Stereoscopic illusion based on the proximity principle

A class of ambiguous random-dot stereograms were created that share the following interesting property: Although the binocular disparity forms a periodic 'sawtooth' waveform as a function of row number (the disparity is constant for a given row), these stimuli yield a monotonically increasing depth percept along the rows. The random-dot pattern of each row is periodic along the horizontal direction for the purpose of producing an ambiguous depth percept. It is this ambiguity that makes it possible for the periodic stimulus to give rise to a monotonic percept. This monotonic percept is substantially enhanced when the rows are shown in temporal sequence instead of all being displayed together. Experiments are reported which indicate that this illusion is due to the proximity, or pulling, effect in stereopsis.     

Musicians' and nonmusicians' short-term memory for verbal and musical sequences: Comparing phonological similarity and pitch proximity

Language-music comparative studies have highlighted the potential for shared resources or neural overlap in auditory short-term memory. However, there is a lack of behavioral methodologies for comparing verbal and musical serial recall. We developed a visual grid response that allowed both musicians and nonmusicians to perform serial recall of letter and tone sequences. The new method was used to compare the phonological similarity effect with the impact of an operationalized musical equivalent — pitch proximity. Over the course of three experiments, we found that short-term memory for tones had several similarities to verbal memory, including limited capacity and a significant effect of pitch proximity in nonmusicians. Despite being vulnerable to phonological similarity when recalling letters, however, musicians showed no effect of pitch proximity, a result that we suggest might reflect strategy differences. Overall, the findings support a limited degree of correspondence in the way that verbal and musical sounds are processed in auditory short-term memory.     

Interactions between intrinsic principles of similarity and proximity and extrinsic principle of common region in visual perception

The interactions between intrinsic grouping principles (by proximity or by similarity in shape or luminance) and extrinsic grouping by common region were examined by presenting both principles acting alone or conjoined with another principle in visual patterns. The procedure used in our study closely mirrored that of Quinlan and Wilton (1998 Perception 27 417-430). However, in the present experiment, the intrinsic and extrinsic grouping principles involved had similar relative salience in order to avoid their possible effects on interactions. The results showed that the grouping effect of conjoined cooperating principles was greater than that of either principle acting alone, and the grouping effect of conjoined competing principles was lower than that of either principle operating alone. Compatibility of data with additive effects of grouping principles has been examined.     

The interdependence of pitch and temporal judgments by absolute pitch possessors

The auditory tau and the kappa effects show that there is time-pitch interdependence in our perception. Our judgments of pitch separation between two tones depend on the temporal interval between them (the auditory tau effect), and our judgments of the tones’ temporal interval depend on their pitch separation (the kappa effect). The mechanisms underlying this interdependence were investigated by studying the auditory tau and the kappa effect in three experiments. Comparisons were made between results obtained from subjects with absolute pitch and those who did not have absolute pitch, and two frequency ranges of pure tones (octave and whole-tone conditions) were selected. The procedures had been used in previous experiments (Shigeno, 1986), in which the auditory tau and the kappa effects were compared in speech and nonspeech stimuli. The present results demonstrate that the auditory tau effect does not occur when possessors of absolute pitch judge the closeness of stimuli in pitch, except when the stimulus continuum consists of tones that do not correspond to musical notes in the whole-tone condition. The kappa effect was obtained in the judgment of possessors of absolute pitch in both the octave and the whole-tone conditions. These findings suggest that the interaction between temporal interval and pitch judgment might be explained in terms of the two different memory modes for retaining the pitch of tones, and that these effects occur at the precategorical level.     

Texture discrimination and the analysis of proximity.

A major theory of early visual processing has recently been proposed by Marr, which considers a number of aspects of visual perception in great detail, including grouping and texture discrimination. New phenomena associated with texture discrimination are described and experiments reported which allow a preliminary comparison of Marr's theory, as it applies to texture discrimination, with more established theories such as that due to Julesz. One experiment produced results which are clearly consistent with Marr's account, but the ability of his theory to deal with additional data on region suppression is not established. The theory of the analysis of proximity relations proposed by Fox offers a broadly satisfactory account of many texture perception results, while relying on the more fundamental parts of Marr's theory of primitive visual processes to deal with the remainder. A further attraction of proximity analysis is that it may shed new light on the classical paradox of symmetry perception. Some ways in which the preliminary proximity analysis model is incomplete are discussed, and it is concluded that development of the model may be profitable for theories of early visual processing.     

On the reciprocity of proximity relations

The degree of reciprocity of a proximity order is the proportion, P(1), of elements for which the closest neighbor relation is symmetric, and the R value of each element is its rank in the proximity order from its closest neighbor. Assuming a random sampling of points, we show that Euclidean n-spaces produce a very high degree of reciprocity, $\text{P(1) ≥}\text{1}\text{2}$, and correspondingly low R values, E(R) ≤ 2, for all n. The same bounds also apply to homogeneous graphs, in which the same number of edges meet at every node. Much less reciprocity and higher R values, however, can be attained in finite tree models and in the contrast model in which the “distance” between objects is a linear function of the numbers of their common and distinctive features.     

On the relation between roll and pitch

Studies have found that rolling the visual environment affects observers' perception of gravitational vertical and horizontal and that pitching the environment affects observers' perception of pitch. However, the relationship between these two perceptions is not fully understood. In the present work, observers performed three tasks while in a visual surround whose pitch and roll was manipulated. In the first task, observers adjusted a rod in the frontal-parallel plane to the horizontal (roll). In a second task, they adjusted a rod along a plane parallel to straight-ahead to the vertical (pitch). In the final task (“in-between”), they adjusted a rod midway between the first two conditions. The typical pitch and roll effects were found, as well as a contribution of both pitch and roll to the in-between task. No interaction between pitch and roll effects was found, indicating independent cognitive representations.     

Contributions of temporal and place cues in pitch perception in absolute pitch possessors

Pitch perception is determined by both place and temporal cues. To explore whether the manner in which these cues are used differs depending on absolute pitch capability, pitch identification experiments with and without pitch references were conducted for subjects with different absolute pitch capabilities and musical experience. Three types of stimuli were used to manipulate place and temporal cues separately: narrowband noises, which provide strong place cues but less salient temporal cues; iterated rippled noises, which provide strong temporal cues but less salient place cues; and sinusoidal tones, which provide both. The results indicated that absolute pitch possessors utilize temporal cues more effectively when they identify musical chroma With regard to the judgment of height, it was indicated that place cues play an important role for both absolute and nonabsolute pitch possessors.     

Training the absolute identification of pitch

Two methods for training the absolute judgment of pitch, reference training and series training, were studied. Reference training concentrated during training on the identification of three reference tones in a set of nine pure tones, while series training gave equal weight during training to the identification of all nine tones. Results of pre- and posttraining tests, scored for the number of correct judgments, showed that reference training was more effective than series training for listeners with musical experience. In addition, discriminability (d′) scaling of pre- and posttest performance indicated that reference training was particularly effective for training listeners with musical experience when the nine tones of a set were grouped into three pitch classes—high, medium, and low pitch. Listeners without musical experience benefited from both training methods, but their overall improvement was less than that for musical listeners.     

Personalized and generalized comparisons: causes and consequences of variations in the focus of social comparisons

When people compare with another person they can focus on how they compare either with just that target (a personalized comparison) or with others more generally (a generalized comparison). Four studies (two event-contingent diary studies, one study of comparisons during a triathlon, and one controlled experiment) showed that personalized comparisons were more likely when the target's attribute was distinctive or there was an interaction or a close or emotional relationship with the target. Perhaps because these conditions that increase interest in the target as a distinct individual were less common during the triathlon than in everyday life, personalized comparisons were relatively uncommon during the triathlon but relatively common in everyday life. Across studies, generalized comparisons magnified the impact of upward comparisons on overall feelings (but not on interpersonal feelings about the self-target relationship), presumably because generalizing broadens the implications of comparisons, whereas personalizing restricts their relevance to the self-target relationship.     

Linking serial residential burglary: comparing the utility of modus operandi behaviours,geographical proximity,and temporal proximity

Whilst case linkage is used with serious forms of serial crime (e.g. rape and murder), the potential exists for it to be used with volume crime. This study replicates and extends previous research on the behavioural linking of burglaries. One hundred and sixty solved residential burglaries were sampled from a British police force. From these, 80 linked crime pairs (committed by the same serial offender) and 80 unlinked crime pairs (committed by two different serial offenders) were created. Following the methodology used by previous researchers, the behavioural similarity, geographical proximity, and temporal proximity of linked crime pairs were compared with those of unlinked crime pairs. Geographical and temporal proximity possessed a high degree of predictive accuracy in distinguishing linked from unlinked pairs as assessed by logistic regression and receiver operating characteristic analyses. Comparatively, other traditional modus operandi behaviours showed less potential for linkage. Whilst personality psychology literature has suggested we might expect to find a relationship between temporal proximity and behavioural consistency, such a relationship was not observed. Copyright © 2010 John Wiley & Sons, Ltd.     

Sugar proximity and human grip strength

In a double-blind experiment with 90 undergraduate students the hypothesis was tested that proximity to sugar reduces human grip strength. An earlier study indicated that sugar proximity does indeed significantly reduce human grip strength. When additional controls were added to this design to reduce random sampling error, the hypothesis was not supported.     

Friendship, proximity, and self-disclosure

Patterns of self-disclosure were explored by means of a questionnaire administered to pairs of roommates and hallmates (non-roommates living on the same floor) in freshman dormitories. It was predicted and found that friendship was more highly related to self-disclosure in intimate than in non-intimate topic areas, whereas proximity was more highly related to disclosure in non-intimate than in intimate areas. It was also found that friendship and intimate disclosure were more highly related among women than among men. These findings emphasize the interplay of personal, role-related, and environmental factors which underlie patterns of friendship and self-disclosure. They also point to the importance of viewing self-disclosure in differentiated terms, rather than as single monolithic entity. Other findings of both substantive and methodological interest are reported. For example, there was a strong tendency for respondents to overemphasize the degree to which their patterns of giving and receiving personal information were symmetrical. There was also a tendency for respondents to report giving more disclosure than they received in non-intimate areas, but not in intimate areas.     

Entropy,semantic relatedness and proximity

Although word co-occurrences within a document have been demonstrated to be semantically useful, word interactions over a local range have been largely neglected by psychologists due to practical challenges. Shannon’s (Bell Systems Technical Journal, 27, 379–423, 623–665, 1948) conceptualization of information theory suggests that these interactions should be useful for understanding communication. Computational advances make an examination of local word–word interactions possible for a large text corpus. We used Brants and Franz’s (2006) dataset to generate conditional probabilities for 62,474 word pairs and entropy calculations for 9,917 words in Nelson, McEvoy, and Schreiber’s (Behavior Research Methods, Instruments, & Computers, 36, 402–407, 2004) free association norms. Semantic associativity correlated moderately with the probabilities and was stronger when the two words were not adjacent. The number of semantic associates for a word and the entropy of a word were also correlated. Finally, language entropy decreases from 11 bits for single words to 6 bits per word for four-word sequences. The probabilities and entropies discussed here are included in the supplemental materials for the article.     

Anchor effects on the discrimination of pitch

Two experiments considered the effects of introducing an extreme stimulus (anchor) upon the differential perception of tonal stimuli. In the first experiment, in which Ss rated series stimuli from 1,000 to 2,000 Hz or from 2,000 to 3,000 Hz, the presence of a 750-Hz anchor apparently disrupted discrimination. A second experiment involved testing for a difference threshold (method of limits) in which the standard was a tone of 1,500 Hz. The uncertainty interval (Iu) was larger when the interval between paired stimulus presentations was filled with a 750-Hz tone, again suggesting that discrimination is impaired by the introduction of a low-frequency anchor. Results are discussed in terms of theories relating range extent and discriminability.     

Memory for the pitch of a tone

Observers attempted to detect the presence of a pitch difference between two successive tones. The percentage of correct judgments was equivalent for tones separated by .95, 4.5, and 8.9 sec. There was a general increase in reports of a pitch difference with increased intertone interval, which is interpreted as arising from hypothesized shifts in the neural locus of the first stimulus during the intertone interval.