Fig 1.
Figure 1 presents a schematic image of the behavioural task. The left hand side of the image illustrates the (fully counterbalanced) sequence of the mini-blocks/tasks across a run (passive viewing baseline, object task, movement task and goal task). On the right, an example of an experimental mini block for each condition is depicted. Note that the image with a red border within each mini-block illustrates a repetition for that condition (e.g. a repeated object, movement or goal).
Table 1.
Pairwise comparison of the goal, movement and object task.
Fig 2.
Unique goal activations & pairwise comparisons of goal, movement and object tasks.
Panel A shows unique activation in the goal task (green), as well as activation shared between goal task and object task (blue). No activations were shared with the movement task. Panel B to D show pairwise comparisons of the three tasks. Panel B: Object task (blue) vs. Movement task (red). Panel C: Goal task (green) vs. Movement task (red). Panel D: Goal task (green) vs. Object task (blue). All activations thresholded at p < 0.005 and whole-brain corrected to a familywise error p < 0.05.
Table 2.
Shared and unique activation in the goal task.
Fig 3.
Shows brain regions showing associations with the participants’ subjective action ratings. Top panel: negative associations with the apparentness of the action goals. Lower panel: negative associations with the amount of prior sensorimotor experience with the actions. All activations thresholded at p < 0.005 and whole-brain corrected to a familywise error p < 0.05.
Table 3.
Whole brain activations varying parametrically with subjective action judgments.
Table 4.
Parametric regions from Movement task.
Parametric trial-by-trial analyses of subjective action ratings (Exp., sensorimotor experience with the actions; App., apparentness of action goals), for each of the regions identified by the movement task (relative to the object task). The values show average across-participants beta values reflecting the relationship between individual participants’ ratings of the actions and brain activation while observing them in the four tasks.
Fig 4.
A simple model of everyday action understanding.
Potential goals are initially identified on the basis of object information in inferior frontal and middle temporal areas (Step 1). Parietal-premotor motor-representation regions verify this initial interpretation or provide additional information (Step 2). If a goal is identified, associated mental states can in turn become activated—via medial prefrontal areas—and integrated with the situational context or prior knowledge about the person (Step 3).