The auditory sensory system of the taxon Hetrodinae has not been studied previously. Males of the African armoured ground cricket, Acanthoplus longipes (Orthoptera: Tettigoniidae: Hetrodinae) produce a calling song that lasts for minutes and consists of verses with two pulses. About three impulses are in the first pulse and about five impulses are in the second pulse. In contrast, the disturban...

1. When the oval organ is stimulated repetitively at frequencies imitating normal scaphognathite beating the responses of the three sensory afferents decline. The number of spikes per response diminishes, the firing rate declines and the latency of the first spike may increase. 2. The term 'sensory habituation' is proposed to describe the decline in response of a primary sensory unit to a repet...

The impulse activity of muscle spindles isolated from the cat tenuissimus muscle was investigated under varying concentrations of the L-type calcium channel blocker nifedipine. At a concentration of 25 microM nifedipine impulse activity was clearly diminished in both primary and secondary endings. However, low concentrations of the drug (5-10 microM) exerted unexpected excitatory effects. The d...

This paper experimentally investigates the nature of impulses in impulse learning. Particularly, we analyze whether positive feedback (i.e., yielding a superior payo in a game) or negative feedback (i.e., yielding an inferior payo in a game) leads to a systematic change in the individual choices. The results reveal that subjects predominantly learn from negative feedback.