatic way (see, e.g., Tucker & Ellis, 2001). The finding of interference effects between object perception and motor actions, however, does not inevitably imply that the detection of action-relevant object features automatically activates motor representations suited for manipulation of objects (Phillips & Ward, 2002).…”

“…More important, the decisions had to be indicated by grasping the manipulandum with either a power grip or a precision grip. We expected the time to initiate reaching to be shorter when it was cued by an object affording the same type of grip rather than a different type of grip, that is, an object affordance effect (Tucker & Ellis, 2001). Taking into account previous research showing an impact of semantic magnitude information on grasping kinematics Lindemann, Abolafia, Girardi, & Bekkering, 2007;Lindemann, Stenneken, van Schie, & Bekkering, 2006), we also expected the perceived object size to affect the aperture of the hand during the reaching phase, as revealed by an enlarged MGA for pictures of large as compared with small objects.…”

“…In four experiments, we required participants to judge the semantic category (i.e., natural or manmade) of presented objects. In contrast to previous studies on stimulus-response compatibility effects in object perception (e.g., Tucker & Ellis, 2001), we required participants to indicate their decisions by performing different types of reach-to-grasp movements. The aim of the first experiment was to determine whether the perception of visual object properties interferes with the planning and execution of natural grasping movements by investigating the effects of object affordances on the reach onset times and movement kinematics of grasping actions.…”

“…Gibson (1979) argued that the affordances of objects are based on their intrinsic perceptual properties, registered automatically and without the need for further cognitive processes such as object recognition. To test this notion, Tucker and Ellis (2001) required their participants to indicate the semantic category of natural and manmade objects by mimicking either a full or a precision handgrip. They found a compatibility effect between the size (large or small) of the presented object and the required response (full or precision handgrip).…”