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Biomedical subjects

R A Finke

Publications and source records attributed to R A Finke.

At least 19 recordsLinked to original sources
PubMed1989

Mental extrapolation and cognitive penetrability: reply to Ranney and proposals for evaluative criteria.

We propose three criteria for establishing that mentally extrapolated motions are impenetrable with respect to one's knowledge, beliefs, or expectations about the nature of corresponding physical motions, and we review recent findings on mental extrapolation and representational momentum that appear to meet these criteria. We also respond to some arguments recently proposed by Ranney (1989) and Hubbard and Bharucha (1988) that representational momentum is cognitively penetrable. We conclude that mental extrapolations are governed to at least some extent by the inherent properties of the underlying internal mechanisms.

Attention↗
PubMed1988

Mental extrapolation and representational momentum for complex implied motions.

A sequence of static displays implying consistent motions of a pattern induces distortions in memory for the last-observed appearance of the pattern. These memory distortions suggest that there is an internal analogue to physical momentum called representational momentum. Two experiments are reported comparing performance on tasks in which observers must remember the final display with those in which they are instructed to extrapolate the implied motions out to the next step in the sequence. In each experiment, the memory shifts were highly correlated with the actual rates at which the implied motions were extrapolated. In addition, the memory shifts were larger when the mental extrapolations occurred along the same directions of implied motion each time. These findings suggest that the memory shifts depend both on the rate at which the mental extrapolations are performed and on how consistently they are performed.

Form Perception↗
PubMed1986

Implied velocity and acceleration induce transformations of visual memory.

In this study, the phenomenon of representational momentum (Freyd & Finke, 1984) is investigated in cases where visual memories are distorted by implied motions of the elements of a pattern. Our theory predicts that these memory distortions should be sensitive not only to the direction of the implied motions but also to changes in the implied velocity. Subjects observed a sequence of dot-pattern displays that implied that the dots were moving at either a constant velocity or constant acceleration, but in separate directions. Discrimination functions for recognizing the final pattern in the sequence revealed that subjects' memories had shifted forward, corresponding to small continuations of the implied motions. The induced memory shifts increased in size as the implied velocity and acceleration of the dots increased, but were eliminated when the display sequence implied a deceleration of the dots to a final velocity of zero. These findings suggest that mentally extrapolated motion may have some of the same inertial properties as actual physical motion.

Acceleration↗
PubMed1986

Some consequences of visualization in pattern identification and detection.

The goal of this study was to establish some of the conditions under which mental imagery facilitates or interferes with the identification and detection of visual patterns. In Experiment 1, subjects identified simple bar patterns presented at orientations 90 degrees apart under normal viewing conditions. Their reaction times were shorter when they had imagined seeing the patterns in advance at the same orientation, but were longer when they had imagined seeing the patterns at orientations that were in-between those of the actual presented patterns, relative to baseline conditions in which they were instructed not to imagine the patterns. In Experiment 2, where the subjects had only to detect the target patterns without identifying them, there was no effect of image formation or image-target alignment. In Experiment 3, where the detection task was repeated but where the target exposure duration was reduced, imagery significantly interfered with detection. In contrast to the results of Experiment 1, reaction time and error rate in this case were greatest when the imagined patterns were perfectly aligned with the target patterns. These findings demonstrate that whether imagery facilitates or interferes with performance on a visual task depends on the nature and difficulty of the task and on how closely the imagined and presented patterns correspond.

Discrimination Learning↗
PubMed1985

Transformations of visual memory induced by implied motions of pattern elements.

Four experiments measured distortions in short-term visual memory induced by displays depicting independent translations of the elements of a pattern. In each experiment, observers saw a sequence of 4 dot patterns and were instructed to remember the third pattern and to compare it with the fourth. The first three patterns depicted translations of the dots in consistent, but separate directions. Error rates and reaction times for rejecting the fourth pattern as different from the third were substantially higher when the dots in that pattern were displaced slightly forward, in the same directions as the implied motions, compared with when the dots were displaced in the opposite, backward directions. These effects showed little variation across interstimulus intervals ranging from 250 to 2,000 ms, and did not depend on whether the displays gave rise to visual apparent motion. However, they were eliminated when the dots in the fourth pattern were displaced by larger amounts in each direction, corresponding to the dot positions in the next and previous patterns in the same inducing sequence. These findings extend our initial report of the phenomenon of "representational momentum" (Freyd & Finke, 1984a), and help to rule out alternatives to the proposal that visual memories tend to undergo, at least to some extent, the transformations implied by a prior sequence of observed events.

Adolescent↗
PubMed1984

Facilitation of length discrimination using real and imaged context frames.

In the first experiment we showed that difficult length discriminations can be facilitated by imagining a visual context frame that serves to emphasize small length differences between pairs of horizontal and vertical lines. This facilitative effect of imagery cannot be attributed to response-bias or expectancy effects because we have separated the object to be imagined from the objects to be discriminated. In the second experiment we showed that real context facilitates the line-length discrimination in much the same way as imagined context does. The results from these experiments suggest that (a) functional interactions can occur between imagery and perception at feature-processing levels of the visual system, and (b) there is a functional equivalence between the imagination and perception of helpful context. Results of a third experiment suggest that although imagery and perception may be functionally equivalent at the levels of visual processing where parts of patterns are combined, they are not functionally equivalent at the lower levels of simple detection.

Cues↗
PubMed1983

Directional scanning of remembered visual patterns.

We report a set of experiments that helps to define the conditions under which mental image scanning may be used spontaneously for specific, practical purposes. Subjects were shown a dot pattern, followed by an arrow, and their task was to say whether the arrow was pointing at any of the previously seen dots. When no advance information was provided about the arrow's location, reaction time for correctly verifying that an arrow was pointing at a dot increased linearly with increasing arrow-dot distance, and the subjects almost always reported scanning a mental image in order to make their judgments. However, when a cue for the arrow's location was presented 2 sec beforehand, reaction time was uncorrelated with distance, and most of the subjects reported using an alternative strategy based on the determination in advance of correct directions from that location to the dots. When given only 1 sec of advance information about arrow location, most subjects reported using a combined image-scanning and advanced determination strategy, resulting in a reaction time function that increased only for the farthest distances. Because in each of these experiments instructions to form or to scan mental images were never given, these findings address the most common criticisms of the image-scanning paradigm.

Form Perception↗
PubMed1982

Spontaneous imagery scanning in mental extrapolation.

We report an experiment that suggests a functional application of mental-image scanning. After subjects inspected a simple dot pattern, the pattern was removed, and they were then shown an arrow at an unexpected location. Their task was to judge as quickly as possible whether the arrow pointed at any of the dots in the previously observed pattern. Although the subjects were never instructed to form or scan mental images, most of them reported having done so in order to make their judgments, and their reaction times were directly proportional to the distances separating the dots and the arrows, as typically found in image-scanning experiments. Imagery scanning may therefore serve a useful function when one must judge spatial relations between the positions of remembered objects and newly specified locations.

Discrimination Learning↗
PubMed1981

Mapping the visual field in mental imagery.

We describe a simple psychophysical technique for measuring the size and shape of visual fields in mental imagery, and use this technique to compare fields in imagery and perception within which bar gratings of various spatial frequencies can be resolved. The first experiment demonstrates that the size of fields of resolution obtained when bar gratings are imagined decreases with increasing spatial frequency of the gratings, in the same way that the size of fields obtained when the gratings are actually observed decreases. This experiment also shows that imagery and perceptual fields are very similar in shape, both being elongated horizontally and extending farther below the point to which one's gaze is directed than above. The second experiment shows that experimental subjects are not able to anticipate the more subtle characteristics of these fields, such as the precise rate at which field size decreases with increasing spatial frequency--characteristics that most clearly reveal the very close correspondence between the imagery and perceptual fields. The third experiment shows that the size of the imagery fields can serve to discriminate between vivid and nonvivid imagers when the task of imagining the gratings is made sufficiently difficult. We interpret these findings as evidence that visual imagery involves the activation of mechanisms in the visual system that are specifically designed to process information about spatial frequency. In particular, we claim that constraints that these mechanisms impose on the resolution of high spatial frequencies in perception are also imposed in mental imagery, restricting how well fine details of an object can be imagined. We then discuss implications of these findings for theories about spatial-frequency analysis in vision and for the general issue of the functional value of mental imagery.

Form Perception↗
PubMed1981

Area and contrast effects upon perceptual and imagery acuity.

We measured the size of visual fields within which actual and imagined circular patterns could be resolved, as the patterns varied in both area and relative contrast. As pattern area increased, imagery fields increased in size at the same rate as perceptual fields. However, as the relative contrast between parts of the patterns was reduced, perceptual fields diminished in size, while imagery fields did not. for all variations of pattern area and contrast, fields in imagery were roughly the same shape as fields in perception. A control experiment provided no support for the possible criticism that these results might be explained on the basis of subjects' expectations for the size and shape of the imagery fields, especially since control subjects falsely believed that reductions in contrast would reduce considerably the size of these fields. Although these findings suggest that images and physical objects are functionally equivalent at pattern-processing levels of the visual system, they demonstrate that images and objects are not functionally equivalent at certain levels of the visual system where information about relative contrast is processed.

Discrimination Learning↗
PubMed1981

Methodological considerations in experiments on imagery acuity.

We examine the possible reasons why the results of our recent study on imagery acuity differed from those of an attempted replication by Intons-Peterson and White. Comparison of the two studies suggests that the differences in results are likely to be due to differences in procedures for giving imagery instructions and measuring the fields of resolution, and not to the presence or absence of experimenter bias. Accordingly, we discuss the importance of using skilled and practiced experimenters when conducting imagery acuity experiments. In addition, we address issues raised by Banks concerning the identification of particular levels of functional equivalence in imagery and perception.

Discrimination Learning↗