Figure 1.
A summary of randomized stimuli presentation.
Facilitation phase: one set of 20 pictures were presented three times on two separate occasions (six times total), simultaneously with a semantic auditory question, for yes/no response by computer mouse button (LT prime). Testing phase (during scan): the long-term facilitated set were presented again for naming (LT target); a set of 20 pictures were presented twice - once as a prime along with an auditory question for yes/no response (ST prime) and then presented again (6 to 12 trials later) for naming (ST target); and one set of 20 unfacilitated pictures was also presented once for naming (UN), along with an additional set of 20 unfacilitated non-critical fillers. * indicates the three main naming conditions of interest – unfacilitated, long-term facilitated and short-term facilitated.
Figure 2.
Facilitation effects in behavioral data.
A. Mean reaction times and standard errors for each condition. B. Mean percentage accuracy for each condition. Significant differences were found between all conditions for naming latency (p<0.05). No significant differences were identified between conditions for percentage accuracy. Error bars indicate standard error mean.
Figure 3.
Figure displays the a priori defined region of interest (the mid-portion of the middle temporal gyrus), within which significant differences in activation (p<0.05) were identified for two key contrasts. Bar graph indicates relative mean percentage BOLD signal change as a function of facilitation, compared to the unfacilitated condition. * indicates significant changes in mean signal intensity compared to the unfacilitated baseline (p<0.05) and ** indicates a significant difference between long-term (LT) and short-term (ST) facilitated conditions. Error bars indicate standard error mean.
Figure 4.
Regions showing significant BOLD response for relevant contrasts of interest (at p<0.001) for clusters greater than 23 contiguous voxels (as per 3dClustSim minimum cluster size) displayed on the SPM5 T1 canonical brain in a series of sagittal slices. Parameter estimates: ST>UNF = 0.04±0.01 and ST>LT = 0.0185±0.0055.
Table 1.
Whole brain results.