In Experiment 2, the target was accompanied by context discs that were larger and smaller than the range of target sizes. In this case, there was no contrast effect, and a perseveration effect was observed over the course of the movement trajectory. In a third experiment, a sequential contrast effect was found when subjects did not grasp the disc but merely estimated its size. Our interpretation check details is that there are two mechanisms producing sequential effects: a perceptual contrast effect in which the target appears larger following a smaller disc, and a motor perseveration effect in which subjects tend to
reuse similar motor control parameters from trial to trial. These effects were overlaid in Experiment 1, producing the observed biphasic response. However, Cediranib in vitro in Experiment 2, the context eliminated sequential perceptual contrast, and grip aperture only showed an effect of perseveration. In Experiment 3, only the perceptual effect was found because subjects did not need to grasp the disc. (C) 2008 Elsevier Ltd. All rights reserved.”
“The perception-action model Proposes that vision for perception and vision for action are subserved by two separate cortical systems, the ventral and
dorsal streams, respectively [Milner, A. D., & Goodale, M. A. (1995). The visual brain in action (1 st ed.). Oxford: Oxford University Press; Milner, A. D., & Goodale, M. A. (2006). The visual brain in action (2nd ed.). Oxford: Oxford University Press Inc.]. The dorsal stream codes spatial information egocentrically, that is, relative to the observer. Egocentric representations are argued to be highly transient; therefore, it might be expected that egocentric information cannot be used for spatial memory tasks, even when the visual information only needs to be retained fora few seconds. Here, by applying a spatial priming paradigm to a visual search task, we investigated whether short-term spatial memory CDK inhibitor can use egocentric information. Spatial priming manifests itself in speeded detection times for a target when that target appears
in the same location it previously appeared in. Target locations can be defined in either egocentric or allocentric (i.e. relative to other items in the display) frames of reference; however, it is unclear which of these are used in spatial priming, or if both are. Our results show that both allocentric and egocentric cues were used in spatial priming, and that egocentric cues were in fact more effective than allocentric cues for short-term priming. We conclude that egocentric information can persist for several seconds; a conclusion which is at odds with the assumption of the perception-action model that egocentric representations are highly transient. (C) 2008 Elsevier Ltd. All rights reserved.”
“Interactions between perception and action were examined by assessing the effects of action programming on extinction and neglect.