Tactual roughness perception: Spatial and temporal determinants.

Investigated M. M. Taylor and S. J. Lederman's (see record 1975-10788-001) model of tactual roughness perception. According to this model, felt roughness is best predicted by modeling the intensive aspects of instantaneous skin displacement, as determined primarily by groove and ridge width and by finger force. Two experiments involving a total of 14 young right-handed adults were conducted. Exp I showed that magnitude estimates of the felt roughness of linear gratings were not affected by either spatial period or groove-to-ridge ratio. Exp II found only negligible effects on perceived roughness of varying the relative speed of motion between skin and surface, whether active or passive touch was used. The results of both experiments argue strongly against a temporal coding theory of roughness perception, and serve to clarify and strengthen Taylor and Lederman's model. (French abstract) (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Picture perception: Toward a theoretical model.

Describes J. J. Gibson's new theory of picture perception and a program of research within his framework. An analysis of pictorial information is proposed in which a systematic investigation of the structural components of pictures and their varying effects on perception is seen as preliminary to the postulation of hypothetical pick-up mechanisms. The basic components of pictures are described, and literature is reviewed in the problem areas of distorted and impoverished information, observation from the wrong station point, coexisting flatness and depth information, and the ambiguity of the source of a single projection. The feasibility of the Gibsonian enterprise is demonstrated, and further avenues for research into a structural analysis of pictorial information are noted. (48 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Auditory perception of position and speed.

2 experiments were carried out to test the ability of train drivers to use sounds for the recognition of position and speed. The procedure involved playing tape recordings of 2 steam locomotives leaving known points and traveling at known speeds to experienced train drivers in a laboratory situation. Results show that Ss were able to recognize the position recordings better than predicted by chance, and that they were able to rank the speed recordings relative to each other, but they were not able to assign accurate values to the latter in terms of miles per hour. There were no significant differences in respect of the 2 locomotives. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Continuous symmetry: a model for human figural perception

Symmetry is usually viewed as a discrete feature: an object is either symmetric or non-symmetric. In this presentation, symmetry is treated as a continuous feature and a continuous measure of symmetry (the Symmetry Distance) is defined. This measure can be easily evaluated for any shape or pattern in any dimension. A preliminary study presented here shows that the Symmetry Distance is commensurate with human perceptual experience. Good correlation is found between the continuous symmetry values and the perceived goodness of figures.     

Attention and the perception of temporal order.

The effect of directing attention to a particular location in space has been widely examined in the study of human information processing. Current models assume that attention modulates the speed of information flow such that attended signals are transmitted more rapidly through the perceptual system than unattended signals. This assumption that attention modulates the speed of information flow was examined in the present research by having observers judge the temporal order of two visual stimuli while directing their attention towards one of the stimuli or away from both stimuli. In one experiment, attended stimuli were perceived with a shorter latency than unattended stimuli, supporting the assumption that attention influences the speed of information transmission in the visual system. The results of another experiment indicate that attention alters the temporal profile of the visual responses, such that visual responses at the attended location are more sharply tuned than responses at the unattended location. It is concluded that attention has two effects on visual responses: It affects the transmission speed of information in the visual system and it alters the temporal profile of the responses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Auditory temporal order perception in younger and older adults

This investigation examined the abilities of younger and older listeners to discriminate and identify temporal order of sounds presented in tonal sequences. It was hypothesized that older listeners would exhibit greater difficulty than younger listeners on both temporal processing tasks, particularly for complex stimulus patterns. It was also anticipated that tone order discrimination would be easier than tone order identification for all listeners. Listeners were younger and older adults with either normal hearing or mild-to-moderate sensorineural hearing losses. Stimuli were temporally contiguous three-tone sequences within a 1/3 octave frequency range centered at 4000 Hz. For the discrimination task, listeners discerned differences between standard and comparison stimulus sequences that varied in tonal temporal order. For the identification task, listeners identified tone order of a single sequence using labels of relative pitch. Older listeners performed more poorly than younger listeners on the discrimination task for the more complex pitch patterns and on the identification task for faster stimulus presentation rates. The results also showed that order discrimination is easier than order identification for all listeners. The effects of hearing loss on the ordering tasks were minimal.     

Intrasensory and intersensory perception of temporal sequences during infancy.

Investigated sensory integration in infants. 40 Ss in 2 groups were repeatedly presented with a standard visual or auditory temporal sequence in a habituation period. In the test period, each group was divided into 4 subgroups in which the presentation modality and/or the temporal sequence remained the same or were different. Ss who were presented a different temporal sequence in the test period produced larger responses than did Ss who were presented the same standard temporal sequence. This differential magnitude of responding occurred regardless of the sensory modality in which the temporal sequences were presented. Results support the conclusion that infants as young as 7 mo of age are capable of perceiving equivalences and differences in temporal sequential information within and across sensory modalities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of a dynamical model of speech perception

Previous work (Tuller, Case, Ding, & Kelso, 1994) has revealed signature properties of nonlinear dynamical systems in how people categorize speech sounds. The data were modeled by using a two-well potential function that deformed with stimulus properties and was sensitive to context. Here we evaluate one prediction of the model--namely, that the rate of change of the potential's slope should increase when the category is repeatedly perceived. Judged goodness of category membership was used as an index of the slope of the potential. Stimuli from a "say"-"stay" continuum were presented with gap duration changing sequentially throughout the range from 0 to 76 to 0 msec, or from 76 to 0 to 76 msec. Subjects identified each token as either "say" or "stay" and rated how good an exemplar it was of the identified category. As predicted, the same physical stimulus presented at the end of a sequence was judged a better exemplar of the category than was the identical stimulus presented at the beginning of the sequence. In contrast, stimuli presented twice near the middle of a sequence with few (or no) stimuli between them, as well as stimuli presented with an intervening random set, showed no such differences. These results confirm the hypothesis of a context-sensitive dynamical representation underlying speech.     

Aging and perception of visual form from temporal structure.

In this study, the authors examined age-related changes in participants' ability to perceive global spatial structure defined by temporal fine structure among elements undergoing rapid, irregular change. Participants were also tested on a task involving form recognition from luminance contrast and on a task dependent on perception of 3-dimensional shape from motion. Compared with young adults, older individuals were less sensitive to spatial form defined by temporal structure. In contrast, older observers performed as well as young adults on the other two tasks that were not dependent on temporal sensitivity, ruling out nonsensory factors as the cause of the deficits on the temporal structure task. This selective deficit may reveal reduced sensitivity within the temporal impulse response of the aging visual system, a deficit that could be related to reduced effectiveness of neural inhibition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Duct-parenchymal ratio predicts exocrine pancreatic function after pancreatoduodenectomy and distal pancreatectomy

U tubes have been used for a wide variety of hepatobiliary problems. We report a patient with multiple complications possibly related to the use of a U tube. These include secondary biliary cirrhosis, intrahepatic bilomas, and enterocutaneous fistula. The relatively rare entities of intrahepatic biloma and enterocutaneous fistula are reviewed.     

Infants' perception of rhythm: Categorization of auditory sequences by temporal structure.

80 infants (aged 7–9 mo) were presented with repetitions of 3- or 4-tone sequences characterized by a particular rhythmic structure (RHS). Ss' detection of changes in RHS was evaluated in the context of randomly presented variations in tempo (rate) and frequency. Ss categorized 3- and 4-tone sequences on the basis of similar temporal structure or rhythm. Data indicate that relational processing of auditory sequences is evident in the temporal domain as it is in the pitch domain (e.g., A. J. Cohen et al; see record 1988-16488-001). (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Smoothness maximization along a predefined path accurately predicts the speed profiles of complex arm movements

The speed profiles of arm movements display a number of regularities, including bell-shaped speed profiles in straight reaching movements and an inverse relationship between speed and curvature in extemporaneous drawing movements (described as a 2/3 power law). Here we propose a new model that simultaneously accounts for both regularities by replacing the 2/3 power law with a smoothness constraint. For a given path of the hand in space, our model assumes that the speed profile will be the one that minimizes the third derivative of position (or "jerk"). Analysis of the mathematical relationship between this smoothness constraint and the 2/3 power law revealed that in both two and three dimensions, the power law is equivalent to setting the jerk along the normal to the path to zero; it generates speed predictions that are similar, but clearly distinguishable from the predictions of our model. We have assessed the accuracy of the model on a number of motor tasks in two and three dimensions, involving discrete movements along arbitrary paths, traced with different limb segments. The new model provides a very close fit to the observed speed profiles in all cases. Its performance is uniformly better compared with all existing versions of the 2/3 power law, suggesting that the correlation between speed and curvature may be a consequence of an underlying motor strategy to produce smooth movements. Our results indicate that the relationship between the path and the speed profile of a complex arm movement is stronger than previously thought, especially within a single trial. The accuracy of the model was quite uniform over movements of different shape, size, and average speed. We did not find evidence for segmentation, yet prediction error increased with movement duration, suggesting a continuous fluctuation of the "tempo" of discrete movements. The implications of these findings for motor planning and on-line control are discussed.     

Processing of observed pupil size modulates perception of sadness and predicts empathy.

Facial autonomic responses may contribute to emotional communication and reveal individual affective style. In this study, the authors examined how observed pupillary size modulates processing of facial expression, extending the finding that incidentally perceived pupils influence ratings of sadness but not those of happy, angry, or neutral facial expressions. Healthy subjects rated the valence and arousal of photographs depicting facial muscular expressions of sadness, surprise, fear, and disgust. Pupil sizes within the stimuli were experimentally manipulated. Subjects themselves were scored with an empathy questionnaire. Diminishing pupil size linearly enhanced intensity and valence judgments of sad expressions (but not fear, surprise, or disgust). At debriefing, subjects were unaware of differences in pupil size across stimuli. These observations complement an earlier study showing that pupil size directly influences processing of sadness but not other basic emotional facial expressions. Furthermore, across subjects, the degree to which pupil size influenced sadness processing correlated with individual differences in empathy score. Together, these data demonstrate a central role of sadness processing in empathetic emotion and highlight the salience of implicit autonomic signals in affective communication. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neurobiological model of perception: Considerations for transference.

Transference is a key concept in psychoanalysis, distinguishing the analytic treatment from other forms of psychotherapy. In this essay, the authors place transference into the context of a general psychology of human functioning and link it to the neurobiology of perception. The authors briefly review the literature within and outside of psychoanalysis, define transference through the lens of perception, and propose that it is ubiquitous in humans. When not impaired, transference is an adaptive ego function that emerges, along with countertransference, in the context of any interpersonal situation of significant emotional import. The authors draw on W. Freeman's (2003, 2004) research on olfaction, which has since been replicated in other sensory modalities, for a neurodynamic basis for their model of perception and describe how transference may be thought of as an evolved form of it. The authors' view is that transference is a hierarchically integrated perceptual modality of a higher order, although it depends on the same neurodynamic processes as those found in each sensory modality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The development of intersensory temporal perception: An epigenetic systems/limitations view.

Several theories have stressed the importance of intersensory integration for development but have not identified specific underlying integration mechanisms. The author reviews and synthesizes current knowledge about the early development of intersensory temporal perception and offers a theoretical model based on epigenetic systems theory, proposing that responsiveness to 4 basic features of multimodal temporal experience—temporal synchrony, duration, temporal rate, and rhythm—emerges in a sequential, hierarchical fashion. The model postulates that initial developmental limitations make intersensory synchrony the basis for the integration of intersensory temporal relations and that the emergence of responsiveness to the other, increasingly more complex, temporal relations occurs in a hierarchical, sequential fashion by building on the previously acquired intersensory temporal processing skills. This article focuses on how and under what conditions infants perceive equivalent intersensory temporal relations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Auditory temporal pattern perception in 6- and 12-month-old infants.

A go/no-go conditioned head-turn paradigm was used to examine 20 6- and 20 12-mo-olds' abilities to discriminate changes in temporal grouping and their perception of absolute and relative timing information when listening to patterns of white-noise bursts. 6-mo-olds performed absolute timing discriminations both when the number of groupings of a pattern were changed and when the number of groupings remained invariant and the duration parameters of elements comprising a single group were altered. They did not, however, reliably discriminate changes in relative timing information that resulted in the number of groups remaining invariant while the number of elements comprising a group changed. 12-mo-olds readily performed both types of temporal grouping discriminations, demonstrating equally high performance for absolute and relative timing-discrimination conditions. For the absolute timing parameters tested, there was no evidence of any age-related change in the temporal resolving power of the auditory system. Ss at both ages reliably performed signal–silence duration discriminations spanning .04–.06 to .10–.15 sec. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

冷连轧生产线的速度控制模型研究

在秒流量方程的基础上,充分考虑厚度偏差和张力波动对速度的影响,推导并建立了1个冷连轧综合速度控制模型,并根据动态结构图配置了控制器.通过对比仿真研究,进一步优化了控制器参数,在某1 550 mm冷连轧生产应用中,将张力、厚度指标作为控制目标.速度参数作为控制对象,使张力波动从调整前的300 kg减小到目前的90 kg,...     

Psychosocial resources, threat, and the perception of distance and height: Support for the resources and perception model.

Threatening things are often perceptually exaggerated, such that they appear higher, closer, of greater duration, or more intense than they actually are. According to the Resources and Perception Model (RPM) psychosocial resources can prevent this exaggeration, leading to more accurate perception. Two studies tested RPM. Study 1 showed that the perceived closeness of a threatening object (a live tarantula) but not an innocuous object (a cat toy) was moderated by induced self-worth. Further, the more self-worth that participants experienced, the less close the tarantula appeared to them. Study 2 showed that greater levels of self-esteem reduced perceived height, but only among participants prevented from holding a protective handrail while looking down. Together, these studies confirm that resources moderate the physical perception of both distance and height, that resources moderate perception of threats but not nonthreats, that different resources have similar moderating effects, and that psychosocial resources can supplant physical resources. (PsycINFO Database Record (c) 2011 APA, all rights reserved)