Saliency metric for subadditive dissimilarity judgments of rectangles

Previous findings that dissimilarity judgments for rectangles are strongly subadditive, that qualitative individual differences are always present, and that four-parameter psychophysical maps can reproduce the average ratings (Sch?nemann & Lazarte, 1987) are replicated. However, the present study in addition suggests that the metric for bounded response transformation, previously used to restore additivity of responses, has a modest effect on the fits of the psychophysical maps. The differential weighing of the coordinates already incorporates segmental subadditivity predictions into the maps. In fact, the psychophysical maps define a subadditive saliency metric that depends on assigning larger weights to larger coordinates. This constraint on the weights of these maps, together with the response times, allows us to identify a strategy shift when subjects respond to two classes of stimulus pairs: For rectangle-rectangle pairs, subjects center on the shape and size of the rectangles; for square-rectangle pairs, the focus is on height and width.     

Naloxone modulates visual judgments of similarity but not dissimilarity

Endogenous opioids have been implicated in mediating (placebo) analgesia, in reward processes, and in the regulation of socially relevant emotions. To explore their potential contributions to higher cognitive functions, we used a novel task with tachistoscopically presented (for 150 ms) pairs of meaningless figures. Healthy right-handed men judged the similarities and dissimilarities between the two figures on a visual analogue scale (VAS) in two separate runs. In a double-blind, between-subjects design, subjects were administered intravenously either 0.2-mg/kg naloxone or placebo 10 min prior to the task, and VAS judgments and response latencies were measured. We found a significant interaction between substance group and type of judgment: The magnitude of the similarity judgments was lower in the naloxone than in the placebo group, while dissimilarity judgments remained uninfluenced by the treatment. Reaction latencies and mood scores, assessed before and after substance administration, did not differ between the two groups, indicating that the findings did not rely on altered motor performance or motivation. We suggest that naloxone decreased the “similarity criterion” in comparative judgments, indicating its potentially modulatory effect on visual cognition. The task introduced here could be used for the implicit study and quantification of subtle affective–cognitive processes beyond the level of mere questionnaire data.     

The role of similarity and dissimilarity focus in sequential judgments of physical attractiveness

The present results indicate that procedurally priming comparison focus can change the contrast effect in judgments of physical attractiveness (Kenrick & Gutierres, 1980). Participants were primed to search for similarities vs. differences between target and standard of comparison in a task using material irrelevant to the subsequent physical attractiveness judgment. Focusing participants on similarities testing produced the assimilation effect: evaluation of target and comparison standard as being similar. Focusing participants on dissimilarity testing produced the contrast effect: evaluating the target as different from the standard of comparison.     

Anchoring in sequential judgments

Building on the scale distortion theory (Frederick & Mochon, 2012), we explore the boundary conditions of anchoring outside of the standard paradigm. We argue that the conditions needed for anchoring effects are much more restrictive than those suggested by some theories, but much less restrictive than those suggested by others. Our findings illuminate both the scope and limits of this well-known effect and provide a framework for predicting its occurrence in novel settings.     

Refractoriness in same-different judgments

Subjects judged as “same” or “different” pairs of visual stimuli, each either an X or an O, whose onsets were separated by intervals of 50, 100, 150 or 200 ms. When the interstimulus interval (ISI) was held constant within a block of 40 trials (Experiment I), decision time was independent of ISI. But when ISI was varied unpredictably from trial to trial (Experiments II and III), decision times increased the shorter the ISI. This effect was more marked for “same” than for “different” decisions. These results fail to support a single-channel interpretation, but suggest that variations in decision time depend on the subject's expectancy as to when the second stimulus will follow the first.     

Similarity and dissimilarity as evidence in perceptual categorization

In exemplar models the similarities between a new stimulus and each category exemplar constitute positive evidence for category membership. In contrast, other models assume that, if the new stimulus is sufficiently dissimilar to a category member, then that dissimilarity constitutes evidence against category membership. We propose a new similarity-dissimilarity exemplar model that provides a framework for integrating these two types of accounts. The evidence for a category is assumed to be the summed similarity to members of that category plus the summed dissimilarity to members of competing categories. The similarity-dissimilarity exemplar model is shown to mimic the standard exemplar model very closely in the unidimensional domain.     

Subadditive versus hyperbolic discounting: A comparison of choice and matching

Impulsive and myopic choices are often explained as due to hyperbolic discounting, meaning that people are impatient for outcomes available immediately, and become increasingly more patient the more the outcome is delayed. Recent research, however, has suggested that much experimental evidence for increasing patience is actually due to subadditive discounting: people are less patient (per-time-unit) over shorter intervals regardless of when they occur. Because previous research into subadditive discounting has used a choice elicitation procedure, the present paper tests whether it generalises to matching. We find strong evidence that it does, but also find weak evidence of increasing patience for matching. We suggest, however, that subadditive discounting alone may be sufficient to account for all of our results. We conclude by questioning the contribution that hyperbolic discounting makes to our understanding of time preference.     

Bicriterion methods for partitioning dissimilarity matrices

Partitioning indices associated with the within‐cluster sums of pairwise dissimilarities often exhibit a systematic bias towards clusters of a particular size, whereas minimization of the partition diameter (i.e. the maximum dissimilarity element across all pairs of objects within the same cluster) does not typically have this problem. However, when the partition‐diameter criterion is used, there is often a myriad of alternative optimal solutions that can vary significantly with respect to their substantive interpretation. We propose a bicriterion partitioning approach that considers both diameter and within‐cluster sums in the optimization problem and facilitates selection from among the alternative optima. We developed several MATLAB‐based exchange algorithms that rapidly provide excellent solutions to bicriterion partitioning problems. These algorithms were evaluated using synthetic data sets, as well as an empirical dissimilarity matrix.     

Classification of concatenation measurement structures according to scale type

A relational structure is said to be of scale type (M,N) iff M is the largest degree of homogeneity and N the least degree of uniqueness (Narens, 1981a, Narens, 1981b) of its automorphism group.Roberts (in Proceedings of the first Hoboken Symposium on graph theory, New York: Wiley, 1984; in Proceedings of the fifth international conference on graph theory and its applications, New York: Wiley, 1984) has shown that such a structure on the reals is either ordinal or M is less than the order of at least one defining relation (Theorem 1.2). A scheme for characterizing N is outlined in Theorem 1.3. The remainder of the paper studies the scale type of concatenation structures 〈X, ?, ° 〉, where ? is a total ordering and ° is a monotonic operation. Section 2 establishes that for concatenation structures with M>0 and N<∞ the only scale types are (1,1), (1,2), and (2,2), and the structures for the last two are always idempotent. Section 3 is concerned with such structures on the real numbers (i.e., candidates for representations), and it uses general results of Narens for real relational structures of scale type (M, M) (Theorem 3.1) and of Alper (Journal of Mathematical Psychology, 1985, 29, 73–81) for scale type (1, 2) (Theorem 3.2). For M>0, concatenation structures are all isomorphic to numerical ones for which the operation can be written $\text{x°y = yf(}\text{x}\text{y}\text{)}$, where f is strictly increasing and $\text{f(x)}\text{x}$ is strictly decreasing (unit structures). The equation f(x^?)=f(x)^? is satisfied for all x as follows: for and only for ? = 1 in the (1,1) case; for and only for ?=kⁿ, k > 0 fixed, and n ranging over the integers, in the (1, 2) case; and for all ?>0 in the (2, 2) case (Theorems 3.9, 3.12, and 3.13). Section 4 examines relations between concatenation catenation and conjoint structures, including the operation induced on one component by the ordering of a conjoint structure and the concept of an operation on one component being distributive in a conjoint structure. The results, which are mainly of interest in proving other results, are mostly formulated in terms of the set of right translations of the induced operation. In Section 5 we consider the existence of representations of concatenation structures. The case of positive ones was dealt with earlier (Narens & Luce (Journal of Pure & Applied Algebra27, 1983, 197–233). For idempotent ones, closure, density, solvability, and Archimedean are shown to be sufficient (Theorem 5.1). The rest of the section is concerned with incomplete results having to do with the representation of cases with M>0. A variety of special conditions, many suggested by the conjoint equivalent of a concatenation structure, are studied in Section 6. The major result (Theorem 6.4) is that most of these concepts are equivalent to bisymmetry for idempotent structures that are closed, dense, solvable, and Dedekind complete. This result is important in Section 7, which is devoted to a general theory of scale type (2, 2) for the utility of gambles. The representation is a generalization of the usual SEU model which embodies a distinctly bounded form of rationality; by the results of Section 6 it reduces to the fully rational SEU model when rationality is extended beyond the simplest equivalences. Theorem 7.3 establishes that under plausible smoothness conditions, the ratio scale case does not introduce anything different from the (2, 2) case. It is shown that this theory is closely related to, but somewhat more general, than Kahneman and Tversky's (Econometrica47, 1979, 263–291) prospect theory.     

Velocity concatenation and velocity as rate of position dissimilation

If velocity is interpreted as rate of position dissimilation the model of dissimilarity previously developed (Junge, 1978) can be used to account for the relativistic concatenation rule for velocity (Einstein's rule).     

Cognitive processes involved in blame and blame-like judgments and in forgiveness and forgiveness-like judgments

Experiment 1 compared the cognitive processes involved in blame and forgiveness judgments under identical experimental conditions. Experiment 2 was a replication of Experiment 1 with 4 judgment scales: willingness to prosecute, willingness to avenge, resentment level, and willingness to make up. Participants were presented with 32 scenarios in which a doctor made a medical error. These situations contained 5 items: the degree of proximity with the doctor (e.g., a family doctor known since childhood), the degree of negligence, the severity of consequences, apologies or contrition, and cancellation of consequences. Functional cognitive analysis grouped judgments into 2 categories: blame-like judgments (blame, prosecution, and revenge) and forgiveness-like judgments (resentment, forgiveness, and reconciliation). Blame-like judgments were characterized by additive integration rules, with negligence followed by apologies as the 2 main cues. Forgiveness-like judgments were characterized by an interactive integration rule, with apologies followed by negligence as the 2 main cues.     

Visual-manual commonality in size judgments

Visual-manual commonality was studied in terms of commonality of process and commonality of achievement. Fifty-four Ss madelarge-small categorical judgments about a set of stimuli presented in counterbalanced order through both the visual modality and the haptic, touch, or kinesthetic modality. Using a linear discriminant function model, analyses of the several visual-manual pairings were made on the basis of intra-S absolute differences in the weighting of the physical dimensions (process) and the degree of category separation (achievement). A correlational analysis revealed the independence of these measures, and analyses of variance revealed greater visual-haptic commonality for weighting systems and similar visual-haptic and visual-touch commonality for category separation. The results were interpreted in terms of similarities and differences in information gathering and processing characteristics.     

Hindsight bias in gustatory judgments

Being in hindsight, people tend to overestimate what they had known in foresight. This phenomenon has been studied for a wide variety of knowledge domains (e.g., episodes with uncertain outcomes, or solutions to almanac questions). As a result of these studies, hindsight bias turned out to be a robust phenomenon. In this paper, we present two experiments that successfully extended the domain of hindsight bias to gustatory judgments. Participants tasted different food items and were asked to estimate the quantity of a certain ingredient, for example, the residual sugar in a white wine. Judgments in both experiments were systematically biased towards previously presented low or high values that were labeled as the true quantities. Thus, hindsight bias can be considered a phenomenon that extends well beyond the judgment domains studied so far.     

Accuracy in judgments of aggressiveness

Perceivers are both accurate and biased in their understanding of others. Past research has distinguished between three types of accuracy: generalized accuracy, a perceiver's accuracy about how a target interacts with others in general; perceiver accuracy, a perceiver's view of others corresponding with how the perceiver is treated by others in general; and dyadic accuracy, a perceiver's accuracy about a target when interacting with that target. Researchers have proposed that there should be more dyadic than other forms of accuracy among well-acquainted individuals because of the pragmatic utility of forecasting the behavior of interaction partners. We examined behavioral aggression among well-acquainted peers. A total of 116 9-year-old boys rated how aggressive their classmates were toward other classmates. Subsequently, 11 groups of 6 boys each interacted in play groups, during which observations of aggression were made. Analyses indicated strong generalized accuracy yet little dyadic and perceiver accuracy.     

Contextual effects in difference judgments

Manipulating stimulus spacing, stimulus frequency, or stimulus range usually affects intensity judgments. In six experiments, I investigated the locus of analogues of these contextual effects in a “difference” estimation task. When all stimuli elicited the same taste quality, stimulus distribution affected the scale values only when water was included in the stimulus set (Experiments 1–3). When the subjective ranges of two taste qualities were manipulated, different scale values were obtained for the separate qualities in the two conditions (Experiment 4). Manipulation of the expected response distribution did not affect the scale values or the responses (Experiments 5–6). It is concluded that shifts in stimulus distributions or stimulus ranges result in shifts in subjective scale values. The contextual effects can be interpreted as relative shifts of a number of gustatory continua, with water lying on a separate continuum. Proposed is a model for context-dependent judgments, consisting of four stages: stimulus classification, stimulus placement, continuum placement, and continuum projection.     

Hemispheric differences in semantic-relatedness judgments

Subjects judged the semantic relatedness of word pairs presented to the left or right visual field. The word pairs were presented one below the other. On critical trials, the words' referents had a typical spatial relation, with one referent oriented above the other (e.g. ATTIC/BASEMENT). The spatial relation of the words either matched or mismatched the spatial relation of their referents. When presented to the left hemisphere, the match or mismatch did not have an effect. However, there was a reliable mismatch effect for pairs presented to the right hemisphere. The results are interpreted in the context of perceptual theories of mental representation.