Multidimensional scaling of pictorial informativeness.

The dimensions used in the judgment of the informativeness of picture sections were investigated by means of a recently proposed methodology, multidimensional similarity analysis. 10 judges (college students) rated the informational similarity of 32 areas within a single picture. The five extracted dimensions accounted for 86% of the judgmental variance and were all readily interpretable. These dimensions were discussed with respect to an earlier study in which eye movements of subjects viewing this picture were recorded.     

Size scaling in visual pattern recognition

Human visual recognition on the basis of shape but regardless of size was investigated by reaction time methods. For successive matching of random figures, reaction time increased linearly with the linear size ratio of stimulus pairs. For single-character classification, reaction time increased with divergence between cued size format and stimulus format such that for character nonrepetitions, the increment in latency was approximately proportional to the logarithm of the linear size ratio of the two formats. However, when reactions to character repetitions were faster than those to nonrepetitions, the repetition reaction time function was similar to that for successive matching of random figures. The results suggested two processes of size scaling: mental-image transformation and perceptual-scale transformation. Image transformation accounted for matching performance based on visual short-term memory, whereas scale transformation accounted for size invariance in recognition based on comparison against visual representations in long-term memory.     

Memory for spatial location in two-dimensional arrays

Memory for spatial location in a two-dimensional display was studied in two experiments by means of a recognition task. The first experiment investigated the effects of presenting multiple reference points at the same time as sequentially shown to-be-remembered (TBR) locations. In the second experiment, the TBR locations were presented either one by one or four at a time with and without multiple reference points. The reference points tended to decrease the false alarm rate during acquisition, rather than to increase the hit rate, which suggests that they affected the precision rather than the amount of systematic bias in memory for the locations. Similar effects were obtained when the TBR locations were presented four at a time. The reference points were also found to serve as effective retrieval cues in a final recognition test. Reference points may thus facilitate both acquisition and retrieval of information about spatial location.     

Size scaling and its effect on letter detection

Two ways of scaling letter size across eccentricity were investigated in a choice reaction time (CRT) task. Experiments 1 and 2 tested cortical magnification theory (M-scaling), while Experiment 3 used scaled sizes drawn from Anstis’s regression formula (A-scaling). Experiment 4 compared both scaling techniques, together with the effect of exposure duration and the absolute size of the foveal letter. Results showed that scaling effectiveness improved when large rather than small foveal letters were used. A-scaling with a large foveal letter provided a good fit for the data at parafoveal locations, but underestimated the letter sizes needed at large eccentricities. M-scaling with a large foveal letter size produced CRTs that were independent of eccentricity. Exposure duration did not substantially affect performance.     

Correspondence in pictorial space

ATR Human Information Processing Research Laboratories, Kyoto, Japan We have investigated psychophysically determined image correspondences between pairs of photographs of a single three-dimensional (3-D) object in various poses. These correspondences were obtained by presenting the pictures simultaneously, side by side, and letting the subject match a marker in one picture with a marker (under manual control) in the other picture. Between poses, the object was rotated about a fixed vertical axis; thus, the shifts of the veridical correspondences (with respect to the surface of the object) were very nearly horizontal. In fact, the subjects produced appreciable scatter in both horizontal and vertical directions. The scatter in repeated sessions and between data depends on the local (landmarks) and global (interpolation) structure of the pictures. Since the object was fairly smooth (white semigloss finish) and nontextured, the only way to establish the correspondence is by way of the “pictorial relief.” The relief is some largely unknown function of the image structure and the observer. Apparently, more immediate entities (e.g., the shading or the contour) cannot be used as such, since they vary with the pose. We compare these data with results obtained with a surface attitude probe on a single picture. We studied various measures of consistency both within a single method and between methods. We found that subjects were confident in establishing correspondences, but results scattered appreciably in a way that depended on both global and local image structure. Correspondence results for various pose angles were mutually very consistent, but only to a minor extent with results of attitude measurements. The main finding was that subjects could establish correspondence on the basis of their 3-D interpretation (pictorial relief), even if the 2-D graytone distributions are quite different.     

Ambiguity in pictorial depth

Pictorial space is the 3-D impression that one obtains when looking 'into' a 2-D picture. One is aware of 3-D 'opaque' objects. 'Pictorial reliefs' are the surfaces of such pictorial objects in 'pictorial space'. Photographs (or any pictures) do in no way fully specify physical scenes. Rather, any photograph is compatible with an infinite number of possible scenes that may be called 'metameric scenes'. If pictorial relief is one of these metameric scenes, the response may be considered 'veridical'. The conventional usage is more restrictive and is indeed inconsistent. Thus the observer has much freedom in arriving at such a 'veridical' response. To address this ambiguity, we determined the pictorial reliefs for eight observers, six pictures, and two psychophysical methods. We used 'methods of cross-sections' to operationalise pictorial reliefs. We find that linear regression of the depths of relief at corresponding locations in the picture for different observers often lead to very low (even insignificant) R2s. Thus the responses are idiosyncratic to a large degree. Perhaps surprisingly, we also observed that multiple regression of depth and picture coordinates at corresponding locations often lead to very high R2s. Often R2s increased from insignificant up to almost 1. Apparently, to a large extent 'depth' is irrelevant as a psychophysical variable, in the sense that it does not uniquely account for the relation of the response to the pictorial structure. This clearly runs counter to the bulk of the literature on pictorial 'depth perception'. The invariant core of interindividual perception proves to be of an 'affine' rather than a Euclidean nature; that is to say, 'pictorial space' is not simply the picture plane augmented with a depth dimension.     

Interference in memory for pictorial information

Subjects studied either faces composed from visual features or verbal facts composed from concepts. Recognition times were increased for both faces and facts when they were composed of elements that occurred in multiple study items. In Experiment 1 the interfering effect of other study items was much larger for verbal facts than for faces. This difference was largely eliminated in Experiment 2 where care was taken to control the features by which the faces were encoded. Experiment 2 also showed that verbal information could interfere with pictorial information and vice versa. However, this cross-modality interference was much weaker than within-modality interference. The data are consistent with the ACT theory in which pictorial material and verbal material are stored together in an abstract propositional network. The subnode model (Anderson, Language, memory, and thought, Hillsdale, N. J.: Lawrence Erlbaum, 1976) can account for the greater within- than cross-modality interference.     

Recognition memoryfor pictorial events

Subjects viewed sequences of slides depicting everyday events, and in later recognition tests, they correctly rejected distractors that were inconsistent with some invariant of the event but falsely accepted consistent distractors. J. J. Jenkins has accounted for the differential recognition of consistent and inconsistent slides of pictorial sequences in terms of fusion, the abstraction of an event from a series of temporally related items. The conditions under which event fusion was likely to occur were manipulated in three experiments: degree of ordering of the action-sequence slides, semantic vs. nonsemantic orienting tasks during acquisition, and duration of retention interval Recognition performance was generally more accurate under conditions of semantic processing, ordered acquisition sequences (for the semantic task), and shorter retention intervals. However, these variables did not affect differential recognition of consistent vs. inconsistent slides. A further experiment showed that the absence of an effect of disordering acquisition sequences on differential recognition could not be attributed to subjects’ reordering the disordered sequences in a way consistent with the original event. The data did not support the hypothesis that recognition performance was based on fusion of events depicted by temporally ordered slide sequences. It was suggested that memory for featural detail is a relevant factor in performance.     

Common and specific features in pictorial analogies

Pictures belonging to different domains (cups and persons), as well as pictures belonging to the same domains (cups or persons only), were used to construct analogies of various paradigms. Pictures from different domains shared three common features, while pictures within each domain had two features specific to that domain. When no specific feature change was introduced, an asymmetry of the paradigms IA cup is to B cup as R person is to S person and P person is to Q person as C cup is to D cup) was obtained as an extension of the theory of metaphoricity (Ortony, 1979) predicted. When specific feature changes were introduced, however, the obtained results were not as the extended theory would predict. An alternative model that emphasizes the function of a set of reference feature changes in extraction and comparison of the feature changes that may exist in the first and second terms was proposed to account for the experimental findings.     

Generation of a pictorial code

In Experiments I and II direct measures were obtained of the time required to convert a picture or a sentence to a report of visualization or to a simple drawing, latencies were faster for pictures than for sentences and were affected by the surface form of the sentence. In Experiment Ill, Ss matched pictures or sentences against a test picture under conditions of simultaneous or successive presentation. “Yes” and “No” response times were affected by sentence form under both conditions, although the difference between sentence-picture and picture-picture comparisons was virtually eliminated under the successive condition. In Experiment IV, Ss held a sentence or picture in memory over a 1,500-msec interval at the end of which a test picture or an instruction to draw the design was presented. Construction latencies were shorter in response to pictures than sentences, and there were effects of sentence form on verification time. Some implications of these results are discussed.     

Viewing direction and pictorial representation

During prolonged monocular observation from afar, an upright wire cube (Necker cube) or a drawing of such a cube inverts continuously so that the lower of the two frontal faces appears to be either in front (version A) or in back (version B). Version A is perceived as if it were viewed obliquely from above and version B as if seen from below. In our experiments, timing the durations of the versions showed that version A lasted longer than version B. When a wire cube was shifted upward so that it was actually viewed slightly from below, version B lasted longer than version A. The actual viewing direction was apparently taken into account by the subjects, which was not the case when the cube was replaced by a drawing showing the projection of the cube. In that case, version A always lasted longer, regardless of the actual viewing direction. This finding conforms with picture viewing in general, where a three-dimensional object’s orientation does not change when the observer’s viewing direction changes.     

The origins of pictorial competence

Pictorial competence , which refers to the many factors involved in perceiving, interpreting, understanding, and using pictures, develops gradually over the first few years of life. Although experience is not required for accurate perception of pictures, it is necessary for understanding the nature of pictures. Infants initially respond to depicted objects as if they were real objects, and toddlers are remarkably insensitive to picture orientation. Only gradually do young children figure out the nature of pictures and how they are used.     

Mental imagery and pictorial memory

Previous research has failed to show consistent effects upon memory performance of individual differences in the use of mental imagery. A test of pictorial memory was devised which varied the ease with which the stimulus patterns could be verbally encoded. A factor analysis related performance in this task to a variety of other individual characteristics. The recall of material which could not be readily verbalized defined a factor within the solution which showed significant loadings of age and performance in the Progressive Matrices, but not of subjective ratings of the vividness of experienced imagery. The recall of material which could be readily verbalized did not contribute to the factorial structure of the results. It was concluded that the two sorts of pictorial material are remembered in quite different ways.