Strategic and perceptual factors producing tilt contrast in dot localization

Encoding spatial location in a frame of reference is often biased by both perceptual and strategic factors. For example,tilt contrast occurs when a line presented in the frame of horizontal and vertical axes appears to be repulsed from the nearest axis, including the diagonal axis of symmetry, due to symmetry perception mechanisms. Research has demonstrated, however, that people can adopt particular viewing strategies that eliminate this effect. In Experiment 1, a similar tilt contrast effect was observed when subjects reproduced from memory the position of a single dot in this reference frame. It was hypothesized that this effect resulted from a combination of strategic and perceptual factors. Specifically, people employ anorigin strategy, coding the location of the dot relative to the origin of the horizontal and vertical axes, thereby establishing a virtual line that appears tilted away from the axes due to the same perceptual processes affecting physically present lines. Two additional experiments support this hypothesis. In Experiment 2, no clear tilt contrast effect was observed in a perception condition, indicating that the tilt effect for dots cannot be accounted for by purely perceptual processes. In Experiment 3, the tilt contrast effect was found to be contingent upon the use of the origin strategy as opposed to a different strategy. The results demonstrate the importance of a viewer's strategy in determining the pattern of distortion observed in spatial encoding.     

Visual half-field symmetry in orientation perception

The perception of orientation in the left and right visual half-fields has been investigated. No evidence for interfield differences was obtained for the discrimination of single lines by line matching or in magnitude of the systematic orientation distortion in orientation contrast and rod-and-frame experiments. Furthermore, increasing the time interval between test and comparison lines in successive matching provides no evidence for a differential operation of short-term spatial memory in the two hemispheres. It is concluded that hemispheric asymmetries do not arise at the level of sensory processing of spatial signals.     

A timing-specific memory distortion effect in young children

It has been suggested that there are systematic distortions in children's memory for temporal durations, such that children's memory is not just less accurate than that of adults but qualitatively different. Experiment 1 replicated the memory distortion effect by demonstrating developmental change in the tendency to confuse a reference duration with one that is shorter rather than longer than it. When the long-term memory demands of the task were reduced by providing reminders of the reference duration on every trial, there were no such qualitative changes in error patterns (Experiment 2). Further evidence for developmental changes in memory distortion was found in the temporal generalization task of Experiment 3, in which stimuli were spaced logarithmically rather than linearly. In Experiment 4, a similar distortion pattern was absent in a task in which children made judgments about the pitch rather than the duration of stimuli, suggesting the effect may be specific to time estimation.     

Compressing perceived distance with remote tool-use: real, imagined, and remembered

Reaching for an object with a tool has been shown to cause a compressed perception of space just beyond arm's reach. It is not known, however, whether tools that have distal, detached effects at far distances can cause this same perceptual distortion. We examined this issue in the current study with targets placed up to 30m away. Participants who illuminated targets with a laser pointer or imagined doing so consistently judged the targets to be closer than those who pointed at the targets with a baton. Furthermore, perceptual distortions that arose from tool-use persisted in memory beyond the moment of interaction. These findings indicate that remote interactions can have the same perceptual consequences as physical interactions, and have implications for an action-specific account of perception.     

Structure and strategy in encoding simplified graphs

Tversky and Schiano (1989) found a systematic bias toward the 45 degrees line in memory for the slopes of identical lines when embedded in graphs, but not in maps, suggesting the use of a cognitive reference frame specifically for encoding meaningful graphs. The present experiments explore this issue further using the linear configurations alone as stimuli. Experiments 1 and 2 demonstrate that perception and immediate memory for the slope of a test line within orthogonal "axes" are predictable from purely structural considerations. In Experiments 3 and 4, subjects were instructed to use a diagonal-reference strategy in viewing the stimuli, which were described as "graphs" only in Experiment 3. Results for both studies showed the diagonal bias previously found only for graphs. This pattern provides converging evidence for the diagonal as a cognitive reference frame in encoding linear graphs, and demonstrates that even in highly simplified displays, strategic factors can produce encoding biases not predictable solely from stimulus structure alone.     

从表征和认知过程上看表象与知觉、记忆的关系

表象、知觉和记忆是一个整合的认知系统。由于知觉和记忆提供了表象生成的材料,因而三者共享相似的表征,并激活广泛而相似的脑区。然而在认知加工过程上三者存在一定的差异。与知觉相比,表象的编码方式更抽象、更依赖过去经验的参与且处理细节能力更弱;与记忆相比,表象更容易受无关信息的干扰。未来对三者关系的研究应关注不同来源和不同类型的表象与知觉、记忆之间的关系,以及工作记忆在三者关系中所起的作用。     

On the persuadability of memory: Is changing people's memories no more than changing their minds?

The observation of parallels between the memory distortion and persuasion literatures leads, quite logically, to the appealing notion that people can be ‘persuaded’ to change their memories. Indeed, numerous studies show that memory can be influenced and distorted by a variety of persuasive tactics, and the theoretical accounts commonly used by researchers to explain episodic and autobiographical memory distortion phenomena can generally predict and explain these persuasion effects. Yet, despite these empirical and theoretical overlaps, explicit reference to persuasion and attitude‐change research in the memory distortion literature is surprisingly rare. In this paper, we argue that stronger theoretical foundations are needed to draw the memory distortion and persuasion literatures together in a productive direction. We reason that theoretical approaches to remembering that distinguish (false) beliefs in the occurrence of events from (false) memories of those events – compatible with a source monitoring approach – would be beneficial to this end. Such approaches, we argue, would provide a stronger platform to use persuasion findings to enhance the psychological understanding of memory distortion.     

An exploration of perception of body boundary, personal space, and body size in elderly persons.

A study of 108 elderly persons using the Body Distortion Questionnaire and the personal space simulation technique test did not support hypotheses that elderly persons with a large personal space will have a larger distortion of body boundary, a larger perception of large body size, a smaller perception of small body size, a larger distortion of body size, and a larger body distortion than elderly persons with a small personal space. The analyses with one-tail t tests showed elderly persons with a small personal space have a larger perception of large body size and a larger distortion of body size than elderly persons with a large personal space. When the extremes of personal space were used the results were the same. Males have a larger personal space and greater distortion of skin perceptions than females.     

What if you went to the police and accused your uncle of abuse? Misunderstandings concerning the benefits of memory distortion: A commentary on

In a recent paper, Fernández (2015) argues that memory distortion can have beneficial outcomes. Although we agree with this, we find his reasoning and examples flawed to such degree that they will lead to misunderstandings rather than clarification in the field of memory (distortion). In his paper, Fernández uses the terms belief and memory incorrectly, creating a conceptual blur. Also, Fernández tries to make the case that under certain circumstances, false memories of abuse are beneficial. We argue against this idea as the reasoning behind this claim is based on controversial assumptions such as repression. Although it is true that memory distortions can be beneficial, the examples sketched by Fernández are not in line with recent documentation in this area.     

How time flies: a study of novice skydivers

Although time distortion is commonly reported during a traumatic experience, there is little research addressing the phenomenon. This study investigated the role of affect in time perception in a very stressful experience by indexing novice tandem skydivers' (N=76) levels of fear and excitement before the skydive and soon after landing. Estimations of how long skydivers thought their experience lasted were obtained after landing. Whereas increased fear was associated with the perception of time passing slowly, increased excitement was associated with the perception of time passing quickly. These data support models of time perception based on avoidance and approach motivations influencing time distortion.     

Negotiating false memories: interviewer and rememberer characteristics relate to memory distortion

In a recent study, more than half of the participants were led to create a partial or complete false memory for an emotional childhood event (e.g., serious animal attack). Using a subsample from that study, we examined the hypothesis that memory distortion is related to characteristics of interviewers and rememberers. The relations between susceptibility to memory distortion and (a) dissociation (Dissociative Experiences Scale) and (b) personality traits (NEO-Five Factor Inventory) were investigated. Results indicated that participants who exhibited memory distortion scored significantly higher on the dissociative scale than their counterparts who did not exhibit memory distortion. Further, susceptibility to memory distortion was associated with higher extraversion scores in interviewers and lower extraversion scores in participants. This pattern of findings suggests that false memories may derive from a social negotiation between particular interviewers and rememberers.     

Sensory memory for ambiguous vision

In recent years the overlap between visual perception and memory has shed light on our understanding of both. When ambiguous images that normally cause perception to waver unpredictably are presented briefly with intervening blank periods, perception tends to freeze, locking into one interpretation. This indicates that there is a form of memory storage across the blank interval. This memory trace codes low-level characteristics of the stored stimulus. Although a trace is evident after a single perceptual instance, the trace builds over many separate stimulus presentations, indicating a flexible, variable-length time-course. This memory shares important characteristics with priming by non-ambiguous stimuli. Computational models now provide a framework to interpret many empirical observations.     

The reference frame for encoding and retention of motion depends on stimulus set size

The goal of this study was to investigate the reference frames used in perceptual encoding and storage of visual motion information. In our experiments, observers viewed multiple moving objects and reported the direction of motion of a randomly selected item. Using a vector-decomposition technique, we computed performance during smooth pursuit with respect to a spatiotopic (nonretinotopic) and to a retinotopic component and compared them with performance during fixation, which served as the baseline. For the stimulus encoding stage, which precedes memory, we found that the reference frame depends on the stimulus set size. For a single moving target, the spatiotopic reference frame had the most significant contribution with some additional contribution from the retinotopic reference frame. When the number of items increased (Set Sizes 3 to 7), the spatiotopic reference frame was able to account for the performance. Finally, when the number of items became larger than 7, the distinction between reference frames vanished. We interpret this finding as a switch to a more abstract nonmetric encoding of motion direction. We found that the retinotopic reference frame was not used in memory. Taken together with other studies, our results suggest that, whereas a retinotopic reference frame may be employed for controlling eye movements, perception and memory use primarily nonretinotopic reference frames. Furthermore, the use of nonretinotopic reference frames appears to be capacity limited. In the case of complex stimuli, the visual system may use perceptual grouping in order to simplify the complexity of stimuli or resort to a nonmetric abstract coding of motion information.     

Apparent brightness of a rotating arc-line as a function of speed of rotation

52 Ss were required to adjust the brightness of a center fixation line to equal that of the apparent brightness of an arc line viewed at a distance from the fixation point subtending an angle of 12° to the eye. Adjustments were made when the arc-line was stationary and rotating at speeds of 30, 45, 60 and 75 rpm. It was found that brightness enhancement occurred with increase in speed. This result was interpreted as supporting Ansbacher's account of distortion in the perception of moving arc-lines.     

The interaction between sensory and tonic factors in the perception of the vertical in pigeons

In two separate experiments, 21 pigeons were given 10 days of training to peck a key on which a white vertical line was exposed. Next, the birds were given generalization tests along the angularity dimension with the floor tilted 24° to the right or to the left. Reliable asymmetrical gradients were obtained with enhanced responding to the side toward which the floor was tilted. This posturally induced distortion in the visual perception of the vertical indicates that sensory-tonic interactions typically observed in humans have a parallel in this lower species.     

Figural aftereffects in the perception of faces

We examined figural aftereffects in images of human faces, for which changes in configuration are highly discriminable. Observers either matched or rated faces before or after viewing distorted images of faces. Prior adaptation strongly biases face perception by causing the original face to appear distorted in a direction opposite to the adapting distortion. Aftereffects transferred across different faces and were similar for upright or inverted faces, but were weaker when the adapting and test faces had different orientations (e.g., adapt inverted and test upright). Thus the aftereffects depend on which images are distorted, and not simply on the type of distortion introduced. We further show that the aftereffects are asymmetric, for adapting to the original face has little effect on the perception of a distorted face. This asymmetry suggests that adaptation may play an important normalizing role in face perception. Our results suggest that in normal viewing, figural aftereffects may strongly influence form perception and could provide a novel method for probing properties of human face perception.     

Perceptual enhancement: persistent effects of an experience

Presenting a word enhances its later perceptual identification. This article focuses on the relation between this effect on perception and recognition memory. Prior experiments have revealed that perceptual enhancement is independent of recognition memory and have led to the two types of task being identified with separate memory systems. In contrast, the present experiments reveal parallel effects on the two types of task. Perceptual enhancement persists over days but, like recognition memory, is influenced by manipulations of retrieval conditions. I conclude that both perceptual and memory tasks rely on the retrieval of memory for whole prior processing episodes but can differ in terms of the number and nature of retrieval cues that they provide. I describe perception and memory within a common framework.     

Visual short-term memory is influenced by haptic perception

The present study investigated whether and how visual memory and haptic perception are related. Participants were required to compare a visual reference velocity with a visual test velocity separated by a 4-s interval. During the retention interval, a fast or slow hand movement was performed. Although the hand movement was not visible, effects of the speed of the distracting body movement occurred. Slow movements resulted in a lowering of the represented visual velocity, whereas fast movements heightened the represented velocity. Subsequent experiments extended the effect to body movements that differed from the visual motion and ruled out the possibility that the effect was due to changes in visual perception or interference from semantic, verbal, and acoustic memory codes. Perhaps haptic velocity information and visual velocity information stored in short-term memory are blended.