Practice and Brain Activity

<p>Tests for significant effects of practice on encoding activity averaged over all encoding ROIs and response selection activity averaged over all response selection ROIs. Signals were tested over all runs (1^st row) and between novel task (NT) and each practice run (PT). Significant results are displayed in bold.</p

Practice and Performance

<p>a. reaction time (top) and b. error rate (bottom). Measures were tested over all runs (1st row) and between novel task (NT) and each practice run (PT), across one-letter (MS1) and five-letter (MS5) memory set trials (1st column) and for MS1 trials vs. MS5 trials (2nd column). Significant results are displayed in bold.</p

Practice and Encoding Activity

<p>Multivariate tests for signals in ROIs related to encoding. Signals were tested over all runs (1st column) and between novel task (NT) and each practice run (PT). Significant results are displayed in bold. (For abbreviations see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0003270#pone-0003270-t002" target="_blank">table 2</a>).</p

Heterogeneous effect of practice on regions activated by both encoding and response selection.

<p>Example of bold activity (arbitrary units) in regions activated by both phases: a. left DLPFC (top) and b. anterior cingulate cortex (bottom) during the novel task (left), after one practice run (middle) and six practice runs (right); showing the heterogeneous effects of practice for encoding and response selection.</p

Response Selection ROI's.

<p>ROIs showing activity related to the response selection. The numbers in the color bar refer to the response selection ROIs (RS1–RS14) in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0003270#pone-0003270-t003" target="_blank">table 3</a>.</p

Practice and Response Selection Activity

<p>Multivariate tests for ROI signals related to response selection. Signals were tested over all runs (1st column) and between novel task (NT) and each practice run (PT). Significant results are displayed in bold. (For abbreviations see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0003270#pone-0003270-t003" target="_blank">table 3</a>).</p

Response Selection ROI's

<p>Description of ROIs showing activity correlated with response phase. Abbreviations: RS = response selection; BA = Brodmann Area; NV = number of voxels in ROI (size of ROI); x, y, z = MNI coordinates of voxel with highest t-value in ROI; tmax: maximum t-value in ROI).</p

Encoding ROI's

<p>Description of ROIs showing activity correlated with encoding phase. (Abbreviations: E = encoding; BA = Brodmann Area; NV = number of voxels in ROI (size of ROI); x, y, z = MNI coordinates of voxel with highest t-value in ROI; tmax: maximum t-value in ROI).</p

Cognitive Paradigm.

<p>The timeline is shown for the cognitive experiment. Two m-sequences (m.seq.) of 63 bits control the encoding phase (1) and the response phase (2). Each trial starts with the encoding phase followed by a brief delay and the response phase. Where bits are 0 (baseline); memory sets with 1 letter (MS1) are presented during the encoding phase and blank trials are presented during the response phase. Where bits are 1; 5-letter memory sets (MS5) are presented during the encoding phase and a probe stimulus during the response phase. In the novel task the letters presented during the encoding phase were different in each MS1 and MS5 trial. In the practiced task, the same five letters were repeated in each MS5 trial.</p

Encoding ROI's.

<p>ROIs showing activity related to encoding. The numbers in the color bar refer to the encoding phase ROIs (E1–E7) in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0003270#pone-0003270-t002" target="_blank">table 2</a>.</p