Instructions and decision times of size-constancy responses

The current study investigated the effect of instructions and stimulus discriminability on size-constancy responses and decision times in a task allowing separate evaluation of the effects of instructions and of dimensional choices by the subjects in the size-constancy task. Objective, perspective, or distance matches were influenced both by the instructions given the subject and by the relative discriminability of the stimuli in each dimension, so that subjects did not always successfully follow their instructions. Decision times were found to be fastest with perspective rather than objective or apparent instructions, but times taken to produce objective and perspective matches did not differ. Apparently, both objective and perspective judgments are available to the perceiver before a response is made, but instructions affect postperceptual response times.     

Dissociating between cardinal and ordinal and between the value and size magnitudes of coins

In mathematics, the ordinal (relative) magnitude of a numerical object conveys a separate meaning from its cardinal (absolute) magnitude, whereas its physical size bears no inherent relationship to its magnitude. In numerical cognition, the ordinal-cardinal distinction has been scarcely addressed, whereas the size-magnitude distinction has been studied extensively, with the surprising demonstration of an interaction between semantic magnitude and physical size (Besner & Coltheart, 1979). The present work used coins to study the intricate relations between these meanings. In two experiments, Israeli observers (Experiment 1) and American observers (Experiment 2) performed numerical and physical comparative judgments of coins. Consensual markers of magnitude activation (e.g., the size congruity effect and the distance effect) were obtained. The results of the two experiments converged on the same conclusions. Comparisons of value were governed by ordinal magnitude. Magnitude interfered with comparisons of size, but size did not affect value. The results provided a set of clear dissociations between cardinal and ordinal magnitude and between value and size of coins. They highlight the important role played by ordinal information in magnitude processing.     

Gestalts are more closely associated with performance on a discrimination task than are component stimuli

Distance, similarity, and other components of the physical stimulus but also gestalts are associated with the ability to discriminate between two objects. The present research bears on this confound. Identical lines were added to the opening and closing bracket of a pair of brackets to form two identical rectangles. A stimulus consisted of either one or two of these brackets, lines, or rectangles. Subjects indicated as quickly as possible whether one or two objects occurred. The discriminations between two near brackets and two near lines were more difficult than the discrimination between two near rectangles. A large distance between two objects improved the bracket and line discriminations more than the rectangle discrimination. Single brackets and lines did not result in poorer performance than did single rectangles. These results disconfirm the distance, similarity (including relational similarity), good continuation, location of geometric centers, size, closedness, symmetry, spatial frequency, redundancy, and number of lines component stimulus predictions at least twice. Both the two near brackets and the two near lines produce single gestalts, whereas each remaining 2-object stimulus results in two gestalts. Therefore, gestalts predicted performance better than did component stimuli. Another result was that the 2-object responses were faster than the 1-object responses for far objects.     

Figural preference and the visual field

Three experiments tested a hypothesis that the shape and relative dimensions of the binocular visual field determine a preference for rectangles possessing dimensions similar to those of the golden section. The results were that Ss horizontally oriented the rectangles they had drawn in correspondence with the shape of the binocular visual field but when Ss chose the most pleasing rectangles there was no significant preference for rectangles whose long side was horizontal. For all experiments there was little preference for rectangles whose ratio of short to long side approximated the golden section. There was some evidence that the placement of the rectangles with respect to the background affects preference.     

The effect of insstructions on judgment of the Müller-Lyer illusion with normal and haptically mediated visual inspection

An experiment with the Müller-Lyer figure is reported in which variation in instructions resulted in a change in the magnitude of the visual illusion under normal viewing conditions. Variation in instructions did not, however, have a differential effect on the magnitude of the illusion when Ss inspected the figure by means of a point source of light attached to one fingertip. These results are equivalent to differences found between the effect of instructions on visual and haptic illusions using the same illusion figure and support the view that variation in inspection patterns rather than differences in higher processingof sensory input might account for differences between the two modalities.     

对恐怖情绪的调节：认知重评优于表达抑制 ——一样ERP研究

摘要 本研究采用事件相关电位（ERP）技术,通过测量由视觉诱发的脑电成分晚正波（LPP）来比较情绪调节策略在生理电特征上的差异,进一步探讨认知重评和表达抑制的优劣。实验结果表明：（1）从波幅的角度来比较：在400-600ms时间窗口内,认知重评条件下恐怖图片诱发的LPP波幅显著小于在自由观看条件下的波幅,而表达抑制和自由观看组所诱发的LPP波幅差异较小。（2）从时间进程的角度来比较：认知重评与自由观看组的差异发生在400ms并持续到600ms,甚至以后;而表达抑制和自由观看之间的差异发生在450ms但是只持续到550ms。这表明认知重评相较于表达抑制,对负性情绪起调节作用开始较早,并且持续时间较长。这为认知重评优于表达抑制策略提供了神经生理学上的证据。     

Perceptual assumptions and projective distortions in a three-dimensional shape illusion

We examine a shape illusion, in which the balconies of a building appear to tilt up or down, depending on the viewpoint. The balconies are actually level parallelogram shapes, but appear as tilted rectangles. We measured the illusory tilts observed when parallelogram shapes are viewed above the line of sight, using three-dimensional stimuli consisting of parallelograms of various tilts viewed at different orientations. Under perspective projection, parallelism and orthogonality are not preserved. However, perspective distortions alone cannot account for the perceived tilts measured in these experiments, since observers perceived illusory tilts even for stimuli in the frontoparallel plane. We introduce a model, based on the theory that observers assume ambiguously projected three-dimensional angles to be equal to 90 degrees, but revise their predictions on the basis of observation. In the model, perceived tilt is predicted as a weighted sum of the tilts predicted by the assumptions that the shape is rectangular, and that the shape is level (i.e. that the angle between the shape and the vertical backboard is equal to 90 degrees). We prove that it is mathematically impossible for a planar rectangle to share a projection with a nonrectangular parallelogram. A less restrictive assumption that just the two leading internal angles are equal to 90 degrees is suggested as an alternative, and it is further proven that this new configuration of angles leads to a unique perceived tilt. The relative weights in the model reflect the amount that each prediction is revised, and are shown to vary systematically with stimulus orientation. For some observers a better fit was found by replacing the level-tilt assumptions with an assumption that physical tilt was equal to the projected tilt.     

Shape discrimination for motion-defined and contrast-defined form: squareness in special.

Shape discrimination was measured for: (i) two-dimensional rectangular targets that were perfectly camouflaged within a stationary pattern of random dots and rendered visible by relative motion of the dots, and (ii) similar dotted rectangles that were rendered visible by luminance contrast. Shape discrimination was disconfounded from size discrimination by requiring subjects to discriminate the aspect ratios of rectangles whose areas were altered independently of aspect ratio. When dot speed and contrast were both high, the aspect-ratio discrimination threshold was as acute for motion-defined (MD) rectangles as for contrast-defined (CD) rectangles and, at 2-3%, corresponded to a change of side length of about 24 s arc compared to a mean dot separation of 360 s arc. Discrimination of MD rectangles collapsed at low dot speeds and could not be measured at speeds less than about 0.03-0.08 deg s-1, but discrimination of CD rectangles was almost unaffected by dot speed. The aspect-ratio discrimination threshold was lowest for a square and progressively increased as the rectangle became more asymmetric. It is suggested that the visual system contains a mechanism that compares the separations of pairs of contours along different azimuths, and that, during visual development, this shape-discrimination processing of MD and CD targets is driven by the same environmental and behavioural pressures towards a common end point. The human equivalent of a pathway that includes the cortical area MT is thought to be important for shape discrimination of MD forms.     

Comparison of two theories of "ratio" and "difference" judgments

This article examines the hypothesis that judges compare stimuli by ratio and subtractive operations when instructed to judge" "ratios" and "differences." Rule and Curtis hold that magnitude estimations are a power function of subjective values, with an exponent between 1.1 and 2.1. Accordingly, the two-operation model tested assumes magnitude estimations of "ratios" are a comparable power function of subjective ratios. In contrast, Birnbaum and Veit theorize that judges compare two stimuli by subraction for both "ratio" and "difference" instructions and that magnitude estimations of "ratios" are approximately an exponential function of subjective differences. Three tests were used to compare the theory of one operation with the two-operation theory for the data of nine experiments. The results strongly favor the theory that observers use the same operation for both instructions.     

The visual discrimination of shape by Octopus: The effects of stimulus size

Octopuses were trained in a successive situation to discriminate between vertical and horizontal rectangles: Group S was trained with rectangles of side length 5 × 1 cm., Group M with 10 × 2 cm. rectangles, and Group L with 20 × 4 cm. rectangles. The larger the shapes used, the more readily were they discriminated, both in terms of speed of learning and of the asymptote of performance. After training, each group was given transfer tests with the two pairs of rectangles not used in training and with two further pairs of 2.5 × 0.5 cm. and 40 × 8 cm. The results can be summarized in three generalizations: (1) When the size of a shape is changed, performance is worse than on the original training shape. (2) The bigger the change in proportionate size, the less transfer is shown. (3) For corresponding changes of proportionate size, there is better transfer to larger shapes than to smaller. These generalizations are supported by data from earlier experiments on the question of transfer to different sized shapes: some of these data were reworked and are presented in detail here. The theoretical implications of the results are discussed.     

Hierarchical forms processing in adults and children

Two experiments examined child and adult processing of hierarchical stimuli composed of geometric forms. Adults (ages 18-23 years) and children (ages 7-10 years) performed a forced-choice task gauging similarity between visual stimuli consisting of large geometric objects (global level) composed of small geometric objects (local level). The stimuli spatial arrangement was manipulated to assess child and adult reaction times and predisposition toward local or global form categorization under two distinct trial conditions, with varied density of the local forms comprising the global forms. In Experiment 1, children and adults were presented with common, simple geometric shape hierarchical forms composed of ovals and rectangles. In Experiment 2, adults were presented with hierarchical forms composed of the simple geometric shapes, ovals and rectangles, and additional novel complex geometric shapes, “posts” and “arches.” Results show a clear increase of global processing bias across the age ranges of the individuals in the study, with children at 10 years performing similarly to adults on the simple stimuli. In addition, adults presented with the novel complex geometric shapes showed a significant reduction in global processing bias, indicating that form novelty and complexity lead to additional attention to local features in categorization tasks.     

Shape equivalence under perspective and projective transformations

When a planar shape is viewed obliquely, it is deformed by a perspective deformation. If the visual system were to pick up geometrical invariants from such projections, these would necessarily be invariant under the wider class of projective transformations. To what extent can the visual system tell the difference between perspective and nonperspective but still projective deformations of shapes? To investigate this, observers were asked to indicate which of two test patterns most resembled a standard pattern. The test patterns were related to the standard pattern by a perspective or projective transformation, or they were completely unrelated. Performance was slightly better in a matching task with perspective and unrelated test patterns (92.6%) than in a projective-random matching task (88.8%). In a direct comparison, participants had a small preference (58.5%) for the perspectively related patterns over the projectively related ones. Preferences were based on the values of the transformation parameters (slant and shear). Hence, perspective and projective transformations yielded perceptual differences, but they were not treated in a categorically different manner by the human visual system.     

Saliency metric for subadditive dissimilarity judgments of rectangles

Previous findings that dissimilarity judgments for rectangles are strongly subadditive, that qualitative individual differences are always present, and that four-parameter psychophysical maps can reproduce the average ratings (Sch?nemann & Lazarte, 1987) are replicated. However, the present study in addition suggests that the metric for bounded response transformation, previously used to restore additivity of responses, has a modest effect on the fits of the psychophysical maps. The differential weighing of the coordinates already incorporates segmental subadditivity predictions into the maps. In fact, the psychophysical maps define a subadditive saliency metric that depends on assigning larger weights to larger coordinates. This constraint on the weights of these maps, together with the response times, allows us to identify a strategy shift when subjects respond to two classes of stimulus pairs: For rectangle-rectangle pairs, subjects center on the shape and size of the rectangles; for square-rectangle pairs, the focus is on height and width.     

Individual differences in visual comparison processes

Two experiments are reported in which subjects compared the shape of two successively presented random visual forms. The first stimulus in the pair was one of five “standard” shapes, and the second stimulus was either the same as the standard or different by virtue of a perturbation in shape or an overall reflection. Marked individual differences were found in reaction time for the same-different comparison. For one type of subject “same” responses were faster than “different” responses, speed of “different” responses was unaffected by similarity of the test shape to the standard, and error rates and reaction times were not systematically related. For the other type of subject, “different” responses were generally faster than “same” responses, “different” reaction time decreased as the standard shape and the test shape became increasingly dissimilar, and error rates and reaction times were positively correlated. Implications of these individual differences for models of the same-different comparison process are discussed.     

Numerical and physical magnitudes are mapped into time

In two experiments we investigated mapping of numerical and physical magnitudes with temporal order. Pairs of digits were presented sequentially for a size comparison task. An advantage for numbers presented in ascending order was found when participants were comparing the numbers' physical and numerical magnitudes. The effect was more robust for comparisons of physical size, as it was found using both select larger and select smaller instructions, while for numerical comparisons it was found only for select larger instructions. Varying both the digits' numerical and physical sizes resulted in a size congruity effect, indicating automatic processing of the irrelevant magnitude dimension. Temporal order and the congruency between numerical and physical magnitudes affected comparisons in an additive manner, thus suggesting that they affect different stages of the comparison process.     

Golden section: Preferred figural orientationI

A hypothesis that the shape of the binocular visual field determines the supposed preference for rectangles possessing dimensions similar to those of the golden section was tested by having Ss draw pleasing rectangles. The results indicated that rectangles were oriented in correspondence with the shape of the visual field but there was, generally, a failure to obtain ratios approximating the golden section.     

Golden section: Preferred figural orientation

A hypothesis that the shape of the binocular visual field determines the supposed preference for rectangles possessing dimensions similar to those of the golden section was tested by havltlg Ss draw pleasing rectangles. The results iudicated that rectangles were oriented in correspondence with the shape of the visual field but there was, generally, a failure to obtain ratios approximating the golden section.     

Quantitative functions for size and distance judgments

A psychophysical approach was used to obtain judgments of visual extent under three conditions. In tuvo conditions a comparison stimulus at each of two distances was matched in size to a standard which varied in distance. Stimuli were presented on a well-lighted table and were judged by two observers under Objective instructions. Both the standard and comparison were located in either a frontal or longitudinal plane. In a third condition relative distance estimates were given of two stimuli which varied in their relative positions along the table. The mean results for all conditions were described as a power function of physical stimulus measures. The exponent was greater than 1.0 for frontal size and usually less than 1.0 for flat size and distance. The position of the comparison affected the magnitude of the exponents to a lesser degree. These findings have relevance for interpretations of size and distance judgments.     

The impact of anxiety on analogical reasoning

The effect of state anxiety on analogical reasoning was investigated by examining qualitative differences in mapping performance between anxious and non-anxious individuals reasoning about pictorial analogies. The working-memory restriction theory of anxiety, coupled with theories of analogy that link complexity of mapping with working-memory capacity, predicts that high anxiety will impair the ability to find correspondences based on relations between multiple objects relative to correspondences based on overlap of attributes between individual objects. Anxiety was induced in one condition by a stressful speeded subtraction task administered prior to the analogy task. Anxious participants produced fewer relational responses and more attribute responses than did non-anxious participants, both in the absence of explicit instructions to find relational mappings (Experiment 1) and after receiving such instructions (Experiment 2). The findings support the postulated links among anxiety, working memory, and the ability to perform complex analogical mapping.     

Effects of reinforcement and guidance procedures on instruction-following behavior of severely retarded children

Positive reinforcement, physical guidance, and fading procedures were used to teach two severely retarded children motor responses to a variety of verbal instructions. Subjects' responses to one set of instructions provided the focus for the training procedures. Their responses to a second set of instructions were used to assess the generalized effects of training. The frequency of responses to both sets of instructions was evaluated during Baseline 1, Training 1, Baseline 2, and Training 2 periods. During the training periods, this evaluation was made after the daily training sessions when no training procedures were in effect. Results indicated that the subjects showed pronounced increases in instruction-following behaviors (both trained and untrained) during training periods with decreases in such behavior occurring during the Baseline 2 period. The general findings demonstrate the applicability of the training procedures for producing and maintaining instruction-following behaviors in severely retarded children and for facilitating appropriate responding to instructions not directly involved in training.