Whom to trust? Inferred source credibility and response borrowing in a memory task.

We investigated whether people can discriminate between sources of information that are either credible or respond at random, based only on their own knowledge and the responses provided by these sources. In three experiments, participants were asked to judge the validity of trivia statements. Some statements were accompanied by true/false responses provided by either a credible source or a source whose responses were random. In Experiment 1, participants first saw a set of easy questions, which provided the basis for assessing the relative credibility of the sources, before responding to a set of difficult questions, where response borrowing was assessed. In Experiments 2 and 3, participants solved a test composed of difficult questions only, but only after studying the correct responses to all these questions. In Experiment 2, there was no delay between the study and test phases, whereas in Experiment 3, the delay was 24 hours. In all experiments, more participants explicitly identified the more credible source in the postexperimental questionnaire than misidentified the noninformative source as credible. However, differentiated response borrowing-borrowing more responses from the credible than the noninformative source-emerged only in Experiment 2. Therefore, people can often explicitly infer source credibility from the responses the sources provide. However, using these inferences to regulate response borrowing is relatively less likely and happens only under specific, favorable circumstances.

A shared code for Braille and Arabic digits revealed by cross-modal priming in sighted Braille readers.

Quantities can be represented by different formats (e.g. symbolic or non-symbolic) and conveyed via different modalities (e.g. tactile or visual). Despite different priming curves: V-shape and step-shape for place and summation coded representation, respectively, the occurrence of priming effect supports the notion of different format overlap on the same mental number line. However, little is known about tactile-visual overlap of symbolic numerosities i.e. Braille numbers to Arabic digits on the magnitude number representation. Here, in a priming experiment, we tested a unique group of sighted Braille readers to investigate whether tactile Braille digits would activate a place-coding type of mental number representation (V-shape), analogous to other symbolic formats. The primes were either tactile Braille digits presented on a Braille display or number words presented on a computer screen. The targets were visually presented Arabic digits, and subjects performed a naming task. Our results reveal a V-shape priming function for both prime formats: tactile Braille and written words representing numbers, with strongest priming for primes of identical value (e.g. "four" and "4"), and a symmetrical decrease of priming strength for neighboring numbers, which indicates that the observed priming is due to identity priming. We thus argue that the magnitude information is processed according to a shared phonological code, independent of the input modality.