The effect of perceived distance on perceived movement

Equations were developed to predict the apparent motion of a physically stationary object resulting from head movement as a function of errors in the perceived distances of the object or of its parts. These equations, which specify the apparent motion in terms of relative and common components, were applied to the results of two experiments. In the experiments, the perceived slant of an object was varied with respect to its physical slant by means of perspective cues. In Experiment I, O reported the apparent motion and apparent distance of each end of the object independently. The results are consistent with the equations in terms of apparent relative motion, but not in terms of apparent common motion. The latter results are attributed to the tendency for apparent relative motion to dominate apparent common motion when both are present simultaneously. In Experiment II, a direct report of apparent relative motion (in this case, apparent rotation) was obtained for illusory slants of a physically frontoparallel object. It was found that apparent rotations in the predicted direction occurred as a result of head motion, even though under these conditions no rotary motion was present on the retina.     

The effect of similarities in skin texture and hand shape on perceived ownership of a fake limb

In the rubber-hand illusion (RHI), people attribute an artificial object to their own body. In the present study, we investigate the extent to which RHI is affected by visual discrepancies between the artificial object and a human hand. We tested Armel and Ramachandran's (2003) hypothesis that people will experience a stronger RHI when the artificial object is a skin-like textured sheet instead of a tabletop. We did not find support for their hypothesis, but the strength of the RHI diminished when the texture of a hand-shaped object did not resemble the human skin (manipulated by putting a white glove over the cosmetic prosthesis). We provide an alternative explanation for this finding, based on a skill-based sensorimotor account of perceived body ownership. Such an explanation supports Armel and Ramachandran's more general claim that discrepancies in the nature of expected and felt touch diminish the RHI.     

The effect of texture relief on perception of slant from texture

Texture can be an effective source of information for perception of slant and curvature. A computational assumption required for some texture cues is that texture must be flat along a surface. There are many textures which violate this assumption, and have some sort of texture relief: variations perpendicular to the surface. Some examples include grass, which has vertical elements, or scattered rocks, which are volumetric elements with 3-D shapes. Previous studies of perception of slant from texture have not addressed the case of textures with relief. The experiments reported here test judgments of slant for textures with various types of relief, including textures composed of bumps, columns, and oriented elements. The presence of texture relief was found to affect judgments, indicating that perception of slant from texture is not robust to violations of the flat-texture assumption. For bumps and oriented elements, slant was underestimated relative to matching flat textures, while for columns textures, which had visible flat top faces, perceived slant was equal or greater than for flat textures. The differences can be explained by the way different types of texture relief affect the amount of optical compression in the projected image, which would be consistent with results from previous experiments using cue conflicts in flat textures. These results provide further evidence that compression contributes to perception of slant from texture.     

Two varieties of perceived length

The perception of length depends on the mode of stimulation. When Ss were asked to judge the apparent lengths of blocks presented either visually or proprioceptively (between thumb and finger of one hand), visual length was proportional to block length, whereas proprioceptive length was an accelerating function of block length. When both visual and proprioceptive stimulation occurred simultaneously (S both saw and felt a block), the visual input was preemptive.     

The effect of perceived motion-in-depth on time perception

The present study examined the effect of perceived motion-in-depth on temporal interval perception. We required subjects to estimate the length of a short empty interval starting from the offset of a first marker and ending with the onset of a second marker. The size of the markers was manipulated so that the subjects perceived a visual object as approaching or receding. We demonstrated that the empty intervals between markers was perceived as taking shorter to view when the object was perceived as approaching than when it was perceived as receding. We found in addition that the motion-in-depth effect disappeared when the shape continuity between the first and second marker was broken or when the object approached but missed the face. We conclude that anticipated collision of an approaching object altered perception of an empty interval.     

The effect of perceived distance on induced movement

The magnitude of induced movement was measured as a function of the perceived depth between the test object and the plane of the induction object, with this perceived depth produced by stereoscopic cues. Three experiments were conducted. In each experiment, the induction object (a frame of constant physical size) was positioned at one of three distances with the test object (a point of light) placed successively at each of the three distances. Predictions of the magnitude of induction as a function of the depth separation of the test and induction object were made from the subject-relative and object-relative hypotheses of induced motion. It was expected, however, that neither of these hypotheses would predict the results independently of a factor described in the adjacency principle. This principle states that the effectiveness of whatever cues or processes determine the induced movement will decrease with increased depth between the test and induction object. The data indicate that the adjacency principle must be considered in explaining the results. The subject-relative rather than object-relative hypothesis as modified by the adjacency principle was most successful in predicting the results. Control conditions in which the frame was stationary and the point of light was physically moving were also used. Despite the fact that the relative displacement of the objects on the eye in the experimental and control conditions were the same, the results indicate that O could distinguish between these two kinds of conditions. Although the apparent movement was greater in the control conditions than in the experimental conditions, the reverse is true if the total perceived movement of the test and induction object are considered together.     

The effect of perceived message choice on persuasion

We argue that giving individuals a sense of choice over the product information they receive (i.e., message choice) can have important subsequent effects when individuals are prompted to make inferences about the company. Even when the product information that is received is exactly the same, being given a sense of choice can produce more favorable company evaluations and in turn, more favorable product judgments. The first two experiments support these hypotheses using different means of prompting company inferences: when prompted, those who had been given message choice judged the company more favorably and were more willing to purchase from that company. The third experiment illustrates when message choice effects can backfire. Specifically, when the company itself highlights the provision of message choice in the ad, and consumers are prompted to make inferences about the company, message choice can backfire because it may be perceived as a persuasion tactic rather than a sincere attempt to inform. The results support company evaluations as the mediator of message choice effects and rule out alternate accounts based on dissonance, elaboration, reactance and self-labeling explanations. These findings are important in interactive media environments where marketers have opportunities and imperatives to give consumers a sense of choice in message selection.     

The effect of increased parasympathetic activity on perceived duration

Theories of human temporal perception suggest that changes in physiological arousal distort the perceived duration of events. Behavioural manipulations of sympathetic nervous system (SNS) activity support this suggestion, however the effects of behavioural manipulations of parasympathetic (PSNS) activity on time perception are unclear. The current study examined the effect of a paced respiration exercise known to increase PSNS activity on sub-second duration estimates. Participants estimated the duration of negatively and neutrally valenced images following a period of normal and paced breathing. PSNS and SNS activity were indexed by high-frequency heart-rate variability and pre-ejection period respectively. Paced breathing increased PSNS activity and reduced the perceived duration of the negative and neutrally valenced stimuli relative to normal breathing. The results show that manipulations of PSNS activity can distort time in the absence of a change in SNS activity. They also suggest that activities which increase PSNS activity may be effective in reducing the perceived duration of short events.     

The effect of perceived locomotor constraints on distance estimation

Two experiments were conducted to examine the ways in which the visual estimation of distance to a target is affected by constraints perceived to be placed on the subsequent locomotion to the target without vision. We hypothesized that an appraisal of impending effort would play a role in ascertaining the distance to be walked. In Experiment 1, the amount of resistance to walking was variable and unpredictable. One group of subjects performed against relatively low resistance, whereas another group performed against substantially greater resistance. In the low-resistance condition, no significant differences in CE, VE, time to target, or number of steps to target were found between any of the eight combinations of predictable or unpredictable resistances during walking. In the high-resistance condition, however, significant differences were found for CE and number of strides to target when resistance varied unpredictably during walking. Experiment 2 was similar in design but required subjects to walk with combinations of normal or short steps after they had viewed the target knowing only the gait type that would be used to begin locomotion. No differences in CE, VE, or time to target were found between four different combinations of gait type and predictability, under subjectively controlled conditions. When the step constraints were externally imposed, however, differences were found for CE. None of the results from either experiment, in which the number of strides needed to reach the target or the predictability of gait did not change from normal, supported the hypothesis that motor output requirements are necessary in forming a mental representation of the target position that can be used to walk to the target with eyes closed. Whichever locomotor technique was used to walk the estimated distance in these cases, the representation was able to be used independently. When walking mechanics were altered by externally imposed constraints, however, the success at reaching the estimated target position was reduced. These latter results are consistent with those obtained using up, down, and level walking and support the premise that mental representations used in blind walking are linked to the locomotor mechanics afforded by environmental conditions.     

The effect of perceived financial vulnerability on prosocial activity

Our research examines the effect of subjective financial vulnerability on prosocial activity. First, data from the European Survey of Health, Aging and Retirement (SHARE) revealed that higher assessment of one's financial vulnerability might be associated with prosocial motivation for social activities. Next, we manipulated participants' perception of their relative financial position compared to their peers and found that participants randomly assigned to the low financial position condition were more willing to volunteer than participants assigned to the high financial position condition. In Study 3, we manipulated participants' financial advantage. Participants who were disadvantaged in the experimental settings were more willing to volunteer and donate to charity compared to participants with financial advantage. In our final study, we examined willingness to donate to in‐group and out‐group help organizations and found that individuals of lower perceived financial standing may be motivated by the goal of increasing the strength of the social group, rather than by expectations of direct reciprocity. We also found that emotional distress mediates the relationship between perceived financial vulnerability and prosocial behavior. In line with earlier research illustrating that lower financial status promotes prosociality on an interpersonal level, we demonstrate that even momentary perception of relative financial disadvantage and vulnerability promotes prosociality in the broader social context.     

Interference in the perceived segregation of equal-luminance element-arrangement texture patterns

Perceived segregation in element-arrangement patterns composed of squares of equal size and luminance, but of two different hues, was investigated in two experiments. Element-arrangement patterns consist of two types of elements, arranged in alternating vertical stripes in the top and bottom regions and in a checkerboard pattern in the center region. Perceived segregation of the striped and checkerboard regions decreased with increasing luminance of the interspaces between the squares, a high-luminance surround, and the increased spacing of the squares. When the luminance of the horizontal interspaces was increased, the decrease in perceived segregation was greater than that when the luminance of the vertical interspaces was increased. Two explanations of the interference of the interspace luminance are discussed. One explanation is in terms of inhibitory interactions among cortical filters tuned to spatial frequency and orientation. A second explanation is in terms of interference with preattentive grouping processes.     

The effect of texture oil the magnitude of

The magnitude of simultaneous brightness contrast was measured while the coarseness of the textural overlay was varied. Remits from 10 Ss indicate that as the size of elements in the texture increases, the amount of obtained contrast decreases. An interpretation of these results in terms of the spread of lateral inhibitory effects is offered.     

The effect of line configuration on perceived numerosity of dotted lines

Estimates of the number of objects in a line are made in many different situations. This paper demonstrates that besides the actual number of dots, aspects of line configuration affect the perceived numerosity of dotted lines. Experiment 1 provides evidence that the highly studied “clutter effect” in distance perception research replicates to the numerosity domain so that lines made up of more segments are perceived to contain more dots. Experiments 2–5 provide nomological validity for the recently proposed “direct distance” effect in distance perceptions by showing that numerosity perceptions are higher the greater the euclidean length between the line end points and by manipulating euclidean length in three orthogonal ways: the relative length of segments (Experiment 2), the angle between segments (Experiment 3), and the general direction of segments (Experiment 4). Experiment 5 conceptually replicates the results of Experiments 2–4 utilizing stimuli-based versus memory-based judgments and a discrimination task. Experiments 6 and 7 extend the research on spatial perception by demonstrating that the use of euclidean length as a source of information is inversely related to line width, with width varied through clutter (Experiment 6) and total line length (Experiment 7). Overall, the results demonstrate that the robustness of the euclidean length effect is contingent on the salience of alternative spatial heuristics-specifically, euclidean width. Theoretical implications are discussed.     

The effect of visual magnification and reduction on perceived hand size

The aim of the present study was to clarify the mechanisms underlying body understanding by examining the impact of visual experience (magnification and reduction) on perception of hand size and neutral external objects (squares). Independent groups of participants were asked to look through a 2× magnification lens, a ½-× reduction lens, or a control UV filter and to make visual size judgments about square stimuli and their hands. In Experiment 1, participants used a measuring device with unmarked wooden slats orientated in horizontal and radial/vertical space for their visual judgments. In Experiment 2, participants used an upright frontal slat for visual length judgments of their hands to eliminate any potential foreshortening in viewing the measurement apparatus. The results from the two experiments demonstrate that participants significantly underestimated both the square stimuli and their hands when they viewed them under a reduction lens. While overestimation and underestimation of squares was found for females in Experiment 2, males generally underestimated the squares. However, overestimation was not seen when the participants viewed their hands under a magnification lens. Implications of these findings are discussed.     

The effect of red color on perceived self‐attractiveness

Recent research showed that individuals are perceived as more attractive when presented with the color red. We seek to extend these findings by studying the effects of red color on individuals' perception of self‐attractiveness, rather than the attractiveness of others. Based on the color‐in‐context theory, we hypothesized that individuals would perceive themselves as more attractive under red chromatic conditions. In three experiments, participants were asked to wear a red or a blue shirt and rated their own attractiveness. As expected, participants in the red shirt condition indicated a higher level of self‐attractiveness than participants in the blue condition. Moreover, the results showed that the self‐perception red effect was mediated by the individuals' self‐perceived sexual receptivity and self‐perceived status.