Objects in action observation
Prior work has argued that action understanding relies primarily no kinematic information that automatically activates own motor knowledge. However, there is no one-to-one mapping between goals and motor behaviours. The same goal can be achieved with multiple actions (e.g. paying with credit card or cash) and the same actions can support various goals (e.g. inserting a credit card into a cash machine or a ticket into ticket canceller). How then can people nevertheless predict others' actions from their goals, and - conversely - understand their goals from their motor behaviours?
We argue (Bach et al., 2014; Bach & Schenke, 2017) that objects carry the necessary information, sometimes over and above what is available from action kinematics. People know,from their own action experience both which goals can be achieved with an object (i.e. function knowledge: a hammer is "for" hammering in nails) and which body movements are required for them (manipulation knowledge: forceful swinging motions). This knowledge can directly inform action observation: as soon as one knows about the goals of another person, and sees them act upon an object, one can predict - via manipulation knowledge - which motor behaviour they will carry out. Conversely, seeing someone act on an object allows one to understand - via function knoweldge - which goal they are trying to achieve.
Several studies from ours and others' labs have tested this role of goals and objects on action prediction. We have shown, for example, using behavioral (Bach et al., 2005), EEG/ERP (Bach et al., 2008) and fMRI measures (Bach et al., 2010) that goals and motor knowledge is intertwined in object representations during action observation, and that seeing objects that evoke such goals (e.g. screwdriver and screw) also evokes (predicts) the associated motor actions. Similar data come from automatic imitation experiments, where the kinematic components of an observed action are only represented if they are part of an action that is appropriate for the goal object (Bach, Bayliss & Tipper, 2011).
Most recently, we have used fMRI to directly test kinematic and object based models of action understanding against each other. The data did indeed show that action goal understanding draws heavily on regions involved in object identity processing, and that regions involved in motor/kinematic processing were only activated in cases of uncertainty or when the goal could not be directly derived from object information alone, even when stimuli in each task were identical (Nicholson, Roser & Bach, 2017).
Bach, P., Fenton-Adams, W., & Tipper, S.P. (2014). Can't touch this: the first-person perspective provides privileged access to predictions of sensory action outcomes. Journal of Experimental Psychology: Human Perception and Performance. Publisher – PDF – Data
Morrison, I., Tipper, S. P., Fenton‐Adams, W. L., & Bach, P. (2012). “Feeling” others' painful actions: The sensorimotor integration of pain and action information. Human Brain Mapping, 34(8), 1982–1998. PDF
Bach, P., Bayliss, A.P., Tipper, S.P. (2011). The predictive mirror: interactions of mirror and affordance processes during action observation. Psychonomic Bulletin & Review, 18(1), 171-6. PDF
Bach, P., Peelen, V.M., Tipper, S.P. (2010). On the role of object information in action observation: an fMRI study. Cerebral Cortex. PDF
Bach, P., Gunter, T.C., Knoblich, G., Prinz, W., & Friederici, A.D. (2009). N400-like negativities in action perception reflect two components of an action representation. Social Neuroscience, 4(3), 213-232. PDF
Bach, P., Knobpch, G., Gunter, T.C., Friederici, A.D., Prinz, W. (2005). Action Comprehension: Deriving Spatial and Functional Relations. Journal of Experimental Psychology: Human Perception & Performance, 31(3), 465-479. PDF