Figure 1.

Experimental task set up. Both the trainee (A) and trainer (B) control the virtual instruments, each with two haptic manipulators (Phantom Omni, SensAble Tech, USA). The trainer’s right hand manipulator is highlighted (yellow). Gaze behavior is detected with portable eyetracker (X50 eyetracker, Tobii Technologies, Sweden) situated below both monitors (trainer eyetracker highlighted yellow). An Optical topography (OT) system (ETG-4000, Hitachi Medical Corp. Japan) positioned outside the trainee’s field of view (left, highlighted) records cortical hemodynamic data from 24 cortical loci (channels). Appropriate channel locations (yellow circles) are understood by projecting 3D positional data onto a T1 weighted MRI image (upper subplot). The lowermost row of channels was centered on Oz of the International 10–10 system (Jurcak et al., 2007). Task images can be appreciated on trainer and trainee monitors and sample screen shots are represented in which the trainee’s instruments are located inferiorly (i–iv). With the collaborative gaze channel (CGC) enabled, the trainee regards the blue cross indicating the intended biopsy target (i). The trainee then grasps the nodule (black circle) (ii) and passes it to the trainer’s instrument (iii–iv). With the channel disabled, the trainee performs identical maneouvres but only with verbal instructions from the trainer.