Four experiments demonstrated that more time is required to scan further distances across visual images, even when the same amount of material falls between the initial focus point and the target. Not only did times systematically increase with distance but subjectively larger images required more time to scan than did subjectively smaller ones. Finally, when subjects were not asked to base all judgments on examination of their images, the distance between an initial focus point and a target did not affect reaction times. Introspections about visual imagery very often include references to "scanning " across images. Kosslyn (1973) attempted to demonstrate that scanning of images is a functional cognitive process, and his experiment indicated that more time was required to traverse greater distances across mental images. However, in the course of scanning longer distances, 1 people in Kosslyn's experiment also passed over more parts of the imaged object. For example, in scanning from the motor to the porthole of an imaged speedboat, a person passed over the rear deck and part of the cabin; in scanning from the motor to the more distant anchor, one scanned over all of these parts plus the front deck and bow. Given this confounding, then, we have no way of knowing whether Kosslyn's results were a consequence of people actually scanning over a quasi-pictorial, spatial image. One could argue that the image itself was epiphenomenal in this situation and that the apparent effects of distance actually were a consequence of how

Subjects read narratives describing directions of objects around a standing or reclimng observer, who was periodically reoriented. RTs were measured to identify which object was currently located beyond the observer's head, feet, front, back, fight, and left. When the observer was standing, head/feet RTs were fastest, followed by front/back and then right/left. For the reclining observer, front/back RTs were fastest, followed by head/feet and then right/left. The data support the spatial framework model, according to which space is conceptualized in terms of three axes whose accessibility depends on body asymmetries and the relation of the body to the world. The data allow rejection of the equiavailability model, according to which RTs to all directions are equal, and the mental transformation model, according to which RTs increase with angular disparity from front. Consider the following passage ("The Gambler, the Nun, and the Radio, " Hemingway, 1927, p. 41): Out of the window of the hospital you could see a field with tumbleweed coming out of the snow, and a bare clay butte.... From the other window, if the bed was turned, you could see the

Work in philosophy and psychology has argued for a dissociation between perceptuallybased similarity and higher-level rules in conceptual thought. Although such a dissociation may be justified at times, our goal is to illustrate ways in which conceptual processing is grounded in perception, both for perceptual similarity and abstract rules. We discuss the advantages, power and influences of perceptually-based representations. First, many of the properties associated with amodal symbol systems can be achieved with perceptually-based systems as well (e.g. productivity). Second, relatively raw perceptual representations are powerful because they can implicitly represent properties in an analog fashion. Third, perception naturally provides impressions of overall similarity, exactly the type of similarity useful for establishing many common categories. Fourth, perceptual similarity is not static but becomes tuned over time to conceptual demands. Fifth, the original motivation or basis for sophisticated cognition is often less sophisticated perceptual similarity. Sixth, perceptual simulation occurs even in conceptual tasks that have no explicit perceptual demands. Parallels between perceptual and conceptual processes suggest that many mechanisms typically associated

Abstract not found

Multimedia is being used increasingly to provide computer based instruction. One reason for this trend may be the assumption that multimedia information helps people learn. To find out whether there is empirical support for this assumption, this paper reviews studies from a wide variety of fields to show that multimedia-may be able to help people learn more information more quickly compared to traditional classroom lecture. Redundant multimedia does not always improve learning compared to "monomedia." Specific situations in which multimedia information may help people to learn include (a) when the media encourage dual coding of information, (b) when the media support one another, and (c) when the media are presented to learners with low prior knowledge or aptitude in the domain being learned. There is empirical support for concluding that specific multimedia can be used to help people learn specific kinds of information. Multimedia is the use of text, graphics, animation, pictures, video, and sound to present information. Since these media can now be integrated using a computer, there has been a virtual explosion of computer based multimedia instructional applications. These applications run the gamut from serious computer-based tutorials for adults to the new category of "edutainment " products for children. These very diverse applications seem to share a common assumption-multimedia information helps people learn. This assumption seems to be based more on personal opinion than on scientifically based fact. People enjoy multimedia, prefer multimedia learning materials, and believe that multimedia

Human activity takes place in space. To act effectively, people need mental representations of space. People’s mental representations of space differ from space as conceived of by physicists, geometers, and cartographers. Mental representations of space are constructions based on elements, the things in space, and the spatial relations among them relative to a reference frame. People act in different spaces, depending on the task at hand. The spaces considered here are the space of the body, the space around the body, the space of navigation, and the space of graphics. Different elements and spatial relations are central for functioning in the different spaces, yielding different mental representations. Mental Spaces 3

................................................................................................3 Introduction ...........................................................................................4 Learners ............................................................................................4 Prior Knowledge ...............................................................................4 Aptitude..........................................................................................4 Materials ............................................................................................5 Spatial Information.............................................................................5 Verbal Information .............................................................................5 Tasks................................................................................................6 Information Processing..........................................................................

Is our knowledge about the appearance of objects more closely related to verbal thought or to perception? In a behavioural study using a property verification task, Kosslyn (1976) reported that there are both amodal and perceptual representations of concepts, but that amodal representations may be more easily accessed. However, Solomon (1997) argued that due to the nature of Kosslyn’s stimuli, subjects may be able to bypass semantics entirely and perform this task using differences in the strength of association between words in true trials (e.g., cat–whiskers) and those in false trials (e.g., mouse–stinger). Solomon found no evidence for amodal representations when the task materials were altered to include associated false trials (e.g., cat–litter), which require semantic processing, as opposed to associative strategies. In the current study, we used fMRI to examine the response of regions of visual association cortex while subjects performed a property verification task with either associated or unassociated false trials. We found reliable activity across subjects within the left fusiform gyrus when true trials were intermixed with associated false trials but not when true trials were intermixed with unassociated false trials. Our data support the idea that conceptual knowledge is organised visually and that it is grounded in the perceptual system. One of the leading theories of the organisation of

1.1. Conceptual systems 621 1.2. Semantic memory 621

Physical imagery occurs when people imagine one object causing a change to a second object. To make inferences through physical imagery, people must represent information that coordinates the interactions among the imagined objects. The current research contrasts two proposals for how this coordinating information is realized in physical imagery. In the traditional kinematic formulation, imagery transformations are coordinated by geometric information in analog spatial representations. In the dynamic formulation, transformations may also be regulated by analog representations of force and resistance. Four experiments support the dynamic formulation. They show, for example, that without making changes to the spatial properties of a problem, dynamic perceptual information (e.g., torque) and beliefs about physical properties (e.g., viscosity) affect the inferences that people draw through imagery. The studies suggest that physical imagery is not so much an analog of visual perception as it is an analog of physical action. A simple model that represents force as a rate helps explain why inferences can emerge through imagined actions even though people may not know the answer explicitly. It also explains how and