Showing papers in "Perception in 1979"
TL;DR: Using a stereoscopic matching task, the second experiment showed that the perceived depth from parallax transformations is in close agreement with the degree of relative image displacement, as well as producing a compelling impression of three-dimensionality not unlike that found with random-dot stereograms.
Abstract: The perspective transformations of the retinal image, produced by either the movement of an observer or the movement of objects in the visual world, were found to produce a reliable, consistent, and unambiguous impression of relative depth in the absence of all other cues to depth and distance. The stimulus displays consisted of computer-generated random-dot patterns that could be transformed by each movement of the observer or the display oscilloscope to simulate the relative movement information produced by a three-dimensional surface. Using a stereoscopic matching task, the second experiment showed that the perceived depth from parallax transformations is in close agreement with the degree of relative image displacement, as well as producing a compelling impression of three-dimensionality not unlike that found with random-dot stereograms.
673 citations
TL;DR: It is argued that the internal representation for familiar faces may be qualitatively different from that for faces seen just once and some advantage in feature saliency may accrue to the internal or ‘expressive’ features of familiar faces.
Abstract: Three experiments are reported in which recognition of faces from whole faces or internal or external features was compared. In the first experiment, where the faces were of famous people, an advantage was found for identification from internal features. In the second experiment involving unfamiliar faces, however, no difference was found in recognition rates when subjects were given the internal or the external features. In a third experiment famous faces were presented and mixed with other famous faces for a recognition test. As in experiment 1, better recognition occurred from internals as compared with external features. It is argued that the internal representation for familiar faces may be qualitatively different from that for face seen just once. In particular some advantage in feature saliency may accrue to the internal or 'expressive' features of familiar faces. The implications of these results are considered in relation to general theories of face perception and recognition.
658 citations
TL;DR: In this study a number of descriptive analyses of eye movements in reading were carried out, and the results were supportive of models which suggest that determining where to look next while reading is made on a nonrandom basis.
Abstract: Three broad categories of models of eye movement guidance in reading are described. According to one category, eye movements in reading are not under stimulus or cognitive control; the other two categories indicate that cognitive activities or stimulus characteristics are involved in eye guidance. In this study a number of descriptive analyses of eye movements in reading were carried out. These analyses dealt with fixation locations on letters within words of various lengths, conditional probabilities that a word will be fixed given that a prior word was or was not fixated, and average saccade length as a function of the length of the word to the right of the fixated word. The results of these analyses were supportive of models which suggest that determining where to look next while reading is made on a nonrandom basis.
558 citations
TL;DR: Three experiments suggest that adults' judgments of collision time are best predicted by two-dimensional spatiotemporal values which are invariant over object sizes, distances traversed, approach velocities, and several lower-order variables such as absolute angular size.
Abstract: Many subhuman species and human infants, children, and adults can use two-dimensional information of relative rate of angular-size change to anticipate collisions between the self and approaching objects or surfaces. But extant studies have not determined what information is used when subjects view simulated approach events providing two-dimensional information and three-dimensional information (distance and distance change), as well as lower-order visual information contained in real approach events. Three experiments suggest that, given these several possibilities, adults' judgments of collision time are best predicted by two-dimensional spatiotemporal values which are invariant over object sizes, distances traversed, approach velocities, and several lower-order variables such as absolute angular size. However, collision time is substantially underestimated, with absolute amount of underestimation increasing as a function of actual time-to-collision. Large constant errors and loss of judgment linearity ...
382 citations
TL;DR: By substituting mid-grey bars for the black bars in one region of a black-white grid, and for the white bars in another region, an apparent difference in the lightness of the grey bars in the two regions is produced.
Abstract: By substituting mid-grey bars for the black bars in one region of a black-white grid, and for the white bars in another region, an apparent difference in the lightness of the grey bars in the two regions is produced. The grey bars alternating with the white bars look much lighter than those alternating with the black bars (figure 1). The effect is stronger at higher spatial frequencies; the illusion is enhanced by observing figure 1 from a distance of a few meters. However, this illusion, unlike the assimilation effect investigated by Helson and others (e.g., Helson 1963), does not disappear at low spatial frequencies; the new illusion is still present when figure 1 is observed from a distance of only a few centimeters.
226 citations
TL;DR: The perception of certain figures with illusory contours entails a reversal of figure and ground and it is hypothesized that this process occurs in two stages, namely, alignment of physically present contours, recognition of parts of the stimulus array, and set.
Abstract: The perception of certain figures with illusory contours entails a reversal of figure and ground. It is hypothesized that this process occurs in two stages. First, some factor must suggest or cue the reversal. Experiments are described that isolate three such factors, namely, alignment of physically present contours, recognized incompletion of parts of the stimulus array, and set. Once cued, however, other experiments indicate that in a further stage of processing the solution is examined with respect to its compatibility with the stimulus display or with other perceptual properties to which the display gives rise. Only if such compatibility is present will the perception of a figure with illusory contours be maintained.
168 citations
TL;DR: Three experiments were performed to examine the reverberation cue to egocentric auditory distance and to determine the extent to which such a cue could provide ‘absolute’, as contrasted with ‘relative’; information about distance.
Abstract: Three experiments were performed to examine the reverberation cue to egocentric auditory distance and to determine the extent to which such a cue could provide ‘absolute’, as contrasted with ‘relative’, information about distance. In experiment 1 independent groups of blindfolded observers (200 altogether) were presented with broadband noise from a speaker at one of five different distances (0·55 to 8 m) in a normal hard-walled room. Half of each group of observers were presented with the sound at 0 deg azimuth, followed (after a delay) by the identical sound at 90 deg azimuth. The order of presentation was reversed for the remaining observers. Perceived distance varied significantly as a function of the physical distance to the speaker, even for the first presentations. The change in the binaural information between the 0 deg and 90 deg presentations did not significantly modify the results. For both orientations, near distances were overestimated and far distances were underestimated. Experiments 2 and ...
159 citations
TL;DR: A set of three studies was designed to investigate the role of touch-produced sounds in the perception of surface texture and found subjects were capable of judging roughness on the basis of sounds alone.
Abstract: A set of three studies was designed to investigate the role of touch-produced sounds in the perception of surface texture. Subjects were capable of judging roughness on the basis of sounds alone. Auditory judgments were similar, but not identical to corresponding haptic touch judgments. When both sources of information were available, subjects tended to use the tactile cues. The nature of the auditory stimulus for roughness is considered.
138 citations
TL;DR: It is suggested that contiguous regions of different luminance (and contiguous colour regions) are normally held in spatial register by locking from common luminance boundaries by producing inappropriate contour shifts from neighbouring regions of contrasting luminance when separated by narrow gaps of neutral luminance.
Abstract: The Cafe Wall illusion (seen on the tiles of a local cafe) is a Munsterberg chequerboard figure, but with horizontal parallel lines which may have any luminance separating the rows of displaced squares. These (the ‘mortar’ lines) display marked wedge distortion which is especially affected by: contrast of the squares (‘tiles’); width of the ‘mortar’ lines, and their luminance which must not be significantly higher than that of the light squares or lower than that of the dark squares for distortion to occur. An experiment is described from which quantitative data have been obtained by varying these parameters. It is suggested that contiguous regions of different luminance (and contiguous colour regions) are normally held in spatial register by locking from common luminance boundaries. The Cafe Wall illusion is attributed to this border locking producing inappropriate contour shifts from neighbouring regions of contrasting luminance when separated by narrow gaps of neutral luminance. Further implications on...
109 citations
TL;DR: It was found that the persistence of low- Contrast gratings was longer than that of high-contrast stimuli for all spatial frequencies investigated and at higher contrast levels, a tendency for persistence to be independent of contrast was observed.
Abstract: The visual persistence of sinusoidal gratings of varying spatial frequency and contrast was measured. It was found that the persistence of low-contrast gratings was longer than that of high-contrast stimuli for all spatial frequencies investigated. At higher contrast levels of 1 and 4 cycles deg-1 gratings, a tendency for persistence to be independent of contrast was observed. For 12 cycles deg-1 gratings, however, persistence continued to decrease with increasing contrast. These results are compared with recently published data on other temporal responses, and are discussed in terms of the different properties of sustained and transient channels.
109 citations
TL;DR: The neon effect may occur in line patterns made up of elements of different color or brightness as discussed by the authors, and the luminance relations between the different line elements in the pattern and between these line elements and their background appear to be critical for the occurrence of the effect.
Abstract: The neon effect, i.e. an illusion of light projected onto a homogeneous lattice, may occur in line patterns made up of elements of different color or brightness. Particular luminance relations between the different line elements in the pattern and between these line elements and their background appear to be critical for the occurrence of the effect.
TL;DR: The meaning of the results of the analysis of Fourier image decompositions to describe suprathreshold visual-texture perception is explained.
Abstract: Recent discoveries of nonlinear perceptual analyzers in effortless texture discrimination cast serious doubt on the usefulness of Fourier image decompositions to describe suprathreshold visual-texture perception. We now explain the meaning of these results.
TL;DR: It would seem that lower adaptation levels elicit lower thresholds, higher intensity estimates, and altered quality descriptions with predictable effects on psychophysical measures.
Abstract: The paper reviews how adaptation to sodium chloride, changing in concentration as a result of various experimental procedures, affects measurements of the sensitivity, intensity, and quality of the salt taste. The development of and evidence for the current model that the salt taste depends on an adaptation level (taste zero) determined by the sodium cation concentration is examined and found to be generally supported, despite great methodological complications. It would seem that lower adaptation levels elicit lower thresholds, higher intensity estimates, and altered quality descriptions with predictable effects on psychophysical measures.
TL;DR: One group of subjects rated differences in brightness and another the clarity of illusory contours for eight figure — ground combinations of the Kanizsa and Ehrenstein patterns made from Munsell papers, supporting the argument that illusORY contours derive primarily from contrast-induced differences in brighter regions.
Abstract: One group of subjects rated differences in brightness and another the clarity of illusory contours for eight figure-ground combinations of the Kanizsa and Ehrenstein patterns made from Munsell papers. For four combinations there was a difference in Munsell value (brightness) between figure and ground and for another four no difference. For the latter the pattern was derived from differences in hue or colour quality. For the combinations with a Munsell value difference the ratings of both brightness difference and contour clarity were high and for those of uniform value both were low. The results are interpreted as supporting the argument that illusory contours derive primarily from contrast-induced differences in brightness and possibly in colour between contiguous, physically uniform regions.
TL;DR: Findings provide converging lines of evidence that suppression occurs at a site in the human visual system after the locus of grating adaptation and, hence, after the striate cortex.
Abstract: Two experiments were performed to localize the site of binocular rivalry suppression in relation to the locus of grating adaptation. In one experiment it was found that phenomenal suppression of a high-contrast adaptation grating presented to one eye had no influence on the strength of the threshold-elevation aftereffect measured interocularly. Evidently information about the adaptation grating arrives at the site of the aftereffect (presumably binocular neurons) even during suppression. In a second experiment 60 s of grating adaptation was found to produce a short-term reduction in the predominance of the adapted eye during binocular rivalry. These findings provide converging lines of evidence that suppression occurs at a site in the human visual system after the locus of grating adaptation and, hence, after the striate cortex.
TL;DR: This explanation satisfactorily accounts for the data with the proviso that, when inverted faces are to be remembered, the best strategy is not to attempt to correct their orientation, but to learn isolated features of the face.
Abstract: An investigation of ninety-five university admission candidates failed to replicate the finding by Yin of a negative correlation between the ability to recognise upright and inverted faces. A zero correlation was obtained when unknown faces were both learned and recognised upside down, but when well-known faces were presented normally and upside down for identification, a significant positive correlation appeared. Rock has suggested that inverted faces are difficult to recognise because they overtax a mechanism for correcting disoriented stimuli. This explanation satisfactorily accounts for the data with the proviso that, when inverted faces are to be remembered, the best strategy is not to attempt to correct their orientation, but to learn isolated features of the face. This describes the data more parsimoniously than Yin's face-specific mechanism.
TL;DR: The apparent differences between the VA and the VP conflict situations are discussed with regard to the feasibility of generating a unitary explanation of localization conflict results and several further factors are discussed that must be explored before undertaking such a unitARY formulation.
Abstract: Visual–auditory (VA) and visual–proprioceptive (VP) localization conflict paradigms were varied to explore the comparability of the conflict situations. In experiment 1 various attempts were made to decrease the dominance of visual information over proprioceptive and auditory target information. Pairing auditory with proprioceptive information against conflicting visual information did not lessen the visual dominance, nor did dimming the visual field. A ‘cognitive’ manipulation, in which the subject was led to doubt the reliability of the visual information, reduced visual dominance over audition but not visual dominance over proprioception. This difference between the two conflict situations was further explored and corroborated in experiment 2. In experiment 3 no attempt was made to lead the subject to believe that paired discrepant targets were related, and the visual dominance of audition was strong while the visual dominance of proprioception did not occur.The apparent differences between the VA and ...
TL;DR: Two properties of an object, substance and shape, thus appear to be detectable as invariant in an event sequence, an instance of ‘phenomenal doubling’ at an early age.
Abstract: Three experiments investigated the perception of substance and shape as invariant properties of objects by three-month-old infants. In experiment 1, infants were habituated to two differently shaped objects undergoing a rigid motion. After habituation of the infants, the objects were presented undergoing a different rigid motion, or undergoing a deforming motion, or undergoing the same rigid motion. Habituation was maintained to the new rigid motion, indicating that the two rigid motions were perceived as sharing an invariant property. Dishabituation, on the other hand, occurred when a deforming motion followed a rigid one. In experiment 2, infants were habituated to one shape undergoing two different rigid motions. After habituation, the shape was changed but the same two motions continued. Dishabituation occurred, compared to a group with no shape change, indicating that shape is distinguished as an invariant property over two rigid motions. In experiment 3, habituation to a shape undergoing two rigid motions was followed by a new shape presented motionless, or the same shape presented motionless. Cessation of motion did not prevent recognition of shape as invariant. Two properties of an object, substance and shape, thus appear to be detectable as invariant in an event sequence, an instance of "phenomenal doubling" at an early age.
TL;DR: In this article, the convergence-altering prism spectacles were used to train subjects for 8 min with either convergence-increasing or convergence-decreasing prisms, and both the preadaptation and postadaptation estimates showed that the reciprocal of estimated target distance is linearly related to convergence.
Abstract: Adaption to convergence-altering prism spectacles was studied. The subjects were trained for 8 min with either convergence-increasing or convergence-decreasing prisms. Before and after training they estimated the distance to a binocular dot varying in the stimulus it provided to convergence. Both the preadaptation and postadaptation estimates showed that the reciprocal of estimated target distance is linearly related to convergence. Further there was a consistent change in the direction of adaptation expected from the preadaptation to the postadaptation test. This change was accounted for in terms of a recalibration of the effective absolute convergence level.
TL;DR: The role of visual experience in coding spatial position by movements or by external cues was examined in simple (nonrotational) shift tasks with blind and sighted children, and it was argued that visual experience affects coding by drawing attention to external cues, and by providing more adequate spatial information than other sources usually available to the blind.
Abstract: The role of visual experience in coding spatial position by movements or by external cues was examined in simple (nonrotational) shift tasks with blind and sighted children. Age and the salience of external cues were also of interest. Results showed that the congenitally totally blind used movement cues significantly more even when external cues were present and prominent. The blind with minimal visual experience coded by external cues, but made errors beyond the age by which blindfolded sighted children performed correctly. It was argued that visual experience affects coding by drawing attention to external cues, and by providing more adequate spatial information than other sources usually available to the blind. In its absence, movement coding and self-reference can become preferred strategies.
TL;DR: It is shown that if the vertically and horizontally symmetrical arrays are spatially filtered, so that their respective spectra are 2 octaves apart, then their superposition does not appear random, but both symmetries can be simultaneously perceived.
Abstract: It is known that the sum of a random-dot array with vertical bilateral symmetry and one with horizontal bilateral symmetry appears as a random array. Here we show that if the vertically and horizontally symmetrical arrays are spatially filtered, so that their respective spectra are 2 octaves apart, then their superposition does not appear random, but both symmetries can be simultaneously perceived. The low-band array has a stronger perceptual weight than the high-band array. These demonstrations give further evidence that frequency channels are before symmetry perception.
TL;DR: Overestimation of focal length was larger than underestimation for both illusions and aftereffects despite the fact that identical stimuli produced effects in opposite directions in the two paradigms.
Abstract: When two lines were presented simultaneously, in an illusion paradigm, the judged length of one of the lines (the focal line) assimilated toward the length of the contextual line. When the lines were presented sequentially, in an aftereffect paradigm, the apparent length of the focal line was displaced away from the length of a previously presented contextual line (i.e. contrast). The largest effects obtained at inverse contextual-to-focal length ratios: 1·67:1 for contextual lines longer than the focal line and 0·60:1 for contextual lines shorter than the focal line. Overestimation of focal length was larger than underestimation for both illusions and aftereffects despite the fact that identical stimuli produced effects in opposite directions in the two paradigms. Results were discussed in terms of a neural length-coding model and were related to visual size constancy.
TL;DR: The data indicate that monkeys have an oblique effect similar to that found in humans, implying that the monkey is a useful animal model for investigating the development of meridional anisotropies.
Abstract: Monkeys aligned a cursor bar with high-contrast square-wave gratings presented in a variety of orientations. Alignment time increased with increasing spatial frequency from 6 to 24 cycles deg−1 regardless of the orientation of the grating. At higher spatial frequencies, alignment tasks took longer for obliquely oriented gratings than for horizontal and vertical ones. Reducing grating contrast by blurring the image of the 24 cycle deg−1 grating also produced longer alignment times for the obliques. These data indicate that monkeys have an oblique effect similar to that found in humans, implying that the monkey is a useful animal model for investigating the development of meridional anisotropies.
TL;DR: These results suggest that responses to visual-geometric illusions, mediated by optical or neural interactive mechanisms, show patterns of familial resemblance which may be based upon heritable factors.
Abstract: The Muller-Lyer and Ebbinghaus illusions were tested in 203 mother-father-offspring triads and 303 sibling pairs. Significant familial resemblances were found in all but the overestimated segment of the Ebbinghaus illusion. These results suggest that responses to visual-geometric illusions, mediated by optical or neural interactive mechanisms, show patterns of familial resemblance which may be based upon heritable factors.
TL;DR: In the absence of olfactory or tactile stimulations, few subjects altered parotid or whole-mouth secretion rates in response to viewing food or photographs of food, and subjects demonstrated large differences in their patterns of affective responses to full-strength and diluted lemon juice, which were independent of salivary flow.
Abstract: There was no significant change in flow rates of parotid saliva in nineteen of twenty subjects while they viewed photographs of lemons, or in fourteen of twenty subjects while they cut lemons in a glove box. Neither parotid nor whole-mouth secretion changed from baseline when subjects viewed fresh lemons and lemonade presented in a plastic box. Further, no significant changes in whole-mouth secretion rates were observed when subjects viewed photographs of two appetizing foods, or of fresh doughnuts in a plastic box, even though subjects knew they could eat the doughnuts after the experiment. In most cases, sniffing of the lemons or of the doughnuts resulted in increased flow rates. Subjects demonstrated large differences in their patterns of affective responses to full-strength and diluted lemon juice, which were independent of salivary flow. In the absence of olfactory or tactile stimulations, few subjects altered parotid or whole-mouth secretion rates in response to viewing food or photographs of food. A reevaluation of findings on 'psychic' stimulation of saliva may be in order to ascertain the role of olfactory, tactile, and even trigeminal clues in salivary response to food stimuli.
TL;DR: It is suggested that two different contour-shifting effects operate in this illusion, and these are named the ‘symmetrical effect’ and the “corner effect” respectively.
Abstract: The Munsterberg illusion is a compelling phenomenon for which there is no generally accepted explanation. It is suggested that two different contour-shifting effects operate in this illusion, and these are named the 'symmetrical effect' and the 'corner effect' respectively. It is further suggested that both of these effects are caused by 'irradiation', and an attempt is made to cast some light upon the phenomenon of irradiation, which is itself only poorly understood.
TL;DR: The test provides a quick and reliable way of screening animals for stereopsis by measuring the smallest separation in depth that can be discriminated between two adjacent stimuli under both monocular and binocular viewing conditions.
Abstract: A behavioural method is described for the assessment of depth perception of kittens. Measurement is made of the smallest separation in depth that can be discriminated between two adjacent stimuli under both monocular and binocular viewing conditions. Normal animals can discriminate much smaller separations in depth when using two eyes than with monocular viewing, implying the presence of a cue to depth that is uniquely available with binocular viewing. The test provides a quick and reliable way of screening animals for stereopsis.
TL;DR: This demonstration shows that binocular depth inversion cannot be explained by a complete loss of stereoscopic information, or by a process analogous to pseudoscopic viewing whereby retinal disparities are incorporated into perception, but with their signs uniformly reversed.
Abstract: Inside-out relief masks of faces can be depth-inverted (i.e. seen in reverse perspective) during close-up binocular viewing. If a random-dot stereogram is projected onto such a mask, stereopsis can be achieved for the stereogram, and its depth planes are correctly seen while the mask itself, including the region covered by the stereogram, is simultaneously perceived as depth-inverted. This demonstration shows that binocular depth inversion cannot be explained by a complete loss of stereoscopic information (e.g. through monocular suppression), or by a process analogous to pseudoscopic viewing whereby retinal disparities are incorporated into perception, but with their signs uniformly reversed.
TL;DR: Accuracy of ‘same’/‘different’ judgments of four dry, white wines improved and confidence ratings were obtained so that the area under the isosensitivity curve could be computed as a bias-free measure of accuracy while the wine used for same pairs was held constant.
Abstract: Over three test sessions alternated with two training sessions, accuracy of 'same'/'different' judgments of four dry, white wines improved 14%. Confidence ratings were obtained so that the area under the isosensitivity curve could be computed as a bias-free measure of accuracy while the wine used for same pairs was held constant. An initial bias for 'different' judgments persisted, rather than disappearing as Walk found. While perceptual learning did occur, the problem of attending to irrelevant differences was not overcome.
TL;DR: The tilt illusion was investigated by using both short and long test lines, at three angles of test line-inducing line separation, and found that both the vertical judgment and the parallel matching task provided similar, classic TI angular functions.
Abstract: The tilt illusion (TI) was investigated by using both short (19 min) and long (2 deg 6 min) test lines, at three angles of test line-inducing line separation (15 degrees, 45 degrees, and 75 degrees). Three groups of ten observers each provided data under one of three task conditions: vertical judgment, parallel matching, and dot alignment on a common visual display. The main result was that both the vertical judgment and the parallel matching task provided similar, classic TI angular functions with the means ordered 15 degrees greater than 45 degrees greater than 75 degrees and with small attraction effects at 75 degrees in three of the four relevant functions. The third task, dot alignment, yielded results different from the average of the other two: no attraction effects occurred and, with the short test line, the obtained mean illusion at 45 degrees exceeded those at the other intersect angles. These results are consistent with alignment data reported by others. One explanation is that the inducing line produces an apparent bowing of the test line which would be reflected in dot alignments but not in vertical setting or in parallel matching. However, direct evidence does not support this hypothesis. An alternate hypothesis, for which independent evidence exists, is that alignment errors reflect perceptual mistracking but that the origin of these errors is not the tip of the test line but within it. Although this does not explain dot alignment errors, it highlights their complexity and the need to interpret them with caution.