(a) Left, ensemble PN response trajectory is shown for 6 s long hexanol pulse. ON and OFF trajectories are identified using red and blue colours, respectively. Right, PN response trajectory is shown for 2 s ON–2 s OFF–2 s ON hexanol pulse. Red and purple portions of the trajectories indicate the ensemble ON activity during the first and second hexanol pulse (ON responses), and the blue/cyan trajectories trace the PN ensemble responses following the termination of the first and the second hexanol pulse. (b) Results from a classification analysis are shown in a bin-by-bin, trial-by-trial fashion. Based on the closest template, a class label has been assigned for each 50 ms time bin. hex ON response template—‘red tick mark’, hex OFF response template—‘blue tick mark’, and time bins when the ensemble neural activities that differed significantly from both hex ON and OFF response templates were labelled using a ‘black tick mark’. Classification for ten trials are shown for 6s hex pulse and 2 s ON–2 s OFF–2 s ON hexanol pulse. A leave-one-trial-out validation was used for generating these results. The coloured bar on the top indicates stimulus exposure periods. (c) The probabilities of pattern-match with hex-ON and hex-OFF templates are plotted as a function of time for a uninterrupted 6 s hexanol pulse and a 2 s ON–2 s OFF –2 s ON hexanol pulses. (d) Behavioral palp opening responses are plotted (median±s.e.m., n=27 Locusts) for hex 6 s and hex 2 s ON–2 s OFF–2 s ON pulses. The prediction from the ON–OFF model (purple trace) is also shown for comparison.