We quantify the amount of information about movement timing present in each of these two populations using a decoding analysis in which we decode the RT of either reach or saccade movements on each trial from the firing rates. The decoding analysis is limited by the number of trials available but the conclusions are consistent with the results of an ANOVA analysis demonstrating that only coherent spiking predicts coordinated movement

RTs. We also find that the role beta-band activity in area LIP plays in movement preparation depends on whether movements are coordinated. Beta-band activity and the spiking coherent with it in area LIP predict coordinated RTs but not saccade RTs when saccades are made alone. ABT-263 supplier The lack of association between area LIP activity and RT when saccades are made alone suggests that performing a coordinated movement alters the role of area LIP beta-band activity in the generation of movement. Beta-band activity in area LIP could measure the linking of areas involved in the preparation of each movement. The coordination of two movements requires information about the timing

of one to be shared with the other. This involves constructing a shared representation of movement preparation that recruits beta-band activity in area LIP. Note that this need not contradict data showing that area LIP has more saccade-related activity than reach-related activity. Beta-band activity may simply modulate already existing activity in area LIP

EGFR inhibitor drugs in order to coordinate too saccades with reaches. Area LIP is one of several posterior parietal regions situated between visual and motor areas. These areas contain spatial representations for visual spatial attention (Bisley and Goldberg, 2010), decision making (Sugrue et al., 2004, Gold and Shadlen, 2007 and Kable and Glimcher, 2009), and movement intention (Andersen and Cui, 2009). Spatial representations in PPC are effector-specific (Colby, 1998 and Andersen et al., 1998). Area LIP activity encodes space for the guidance of saccades in eye-centered coordinates, and PRR encodes space for reaching in eye-centered coordinates (Batista et al., 1999 and Pesaran et al., 2006). These properties of area LIP and PRR position them to share effector-specific representations to control coordinated movements. While previous work studying PPC has emphasized spatial representations, extensive behavioral work shows that eye-hand coordination reliably influences movement RTs; evidence for spatial coupling is relatively less clear (Carey et al., 2002 and Sailer et al., 2000). The eye leads the hand in many tasks, allowing vision to guide the hand to the target (Prablanc et al., 2003 and Johansson et al., 2001). When a reach and a saccade are made simultaneously, reach and saccade RTs are correlated (Dean et al., 2011 and Lünenburger et al., 2000). These correlations mean that the eye tends to arrive at a target at a predictable time before the hand.