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A human homologue of monkey F5c.

Ferri S, Peeters R, Nelissen K, Vanduffel W, Rizzolatti G, Orban GA - Neuroimage (2015)

Bottom Line: By presenting the two grasping actions (actor, hand) and varying the low level visual characteristics, we localized a putative human homologue of area F5c (phF5c) in the inferior part of precentral sulcus, bilaterally.In contrast to monkey F5c, phF5c is asymmetric, with a right-sided bias, and is activated more strongly during the observation of the later stages of grasping when the hand is close to the object.The latter characteristic might be related to the emergence, in humans, of the capacity to precisely copy motor acts performed by others, and thus imitation.

View Article: PubMed Central - PubMed

Affiliation: Department of Neuroscience, University of Parma, Parma, Italy.

No MeSH data available.


Experiment 3: Local maxima (white squares, p > 0.01 uncorrected) of the interaction person-action in 18 individual subjects, superimposed on the group interaction site (colored voxels, p < 0.001 unc) in right PCSi, shown on flat map.
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f0035: Experiment 3: Local maxima (white squares, p > 0.01 uncorrected) of the interaction person-action in 18 individual subjects, superimposed on the group interaction site (colored voxels, p < 0.001 unc) in right PCSi, shown on flat map.

Mentions: To assess the status of possible homologues of F5c among the four PMv interaction sites, we exploited the four statistically validated functional properties of F5c as revealed by Experiment 2, listed in Table 3. To examine these properties, we subjected the activity profiles of these four sites (Fig. 4) to a 2 × 2 ANOVA, yielding the expected interaction, but allowing us to test the main effect of action and to perform critical post-hoc t-tests. Also, we used a paired t-test to compare the acting person and baseline fixation conditions. The results showed that two of the four interaction sites share the characteristics of F5c (Table 3). In the right interaction site (Fig. 5b) the static hand condition reached about half the activation level evoked by acting person, yet t-tests showed that the latter condition evoked significantly more activity than the other 3 factorial conditions, or the fixation baseline. Since this site showed no main effect of action, it met all four criteria derived from Experiment 2. In the left hemisphere, only the PCSi site (site 3 in Fig. 4c) met these four criteria (Table 3, Fig. 5b). The lower PCG site (LH2) failed in the criterion comparing observing person grasping to the other factorial conditions, as it was equally active in the static hand and acting person conditions. It also failed the last criterion, as the visual response to person grasping was not significant. The upper PCG site (LH1) had a relatively strong response to the grasping hand, even if the acting person condition significantly exceeded each of the three other factorial conditions. Unlike monkey F5c, however, it showed a main effect of action, failing the third criterion. The location of this LH1 site was indeed similar to the dorsal left hemisphere region which was activated in the two single contrasts in Experiment 1 (Fig. 4a). Experiment 3 thus yielded in addition to the right interaction site, a single left-sided interaction site (site 3, 29 voxels) matching F5c in statistical characteristics (Fig. 5b). This left site was located in a position matching that of the right, since it reached corrected significance using the right site as an a priori ROI. The left site was not only smaller than its right counterpart, it was also less significant as it failed to reach FWE significance at the cluster level (p > .65). We refer to these two sites as left and right phF5c. Single-subject analysis confirmed that the right phF5c was present in all individual subjects in approximately the same cortical location (Fig. 7).


A human homologue of monkey F5c.

Ferri S, Peeters R, Nelissen K, Vanduffel W, Rizzolatti G, Orban GA - Neuroimage (2015)

Experiment 3: Local maxima (white squares, p > 0.01 uncorrected) of the interaction person-action in 18 individual subjects, superimposed on the group interaction site (colored voxels, p < 0.001 unc) in right PCSi, shown on flat map.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4401441&req=5

f0035: Experiment 3: Local maxima (white squares, p > 0.01 uncorrected) of the interaction person-action in 18 individual subjects, superimposed on the group interaction site (colored voxels, p < 0.001 unc) in right PCSi, shown on flat map.
Mentions: To assess the status of possible homologues of F5c among the four PMv interaction sites, we exploited the four statistically validated functional properties of F5c as revealed by Experiment 2, listed in Table 3. To examine these properties, we subjected the activity profiles of these four sites (Fig. 4) to a 2 × 2 ANOVA, yielding the expected interaction, but allowing us to test the main effect of action and to perform critical post-hoc t-tests. Also, we used a paired t-test to compare the acting person and baseline fixation conditions. The results showed that two of the four interaction sites share the characteristics of F5c (Table 3). In the right interaction site (Fig. 5b) the static hand condition reached about half the activation level evoked by acting person, yet t-tests showed that the latter condition evoked significantly more activity than the other 3 factorial conditions, or the fixation baseline. Since this site showed no main effect of action, it met all four criteria derived from Experiment 2. In the left hemisphere, only the PCSi site (site 3 in Fig. 4c) met these four criteria (Table 3, Fig. 5b). The lower PCG site (LH2) failed in the criterion comparing observing person grasping to the other factorial conditions, as it was equally active in the static hand and acting person conditions. It also failed the last criterion, as the visual response to person grasping was not significant. The upper PCG site (LH1) had a relatively strong response to the grasping hand, even if the acting person condition significantly exceeded each of the three other factorial conditions. Unlike monkey F5c, however, it showed a main effect of action, failing the third criterion. The location of this LH1 site was indeed similar to the dorsal left hemisphere region which was activated in the two single contrasts in Experiment 1 (Fig. 4a). Experiment 3 thus yielded in addition to the right interaction site, a single left-sided interaction site (site 3, 29 voxels) matching F5c in statistical characteristics (Fig. 5b). This left site was located in a position matching that of the right, since it reached corrected significance using the right site as an a priori ROI. The left site was not only smaller than its right counterpart, it was also less significant as it failed to reach FWE significance at the cluster level (p > .65). We refer to these two sites as left and right phF5c. Single-subject analysis confirmed that the right phF5c was present in all individual subjects in approximately the same cortical location (Fig. 7).

Bottom Line: By presenting the two grasping actions (actor, hand) and varying the low level visual characteristics, we localized a putative human homologue of area F5c (phF5c) in the inferior part of precentral sulcus, bilaterally.In contrast to monkey F5c, phF5c is asymmetric, with a right-sided bias, and is activated more strongly during the observation of the later stages of grasping when the hand is close to the object.The latter characteristic might be related to the emergence, in humans, of the capacity to precisely copy motor acts performed by others, and thus imitation.

View Article: PubMed Central - PubMed

Affiliation: Department of Neuroscience, University of Parma, Parma, Italy.

No MeSH data available.