Behaviourally we predicted

IOR in the exogenous task and facilitation of RTs in the endogenous tasks. The ERP predictions were less specific, but broadly we expected exogenous attention to influence early somatosensory ERPs and endogenous attention to influence later components. Importantly, contrasting our three tasks allowed us to isolate exogenous from endogenous effects, both in terms of underlying neural correlates and also behavioural performance. In other words, our aim was to detangle how endogenous attention, exogenous attention and find more IOR operate in touch. Twelve paid participants (10 right-handed) took part in this study and all gave written informed consent prior to their participation. The study conformed with ‘The Code of Ethics of the World Medical Association’ (Declaration of Helsinki), and ethical approval was granted by City University London ethics committee. CB-839 clinical trial There were seven males and

five females with a mean age of 25.6 years (range: 20–37 years). Stimuli and apparatus were identical in the exogenous, endogenous predictive and endogenous counter-predictive tasks. Participants sat in a dimly lit, sound-attenuated Faraday cage. Tactile stimuli were presented using 12-V solenoids (5 mm in diameter). The two tactors were fixed (using medical tape) to the left and right index fingers, and the hands were 640 mm apart (see Fig. 1 for schematic view of experimental set-up). White noise (58 dB SPL) was continuously present through two speakers, each located in a direct line behind each hand, to mask any sounds made by the tactile stimulators. Tactile cues and targets consisted of a 50-ms single tap. Responses were made into a microphone, placed directly in front of the participant. A white fixation cross was presented on a monitor located directly in front of the participant, and a black cloth covered the participant’s hands to avoid any visual information of the tactile

stimulation. Stimuli were presented using E-Prime software on a PC in the adjacent room to the Faraday cage. From this PC triggers were also sent to a second PC, which recorded the electroencephalographic (EEG) data using Brain Vision Recorder (Brain Products). The experiment consisted of 13 blocks, five for each of the two endogenous tasks and three blocks for the exogenous task. The task order was counterbalanced across participants. Phosphoglycerate kinase The participant also completed a practice block of each task. In the endogenous predictive task, each block consisted of 112 trials: in 80 trials the cue and target appeared to the same side (expected trial); in 20 trials the target appeared to the opposite side to the cue (unexpected trial); in eight catch trials there was no target but only a cue (four left cues and four right); and in four trials there were ‘fast filler trials’ where the cue target interval was 400 ms for two trials and 500 ms for two, rather than 750 ms as in all other cue–target trials.