 The producers and consumers of mental representations, by contrast, are subsystems of an organism. In very simple cases, the producer is a particular sensory system, and the consumer a motor system. Consider the often-cited example of the frog that visually detects appropriately small, dark, moving objects, and responds to them by darting out its tongue. In this case, the frog’s visual system can be described as the producer, the internal signals produced by it as representations, and the ‘prey-catching system’, i.e. the collection of motor mechanisms that reacts to these signals by generating the tongue-darting response, as the consumer.