No abstract

No abstract

The experiment investigated the orienting response as a function of temporal relations among the stimuli, with GSR the measure. 3 stimuli were employed. The duration of the 1st was 1300, 1050, or 750 msec., with 2 groups at each interval. The duration of the 2nd and 3rd were 600 and 100 msec., respectively. They terminated together and consisted of a tone and 2 different lights. Following 10 presentations of the compound, separate groups were tested to the 1st or 2nd stimulus alone. The shift from triple stimulation to single produced a significant increase in GSR magnitude and also a significant interaction between order and original precedence time.

Facilitating and inhibiting sets were given to human 5s in a differential eyelid conditioning situation as a function of interstimulus interval (ISI). In addition to replicating earlier findings by Hilgard and Humphreys and by Hartman and Grant, it was found that (a) performance with a 400 ISI increased substantially after the first 100 training trials, (6) latency was shorter to CS+ than to CS -(c) ISI interacted with instructional sets, with the sets being more effective to CS-at the longer (800-msec.) ISI, (d) CS+ and CS-sequential probability conformed to expectation from a linear operator model generally independent of instructional set, and (e) latency increased with successive instances of CS+, but did not change with successive instances of CS -.One of the most potent variables in human classical eyelid conditioning is the instructional set given to S just prior to conditioning. In single-stimulus conditioning, inhibitory sets result in reduced response probability and increased latency (e.g., Fishbein & Gormezano, 1966;Miller, 1939;Norris & Grant, 1948), while facilitatory sets result in increased probability and decreased latency (e.g., Gormezano & Moore, 1962;Hartman, Grant, & Ross, 1960), relative to the effects of "standard" or "neutral" instructions.Hilgard and Humphreys (1938) conducted the only experiment to date on the effects of facilitatory and inhibitory instructions in differential eyelid conditioning. In general, response probability increased and latency decreased to both CS+ and CSwith facilitatory instructions; and probability decreased and latency increased with inhibiting instructions. The exception to this was no apparent effect on responding to CS-f-when 5s were instructed to inhibit responding to CS+ and facilitate responding to CS-.One purpose of the present study was in part to replicate the Hilgard-Humphreys experiment. This replication was under-

No abstract