Reaction times and their correlations are learn more not necessarily due to processes that support visual-motor performance

and could be due to several other factors, including processing bottlenecks (Pashler, 1984), common sensory inputs (Lee et al., 2010), and nonspecific influences such as motivation or arousal (Boucher et al., 2007). Recent behavioral and computational modeling work, however, indicates that as saccade and reach movements are dissociated in time, correlations in RTs decay rapidly. RT correlations cannot be fit by a family of models featuring nonspecific interactions and are best fit by models invoking specific interactions between movement representations (Dean et al., 2011). Consequently, saccade and reach RT correlations may be due to interactions that form an effectively shared movement representation. We provide convergent evidence that beta-band signals reflect movement preparation shared between saccades and reaches, which may be sufficient for generating RT correlations and could ultimately

influence movement initiation. The relationship between coordination and RT correlations is likely to involve areas in addition to PPC. PPC works in concert with other areas that prepare and initiate movements, including click here areas in the frontal cortex and basal ganglia (Hanes and Schall, 1996 and Requin and Riehle, 1995). PPC also contains direct connections to the cerebellum (Prevosto et al., 2010), MycoClean Mycoplasma Removal Kit a structure that has been implicated in the timing of coordinated movements (Miall and Reckess, 2002). If the RT selectivity of beta-band activity we observe is also present in other areas, this aspect of beta-band activity may reflect processing across a network of areas that work together to control the timing of movements and coordinate saccades with reaches. Several other lines of convergent evidence support the hypothesis that beta-band activity reflects distributed processing. Correlated beta-band LFP activity is present across long-range circuits (Rougeul et al., 1979) and could

underlie long-range communication between brain regions (Roelfsema et al., 1997, Brovelli et al., 2004, Bressler et al., 1993 and Donner and Siegel, 2011). Beta-band activity may be involved in bottom-up/top-down influences (Buschman and Miller, 2007) and maintaining a motor state (i.e., the status quo) (Engel and Fries, 2010), thus leading to slower response. Beta-band activity is widely modulated during movement tasks (Sanes and Donoghue, 1993) and could be related to attended motor behavior (Bouyer et al., 1987) and sensory-motor integration (Murthy and Fetz, 1992). Beta-band LFP activity in the human and monkey motor cortex may work to influence processing of visual cues and targets (Reimer and Hatsopoulos, 2010, Rubino et al., 2006 and Saleh et al., 2010).