On looking into the black box: Prospects and limits in the search for mental models.

Discusses the ways in which different domains define mental models, characterize the purposes of such models, and attempt to identify their forms, structures, and parameters. The resulting distinctions among domains are described in terms of the nature of model manipulation and the level of behavioral discretion. A variety of salient issues emerge, including accessibility of mental models, forms and content of representation, nature of expertise, cue utilization, and, most importantly, instructional issues. Prospects for dealing with these issues are considered, as well as fundamental limits to identifying or capturing humans' "true" mental models. It is suggested that the search for mental models is most likely to be successful if a more pragmatic perspective is adopted that emphasizes the utility of the mental model construct for understanding and improving instruction, system design, and other applied ends. (105 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual angle of the mind's eye before and after unilateral occipital lobectomy.

Do mental images occur in a spatially mapped (i.e., analog, or array-format) representational medium? S. M. Kosslyn's (1978) method was used to measure the visual angle of "the mind's eye" to estimate the extent of the imagery medium before and after unilateral occipital lobectomy. It was found that the overall size of the largest possible image was reduced following the surgery. In addition, only the horizontal extent, and not the vertical extent, of the imagery medium was reduced. Finally, it was determined that the S understood the tasks, was not aware of any predictions, and was unaffected by a strong demand characteristic in a different imagery task. These results are consistent with the hypothesis that imagery occurs in a spatially mapped representational medium dependent on occipital cortex. (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)     

Clinical uses of mental imagery: Experimental foundations, theoretical misconceptions, and research issues.

Suggests that the growing use of mental imagery in clinical settings has been hampered by major theoretical deficits, notably the virtual absence of interdisciplinary models not constrained by a specific therapeutic orientation. Information-processing data pertaining to the functional and structural properties of imagery are reviewed to illustrate that images may be but incomplete pictures that also convey nonpictorial, abstract information. It is proposed that the imagery and verbal/symbolic processing systems are functionally discrete but comparably influential in image generation, elaboration, and appraisal, a property suggesting that clinical images comprise multiple representational events of a visual, verbal, and affective nature. The notion of the image as a mental photograph has only limited applicability. Methodological concerns associated with the study of clinical imagery are examined, pertinent literature is reviewed for each issue, and data are presented to demonstrate the significance of the problems confronting contemporary imagery researchers. (119 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Feature-recognizing MRI

We describe a new theory of MR imaging that utilizes prior information in the form of a set of "training" images thought to be similar to the "unknown" objects to be scanned. First, the training images are processed to find an orthonormal series representation of these images that is more convergent than the usual Fourier series. The coefficients in this new series can be calculated from a subset of the phase-encoded signals needed to construct the Fourier image representation. The characteristics of the training images also determine exactly which phase-encoded signals should be measured in order to minimize error in the image reconstruction. The optimal phase-encodings are usually scattered nonuniformly in kappa-space. Good results were obtained when this theory was applied to imaging data from simulated objects and to experimental data from phantom scans. This theory provides the basis for developing efficient scanning and image reconstruction techniques that are "tailored" to each body part or to particular disease states.     

The content of awareness is a model of the world.

Outlines an older view of mental representations and shows how this view can provide a unifying framework for interpreting current research. It is argued that the content of awareness may be characterized as a model of the world capable of simulating future events, anticipating present events, and formulating appropriate actions. That is, the mind possesses properties that interact with sensory information to determine conscious experience. The content of awareness consists of constructs that account for sensations by representing patterns of the environment relevant to the set of possible actions that might be taken. Objects are viewed as prototypes for the centrifugal nature of awareness. Empirical evidence from a variety of sources provides support for this notion and helps delineate properties of the model (e.g., amodality, simulation, ambiguity, utility in perception and action). An explicit distinction between the properties of awareness and properties of underlying processes and structures is shown to be useful in accounting for a variety of experimental findings. It is argued that many of these findings must be interpreted as revealing the nature of awareness rather than the nature of underlying structures of processes, which remain obscure. (5 p ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

L. S. Vygotsky and contemporary developmental psychology.

Central themes from L. S. Vygotsky's writings that have particular relevance for contemporary developmental psychology are outlined, and these ideas are extended in light of recent theoretical advances in the social sciences and humanities. The discussion focuses primarily on Vygotsky's claims about the social origins and social nature of higher (i.e., uniquely human) mental functioning and on his understanding of culture. His claims about the social origins of individual mental functioning have implications for the definition of terms such as "cognition" and "memory" as well as for how empirical research on these processes can be pursued. His understanding of culture is shown to be derivative of his account of the "psychological tools" that mediate human mental functioning. It is argued that efforts need to be made to elaborate a notion of culture within a Vygotskian framework that takes into account contemporary ideas and findings in the social sciences and humanities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conceptual representation of pictures and words: Reply to Clark.

Clark (1987) offers a dual coding alternative (Paivio, 1971, 1986) to the conceptual hypothesis that Potter, Kroll, Yachzel, Carpenter, and Sherman (1986) proposed to explain the ease with which people can read and understand rebus sentences in which a picture replaces a noun. We present theoretical and empirical reasons for positing a conceptual representation that is distinct from the representation of an object's name and from a mental image of it. The hierarchical conceptual model has greater explanatory and predictive power and is more parsimonious overall than Clark's alternative. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Blepharoplasty: A classification of selected techniques in the treatment and prevention of lower lid margin distortions

The topographic relations of complex structures and the morphogenesis of organ systems can only be fully understood in their three-dimensional context. Three-dimensional (3-D) reconstruction of physically sectioned specimens has become an indispensable tool in modern anatomical and embryological research. Teaching also makes increasingly use of 3-D representations, in particular in the case of embryonic systems that undergo complicated transformations of form and shape. At present no cheap and simple technique is available that generates accurate 3-D models of sectioned objects. In this study we describe a novel technique that rapidly provides faithful 3-D models of sectioned specimens. The images are captured directly from the cutting surface of the embedding block after each sectioning and "on block" staining step. Automatic image processing generates a stack of binary images of the specimen contour. Binary images of internal structures are obtained both by automatic segmentation and manual tracing. Since these image series are inherently aligned, they can be reconstructed three-dimensionally without time-consuming alignment procedures. The quality and the flexibility of the method are demonstrated by reconstructing three kinds of specimens of different histological composition and staining contrast: a 4 mm mouse embryo together with several of its inner organs, a cavernous sinus region of a human infant, and a segment of a human carotid artery. Very short processing times and the faithful representation of complex structural arrangements recommend this technique for routine use in morphological research and for creating embryologic teaching models or 3-D embryonic staging series.     

Apperception and imagery in blindfold chess

Apperception constructs functional and "meaningful" mental representations. These representations are often built on mental images. Hence it is rational to assume that the contents of some parts of images may be functionally more important than others. This means that the cognitive processing of some parts of the image is more effective than for others. To extract this preferential structure, which we call the functional figure in mental images, five experiments were conducted on blindfold chess imagery. We showed that blindfold chess players have much better recall of functionally significant than of functionally insignificant areas of chess positions. Thus, of the various mental representations of chess board areas, the functionally more significant areas are better represented than others.     

Effects of stimulus complexity on mental rotation rate of polygons.

Both spatial and propositional theories of imagery predict that the rate at which mental images can be rotated is slower the more complex the stimulus. Four experiments (three published and one unpublished) testing that hypothesis found no effect of complexity on rotation rate. It is argued that despite continued methodological improvements, subjects in the conditions of greater complexity may have found it sufficient to rotate only partial images, thereby vitiating the prediction. The two experiments reported here are based on the idea of making the discriminative response sufficiently difficult so as to force the rotation of complete images. The first one scaled the similarity between standard polygons and certain systematically mutated versions. From the ratings so obtained, two levels of perceived similarity, high and low, were defined and served as separate conditions in a response-time, image rotation experiment. The second experiment tested the complexity hypothesis by examining the effect of similarity on rotation rates and its interaction with levels of complexity. The results support the complexity hypothesis, but only for the highly similar stimuli. Rotation times were also generally slower for high as compared with low similarity. It is argued that these results arise because subjects rotate incomplete images when the stimuli are not very similar. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The medium and the message in mental imagery: A theory.

Describes a computational theory of imagery that posits that visual mental images are transitory data structures that occur in an analog spatial medium. These "surface" representations are generated from more abstract "deep" representations in long-term memory and, once formed, can be operated upon in various ways. The theory is described in terms of detailed claims about the mental structures and processes invoked during imagery. In addition, the philosophical and empirical roots of the present theory are briefly reviewed. Further, arguments and data that have been offered against the theory are critically examined, and none are found damaging. An alternative account of the data that purportedly support the theory is also examined and found deficient in several respects. Finally, the current status of the "analog-propositional" debate is reviewed. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of pitch in auditory imagery.

To study the representation of pitch in auditory images, the effects of pitch ratings of named but unheard sounds on auditory images of the sounds were tested. The times to mentally equate the pitch of the 2 images increased, and the time to identify the image with the higher or lower pitch decreased as the difference between the pitch ratings of the 2 sounds increased. The times to identify the image with the higher pitch were faster for sounds rated as high in pitch than for sounds rated as lower in pitch. The opposite trend for lower pitch image identifications did not appear, however. Instead, the "lower" identifications were similar to the "higher" ones, suggesting that the pitch of auditory images is influenced more strongly by sensory-perceptual features than by semantic ones. (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)     

A comparison of young children's understanding of contradictory representations in pretense, memory, and belief

The present study examined the nature of young children's understanding of various mental representations. 3- and 4-year-olds were presented with story protagonists who held mental representations (beliefs, pretenses, and memories) that contradicted reality. Subjects chose 1 of 2 alternate "thought pictures" (depicting either the mental representation or reality) that reflected the mental state. While 4-year-olds performed relatively well on all scenario types, 3-year-olds chose the correct thought picture significantly more often for pretense and memory scenarios than for false belief scenarios. These results suggest that young children conceptualize pretense as involving mental representations, and that they have more difficulty understanding contradictory mental representations that purport to correspond to reality.     

Mental models change rapidly with implicitly acquired information about the local environment: A two-tone image study.

The projection of 3-D objects to 2-D images necessitates a loss of information, thus the shape of volumetric objects depicted in images is inherently ambiguous. The results of 3 experiments suggest observers use mental models of the local visual environment to constrain image interpretation. These models change quickly and dramatically to accommodate implicitly acquired information. Observers viewed very high-contrast (2-tone) images of novel volumetric objects. Before priming, novel 2-tone images appeared 2-D. After incidental exposure to similar objects in grayscale or familiar objects in 2-tone, the test images appeared volumetric. Incidental learning appears to alter observers' mental models, thus causing an alteration in image interpretation in the absence of any image change. Highlights were interpreted more accurately than shadows, suggesting shadows play a secondary role in shape recovery. (PsycINFO Database Record (c) 2010 APA, all rights reserved)