Responses of Atlantic Salmon Parr to Output of Pulsed Ultrasonic Transmitters

The output from some pulsed ultrasonic transmitters commonly used in fish movement studies is faintly audible to humans. This study was undertaken to determine if the output from these and some other transmitters is detectable by Atlantic salmon (Salmo salar) parr. Classical conditioning of cardiac deceleration was attempted using the transmitter's output as the conditioned stimulus. The results from 29 experimental and 14 control fish suggest that the parr were unable to detect the output from these transmitters.

Emotional Processing in the Treatment of Simple Phobia: A Comparison of Imaginal and In Vivo Exposure

Two groups of moderately snake phobic college students were given either imaginal or in vivo exposure treatment. The groups were compared on self-report and physiological measures of fear activation during exposure trials, as well as on within- and across-session habituation of fear responses. On these measures, as well as on treatment outcome, the two groups were found to be very similar. The results lend further support to the importance of the concept of emotional processing in understanding fear reduction processes. Differences in treatment procedure may be important only when one procedure facilitates emotional processing more than another.