Motor processes in mental rotation

Much indirect evidence supports the hypothesis that transformations of mental images are at least in part guided by motor processes, even in the case of images of abstract objects rather than of body parts. For example, rotation may be guided by processes that also prime one to see results of a specific motor action. We directly test the hypothesis by means of a dual-task paradigm in which subjects perform the Cooper-Shepard mental rotation task while executing an unseen motor rotation in a given direction and at a previously learned speed. Four results support the inference that mental rotation relies on motor processes. First, motor rotation that is compatible with mental rotation results in faster times and fewer errors in the imagery task than when the two rotations are incompatible. Second, the angle through which subjects rotate their mental images, and the angle through which they rotate a joystick handle are correlated, but only if the directions of the two rotations are compatible. Third, motor rotation modifies the classical inverted V-shaped mental rotation response time function, favoring the direction of the motor rotation; indeed, in some cases motor rotation even shifts the location of the minimum of this curve in the direction of the motor rotation. Fourth, the preceding effect is sensitive not only to the direction of the motor rotation, but also to the motor speed. A change in the speed of motor rotation can correspondingly slow down or speed up the mental rotation

On Cognitive Neuroscience

Stephen M. Kosslyn is Professor of Psychology at Harvard University and an Associate Psychologist in the Department of Neurology at the Massachusetts General Hospital. He received his B.A. in 1970 from UCLA and his Ph.D. from Stanford University in 1974, both in psychology, and taught at Johns Hopkins, Harvard, and Brandeis Universities before joining the Harvard Faculty as Professor of Psychology in 1983. His work focuses on the nature of visual mental imagery and high-level vision, as well as applications of psychological principles to visual display design. He has published over 125 papers on these topics, co-edited five books, and authored or co-authored five books. His books include Image and Mind (1980), Ghosts in the Mind's Machine (1983), Wet Mind: The New Cognitive Neuroscience (with 0. Koenig, 1992), Elements of Graph Design (1994), and Image and Brain: The Resolution of the Imagery Debate (1994). Dr. Kosslyn has received numerous honors, including the National Academy of Sciences Initiatives in Research Award, is currently on the editorial boards of many professional journals, and has served on several National Research Council committees to advise the government on new technologies.Psycholog

Visual Mental Imagery and Visual Perception: Structural Equivalence Revealed by Scanning Processes

The research reported in the present article investigates whether information is represented the same way in both visual mental imagery and the early phases of visual perception. In Experiment 1, the same participants scanned over patterns of dots in a mental image (with images based on a just-seen pattern), during perception, and in an iconic image. The time to scan increasing distances increased at comparable rates in the three tasks. However, in Experiment 2, when mental images were created from information stored in long-term memory, participants scanned more slowly in the mental image condition. Nevertheless, the rates of scanning in the perceptual tasks were highly correlated with the rates of scanning in the imagery tasks in both experiments. The results provide evidence that mental images and perceived stimuli are represented similarly and can be processed in the same way.Psycholog

Imagining Predictions: Mental Imagery as Mental Emulation

We argue that the primary function of mental imagery is to allow us to generate specific predictions based upon past experience. All imagery allows us to answer 'what if ' questions by making explicit and accessible the likely consequences of being in a specific situation or performing a specific action. Imagery is also characterized by its reliance on perceptual representations and activation of perceptual brain systems. We use this conception of imagery to argue that all imagery is simulation more specifically, it is a specific type of simulation in which the mental processes that 'run' the simulation emulate those that would actually operate in the simulated scenario. This type of simulation, which we label emulation, has benefits over other types of simulations that merely mimic the content of the simulated scenario.Psycholog

Fear Selectively Modulates Visual Mental Imagery and Visual Perception

Emotions have been shown to modulate low-level visual processing of simple stimuli. In this study, we investigate whether emotions only modulate processing of visual representations created from direct visual inputs or whether they also modulate representations that underlie visual mental images. Our results demonstrate that when participants visualize or look at the global shape of written words (low-spatial-frequency visual information), the prior brief presentation of fearful faces enhances processing, whereas when participants visualize or look at details of written words (high-spatial-frequency visual information), the prior brief presentation of fearful faces impairs processing. This study demonstrates that emotions have similar effects on low-level processing of visual percepts and of internal representations created on the basis of information stored in long-term memory.Psycholog

Crime Alert! How Thinking about a Single Suspect Automatically Shifts Stereotypes toward an Entire Group

Crime alerts are meant to raise community awareness and identify individual criminal suspects; they are not expected to affect attitudes and beliefs toward the social group to which an individual suspect belongs. However, psychological principles of learning, categorization, and memory predict that what is learned about an instance can color perception of an entire category. At the intersection of psychology, criminal justice, sociology, and media studies, two experiments were conducted to test the effect that providing individual racial identity in crime alerts has on racial group stereotypes. In Experiment 1, participants visualized four scenarios involving Black or White would-be criminals. Results revealed that in the case where Black would-be criminals were made salient in memory, participants demonstrated significantly more negative implicit stereotypes toward Blacks as a group compared with a condition in which White would-be criminals were more salient in memory. In Experiment 2, participants read a written description of a crime scene with a suspect who was either depicted as White or Black, and then imagined the suspect. On both implicit and explicit measures of group stereotypes obtained afterward, participants who read about a Black criminal reported and revealed more anti-Black/pro-White stereotypes than did those who read about a White criminal. Crime alerts that mention racial identity, whatever their benefit, come with the burden of shifting stereotypes of social groups. In this context, the value of racial identification in crime alerts warrants reconsideration.Psycholog

Is Cognitive Neuropsychology Plausible? The Perils of Sitting on a One-Legged Stool

We distinguish between strong and weak cognitive neuropsychology, with the former attempting to provide direct insights into the nature of information processing and the latter having the more modest goal of providing constraints on such theories. We argue that strong cognitive neuropsychology, although possible, is unlikely to succeed and that researchers will fare better by combining behavioral, computational, and neural investigations. Arguments offered by Caramazza (1992) in defense of strong neuropsychology are analyzed, and examples are offered to illustrate the power of alternative points of view.Psycholog

Dissociation Between Visual Attention and Visual Mental Imagery

Visual mental imagery (which involves generating and transforming visual mental representations, i.e., seeing with the mind's eye) and visual attention appear to be distinct processes. However, some researchers have claimed that imagery effects can be explained by appeal to attention (and thus, that imagery is nothing more than a form of attention). In this study, we used a size manipulation to demonstrate that imagery and attention are distinct processes. We reasoned that if participants are asked to perform each function (imagery and attention) using stimuli of two different sizes (large and small), and that stimulus size affects the two functions differently, then we could conclude that imagery and attention are distinct cognitive processes. Our analyses showed that participants performed the imagery task with greater facility at a large size, whereas attention was performed more easily using smaller stimuli. This finding demonstrates that imagery and attention are distinct cognitive processes.Psycholog

Why are “What” and “Where” Processed by Separate Cortical Visual Systems? A Computational Investigation

In the primate visual system, the identification of objects and the processing of spatial information are accomplished by different cortical pathways. The computational properties of this “two-systems” design were explored by constructing simplifying connectionist models. The models were designed to simultaneously classify and locate shapes that could appear in multiple positions in a matrix, and the ease of forming representations of the two kinds of information was measured. Some networks were designed so that all hidden nodes projected to all output nodes, whereas others had the hidden nodes split into two groups, with some projecting to the output nodes that registered shape identity and the remainder projecting to the output nodes that registered location. The simulations revealed that splitting processing into separate streams for identifying and locating a shape led to better performance only under some circumstances. Provided that enough computational resources were available in both streams, split networks were able to develop more efficient internal representations, as revealed by detailed analyses of the patterns of weights between connections.Psycholog