Movement Trajectories in the Presence of a Distracting Stimulus: Evidence for a Response Activation Model of Selective Reaching

Abstract

Consistent with action-based theories of attention, the presence of a nontarget stimulus in the environment has been shown to alter the characteristics of goal-directed movements. Specifically, it has been reported that movement trajectories veer away from (Howard & Tipper, 1997) or towards (Welsh, Elliott, & Weeks, 1999) the location of a nontarget stimulus. The purpose of the experiments reported in this paper was to test a response activation model of selective reaching conceived to account for these variable results. In agreement with the model, the trajectory changes in the movements appear to be determined by the activation levels of each competing response at the moment of response initiation. The results of the present work, as well as those of previous studies, are discussed within the framework of the model of response activation. In order to effectively reach to and grasp objects in a complex visual environment, two processes must be completed-the target object must be selected from the competing, nontarget objects, and a movement must be planned to interact with the selected object. Although the processes of selective attention and movement organization have been investigated independently, action-based models of visual selective attention have recently surfaced. For example, Rizzolatti and colleagues have proposed a premotor theory of attention (see Rizzolatti, Riggio, & Sheliga, 1994, for a review). Citing evidence such as shared spatial and motor mapping systems, and increased activity in early visual perceptual centres

Salient stimuli capture attention and action

“…If more than one object is attended, multiple action plans are generated (Cisek & Kalaska, 2005), and the actual movement may represent a mixture between these action plans if there was not sufficient time to inhibit the movement plans to the wrong locations. With little time to inhibit conflicting movement plans, the final response represents a mixture between a response to the target and a response to the distractor, which is what was observed in the present and in previous studies (Buetti & Kerzel, 2009;Scherbaum, Dshemuchadse, Fischer, & Goschke, 2010;Welsh, 2011;Welsh & Elliott, 2004).…”

Effects of emotional picture on movement trajectory: The role of meaning and the power of context

“…To this aim, the cognitive system has an inhibitory mechanism that, in normal conditions, rules out the outputs to distractors, in order to achieve subjects' goals (e.g. Welsh and Elliott 2004). This mechanism has been proposed to be efficient but not entirely effective (e.g.…”

Efeitos de estresse e treino na latência e acurácia de respostas motoras a estímulos visuais.

“…An analogy can perhaps be found in the literature on the role of visual nontarget objects (that are not necessarily physical obstacles) in reaching and grasping tasks Tipper, Howard, Jackson, 1997;Welsh, Elliott, Weeks, 1999). These studies have reported that visual non-target objects that surround the target influence the trajectory of the target-directed hand movement by either veering away from Tipper et al, 1997) or towards the visual non-target object (Welsh et al, 1999;Welsh, Elliott, 2004). To explain these effects, the response activation model (Welsh, Elliott, 2004; for an alternative explanation, see Howard, Tripper, 1997) proposes that prior to the execution of an action attention is distributed throughout the environment.…”

“…In fact, Welsh and Elliott (2004) observed with neutral stimuli that if the visual non-target object was present before the onset of action, the inhibitory processes had sufficient time to de-activate the associated action response processes. In the current experiment, the goalkeeper is also presented well before the kicker's run-up, however, in all likelihood the goalkeeper is a salient rather than a neutral visual stimulus.…”

“…These studies have reported that visual non-target objects that surround the target influence the trajectory of the target-directed hand movement by either veering away from Tipper et al, 1997) or towards the visual non-target object (Welsh et al, 1999;Welsh, Elliott, 2004). To explain these effects, the response activation model (Welsh, Elliott, 2004; for an alternative explanation, see Howard, Tripper, 1997) proposes that prior to the execution of an action attention is distributed throughout the environment. As a result, both target and non-target objects activate automatic independent and parallel action response processes.…”