Orientation effects in visual object perception: Recent results that will make your mind spin!

The time needed to identify objects from two-dimensional depictions can be affected sharply by the orientation of the depicted object. Although it is suspected that the magnitude of orientation effects on identification from drawings ought to depend on various characteristics of the objects and of the depictions, almost nothing is known about these relationships. Work in progress in my laboratory is designed to discover which characteristics of objects and depictions lead to large or small effects of orientation and which lead to peaked functions versus dipped functions. The results are summarized in this article. Overall, the results suggest that orientation effects take place at a perceptual stage of processing that is distinct from subsequent stages involved in retrieving a name and producing a response. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Object recognition and object orientation in Alzheimer's disease.

There are a wide variety of neuropsychological deficits in Alzheimer's disease (AD), among which are disorders of visual perception and spatial cognition. The present study investigated the ability of 20 mildly to moderately deteriorated patients with AD (and 174 age- and education-matched controls) on tasks that required them to visually identify, provide the canonical orientation of, and mentally rotate common objects. Some 85% of the AD patients performed poorly on all tasks. The authors were able to identify a small number of individual patients whose pattern of performance represented double dissociations between recognizing objects and knowing their canonical orientation. These findings are interpreted in the context of previous findings, especially as to whether information relating to an object's orientation and identity is independently coded. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual organization of moving stimuli modulates the flash-lag effect.

When a visual stimulus is flashed at a given location the moment a second moving stimulus arrives at the same location, observers report the flashed stimulus as spatially lagging behind the moving stimulus (the flash-lag effect). The authors investigated whether the global configuration (perceptual organization) of the moving stimulus influences the magnitude of the flash-lag effect. The results indicate that a flash presented near the leading portion of a moving stimulus lags significantly more than a flash presented near the trailing portion. This result also holds for objects consisting of several elements that group to form a unitary percept of an object in motion. The present study demonstrates a novel interaction between the global configuration of moving objects and the representation of their spatial position and may provide a new and useful tool for the study of perceptual organization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Micro- and macroreference frames: Specifying the relations between spatial categories in memory.

A substantial amount of research has demonstrated the importance of reference frames in organizing memory of object locations in both small and large environments. However, to date, little research has examined how the object locations represented in one reference frame are specified relative to object locations represented in another. In a series of 4 experiments, we demonstrate that multiple microreference frames can be established in memory for sets of objects that are spatially and semantically distinct, and that the spatial relations between these microreference frames are specified in memory by means of a more global, macroreference frame. Additionally, these experiments demonstrate that an established macroreference frame can influence which of several microreference frames will be coded in memory, but that a previously established microreference frame had no appreciable influence on the subsequent formation of a macroreference frame. These results are interpreted as indicating that the same cognitive mechanisms underlie interobject coding across multiple environmental scales. The implications for reference frame theories and theories positing hierarchical memory organization are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The nesting of search contexts within natural scenes: Evidence from contextual cuing.

In a contextual cuing paradigm, we examined how memory for the spatial structure of a natural scene guides visual search. Participants searched through arrays of objects that were embedded within depictions of real-world scenes. If a repeated search array was associated with a single scene during study, then array repetition produced significant contextual cuing. However, expression of that learning was dependent on instantiating the original scene in which the learning occurred: Contextual cuing was disrupted when the repeated array was transferred to a different scene. Such scene-specific learning was not absolute, however. Under conditions of high scene variability, repeated search array were learned independently of the scene background. These data suggest that when a consistent environmental structure is available, spatial representations supporting visual search are organized hierarchically, with memory for functional subregions of an environment nested within a representation of the larger scene. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Asymmetric object substitution masking.

Object substitution masking occurs when a lateral mask persists beyond the duration of a target, reflecting reentrant processes in vision (V. Di Lollo, J. Enns, & R. Rensink, 2000). The authors studied whether substitution masking is location specific and whether it is symmetric around the target. A brief circular display of letters was presented along with a mask that designated the target. The mask was centered on the target or 1.1° to the central or to the peripheral side. Substitution masking was found even when the target and the mask were at different locations. It was asymmetric and stronger when the mask was to the peripheral side of the target than to the central side. Asymmetric substitution was observed using various masks. It could not be explained by retina acuity gradients and was not attenuated by focused attention. The authors propose that target selection triggers an asymmetric inhibitory surround that is stronger toward the central side of the target. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The space of an object: Object attention alters the spatial gradient in the surround.

Although object-based attention enhances perceptual processing of information appearing within the boundaries of a selected object, little is known about the consequences for information in the object's surround. The authors show that distance from an attended object's center of mass determines reaction time (RT) to targets in the surround. Of 2 targets in the surround, both equidistant from a cue, the target closer to the center of mass was detected faster. Moreover, RT was shown to be a linear function of distance from the center of mass of a fixed, attended object, and changes to the shape of the object and its center of mass predictably altered RT. Object-based attention leads to a pattern of facilitation in the surround that may contribute to the organization of visual scenes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Review of Art and Visual Perception.

Reviews the book "Art and visual perception," by Rudolph Arnheim (see record 1955-03680-000). In reading this book, one realizes why more psychologists have not been concerned with art. Art is a technical specialty in its own right and one must be expert both in psychology and in either creative art or the history of art to write on art. Arnheim's book brings the scientific knowledge of a trained psychologist to bear on the fundamental problems of visual art as it has developed through the ages. The discussion is always with reference to concrete works of art. Many original drawings, diagrams, and figures illustrate basic principles and important points. The writing is superb. The book is full of penetrating insights into questions of art and also into many problems of concern to the psychologist. Fundamentally this book is an argument against the usual art historian's approach, so well described by Arnheim as the purely subjective point of view, that what a person sees in a work of art "depends entirely on who he is, what he is interested in, what he has experienced in the past, and how he chooses to direct his attention". A book which reflects so well the author's urbanity, catholicity, and keenness of mind, as well as his technical grasp of the scientific and the artistic, is no small achievement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use of human visual attention cues by olive baboons (Papio anubis) in a competitive task.

The ability of 4 olive baboons (Papio anubis) to use human gaze cues during a competitive food task was investigated. Three baboons used head orientation as a cue, and 1 individual also used eye direction alone. As the baboons did not receive prior training with gestural cuts, their performance suggests that the competitive paradigm may be more appropriate for testing nonhuman primates than the standard object-choice paradigm. However, the baboons were insensitive to whether the experimenter could actually perceive the food item, and therefore the use of visual orientation cues may not be indicative of visual perspective-taking abilities. Performance was disrupted by the introduction of a screen and objects to conceal food items and by the absence of movement in cues presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Functional Equivalence of Spatial Representations Derived From Vision and Language: Evidence From Allocentric Judgments.

Past research (e.g., J. M. Loomis, Y. Lippa, R. L. Klatzky, & R. G. Golledge, 2002) has indicated that spatial representations derived from spatial language can function equivalently to those derived from perception. The authors tested functional equivalence for reporting spatial relations that were not explicitly stated during learning. Participants learned a spatial layout by visual perception or spatial language and then made allocentric direction and distance judgments. Experiments 1 and 2 indicated allocentric relations could be accurately reported in all modalities, but visually perceived layouts, tested with or without vision, produced faster and less variable directional responses than language. In Experiment 3, when participants were forced to create a spatial image during learning (by spatially updating during a backward translation), functional equivalence of spatial language and visual perception was demonstrated by patterns of latency, systematic error, and variability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Editorial.

This issue features an invited paper by Peter Dodwell, one of Canada's foremost experimental psychologists, who is internationally recognized for his research in visual perception. Dodwell has investigated issues related to spatial vision, motion perception, visual distortion and, recently, mechanisms of the well-known McCulloch Effect. In the article, Dodwell shows that, for all its diversity, his research program has been guided by a couple of central themes. The article reveals, in semi-autobiographical style, the influences that shaped his thinking and the special impact of W. C. Hoffman and his Lie Transformation Group Model of Neuropsychology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging and visual marking: Selective deficits for moving stimuli.

The selective processing of new visual information can be facilitated by the top-down inhibition of old stimuli already in the visual field, a capacity-limited process termed visual marking (D. G. Watson & G. W. Humphreys, 1997). Three experiments assessed the effects of aging on visual marking using stationary (Experiment 1) and moving (Experiments 2 and 3) items. For young participants, visual marking was observed in all experiments. For older participants, visual marking was observed only with stationary items. The results are not consistent with any simple account of general age-related decrements and provide further support for the deployment of different methods of visual marking depending on the properties of the old items and the current task demands. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Review Contemporary Theory in Research in Visual Perception.

Reviews the book, Contemporary Theory in Research in Visual Perception by Ralph Norman Haber (ed.) (1968). In organizing the book, Haber had in mind the idea that perception represents a continuum along the classical problems on sensation and memory. The book has seven major sections. Each section is composed of a number of articles taken from the literature during the last few years. Haber has tried to be up-to-date and, as a result, has eliminated many classical studies. The aim of the book, to give a review of perception using articles and to limit the scope to a specific type of perceptual work or to emphasize a particular type of perceptual work, is an interesting idea. It does limit the experience which a student may have in learning perception, who might at some later date wish to deal with perception in the laboratory, or rather, to become a psychologist working in the laboratory in perception. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perception in Soviet psychology.

The relation between experimental work in perception in the Soviet Union and the orthodox philosophy of the Soviet state is discussed. It is pointed out that both the philosophy derived from Lenin and Marx and the needs of the state exert an influence on the nature of the problems studied and the type of theory developed. Studies in the areas of tactual, auditory, and visual perception are reviewed. These are considered against the background of Leont'ev's motor-copy theory of perception, currently the most systematic Soviet approach to perception. Certain other studies in visual perception conducted in the context of Uznadze's theory of set, as well as some mathematical approaches to perception not fitting into any general theoretical frame are also briefly reviewed. (3 p. ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Introduction to the special issue on object perception and scene analysis.

Work in psychophysics, neuroscience, and visual perception has led to significant recent advances in our understanding of the human visual system. The articles in this special issue represent diverse approaches to the study of visual perception and highlight some of these recent advances, as applied to issues involved in understanding object perception and scene analysis. The special issue grew out of a workshop on object and scene perception held in September 1990 at the University of Leuven. The intent of the original workshop and of the collection of articles in this issue is to bring together the work of researchers using widely differing techniques and theoretical frameworks, and to apply recent results to the issues surrounding object and scene perception. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Combining simultaneous with temporal masking.

Simultaneous and temporal masking are two frequently used techniques in psychology and vision science. Although there are many studies and theories related to each masking technique, there are no systematic investigations of their mutual relationship, even though both techniques are often applied together. Here, the authors show that temporal masking can both undo and enhance the deteriorating effects of simultaneous masking depending on the stimulus onset asynchrony between the simultaneous and temporal masks. For the task and stimuli used in this study, temporal masking was largely unaffected by the properties of the simultaneous mask. In contrast, simultaneous masking seems to depend strongly on spatial grouping and was strongly affected by the properties of the temporal mask. These findings help to identify the nature of both temporal and simultaneous masking and promote understanding of the role of spatial and temporal grouping in visual perception. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The medium is not the message in preattentive vision.

One of the oldest problems in visual perception is the definition of the basic elements of form, shape, and texture. In the past 20 years the question has been focused by the observation that human vision can be separated into two systems. Neisser first made popular the terms preattentive and attentive to characterize this division. The psychophysical experiments I have conducted over the past two years have probed the preattentive system to determine if it is as simple-minded as present theories suggest. One implication of this research involves rethinking theories of preattentive vision. To date this system is thought to be directly linked to what Marr called the "primal sketch" (a retinal-based image-intensity map of visual features such as blobs and blob intersections). My research suggest that it may be more closely tied to Marr's "2 1/2D sketch" (a retinally-based relief map of object-features such as surfaces slanted in depth). A second implication of this research concerns the neural implementation of detectors for slant based on shading and texture. So far we know a great deal about the tilt (two-dimensional orientation) sensitivity of single units in visual cortex, but the sensitivity of neurons to slant remains to be investigated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The autokinetic word technique.

The autokinetic effect is utilized to explore the minimum limits of structure necessary to elicit interpretable responses of a projective nature, in an experimental situation. Ss were asked to report words written by a small, stationary light source presented in a darkened room. All Ss reported words being written by the point of light. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Experimental investigations of the genesis of visual space perception.

The methodology and findings of 3 categories of experimental studies are reviewed and evaluated: (a) studies of organisms that have been deprived of visual stimulation until the time of testing, (b) studies of newborn organisms that are tested soon after birth, and (c) studies in which E controls the visual stimulation to which O is exposed from birth to the time of testing. The evidence provided by these experiments suggests that conclusions about the genetic basis of space perception will differ depending on the stimulus correlates under consideration.—(47 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Coarse-to-fine encoding of spatial frequency information into visual short-term memory for faces but impartial decay.

Face perception studies investigated how spatial frequencies (SF) are extracted from retinal display while forming a perceptual representation, or their selective use during task-imposed categorization. Here we focused on the order of encoding low-spatial frequencies (LSF) and high-spatial frequencies (HSF) from perceptual representations into visual short-term memory (VSTM). We also investigated whether different SF-ranges decay from VSTM at different rates during a study-test stimulus-onset asynchrony. An old/new VSTM paradigm was used in which two broadband faces formed the positive set and the probes preserved either low or high SF ranges. Exposure time of 500 ms was sufficient to encode both HSF and LSF in the perceptual representation (experiment 1). Nevertheless, when the positive-set was exposed for 500 ms, LSF-probes were better recognized in VSTM compared with HSF-probes; this effect vanished at 800-ms exposure time (experiment 2). Backward masking the positive set exposed for 800 ms re-established the LSF-probes advantage (experiment 3). The speed of decay up to 10 seconds was similar for LSF- and HSF-probes (experiment 4). These results indicate that LSF are extracted and consolidated into VSTM faster than HSF, supporting a coarse-to-fine order, while the decay from VSTM is not governed by SF. (PsycINFO Database Record (c) 2011 APA, all rights reserved)