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Table 2 Results of the principal component analysis.

From: Emotional reactivity and cognitive performance in aversively motivated tasks: a comparison between four rat strains

Test/essay measure A) Loadings on the first five factors extracted by PCA, varimax rotation B) Loadings on the first five factors extracted by PCA, varimax rotation, after correction for strain effects: residuals
  Factor 1 Factor 2 Factor 3 Factor 4 Factor 5 Factor 1 Factor 2 Factor 3 Factor 4 Factor 5
open field           
   Time in corners (mean 5 days)     0.73 -0.50     -0.78  
   Line crossings (mean 5 days) -0.92      -0.87     
   Rearings (mean 5 days) -0.91      -0.90     
elevated plus maze           
   Percent time open arms (day 1)      0.86     0.83  
   Percent entries open arms (day 1)      0.89     0.87  
   Rearings (day 1) -0.69      -0.64     
circular Light-dark box           
   Time in dark (mean 3 days)   -0.56   0.59     0.68   
   Line crossings (mean 3 days)     -0.62     -0.71   
   Rearings (mean 3 days) -0.50    -0.67   -0.63   -0.67   
standard MWM           
   Distance swum (mean 5 days) 0.64      0.72     
   Distance swum (linear trend)    0.79     0.62    
   Probe trial time training annulus    -0.74        -0.55
repeated acquisition MWM           
   Delta (odd minus even trials) -0.51          0.75
passive avoidance           
   Log latency entry dark, retention    -0.57     -0.60    
serotonin           
   5-HT turnover in hippocampus -0.51          
   5-HT cortex   0.90      -0.81    
   5-HIAA cortex   0.85      -0.75    
Variance explained (%) 32.0 12.3 11.5 9.0 8.0 24.4 15.1 12.4 10.0 8.1
  1. Loadings, higher than 0.5, on the first five factors extracted by principal component analysis (PCA), after varimax rotation (A), and of residuals obtained after correction for the effect of strain (B), of measures of emotional reactivity, spatial learning and memory in the standard and the repeated acquisition versions of the MWM task, the passive avoidance task, and serotonergic measures in hippocampus and cortex of 32 rats. The percent of total variation explained by each factor is also shown.