Modeling the Effects of Melanoma Education on Visual Detection: A Gradient Shift Analysis

Does Hearing About Cancer Influence Stimulus Control? An Exploratory Study of Verbal Modulation of Stimulus Generalization

“…Endorsement of other images was a positive function of their degree of similarity to S+, and mean generalization gradients were approximately symmetrical, with patterns of endorsement roughly similar for stimuli that were less and more symptomatic than S+. More symptomatic stimuli were slightly more likely than less symptomatic stimuli to be endorsed as Blike the original.^Such mildly asymmetrical gradients are common in stimulus generalization research (Ghirlanda & Enquist, 2003) and our previous studies involving melanoma images have yielded similar gradients (Dalianis et al, 2011;Miller et al, 2015).…”

“…In this respect, gradients for cancer context participants bore similarity to those typically observed following discrimination training which contrasts an S+ stimulus in the moderate range of a stimulus dimension with an S− at one of the dimension's extremes (Ghirlanda & Enquist, 2003;Honig & Urcuioli, 1981). Recently, Miller et al (2015) replicated this gradient-shift effect with melanoma stimuli similar to those of the present study, and the results were very similar to those of the present cancer context groups, for which there was no experimentally programmed S−. Thus, many participants in the cancer context groups behaved as if responding to an S− that was not part of our procedure, at least not in the way that S− conventionally is defined (e.g., Dinsmoor, 1985).…”

“…Also potentially relevant are the presence of an explicit S− stimulus during discrimination learning (recall that some public service media display both symptomatic and asymptomatic lesions). For example, as Miller et al (2015) found, an S− stimulus at one extreme of the dimension in which S+ is centered tends to shift the gradient toward the other extreme. In the present case, had an asymptomatic lesion served as S−, would this have magnified the verbal modulation effect we report here?…”

“…Our previous research has modeled the effects of this Bdiscrimination trainingb y assessing gradients of generalization around the example stimuli. As the medical literature would suggest, we have found that this procedure does not reliably induce detection of subtle melanoma symptoms (Dalianis, Critchfield, Howard, Jordan, & Derenne, 2011;Miller, Reed, & Critchfield, 2015).…”

“…Familiarization with the Boriginal image^and subsequent generalization testing were structured similarly to a procedure employed previously by Dalianis et al (2011) andMiller et al (2015). Participants entered Blackboard® using the same identifier and password used for online access to their confidential university academic and financial information.…”