Behavior and physiology of mechanoreception: separating signal and noise

Abstract

The mechanosensory lateral line is found in all aquatic fish and amphibians. It provides a highly sensitive and versatile hydrodynamic sense that is used in a wide range of behavior. Hydrodynamic stimuli of biological interest originate from both abiotic and biotic sources, and include water currents, turbulence and the water disturbances caused by other animals, such as prey, predators and conspecifics. However, the detection of biologically important stimuli often has to occur against a background of noise generated by water movement, or movement of the fish itself. As such, separating signal and noise is "of the essence" in understanding the behavior and physiology of mechanoreception. Here we discuss general issues of signal and noise in the lateral-line system and the behavioral and physiological strategies that are used by fish to enhance signal detection in a noisy environment. In order for signal and noise to be separated, they need to differ, and we will consider those differences under the headings of: frequency and temporal pattern; intensity discrimination; spatial separation; and mechanisms for the reduction of self-generated noise. We systematically cover the issues of signal and noise in lateral-line systems, but emphasize recent work on self-generated noise, and signal and noise issues related to prey search strategies and collision avoidance.

Performance analysis for lateral-line-inspired sensor arrays

“…The end result is a frequency response that roughly approximates a low-pass filter [58], though the low-frequency response is not flat.…”

Mexican blind cavefish use mouth suction to detect obstacles

“…The dominant frequency of these oscillations is of the order of 5-20 Hz (Fig. 5, Table 1), which is close to the lower end of the sensitivity range of the canal neuromasts [10-100 Hz (Montgomery et al, 2009;van Netten, 2006)]. Thus, the stronger signal produced by mouth suction is also more likely to generate a strong neural response due to the unsteady flows it produces.…”

“…5A). Interestingly, canal neuromasts of A. fasciatus are relatively insensitive to slow flow variations but sensitive to oscillating flows (Montgomery et al, 2009;van Netten, 2006). The mouth gape and the related velocity of the suction flows oscillate in time.…”

Contributions of the Leigh Marine Laboratory to marine science, 1962–2012: sensory neuroethology

“…(Wellenreuther et al 2010) and southern bastard cod (Bassett & Montgomery 2011a). Collectively these studies show that a lateral line contribution to feeding is particularly important in nocturnal fishes, and that hydrodynamic considerations are important in understanding behavioural, morphological and functional contributions to detecting biologically important signals over the top of environmental and selfgenerated noise (Montgomery et al 2009). For example, behavioural and field studies with the dwarf scorpionfish show that they feed at night, and can orient and attack crabs in complete darkness using the lateral line to detect the respiratory flow fields of their prey.…”