Sportopedia Glossary

Basic Action Concepts (BACs)

Basic Action Concepts (BACs)

Basic Action Concepts (BACs), Action, Chunking, Motor learning, Skill acquisition) Researchers from different fields, such as cognitive psychology, cognitive robotics, and sport psychology (Schack & Hackfort, 2007; Schack & Mechsner, 2006; Schack & Ritter, 2013), have provided evidence for socalled basic action concepts (BAC) in the control of human movements. Analogous to the well-established notion of object concepts, BACs are meant to be the mental counterparts of functionally relevant elementary components or transitional states (body postures) of complex movements. BACs are based on the cognitive chunking of body postures and movement events concerning common functions in realizing action goals.

They do not refer to behavior-related invariance properties of objects, as in the case in basic object concepts, but to perception-linked invariance properties of movements.

BAC have been identified as major representation units for mental representation in the context of motor control. Their characteristic set of features arise from the perceptive and functional properties of action effects. These functional features are derived from action goals, which link BACs to levels and modules of mental control. Furthermore, BACs integrate sensory features of partial actions (e.g., through chunking). As a result, they also refer to perceptual effects of movements, which connect BACs to action execution at related motor levels. For example, a BAC like ‘whole body stretch motion’ in tennis is functionally related to providing energy to the ball, transforming tension into swing, stretching but remaining stable, and the like.

Afferent sensory features of the corresponding sub-movement that allow a monitoring of the initial conditions are kinesthetic and tactile information coming from bended knees, tilted shoulder axis, and body weight on the left foot. Referent sensory features that allow monitoring of whether the functional demands of the sub-movements have been addressed successfully are, for instance, proprioceptive and, finally, perhaps visual perceptions of the swinging arm and ball in view.

Results from another line of experimental research have showed that not only the structure formation of mental representations in long-term memory but also chunk formation in working memory is built up on BACs and relates systematically to movement structures (Schack, 2004, 2010). These studies have revealed a plausible relation between chunking and priming processes in working memory and the structure of human movements, suggesting a movement-based chunking. Such findings provide experimental evidence that structures in movement and memory mutually overlap.


Schack, T. (2004). The cognitive architecture of complex movement. International Journal of Sport and Exercise psychology, 2(4), 403 438.

Schack, T. (2010). Die kognitive Architektur menschlicher Bewegungen (The cognitive architecture of human movements). Aachen: Meyer & Meyer.

Schack, T., & Hackfort, D. (2007). Action-theory approach to applied sport psychology. In G. Tenenbaum, & R. C. Eklund (Eds.), Handbook of sports psychology (3rd ed., pp. 332 351). Hoboken, NJ: Wiley.

Schack, T., & Mechsner, F. (2006). Representation of motor skills in human long-term-memory. Neuroscience Letters, 391, 77 81.

Schack, T., & Ritter, H. (2013). Representation and learning in motor action   Bridges between experimental research and cognitive robotics. New Ideas in Psychology, 31(3), 258 269.

***Contributed by Thomas Schack for Hackfort, D., Schinke, R. J., & Strauss, B. (Eds.). (2019). Dictionary of sport psychology: sport, exercise, and performing arts. Academic Press.