Can mental images be ambiguous?

Argues that, although much recent research has emphasized the equivalence between imagery and perception, there are critical differences between these activities. Perception, initiated by an external stimulus, is to a large extent concerned with the interpretation of that stimulus; in contrast, images are created as symbols of something and hence need no interpretive process. Without a construal process, images do not allow reconstrual. In support of this argument, a series of 4 experiments with 65 university students was conducted to test whether Ss could reverse an ambiguous figure (e.g., duck/rabbit) in mental imagery. The S population contained many with vivid imagery, as assessed by a visual elaboration scale and the Vividness of Visual Imagery Questionnaire. In all 4 experiments, Ss were unable to reverse a mental image, but all Ss were able, immediately after this failure, to draw a picture from their mental image and then reconstrue the figure in their own drawing. This failure to reverse images occurs despite hints to the S, some coaching, and a moderate amount of training in figural reversal. Findings emphasize the difference between images and percepts. (46 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An investigation of sex differences in spatial ability: Mental rotation of three-dimensional objects.

Presented 2-dimensional computer-generated representations of 3-dimensional objects in pairs to 20 male and 20 female right-handed undergraduates. Ss were given 15 sec to make a same-different judgment of the objects, one of which was rotated 0°, 40°, 80°, 120°, or 160° from the other. Ss were also assessed on 2 standard spatial ability tests (the Spatial Relations subtest of the Differential Aptitude Tests, Form L, and the Standardized Road-Map Test of Direction Sense) and a verbal-imagery questionnaire. Analyses of the data showed that men were more accurate than women, and that the slope of the function relating response time to degree of rotation was steeper in women. There was a significant linear relation between performance and the degree of rotation. Rate of rotation and accuracy correlated with the other tests of spatial ability. Response time slope correlated with imagery in men but not in women, suggesting that frequent use of visual imagery was related to mental rotation rate in men, but not in women. There were no clear relations between performance and the strategy Ss professed to use in doing the mental rotation. (French summary) (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Levels of equivalence in imagery and perception.

Reviews recent experimental work on imagery, identifying specific levels of information processing within the visual system at which mental images and physical objects and events are functionally equivalent, as revealed by their perceptual and behavioral effects. Findings demonstrate that these functional equivalences can extend even to levels of the visual system where the effects produced cannot be explained by what people might know about objects and events, or by how they expect to perform. Effects produced when images are formed are often smaller than corresponding effects produced when objects and events are observed, and vivid imagers often show larger effects when forming images than nonvivid imagers. On the basis of these findings, it is argued that mental imagery can result in the activation of information-processing mechanisms at many levels of the visual system, even those mechanisms whose operating characteristics are not influenced by how objects and events might be conceptualized. (63 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mental imagery helps eight-year-olds remember what they read.

To determine whether 8-yr-olds can use mental imagery to improve their memory of prose they read, 43 experimental Ss were given practice constructing mental images of progressively longer prose passages (sentences, paragraphs, and a short story) and were shown examples of good images. 43 controls were exposed to the prose material, but did not practice constructing mental images. Experimental Ss read 17 segments of a short story and constructed a mental image for each segment after reading the segment. Control Ss read the same story segments and were instructed to "do whatever you can or have to" in order to remember the story. Experimental Ss answered significantly more short-answer questions about the story than controls did. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial concepts and perception of physical and diagrammed scenes

The accessibility of objects in mental spatial frameworks depends on their relation to the spatial axes of the world and people's typical interactions with space. The current study investigated perception of space. Subjects viewed either a physical model of a person surrounded by objects (Exp. 1) or diagrams of scenes (Exp. 2). Subjects named objects at directions from their own external perspective. For physical scenes, subjects were faster to name objects at Above/Below locations, followed by Front/Behind locations, followed by Left/Right locations. This finding indicates that subjects used spatial frameworks to locate objects perceptually. For diagrams, response times to name objects did not conform to this pattern, perhaps because the spatial axes of a diagram do not correspond to stable spatial axes of the world.     

Fibronectin matrix regulates activation of RHO and CDC42 GTPases and cell cycle progression

This research concerned the use of mental rotation in recognizing rotated objects. Instead of the classic Shepard's paradigm in which subjects were still while observing rotated objects, here subjects had to move (or imagine moving) around stationary three-dimensional objects put in the middle of the trajectory. Thus, depending on the viewing positions, such objects were seen under six different perspectives (from 30 degrees to 180 degrees). The latter task has been thought to be closer to everyday life in which we obtain information regarding objects from their spatial properties. The results do not follow the classic rules of mental rotation of an object predicting a linear increase of the time needed to recognize distorted objects as a function of their angular displacement. They also differ from data in the literature about spatial imagery showing that access to spatial information is facilitated more when people actually move through a path than when they imagine moving. A probable explanation of this difference from the literature is discussed in relation to the particular involvement of the body in the experimental task.     

Cognitive coordinate systems: Accounts of mental rotation and individual differences in spatial ability.

Contends that strategic differences in spatial tasks can be explained in terms of different cognitive coordinate systems that Ss adopt. The strategy of mental rotation featured in many recent experiments uses a coordinate system defined by the standard axes of the human visual world (i.e., horizontal, vertical, and depth axes). Several other possible coordinate systems for solving the problems that occur in psychometric tests of spatial ability are examined. One alternative strategy uses a coordinate system defined by the demands of each test item, resulting in mental rotation around arbitrary, task-defined axes. Another strategy uses a coordinate system defined exclusively by the objects, producing representations invariant with the objects' orientation. Three experiments with 31 university students were conducted to assess differences in strategies used by Ss with high or low spatial ability in cube comparison and Shepard-Metzler (R. Shepard and J. Metzler; see record 1972-28060-001) rotation tasks. Two computer simulation models based on Ss' performance patterns are described. It is suggested that Ss high in spatial ability are faster in their manipulation processes and more flexible in adopting cognitive coordinate systems than their low-ability counterparts. (61 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The imagery debate: Analogue media versus tacit knowledge.

Argues that the main point of disagreement in the debate over the nature of mental imagery concerns the following: (a) whether certain aspects of the way in which images are transformed should be attributed to intrinsic knowledge-independent properties of the medium in which images are instantiated or the mechanisms by which they are processed; or (b) whether images are typically transformed in certain ways because Ss take their task to be the simulation of the act of witnessing certain real events taking place and therefore use their tacit knowledge of the imaged situation to cause the transformation to proceed as they believe it would have proceeded in reality. The tacit knowledge account is seen as more plausible because empirical results demonstrate that both "mental scanning" and "mental rotation" transformations can be critically influenced by varying the instructions given to Ss and the precise form of the task used and, that the form of the influence is explainable in terms of the semantic content of Ss' beliefs and goals. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learning about "famous" people via the keyword method.

106 8th-grade students were asked to learn the purported accomplishments of various individuals, as described in several short fictitious passages. In 2 experiments, Ss who studied the passages according to a mnemonic (keyword) strategy by far outperformed control Ss. This was true whether keyword Ss were provided with actual illustrations or whether they had to generate their own mental images. In the 3rd experiment, the same paradigm was used to gain support for a theoretical distinction between 2 kinds of prose-learning imagery, representational and transformational. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Theories relating mental imagery to perception.

Reviews contemporary theories of relations between mental imagery and perception in terms of structural, functional, and interactive theories. Structural theories propose that mental images exhibit the same spatial and pictorial properties as real physical objects. Functional theories propose that the formation and transformation of mental images contribute to object recognition and comparison. Interactive theories propose that imagery contributes directly to ongoing perceptual processes. The evidence for each type of theory is critically evaluated in view of the following alternative accounts: task-induced demand characteristics, experimenter bias, tacit knowledge, and eye movements. Efforts to rule out these alternatives have had varying degrees of success, with the consequence that the 3 types of imagery theories differ in the extent to which they have been confirmed (i.e., none of the 3 types of imagery theories is universally free from challenges from at least some of the alternative accounts). (4 p ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of imagery on perceptual implicit memory tests.

Four experiments demonstrate that imagery can promote priming on perceptual implicit memory tests. When Ss were given words during a study phase and asked to form mental images of corresponding pictures, more priming was obtained on a picture fragment identification test than from a study condition in which Ss performed semantic analyses of words. Imaginal priming of picture fragment identification occurred for recoverable fragments, but not for nonrecoverable fragments. The imagery effect was restricted to the imaged type of material: Imagining pictures (when presented with words) enhanced priming on a picture fragment identification test but not on word fragment completion. Similarly, when pictures were presented, imagining the corresponding words increased priming on word fragment completion but not on picture fragment identification. Overall, results support the hypothesis that imagining engages some of the same mechanisms used in perception and thereby produces priming. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Constructing mental representations of objects from successive views.

Investigated the effects of complexity on processing objects by testing 3 graduate students and 7 staff members on a 3-dimensional analog of J. Hochberg's (1968) aperture viewing paradigm, the orthogonal slices task developed by J. Metzler and R. N. Shepard (1974), and a sequence matching task. In Exp I, Ss constructed, transformed, and compared mental representations of Shepard-Metzler figures varying in the number of component parts. Findings show that processing time increased with complexity. The results of Exp II show no effects of complexity on processing time when Ss merely judged the equivalence of the patterns used in Exp I presented in sequence. Rather, constructed mental representations appeared to preserve some of the spatial character of the corresponding objects. This conclusion was strengthened by the results of recognition tasks that showed that discrimination of constructed objects from appropriate distractors was better after Ss did the 1st (orthogonal slices) task than after they did the 2nd (sequence matching) task. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of graphic analogies of concepts in chemistry on learning and attitudes.

To test the effects of graphic presentation on learning complex concepts, 2 versions of a lesson on concepts in electrochemistry were designed to elaborate conceptual and topographic information either verbally or pictorially. A PLATO IV computer terminal presented the lesson to 40 undergraduates, who were randomly assigned to the verbal or graphic condition. Tests designed to assess knowledge, comprehension, and application of concepts revealed that external imagery resulted in significantly better learning. Ss also found the graphics versions to be more enjoyable as indicated by semantic differential measures and had a more positive general attitude toward that version. Ss in the external imagery treatment reported experiencing more mental imagery suggesting that the positive effects of pictures may be due to the internal processing that they elicit. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mental imagery and aging.

Young adult (aged 18–23 yrs) and elderly (aged 55–71 yrs) Ss performed 4 visual mental imagery tasks, each of which tapped different processes. The elderly had relatively impaired image rotation and image activation (the process of accessing and activating stored visual memories), and there was a hint that aging may impair the ability to maintain images. In contrast, the elderly were able to compose (the process of generating the segments of the shape, one by one) and scan visual mental images as well as young adults. However, when the authors correlated the mean performance of each age group across all the tasks, they found that the reaction times (RTs) of the elderly were almost perfectly predicted by the performance of the young Ss but that the error rates were not correlated. These findings suggest that although there is slowing with age, individual imagery processes are affected selectively by aging. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Alpha rhythm during three conditions of visual imagery and emergent uncovering psychotherapy: The critical role of anxiety.

2 groups of a total of 17 undergraduates and 9 22-48 yr old psychotherapy clients were monitored by EEG, electrooculogram, GSR, and finger pulse response during free imagery, free imagery recall, dream recall, and emergent uncovering psychotherapy. Results show that visual imagery per se did not desynchronize occipital alpha; however, dream revisualization and images accompanied by an electrophysiological pattern of anxiety ("hot" images) were associated with alpha desynchronization. The effort of revisualization was also an influencing variable, but it was not as desynchronizing as was dream recall. The client Ss showed more direct representation of drives in their visual imagery than the student Ss, and several of them experienced the uncovering of repressed material. 5 of the client Ss and 3 of the student Ss mamifested symptoms during at least 1 of the conditions. The failure of percent alpha to decrease during the appearance of symptoms and subjective distress was inconsistent with the so-called alpha state. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of imagery on explicit and implicit tests of memory in young and old people: A double dissociation.

Examined the effect of imagery on implicit and explicit tests of memory in young and old adults. 48 undergraduates (mean age 21 yrs) and 64 adults (mean age 72.48 yrs) in Canada were presented with 2 separate word lists in a random order and were assigned to imagery or no-imagery instruction conditions. Ss in the imagery instruction condition read the words to themselves, formed a mental image of it, and rated their ability to do so. Ss in the no-imagery instruction condition simply read the words. All Ss were tested on explicit or implicit memory tests and asked to describe the mnemonic strategies used. Results show that imaging the referent of a visually-presented word improved the performance of the young Ss on the explicit memory test, but reduced their performance on the implicit test. Results of the elderly Ss showed a similar trend but did not reach the level of significance observed for young adults. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intact visual imagery and impaired visual perception in a patient with visual agnosia.

Although it is now well accepted that visual mental imagery and visual perception share common underlying mechanisms, there are several reports in which they are dissociated. Evidence for the separability of these processes is provided by a 33-yr-old male patient who has a profound visual object recognition deficit attributable to an impairment in grouping or segmenting visual images. Despite this perceptual deficit, the patient was able to draw objects in considerable detail from memory, and his knowledge of the visual appearance of objects was preserved on a variety of mental imagery tasks. Together with previous cases, these findings confirm the double dissociation between object recognition and perception. Interestingly, the patient could also recognize newly constructed objects in his internal imagery. To accommodate these results, the authors propose a model in which imagery and perception are strongly associated but are also functionally specialized. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

View specificity, array specificity, and egocentrism in young children's drawings.

Examined the concept of egocentrism in an experiment in which 80 children (aged 6 yrs 1 mo to 7 yrs 2 mo) were asked to draw 2 pictures of an array of 2 objects, one characterizing their own view and the other characterizing the view of another child seated in a different position. Ss were able to represent their partner's view when the latter presented few problems in graphic complexity or mental rotation. Ss who were asked to draw their own view after drawing their partner's produced more view specific drawings than Ss asked to draw their own view first. It is concluded that the production of array-specific representations of spatial relations in young children's drawings should not be seen as a manifestation of egocentrism. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)