Psychophysics in the field: Perception and memory for labor pain

Separate groups of women estimated the painfulness of labor contractions either immediately (perceptual judgments) or at time intervals varying from 8 to 48 h after their completion (memorial judgments). The pain judgments of individual uterine contractions were related functionally to the biometrically measured magnitude of these contractions. Perceived and remembered painful sensations were related to referent intensities by power functions governed, as a rule, by exponents greater than unity. Exponents for the memory functions were consistently greater than those for the perceptual functions. Psychophysics done in the field can help decide theoretical issues in addition to providing useful practical information.     

Remembered odors and mental mixtures: tapping reservoirs of olfactory knowledge.

Five experiments explored how (a) perceived and remembered odor intensities relate to concentration; (b) odor intensities integrate in perceptual, memorial, and mentally constructed mixtures; and (c) components vary in intensity in physical versus mental mixtures. Ss estimated the magnitude of unmixed stimuli presented physically (perceptual estimation) or represented symbolically (memorial estimation). Ss also judged mixtures and their components in combinations of perceptual and memorial presentation. Power functions with similar exponents described the relations between both perceived and remembered intensity and concentration. Perceptual, memorial, and mental mixtures all followed much the same interactive rule of integration. Correspondingly, the intensities of components varied similarly in mentally constructed and physical mixtures. The results imply intensive invariance across odor perception and odor memory.     

Memory psychophysics

Summary The relationship between perceptual and cognitive processes has been a topic of increasing interest. This review focuses on the use of techniques and theory drawn from classical psychophysics and applied to the study of mental representation. Several issues including examination of the functions that relate remembered and perceived magnitude to physical intensity, the relationship of memorial to perceptual functions, the effect of time on the memorial function, considerations in the methodology of memory psychophysics experiments, the level of functional equivalence between memorial and perceptual representation, and the use of psychophysical techniques and theory in the study of visual imagery are addressed. While the data suggest that the relationship between remembered magnitude and physical intensity and between perceived magnitude and physical intensity can be described by power functions, a model capable of accounting for the behavior of the memory magnitude for all stimulus dimensions and at all time intervals has not yet been found. Several unresolved issues and typical difficulties with research in memory psychophysics are also discussed.     

The discriminability of remembered magnitudes

Psychometric functions and the associated indices of discriminative performance (i.e., the point of subjective equality [PSE], just noticeable difference, and Weber fraction) were obtained with the method of constant stimuli using perceptual and remembered line-length standards. Three important results were obtained. First, comparisons with a perceptual or a remembered standard were sensitive to variations of absolute stimulus differences with a common ratio; that is, Weber's law was violated. Second, relative to discriminative performance with the longest and shortest remembered standards, comparisons involving mid-range remembered standards displayed increased variability in the PSE and inflated Weber fractions, characteristic of a reduction in the quality of the memorial representation. Finally, large and negative time-order errors (TOE) were observed for successive line judgments but not for those involving remembered standards. The implications of these findings for research concerned with the relationships between perception and memory, as well as the TOE phenomenon, are discussed.     

The role of eye height in perceiving affordances and object dimensions.

In four experiments on perceived object height and width, the effects of shifting participants' effective eye height (EEH) on affordance (intrinsic) and apparent size (extrinsic) judgments were contrasted. In Experiment 1, EEH shifts produced comparable overestimations of height in intrinsic and extrinsic tasks. A similar result was found with a more abstract extrinsic height task (Experiment 2). However, Experiment 3 revealed a dissociation between intrinsic and extrinsic tasks of perceived width. Affordance judgments were affected by EEH shifts, whereas apparent size judgments were not. Experiment 4 compared participants' performance on comparable extrinsic tasks of height and width. Height judgments were affected by EEH shifts, but width judgments were again unaffected. It is concluded that eye height may be a more natural metric for object height than for width. Moreover, this difference reflects a basic flexibility within the human visual system for selectively attuning to the most accessible sources of size information.     

Easily perceived, easily remembered? Perceptual interference produces a double dissociation between metamemory and memory performance

A recent candidate for explaining metamemory judgments is the perceptual fluency hypothesis, which proposes that easily perceived items are predicted to be remembered better, regardless of actual memory performance (Rhodes & Castel Journal of Experimental Psychology: General 137:615–625, 2008). In two experiments, we used the perceptual interference manipulation to test this hypothesis. In Experiment 1, participants were presented with intact and backward-masked words during encoding, followed by a metamemory prediction (a list-wide judgment of learning, JOL) and then a free recall test. Participants predicted that intact words would be better recalled, despite better actual memory for words in the perceptual interference condition, yielding a crossed double dissociation between predicted and actual memory performance. In Experiment 2, JOLs were made after each study word. Item-by-item JOLs were likewise higher for intact than for backward-masked words, despite similar actual memory performance for both types of words. The results are consistent with the perceptual fluency hypothesis of metamemory and are discussed in terms of experience-based and theory-based metamemory judgments.     

The role of eye height in perceiving affordances and object dimensions

In four experiments on perceived object height and width, the effects of shifting participants’ effective eye height (EEH) on affordance (intrinsic) and apparent size (extrinsic) judgments were con-trasted. In Experiment 1, EEH shifts produced comparable overestimations ofheight in intrinsic and extrinsic tasks. A similar result was found with a more abstract extrinsic height task (Experiment 2). However, Experiment 3 revealed a dissociation between intrinsic and extrinsic tasks of perceivedwidth. Affordance judgments were affected by EEH shifts, whereas apparent size judgments were not. Experiment 4 compared participants’ performance on comparable extrinsic tasks of height and width. Height judgments were affected by EEH shifts, but width judgments were again unaffected. It is concluded that eye height may be a more natural metric for object height than for width. Moreover, this difference reflects a basic flexibility within the human visual system for selectively attuning to the most accessible sources of size information.     

Perceptual and memorial constructs in children's judgments of quantity: a law of across-representation invariance

Children at three different ages made judgments of physically presented (perceptual estimation) or symbolically represented (memorial estimation) rectangles. Height and width were integrated according to different, age-dependent algebraic rules. Memorial data obeyed the same integration rules that operated in the original perceptual judgments even when younger children and older children used completely different combination models. Valuation operations were the same in perception and memory for the youngest group (6-year-olds) but became discriminably different at older ages (for the 8- and 10-year olds). Three additional experiments on judgments of volume, liquid quantity, and visual length yielded strong cross-validation support for the general invariance claim (with respect to integration rule theory) but less strong support for the specific invariance claim (with respect to valuation function for the 6-year-old subjects). Results are interpreted as demonstrating lawful and long-enduring ecological constraints on internal representation.     

Memory psychophysics for visual area and length

Independent groups of observers made magnitude estimates of geographical area or interstate distance. In Experiment 1, observers estimated the areas of nations or of states of the United States from memory. In Experiment 2, estimates of state area were made either with a map present or from memory after the map had been studied. Similarly, in Experiment 3, observers made perceptual or memorial estimates of interstate distances. Perceptual estimates of distance and geographical area were related to actual stimulus magnitude by power functions whose exponents were similar to those found with conventional procedures. Memory estimates were also related to actual area and distance by power functions. Comparison of memory and perceptual exponents showed that for both area and distance, the memory exponent was equal to the square of the perceptual exponent. The results of Experiment 3 were predicted by a “re-perceptual” model of memory for continuous dimensions, which was developed to describe the results of Experiment 2.     

Effects of Threat on Police Officers' Shooting Behavior: Anxiety,Action Specificity,and Affective Influences on Perception

In the current study, we investigated the impact of threat and response mode on police officers' distance perception and shooting behavior in relation to a suspect that approached with a knife. To manipulate threat and increase anxiety, the suspect carried either a plastic knife (low threat) or an electrical knife (high threat). Regarding the manipulation of response mode, officers provided either an actual shooting response or indicated their shot verbally. In both cases, perceptual judgments of shooting distances were assessed through visual matching. Results show that high threat led to earlier shooting, but only for actual shooting responses. Although high threat generally induced more anxiety, perceptual judgments remained unaffected by threat and indicated systematic underestimations of the distance to the suspect. It is suggested that in the online control of action, increased anxiety does not affect distance perception but alters the functional relationship between distance and perceived threat, thereby causing officers to shoot the approaching suspect at an earlier stage. Copyright © 2012 John Wiley & Sons, Ltd.     

Boundaries of the relation between conscious recollection and source memory for perceptual details

The relation between conscious recollection and source memory for perceptual details was investigated in three experiments that combined the remember-know paradigm with a multidimensional source monitoring test. Experiment 1 replicated that source memory for perceptual details is better in the case of "remember" than "know" judgments. Experiment 2 showed that the relation between "remember" judgments and source memory for perceptual details is diminished by a semantic orienting task during encoding. Experiment 3 demonstrated that "remember" judgments are related to enhanced source memory for specific and unique kinds of perceptual source information, whereas memory for incomplete and global perceptual source information does not differentiate between "remember" and "know" judgments. The results show that the attentional focus during encoding and the specificity of retrieved source information form boundary conditions for the use of source memory for perceptual details as a basis of "remember" judgments.     

Direct versus indirect tests of memory for source: judgments of modality

We studied the relation between performance on direct versus indirect tests of memory for modality. Subjects read or heard words in a mixed list and then were tested by visual perceptual identification (the indirect test) and direct report of items as read, heard, or new. There was a dependent relation between perceptual identification performance and modality judgments, in accord with the hypothesis that subjects base their judgments of modality on relative perceptual fluency. In Experiment 2, we attempted to change the degree of dependence by providing subjects with an alternative basis for modality judgments. Subjects given a mnemonic to encode modality exhibited less dependence between perceptual identification performance and modality judgments than did subjects who encoded modality incidentally. The relation between direct and indirect tests of memory for source characteristics depends on the basis used for each.     

The role of haptic exploration of ground surface information in perception of overhead reachability

The authors performed an experiment in which participants (N = 24) made judgments about maximum jump and reachability on ground surfaces with different elastic properties: sand and a trampoline. Participants performed judgments in two conditions: (a) while standing and after having recently jumped on the surface in question and (b) while standing on a third control surface, eliminating haptic exploration of the surface in question. There was a high correlation between perceived maximum reachable height and actual maximum reachable height in all conditions. Judging performance on the basis of visual and haptic exploration of ground surface information was slightly overestimated, whereas performance on the basis of visual information alone was underestimated and variable for the different surfaces. The authors discuss possible causes for the observed errors. They emphasize that there is a considerable nonvisual aspect to the nature of the information specifying affordances for overhead reach and jumping and that perceptual performance is degraded when spontaneous exploratory movement is restricted.     

Array models for category learning

A family of models for category learning is developed, all members being based on a common memory array but differing in memory access and decision processes. Within this framework, fully controlled comparisons of exemplar-similarity, feature-frequency, and prototype models reveal isomorphism between models of different types under some conditions but empirically testable differences under others. It is shown that current exemplar-memory models, in which categorization judgments are based on similarities of perceived and remembered category exemplars, can be interpreted as generalized likelihood models but can be modified in a simple way to yield pure similarity models. Distance-based exemplar models are formulated that provide means of investigating issues concerning deterministic versus probabilistic decision rules and links between categorization and properties of perceptual dimensions. Other theoretical issues discussed include aspects of similarity, the role of memory storage versus computation in category judgments, and the limits of applicability of array models.     

Long-term memory for elementary visual percepts: memory psychophysics of context and acquisition effects

In the first phase of each of two experiments, participants learned to associate a set of labels (i.e., consonant-vowel-consonant [CVC]) with a set of line lengths by using a paired-associate learning procedure. In the second phase of each experiment, these learned labels were used as memorial standards in the method of constant stimuli. Psychometric functions and the associated indices of discriminative performance (i.e., Weber fractions [WFs], just noticeable difference, and point of subjective equality) were then obtained for the remembered standards. In Experiment 1, WFs (i.e., the indices of memory precision) obtained with remembered standards were found to be higher (i.e., had poorer discriminability) than were WFs obtained with perceptual standards. In addition, WFs obtained with the remembered standards exhibited serial position effects (i.e., poorer discriminability for central items in the memory ensemble) and systematically varied with set size (i.e., the number of standards in the memory set), but WFs obtained with perceptual standards did not depend on serial position or set size. In Experiment 2, increasing the number of acquisition trials reduced WFs and diminished serial position effects. In addition, WFs did not vary systematically with the "physical" spacing between the standards in memory, but they did with the ordinal spacing. The results are consistent with a noisy analogue representation of remembered magnitudes, whereby central items in a memory ensemble are subject to lateral inhibition and thus reduced discriminability. Finally, presentation order effects, as defined by the classic time-order error, were observed with purely perceptual comparisons but not with comparisons involving a remembered standard. This latter finding is inconsistent with a strong form of the functional equivalence view of perception and memory.     

The perception of distances and spatial relationships in natural outdoor environments

The ability of observers to perceive distances and spatial relationships in outdoor environments was investigated in two experiments. In experiment 1, the observers adjusted triangular configurations to appear equilateral, while in experiment 2, they adjusted the depth of triangles to match their base width. The results of both experiments revealed that there are large individual differences in how observers perceive distances in outdoor settings. The observers' judgments were greatly affected by the particular task they were asked to perform. The observers who had shown no evidence of perceptual distortions in experiment 1 (with binocular vision) demonstrated large perceptual distortions in experiment 2 when the task was changed to match distances in depth to frontal distances perpendicular to the observers' line of sight. Considered as a whole, the results indicate that there is no single relationship between physical and perceived space that is consistent with observers' judgments of distances in ordinary outdoor contexts.     

The monaural localization of tonal stimuli

With one ear occluded, 17 listeners were asked to locate tone bursts, .25, 4, .6, .9. l.4, 2.0, 3.2, 4.8, and 7.2 kHz, generated by a loudspeaker concealed from view. The S’s response was to callout that number, from a series of numbers arranged horizontally, behind which he thought the tone bursts originated. The listeners perceived the sounds as emanating from the side of the unoccluded ear, but their judgments bore no consistent relation to the actual location of the sound source. Rather, the listeners showed a strong tendency to locate a tone burst, within the range of .9 through 7.2 kHz, in a fixed spatial relation to the next higher- and lower-pitched tone burst. Distorting the pinna of the unoccluded ear failed to modify the perceptual pattern. It was suggested that the perceived spatial relations among the various frequencies was a by-product of the tonotopic organization of the auditory nervous system.     

Attention switching between perception and memory

Two experiments were conducted to explore the switching of attention between perception and memory. In Experiment 1, college students performed a task that required them to cycle or switch attention between perceptual and memorial inputs. Switching times of 293 and 376 msec per switch were obtained on the basis of two formulas. In Experiment 2, the attentional load was manipulated by varying the number of perceptual and memorial inputs. Switching time increased as a function of list length, indicating that item load affects both the control processes that set attentional allocation policies and one’s ability to perform memory and/or perceptual tasks. These results suggest that modularity, or encapsulation of item and control-process systems, does not hold. A model is presented that depicts the relation between item and control-process representation in rapidly alternating attention between perception and memory.     

Perceptual fluency effects in judgments of creativity and beauty: creative objects are perceived fluently yet they are visually complex

ABSTRACT

Perceptual fluency typically has a positive influence on aesthetic evaluations of beauty, but few studies have examined its influence on creativity evaluations. Creativity has two facets, originality and quality. If creativity judgments involve estimating product originality, such judgments may be associated with perceptual disfluency, while product quality may be associated with perceptual fluency. We examined the relationship between perceptual fluency and judgments of creativity and beauty across seven experiments. Creativity judgments were affected by most perceptual fluencysources. We observed a highly-fluent-is-beautiful-and-creative relation when testing repeated exposure and figure-ground contrast. Prototypicality displayed a high-fluency–is-beautiful relation, with creativity judgments unaffected. Visual complexity displayed a consistent disfluent-is-creative effect, with mixed results for beauty. For creativity (but not beauty) evaluations, increased saliency of visual complexity led to discounting fluent-is-creative effects, supporting the hypothesis that there are at least two fluency pathways to creativity judgments that take both originality and quality into account.     

知觉组织对时序知觉的双重影响:同时判断任务的证据

本研究探讨知觉组织对时序知觉的双重影响。实验采用三条线段构成的C形为实验材料,操纵图形朝向和SOA水平(实验1和实验2)、图形颜色(实验3)以及反应限制(实验4),要求被试完成同时判断任务。结果发现,在不同的SOA条件下,图形对向条件的同时判断频率均显著高于图形反向条件(实验1),即使在知觉组织线索弱化时这种现象仍然存在(实验2和实验3),而且知觉组织对时序知觉的影响不是由于被试的反应偏向导致的(实验4)。结果说明知觉组织对时序知觉存在双重影响:当两个刺激同时出现时,知觉组织能够提高时序知觉表现; 而当两个刺激非同时出现时,知觉组织显著降低时序知觉表现。