Visuomotor Adaptation in a Viewing Window Task Figure 5. Normalized mean behavioural measures by phase. Behavioural measures of the early, late, and post distortion values are presented relative to the baseline (measures during the pre distortion phase) of each group. A) Velocity of Viewing Window movement. B) Scan Time required to identify object *Both distortion groups demonstrated a significant reduction in scan time in the post distortion phase (p,0.05). C) Percentage of Time off Object. A significant interaction was found between phase and distortion type was found in the percentage of time spent off the object (p,0.001). doi:10.1371/journal.pone.0048759.g005 [18,19], whereas, spatial realignment is believed to rely on the cerebellum [4,20,21,22]. However, to date there have only been a handful of neuroimaging studies investigating the neural correlates of visual motor adaptation [18,23,24,25,26]. We have recently employed the Viewing Window task with large distortions in the form of flips in direction to investigate the neural basis of strategic control using functional magnetic resonance imaging (fMRI) and found in addition to traditional areas associated with visuomotor adaptation, novel recruitment of the claustrum. This task presents several advantages over other tasks previously used as it is computer-based therefore easier to manipulate a range of distortions over a short period of time. This would be difficult to do using prism glasses in an environment such as that during a functional magnetic resonance imaging (fMRI) study. In the future, we will utilize this paradigm to investigate the neural correlates that underlie both mechanisms of visuomotor adapta- tion. Incremental rotations have previously been used to investigate visuomotor adaptation without the awareness of the participant [10,11,25]. However, there are some differences between our experimental design and those used in the past. Kagerer et al. [8] used a rotated mouse task with 10u increments during their gradual rotation condition to a maximum rotation of 90u. In their study, they suggest that using a gradual feedback distortion allows for a more complete adaptation compared to a sudden onset of the distortion [8]. During our 27 trials of distortion we kept increments as small and uniform as possible in order to ensure that distortions would not be apparent to the subject. Therefore, we selected an incremental change of 2.5u to a maximum rotation of 67.5u. The present study task differs from both Kagerer et al [8] and Klassen et al [10] in that subject naturally explored the computer screen without restrictions on directions. Kagerer et al [8] used a target task where subjects used a pen to start a center point and were instructed to draw a line in one of four directions. Similarly, Klassen et al [10] used a point-to-point task in eight directions. The use of the Viewing Window task has several advantages over previous prism studies and anti-pointing tasks. First, the adapta- tion task is hidden within a perceptual task. Subjects do not know that the motor relationship is altered ahead of time. Second, the Viewing Window investigates visuomotor adaptation in a more PLOS ONE | www.plosone.org 7 November 2012 | Volume 7 | Issue 11 | e48759