"Don't know" responding to answerable and unanswerable questions during misleading and hypnotic interviews

"Don't know" (DK) responses to interview questions are conceptually heterogeneous, and may represent uncertainty or clear statements about the contents of memory. A study examined the subjective intent of DK responses in relation to the objective status of information queried, in the context of memory distorting procedures. Participants viewed a video and responded to answerable and unanswerable questions phrased in misleading or nonmisleading formats, while hypnotized or not hypnotized. Subjective meanings of DK responses were queried, and a recognition measure assessed the contents of memory. Lower DK and accuracy rates were consistently associated with unanswerable and misleading questions. One-third of DK responses were statements that the information had no not presented. When these were recoded, accuracy estimates for answerable questions decreased and more so for hypnotized participants. These results demonstrate that DK responses convey different types of information, thus accuracy estimates in studies that permit DK responses may be misestimated. Robust risks associated with asking unanswerable questions and asking questions at all were observed. Implications for working with DK responses during interviews are discussed.     

17,000 years of depicting the junction of two smooth shapes

Competent realistic drawings preserve viewpoint-invariant shape characteristics of simple parts, such that a contour in the object that is straight or curved, for example, is depicted that way in the drawing. A more subtle invariant--a V-shaped singularity of the occluding boundary, containing a T-junction and a contour termination--is produced at the junction between articulated smooth surfaces, as with the leg joining the body of a horse. 45% of the drawings made in 2007 by individuals with only minimal art education correctly depicted such junctions, a proportion that is not reliably different from the incidence (42%) of correct depictions in a large sample of cave art made 17000 years ago. Whether a person did or did not include the invariant in their drawing, all agreed that it made for a better depiction.     

On the Relation between Kanizsa's Bias Towards Convexity and the Gestaltists Prägnanz from the Perspective of Current in Shape Recognition

What is the relation between Kanizsa's bias towards convexity and the Gestaltists' demonstrations that perceptual organization obeys a principle of pragnänz, or simplicity? Why should either kind of bias exist? Textbook accounts assign no functional role for these biases. Geon theory (Biederman 1987) proposes that we can understand these biases in terms of fundamental processes by which complex objects are decomposed into convex (or singly concave) regions at points of matched cusps according to the transversality regularity (Hoffman and Richards 1985). Such decomposition yields simple, convex parts segmented between the concavities. A shape that contains concavities is generally regarded as complex insofar as it can be decomposed into the regions, or parts, between the concavities. It is these simple parts that are the stable elements of shape, not the whole object. In fact, geon theory leads to the expectation that shape recognition proceeds most efficiently when the parts are good (in the pragnänz sense) but the object is bad!     

Attention norms in Siegel’s The Rationality of Perception

Can we be responsible for our attention? Can attention be epistemically good or bad? Siegel tackles these under‐explored questions in “Selection Effects”, a pathbreaking chapter of The Rationality of Perception. In this chapter, Siegel develops one of the first philosophical accounts of attention norms. Her account is inferential: patterns of attention are often controlled by inferences and therefore subject to rational epistemic norms that govern any other form of inference. Although Siegel’s account is explanatorily powerful, it cannot capture a core attention norm in cognitive science: one should balance between exploratory and exploitative attention. For central cases of exploratory attention such as mind‐wandering, child‐like, and creative thinking are non‐inferential. Siegel’s view classifies them as “normative freebies” that are not subject to epistemic evaluation. We’re therefore left with a disjunctive conclusion: either Siegel’s inferentialist theory of attention norms is incomplete or cognitive scientists are wrong about the norms that govern attention.     

Note on lexicographic‐order preservation and stochastic dominance

This note concerns two issues left unresolved in our study of lexicographic‐order preservation and stochastic dominance in settings where preferences are represented by utility vectors, ordered lexicographically, and judgements emerge as matrices that premultiply utility vectors in expected utility sums. First, a generalization of the ‘Conjecture Σ’, which implied transitivity of a stochastic dominance relation under non‐vacuous resolution‐level information, is proved. Second, this paper comments on using resolution‐level information in higher as well as in first degree stochastic dominance analysis. Copyright © 1999 John Wiley & Sons, Ltd.