Final answer:
Quiroga et al. (2008) focused their research on sensory coding by studying grandmother cells, neurons that may respond to complex, specific stimuli like faces.
Step-by-step explanation:
Quiroga et al. (2008) studied sensory coding by examining grandmother cells. These are a type of neuron hypothesized to respond to a highly specific stimulus, such as a familiar face or object, somewhat similar to the concept of 'feature cells' which are associated with processing particular visual features. The research on grandmother cells is a part of understanding how the brain encodes and recognizes complex stimuli. In comparison, research on mirror neurons has focused on how these specialized cells may enable the imitation of actions, which is crucial for mimetic skills and potentially for language development. Meanwhile, cells in the nervous system, such as bipolar cells and chemoreceptors, play roles in the visual system and other sensory systems, respectively, by transducing environmental stimuli into neural signals. This further underscores the complexity of sensory coding within the nervous system.