On the form of stimulus generalization curves for visual intensity

Twelve pigeons were given successive discrimination training involving variable-interval reinforcement for key pecking in the presence of one intensity of monochromatic light randomly alternated with extinction for pecking during another intensity. All of the pigeons were then tested in extinction for generalization along the intensity dimension, and all showed a displacement of maximal responding from the positive stimulus in the direction opposite the negative stimulus. For six of the pigeons, for which the test included only three values beyond the positive stimulus, four showed peaked gradients but two did not, showing monotonic gradients with maximal responding to the most extreme test value. For another six pigeons tested over a wider range, all showed peaked gradients. Thus, when a sufficiently wide range of test values is employed, generalization gradients for visual intensity have the same peaked form as do gradients for qualitative visual dimensions such as wavelength or line angle.     

Social demand characteristics in children's and adults' eyewitness memory and suggestibility: the effect of different interviewers on free recall and recognition

Shortly after viewing a video of a theft, 5‐ and 7‐year‐old children and adults were interviewed with free recall and either misleading or unbiased‐leading questions. After a 2‐day delay, participants were interviewed with free recall and recognition questions administered by either the same or a different interviewer. Results from day 1 replicate previous findings with levels of recall and resistance to suggestibility increasing with age. Counter to predictions, correct recognition performance on day 2 was greater for some participants interviewed by the same as opposed to a different interviewer, and incorrect recognition was greater for all groups of participants for those interviewed by a different as opposed to the same interviewer. Results are discussed in terms of the role of context dependence on memory performance. Copyright © 2000 John Wiley & Sons, Ltd.     

Make it real: Belief in occurrence within episodic future thought

While the cognitive and neural bases of episodic future thinking are well documented, questions remain as to what gives the sense that an imagined event belongs to one’s personal future. Capitalizing on previous research on metacognitive appraisals in autobiographical remembering, we propose that episodic future thinking involves, in varying degrees, a subjective belief in the potential occurrence of imagined future events and we explore the nature and determinants of such belief. To this aim, participants provided justifications for belief in occurrence for a series of past and future events. For each event, they also assessed their subjective feelings (belief in occurrence, autonoetic experience, and belief in accuracy) and rated various characteristics of mental representations that might contribute to these feelings. Results showed that belief in the occurrence of future events mostly related to their integration in a broader autobiographical context, especially their relevance to personal goals and their personal plausibility. We also found that belief in occurrence, autonoetic experience, and belief in accuracy represented distinct subjective appraisals of future events, which depended in part on different determinants. Based on these findings, we propose a new theoretical model of subjective feelings associated with episodic future thinking that conceives of belief in occurrence as arising from metacognitive appraisals that shape the sense that imagined events belong to one’s personal future.