(1994) proposed a dual-process model to account for the Simon effect and its reversal. Their proposal included a distributional analysis whose results, they claimed, support the time-course assumptions they make for the 2 processes of the model. It is shown that the 2 functional components of the dual-process model, the unconditional and conditional automaticity, are equivalent to earlier accounts of the Simon effect and its reversal, namely automatic response activation of the dimensional overlap model (S. Kornblum, T. Hasbroucq, & A. Osman, 1990) and logical receding (A. Hedge & N. W. A. Marsh, 1975), respectively. It is also shown that the distributional analysis is a simple computational procedure that reflects fundamental statistical properties of the underlying reaction time distributions and their interrelationships and that De Jong et al.'s time-course assumptions precluded at least half of these interrelationships. Indeed, experimental results from tasks in which the Simon effect is obtained often violate these assumptions, as is demonstrated in this article. Finally, it is also shown that De Jong et al.'s data are consistent with the hypothesis that the Simon effect and its reversal, irrespective of the task type in which it is obtained, can be accounted for by a common mechanism with 2 independent functional components. During the past 5 years there has been a significant increase in the number of articles published on stimulusresponse compatibility (SRC). This is due in part to the fact that SRC is beginning to be seen as encompassing a broad spectrum of performance complexity, ranging from the relatively simple perceptual-motor tasks first studied by Fitts (Fitts & Deininger, 1954; Fitts & Seeger, 1953) to the cognitively more complex Stroop tasks that have defied explanation from the day the original one was first described (Stroop, 1935). Among the SRC phenomena that have recently attracted a great deal of attention is the Simon effect (e.g.,

Magnetic reconnection is a fundamental process of topology change and energy release, taking place in plasmas on the Sun, in space, in astrophysical objects and in the laboratory. However, observational evidence has been relatively rare and typically only partial. Here we present evidence of fast reconnection in a solar filament eruption using high-resolution H-alpha images from the New Vacuum Solar Telescope, supplemented by extreme ultraviolet observations. The reconnection is seen to occur between a set of ambient chromospheric fibrils and the filament itself. This allows for the relaxation of magnetic tension in the filament by an untwisting motion, demonstrating a flux rope structure. The topology change and untwisting are also found through nonlinear force-free field modelling of the active region in combination with magnetohydrodynamic simulation. These results demonstrate a new role for reconnection in solar eruptions: the release of magnetic twist.

Abstract. Employing data recorded by the Michelson Doppler Imager (MDI) instrument on the Solar and HeliosphericObservatory (SOHO), we have identified 144 pairs of opposite magnetic polarity moving magnetic features (MMFs) in two active regions (NOAA ARs 8375 and 9236). The following results are obtained: (1) The majority of MMF pairs first appears at a distance of 1000 to 5000 km from the outer boundary of the sunspot, although MMF pairs appearing closer to the sunspot may be missed. (2) MMF bipoles are not randomly oriented. The member of an MMF pair further from the sunspot has the polarity of the parent sunspot in 85% of the cases. Furthermore, the orientations of MMF pairs are associated with the twist of the sunspot superpenumbra deduced from Hα images. (3) The mean lifetime of the studied MMFs is around 4 hours. (4) The separation between the two polarities of the MMFs falls in the range of 1100-1700 km. This separation remains almost unchanged, even decreases slightly as the MMF pairs move outwards. (5) MMFs are observed to cluster at particular azimuths around the parent sunspot, in particular in AR 8375. (6) MMF pairs move approximately radially outward from sunspots at an average speed of around 0.5 km s −1 . Their motion is deflected towards large concentrations of magnetic flux of opposite polarity to that of the parent sunspot. A qualitative model based on these and other observations is presented. MMF pairs are proposed to be part of a U-loop emanating from the sunspot's magnetic canopy. Possible mechanisms leading to the formation of such a loop are discussed.

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