Perceptual-cognitive explorations of a toroidal set of free-form stimuli

A polar-coordinate analogue of Fourier synthesis generates organic-appearing “free forms” that can be continuously deformed along any desired number of difficult-to-verbalize dimensions. Since the dimensions are also circular, the forms correspond to points on the surface of a torus which, though conveniently finite, is free of bounding edges. Two experiments explore a particular two-dimensional set of 81 such forms. The first shows that perceived pair-wise similarities among the individual forms are well explained purely in terms of the distances among their corresponding points in the toroidal parameter space. The second, however, establishes that forms that tend to be grouped together as having the same cognitive interpretation define regions in parameter space that are variously shaped or even bimodal and, hence, that cannot be explained solely on the basis of the fixed set of pair-wise similarities. The stimuli appear to offer a novel combination of cognitive richness and low-dimensional parametric control.     

The effect of training and stimulus variables on the reversal-shift ontogeny

Linear functions fitted to the proportion of optional reversal-shifts as a function of log CA were used to assess the effect of stimulus and training variables on the reversal-shift ontogeny. The results were: (1) when the dimensional salience of the two sets of cues in the stimulus compound were similar, there was no significantly different effect of size, color, or form cues on the rate parameter, suggesting that the rates of mediational development for these cues are similar. Reversal-shifts were, however, more likely with the color-form compound than with the size-color compounds throughout the tested age span, indicating that some stimulus conditions are more likely than others to produce mediated processing at all age levels. (2) The facilitative effects of labelling on reversal-shifts were greatest at the younger ages and decreased systematically over age. (3) Overtraining increased reversal-shifts at most ages but whether the facilitative effect interacts with age remains moot. (4) Neither labelling nor overtraining eliminated ontogenetic differences.     

An information-processing approach to attribution of responsibility

The research literature on defensive attribution of responsibility is reviewed within the framework of a nonmotivational information-processing model which proposes that attributed responsibility is a function of the difference between the perceived contingent probability (congruence) of an outcome, given a perpertrator's behavior, and the noncontingent probability (prior expectancy) of that outcome. Results of previous research on effects of the characteristics of outcomes, perpetrator, and victim on responsibility ratings are reinterpreted in terms of the influence these factors have on estimates of congruence and prior expectancy. Secondary analyses of data from a recent study of causal reasoning resulted in a correlation of .78 between attribution of responsibility and a simple additive model of estimated contingent and prior probabilities of an accident.     

The response ratio hypothesis for magnitude estimation

Assume that each presentation of a signal produces two independent random variable representations and that the ratio of responses on successive trials of a magnitude estimation experiment are proportional to the ratio of a representation from the present trial, which representation is then lost, to the remaining one from the previous trial. The mean response to a particular signal depends on the mean of the representation used, but in general exhibits drift over trials and sequential effects due to the preceeding trial; the mean response ratio does not exhibit drift, but it has a simple form only when there are no sequential effects; however, a modified mean ratio function has a simple form. A model suggested by D. V. Cross is a special case of this one. Simple timing and counting models for the representations fail to exhibit sequential effects, contrary to considerable data. However, data of the authors have suggested a version of the timing model in which the sample size of the representation varies by an order of magnitude depending on how close the signal is to the preceding one; this hypothesis accounts for the observed sequential effects and other aspects of the data.     

VOT discrimination by four to six and a half month old infants from Spanish environments.

Thirty 4–6.5 mo-old-infants from monolingual Spanish speaking homes were tested for discrimination of bilabial stop consonants differing in VOT. Discrimination was determined by the habituation and dishabituation of the orienting reflex as indexed by cardiac deceleration. Subjects were placed in one of three groups of ten subjects each. The three groups were used to determine whether bilabial stops with VOT values of ?60 and ?20 msec, ?20 and +20 msec or +20 and +60 msec could be discriminated. Subjects were presented eight trial blocks of ten repetitions of a CV syllable; these eight trial blocks were followed by two trial blocks of ten repetitions of a different CV syllable. The only difference between the CV syllables presented during the first eight and the last two trial blocks was the VOT value of the bilabial stop consonants. Subjects in the ?20 and +20 msec group showed no signs of being able to discriminate these stimuli while the subjects in the ?60 and ?20 msec group and the +20 and +60 msec group did. These results correspond to those reported for infants from English speaking families but do not correspond to those reported for Spanish speaking adults. Thus, the failure to find evidence of discrimination in the ?20 and +20 msec group suggests that experience has little effect in determining bilabial stop phonetic categories in 4–6.5 mo-old infants.     

A mathematical analysis of a natural class of partitions of a graph

Any finite graph (nondirected, no loops) can be coupled with its complementary graph producing what we term a completed graph. This paper studies completed graphs in the context of a structural concept called stratification that is motivated by theoretical work in social psychology and sociology. A completed graph is stratified in case its node (vertex) set can be divided into two nonempty subsets with exactly one of the two types of ties holding between every pair of nodes from distinct sets. A completed graph is totally stratified in case every one of its nontrivial completed subgraphs is stratified. The first part of the paper relates the concept of stratification to the familiar graph property of connectedness. In particular, a completed graph is totally stratified if and only if it does not have a four point completed subgraph that is connected in both the original graph relation and its complementary relation. Using the concept of stratification, completed graphs can be decomposed uniquely into taxonomic structures, that is, nested sets of partitions. An algorithm for the decomposition based on the work with the concept of stratification is developed. The relationship between the notion of stratification and the ideas in balance theory is examined, and stratification is viewed as a generalization of Davis' notion of clustering. It turns out that the concepts of clique, status, and structural equivalence used throughout the social networks literature can be defined in an interesting way for completed graphs. Cliques are sets of nodes with similar internal links and statuses are sets of nodes with similar external links. Structurally equivalent sets are both cliques and statuses. The concepts of status and structural equivalence are closely related to the decomposition algorithm. In particular, for any totally stratified completed graph, the set of all statuses and the set of all maximal structurally equivalent sets can be generated by mathematical operations performed on the taxonomic decomposition of the completed graph. Finally some of our resuls are informally related to the blockmodeling approach to analyzing social network data discussed in several previous Journal of Mathematical Psychology articles.     

Effect of perceived choice,expected outcome,and observed outcome of an action on the causal attributions of actors

An experiment was conducted to test the hypothesis that actors' causal attributions for success and failure would be affected by the degree of perceived choice they had in taking an action. Actors either were assigned, or selected one of four therapeutic outlines which were expected to have either a positive or a negative effect, and which actually had either a positive or negative outcome on a purportedly phobic person. For negative outcomes, it was predicted that perceived choice would induce a sense of personal responsibility when a positive outcome was expected, and lead actors to attribute more responsibility to themselves as a result. Results supported this prediction. For positive outcomes, however, actors attributed responsibility to themselves regardless of expectancy or choice. Actors were also found to attribute generally more responsibility to themselves for positive than negative outcomes. Results were discussed in terms of self-esteem motivation and the information available to the actor.     

Some deterministic models of concept identification

It is shown that deterministic models can compete effectively with stochastic models in summarizing concept identification behavior. Three groups of deterministic models are examined. Examination of individual learners' trial by trial behavior in a concept experiment shows: (1) One person exhibited behavior consistent with a Hypothesis Permutation (HP) model despite being a nonlearner who showed no evidence of improvement over a period of 24 trials. However, when all 50 persons studied in each of two treatment groups were examined, only 22 members of one group and 10 of the other showed no inconsistencies with deterministic local consistency assumptions. (2) Certain deterministic computer programs could find at least one satisfactory order for predicting all responses by 18 of the 22 consistent solvers and 6 of the 10 consistent solvers, respectively, in the two groups just mentioned. For these 24 persons, then, a less restrictive deterministic model is adequate than for the others. (3) Those 38 original members of the first treatment group who met a stringent learning criterion were compared with respect to predictions generated by stochastic and mathematized deterministic models. One deterministic model (RSS-U 9-state) is in some respects the best of the models examined, but this success is a partial reflection of estimating eight parameters from the data.     

An approach to geometry of visual space with no a priori mapping functions: Multidimensional mapping according to Riemannian metrics

A method of multidimensional mapping is described which constructs a configuration of points {P_i} in a Euclidean map of Riemannian space of constant curvature (hyperbolic, Euclidean, and elliptic) from the dissimilarity matrix (d_ij). The method was applied to the distance matrix in visual space where stimulus points Q_i were either small light points in the dark or small black points in the illuminated field surrounded by white curtains and d_ij represent scaled values of perceptual distances. Configuration of points {Q_i} were at intersections of parallel or distance alleys and horopters for the subject in the horizontal plane of the eye level. In contrast to the theoretical equations for {Q_i} by Luneburg and Blank, no a priori assumption on mapping functions between {Q_i} and {P_i} is necessary in this procedure to fit theoretical curves to {P_i} in the Euclidean map. The data were accounted for better by equations in the hyperbolic plane than by ones in the Euclidean plane. Discussions are made on robustness of Euclidean representation and on how to approach geometry of visual space as a dynamic entity under more natural conditions than the traditional frameless condition for alley and horopter experiments.     

Deep and surface structure in children's sentence learning

Fifth-graders were asked to learn 32 syntactically varied, semantically unrelated sentences containing combinations of agentive, objective and instrumental case relations. Five learning trials, each followed by a noun-prompted recall test, were provided. Recall patterns indicated that variations in surface structure complexity (i.e., verb voice and sentential position of noun prompts) exerted less influence on Ss' memory for sentences than deep structures. Several trials were required for Ss to reproduce syntactic details accurately and many transformational errors were observed. Even then, children were unable to learn one syntactic form. Although patterns of recall were more consistent with deep structure predictions, results were not completely supportive of Fillmore's analysis of deep structure in terms of case relations, and the possibility that other non-linguistic means were used to store sentences loomed as an alternative to the deep structure view.     

Focus of attention and causal attributions of actors and observers

An experiment was conducted to test the hypothesis that actors' and observers' causal attributions are a function of their focus of attention. In the presence of observer-subjects, actor-subjects made a choice among several art works in a supposed decision-making study. The experiment was a 2 × 2 × 2 factorial design with the factors (1) source of attribution (actors, observers); (2) camera (actor videotaped, actor not videotaped); and (3) situational stability (stable, dynamic environment). As predicted by the focus of attention-causal attribution notion, it was found that actors attributed more causality to the situation than observers under normal circumstances, when the camera was not operative, but that videotaping the actor reversed the usual actor-observer pattern such that actors attributed less causality to the situation than did observers. Further, when the environment was stable, actors attributed more causality to the situation in the no camera condition than in the camera condition, while observers attributed less to the situation in the no camera conditions than in the camera conditions. Additionally, both actors and observers attributed more causality to the situation when the environment was dynamic than when the environment was stable.     

The perception of interleaved melodies

If the notes of two melodies whose pitch ranges do not overlap are interleaved in time so that successive tones come from the different melodies, the resulting sequence of tones is perceptually divided into groups that correspond to the two melodies. Such “melodic fission” demonstrates perceptual grouping based on pitch alone, and has been used extensively in music.Experiment I showed that the identification of interleaved pairs of familiar melodies is possible if their pitch ranges do not overlap, but difficult otherwise. A short-term recognition-memory paradigm (Expt II) showed that interleaving a “background” melody with an unfamiliar melody interferes with same-different judgments regardless of the separation of their pitch ranges, but that range separation attenuates the interference effect. When pitch ranges overlap, listeners can overcome the interference effect and recognize a familiar target melody if the target is prespecified, thereby permitting them to search actively for it (Expt III). But familiarity or prespecification of the interleaved background melody appears not to reduce its interfering effects on same-different judgments concerning unfamiliar target melodies (Expt IV).     

Sex task and processing strategy effects in hemispheric alpha asymmetries for the recall and recognition of arousal words: results from perceptual and motor tasks in males and females

Hemispheric alpha asymmetries of males and females were observed during perceptual and motor tasks requiring recall and recognition of words controlled for level of arousal (positive, negative, and neutral). Verbal reports of individual processing strategy were collected and analyzed relative to hemispheric alpha ratios. Results showed greater alpha suppression in the left relative to right hemisphere for recall as compared to recognition tasks and for word presentation when contrasted with motor conditions. High positive correlations were found between narrative report of processing strategy and hemispheric alpha data. A separate analysis revealed that seven subjects identified as highly analytic processors showed greater alpha suppression in the left relative to right hemisphere across tasks, conditions, and stimuli than did seven highly visual processors who, in contrast, demonstrated greater right hemispheric alpha suppression. Task difficulty and individual differences in processing style that modify cerebral laterality effects are discussed.     

The development of elaborative propensity in adolescence

A series of three experiments was conducted to verify the hypothesis that age differences in paired-associate learning proficiency across adolescence stem from the development of increasing elaborative propensity. An auxiliary aim was to determine whether previous study-to-study discrepancies in the pertinent age functions should be attributed to corresponding variations in learning materials or in characteristics of the populations sampled. Taken together, the results of the experiments provided support for the hypothesis. They also indicated, however, that students in late adolescence vary markedly in elaborative propensity, to the point that a substantial proportion of them are hardly distinguishable from preadolescents.     

Memory for orientation of forms as a function of their meaningfulness and complexity.

Accuracy of memory for left-right orientation of single figures varying in meaningfulness and complexity was studied in subjects from kindergarten to adulthood. Complexity was an unimportant variable. Orientation of meaningful figures was remembered better than orientation of nonmeaningful figures at all ages. There were no developmental differences in memory for meaningful figures beyond kindergarten, but pronounced developmental differences were found in memory for nonmeaningful figures. It was proposed that a decision to store orientation information is dependent upon a judgment about the meaningfulness of a presented figure, and that young children have more difficulty than adults in finding meaningfulness in unfamiliar forms. The decision to store appears to occur automatically, since there was only a small difference between conditions in which subjects were informed or not informed to remember orientation. It was also suggested that part of the often reported difficulty in remembering diagonal orientation may be due to the symmetry of the diagonal forms typically investigated.     

"Square-wave stimuli" and neonatal auditory behavior: some comments on Ashton (1971), Hutt el al. (1968) and Lenard et al. (1969)

Recent work reporting neonatal auditory responses to complex tones generated by applying electrical square-wave stimuli to loudspeakers is reviewed with reference to the nature of the acoustic stimulus. Attention is particularly drawn to the harmonic structure of such tones in relation to the nonlinear frequency response of small loudspeakers. A $\text{1}\text{3}\text{-}\text{octave}$ band analysis of some “square-wave tones” is given to illustrate the difficulties of interpreting the results of work using such complex stimuli. The findings of the previous studies are ascribed essentially to differences in the stimulus bandwidth, rather than to differences in audiofrequency, and difficulties apparently generated by using differences in stimulus bandwidth as the sole explanation are at least partially resolved.     

Effects of density,activity, and personality on environmental preferences

The effects of room density, type of ongoing activity (party vs studying), and a personality variable (“personal space” or the distance which subjects place between themselves and others) on room liking were investigated. Results supported the prediction that type of activity is an important determinant of whether a high or low density setting is preferred. Evidence was also presented that a mediator between activity type and density preference is whether the presence of other people facilitates or inhibits the individual's goals in the setting. Personality factors also influence density preferences: Close standing Ss preferred a high to a low density setting; far standing Ss showed an opposite preference pattern, but only in the party condition. Correlations between Ss' personal space scores and several background and personality variables are also presented.