Arm movement metrics influence saccade metrics when looking and pointing towards a memorized target location

Saccades are known to influence subsequent arm movements. There is less information to suggest that the characteristics of saccades depend on the reaching movements they accompany. To explore this issue, we studied the systematic errors of saccades generated by two adult female Rhesus monkeys (Macaca Mulata), which were trained to perform center-out saccades and reaching arm movements to the memorized location of targets. The mean error of saccades executed in isolation differed significantly from that of saccades that were executed towards the same target location and accompanied a reaching movement. This difference was observed in both animals whether they used their right or left arm, whether the size of the movement was equal to 10 or 15 degrees and whether there was no delay or a 3 s delay between the extinction of a visual target and the cue to move. Moreover, the endpoints of saccades and those of the arm-reaching movements in the reaching task were significantly correlated. These data suggest that signals specifying the metrics of limb movements influence those specifying the metrics of preceding saccades at a programming stage. © 2008 Springer-Verlag

Salmo macrostigma (Teleostei, Salmonidae): Nothing more than a brown trout ( S. trutta ) lineage?

International audienceWe examined specimens of the macrostigma trout Salmo macrostigma, which refers to big black spots on the flanks, to assess whether it is an example of taxonomic inflation within the brown trout Salmo trutta complex. Using new specimens, publicly available data and a mitogenomic protocol to amplify the control and cytochrome b regions of the mitochondrial genome from degraded museum samples, including one syntype specimen, the present study shows that the macrostigma trout is not a valid species. Our results suggest the occurrence of a distinct evolutionary lineage of S. trutta in North Africa and Sicily. The name of the North African lineage is proposed for this lineage, which was found to be sister to the Atlantic lineage of brown trout, S. trutta