Social animals use communication signals to efficiently coordinate behavior (for example during mating and hunting) and to establish social hierarchies. Communication signals exist across sensory modalities from gestures to smells to sights. Vocal communication in particular has been a focus of study across a variety of taxa in the field of social neuroscience (songbirds, drosophila, frogs, singing mice, laboratory mice, and humans). Vocalizations can coordinate social behavior on short timescales because they afford rapid transmission of information across distance and can be modulated based on sensory feedback and internal states of the animal (e.g. duetting in birds or a human conversation). Major challenges for social neuroscience are: (1) to develop tools to quantify communications and determine their effects on behavior in the context of naturalistic social behaviors and (2) to investigate the underlying neuronal mechanisms.
Weakly electric fish are unique among the animal kingdom in that much of their social communication relies on their ability to generate and detect weak electric fields. This communication regime (termed electrocommunication) is analogous to vocal communication in many ways, but instead of emitting sound waves, these fish emit electric fields. Electrocommunication is likely the most rapid form of communication — electric fields are instantaneous and do not need to propagate through space. Furthermore, electrical communication signals faithfully reflect underlying neural command signals, not being subject to distortion as are vocalizations travelling through air. There are two types of weakly electric fish: (1) wave-type that produce continuous quasi-sinusoidal electric fields and (2) pulse-type that produce briefly pulsed electric fields separated by long pauses. Mormyridae is the largest family of pulse-type fish. Some species are quite gregarious with complex and context-specific social behaviors. How does the patterning of electrocommunication signals among a group reflect this social organization and how does it mediate social interactions?
The waveform shape of the pulsed electric field generated by each fish (generally lasting 0.2-2ms in duration) is extremely stereotyped and conveys information about species, individual, and sexual identity. In contrast, the time between pulses (inter-pulse-interval) is highly variable within individuals and across time — ranging from 10s of milliseconds to seconds in duration. We know that the pattern of pulses emitted by each fish are used to drive social interactions and that fish can coordinate the timing of their pulses with each other, which is thought to play a variety of key social functions, particularly during territorial aggression, courtship, mating, and group hunting. Examples of entrainment and rhythmic perception abilities are ubiquitous across the animal kingdom and across modalities. Why do some animals exhibit the ability to entrain and perceive rhythm while others do not? We are interested in understanding the social function of communicative patterning, and the neural mechanisms coordinating such patterned displays. How does the patterning of electrocommunication signals in electric fish compares to the patterning of social signals exchanged in other animal species?