Integration of visuospatial information encoded from different viewpoints

Two experiments investigated whether separate sets of objects viewed in the same environment but from different views were encoded as a single integrated representation or maintained as distinct representations. Participants viewed two circular layouts of objects that were placed around them in a round (Experiment 1) or a square (Experiment 2) room and were later tested on perspective-taking trials requiring retrieval of either one layout (within-layout trials) or both layouts (between-layout trials). Results from Experiment 1 indicated that participants did not integrate the two layouts into a single representation. Imagined perspective taking was more efficient on within- than on between-layout trials. Furthermore, performance for within-layout trials was best from the perspective that each layout was studied. Results from Experiment 2 indicated that the stable environmental reference frame provided by the square room caused many, but not all, participants to integrate all locations within a common representation. Participants who integrated performed equally well for within-layout and between-layout judgments and also represented both layouts using a common reference frame. Overall, these findings highlight the flexibility of organizing information in spatial memory.     

Effects of noise similarity and redundancy on the information processed from brief visual displays

When a target letter form is presented tachistoscopicalfy and embedded in a matrix of irrelevant letter forms (noise), correct detections of the target at a given matrix size can be used to estimate indirectly the amount of information processed from the display, according to a model developed by Estes. In three experiments, the physical similarity between noise and target letters and noise-letter redundancy were varied to determine if the detection mechanism was responsive to these variables. It was found that increases in the physical differences between noise and target letters and increases in redundancy facilitated detection. It is argued that these data support a detection model that assumes parallel rather than serial information processing.     

Processing of information about location in brief visual displays

Within the context of the selective masking effect (Merikle, Coltheart, & Lowe, 1971), a series of five experiments investigated the utility of bar-marker probes as a poststimulus sampling procedure for partial report of brief visual displays. It was demonstrated that bar markers are inadequate as partial-report cues because subjects cannot properly locate the positions of the probes. An improved bar-marker procedure was developed which removed this problem of cue localization. Furthermore, it was shown that subjects, when given the opportunity, are able to report much more from brief visual displays than the bar-marker procedure typically permits. It was also suggested that subjects’ ability to employ bar-marker probes is governed by quite different factors than their capacity to report the contents of brief visual displays.     

Retrieval of information from multiple ensembles in short-term memory

A recognition memory experiment investigated Ss’ ability to organize information in short-term memory. A paradigm similar to that used by Sternberg was employed. A sequentially presented series of six digits (positive set) was shown with each digit appearing on a red, green, or amber background. The colors defined different ensembles, and responding to a test digit was contingent upon an item’s membership in the positive set and the color-defined ensemble. Reaction time (RT) to the test digits indicated that Ss did organize information into ensembles. Furthermore, when informative cues were presented prior to the test item, Ss directed and confined their search to the cued subset.     

Information search and decision making: The effects of information displays

Information display boards may be used to test assumptions about underlying cognitive processes in decision situations. However, the question may be raised whether information processing in a complex decision situation is indepemdent of the structure of the information display board used. In a study employing 96 subjects, the design of the information display board, the number of alternatives, and the number of attributes were varied. Twelve groups of eight subjects were presented with one hypothetical choice among riskless multiattribute decision alternatives (apartments). Results showed that information search patterns were not influenced by the design of the information display board, but that the relative number of attributes included in the decision process was. The number of available attributes appeared to be the strongest determinant of information search patterns. A higher number of attributes induced information search patterns consistent with the noncompensatory conjunctive decision rule. It is suggested that the decision situation employed, which forced the decision maker to remember each piece of information acquired, underlies the difference between the results in the present study and previous findings.     

Integration of information in visual search

Two experiments studied how information about the nontarget items in a visual search task is used for the control of the search. The first experiment used the detection of “hurdle” stimuli to demonstrate that efficient memory representations of the context items can be established within each particular trial. This finding is explained by a model for the short-term integration of context information. The second experiment which varied the complexity of the local but not the global context provided some information about the nature of the integration operations involved. In its final version the model postulates two stages of processing with independent mechanisms of integration. Spatial integration at the first stage deletes repetitions within small samples. Temporal integration at the second stage stores and primes the memory representations of the context items over larger intervals. It is assumed that transient temporal integration within trials is mediated by the same mechanism that underlies permanent temporal integration between trials.     

Integration of multiple views of scenes

In two experiments, memory was tested for changes in viewpoints in naturalistic scenes. In the key study condition, participants viewed two images of the same scene from viewpoints 40° apart. There were two other study conditions: The two study images were identical or were of different scenes. A test image followed immediately, and participants judged whether it was identical to either of the study images. The scene in the test image was always the same as in a study image and was at least 20° from any study image on different trials. Two models were tested: (1) views stored and retrieved independently and (2) views combined at retrieval. The crucial test of these hypotheses involved a comparison (in the key study condition) of the interpolation condition (the test image was presented between the two study images and 20° from both) and the extrapolation condition (it was 20° from one study image and 60° from the other). Performance in the interpolation condition was far worse than what was predicted by the first model, whereas the second model fit the data quite well. The latter model is parsimonious in that it integrates previous experiences without requiring the integration of the views in memory. We review some of this model’s broader implications.     

The perception of surface orientation from multiple sources of optical information

An orientation matching task was used to evaluate observers’ sensitivity to local surface orientation at designated probe points on randomly shaped 3-D objects that were optically defined by texture, lambertian shading, or specular highlights. These surfaces could be stationary or in motion, and they could be viewed either monocularly or stereoscopically, in all possible combinations. It was found that the deformations of shading and/or highlights (either over time or between the two eyes’ views) produced levels of performance similar to those obtained for the optical deformations of textured surfaces. These findings suggest that the human visual system utilizes a much richer array of optical information to support its perception of shape than is typically appreciated.     

Distributed representation as a principle for the analysis of cockpit information displays

This article examines the representational properties of cockpit information displays from the perspective of distributed representations (Zhang & Norman, 1994). The basic idea is that the information needed for many tasks in a cockpit is distributed across the external information displays in the cockpit and the internal minds of the pilots. It is proposed that the relative distribution of internal and external information is the major factor of a display's representational efficiency. Several functionally equivalent but representationally different navigation displays are selected to illustrate how the principle of distributed representations is applied to the analysis of the representational efficiencies of cockpit information displays.     

Selective encoding from multielement visual displays

When a multiletter display is preceded by a bar designating one of the letters for report, reaction time (RT) to voice the indicated letter decreases. Previous research had indicated that the efficiency of this selective mechanism decreases as the number of display elements increases. Two experiments were conducted to determine whether the effect of display size could be eliminated when the indicator precedes the display at long intervals. Results indicated that the display size effect was maintained. The results could not be attributed to eye movements, but were interpreted in terms of a central encoding mechanism that is limited in its precision of localization and exclusion.     

Integration of visual information for saccade production

To foveate a visual target, subjects usually execute a primary hypometric saccade (S1) bringing the target in perifoveal vision, followed by a corrective saccade (S2) or by more than one S2. It is still debated to what extent these S2 are pre-programmed or dependent only on post-saccadic retinal error. To answer this question, we used a visually-triggered saccade task in which target position and target visibility were manipulated. In one-third of the trials, the target was slightly displaced at S1 onset (so-called double step paradigm) and was maintained until the end of S1, until the start of the first S2 or until the end of the trial. Experiments took place in two visual environments: in the dark and in a dimly lit room with a visible random square background. The results showed that S2 were less accurate for shortest target durations. The duration of post-saccadic visual integration thus appears as the main factor responsible for corrective saccade accuracy. We also found that the visual context modulates primary saccade accuracy, especially for the most hypometric subjects. These findings suggest that the saccadic system is sensitive to the visual properties of the environment and uses different strategies to maintain final gaze accuracy.     

Integration of perceptual information in word access

According to experiential theories of language comprehension, perceptual information plays an essential role when word meanings are accessed. We conducted four experiments to investigate how different types of perceptual information such as colour and shape are combined during word access. One possibility is that the colour and shape of a word's referent are activated independently from one another and are combined in an additive manner. Alternatively, words might activate perceptual representations via a multiplicative integration of colour and shape. Experiment 1 established that participants follow a multiplicative similarity rule when they judge the similarity of schematic pictures to actual fruits and vegetables. In Experiments 2 to 4, participants performed a classification task, a lexical decision task, or a word-naming task on names of fruits and vegetables that were superimposed on a background picture. Responses were facilitated only when both colour and shape of the picture matched the word's referents. Response times were associated negatively with mean similarity ratings and the consistency of these ratings obtained in the first experiment. These results suggest a multiplicative integration of different types of perceptual information during word access.     

On the communication of information by displays of standard errors and confidence intervals

A survey of practices regarding the presentation of information about reliability of means in psychological research publications over the last century reveals some advance in quality of communication, greater for tabular presentations than for graphic presentations, but also substantial room for improvement. In this article, problems of interpretation and communication associated with presentations of standard errors and confidence intervals in research reports are examined from both statistical and psychological perspectives. Four general principles of effective communication are proposed and illustrated in application to presentations of data from common psychological research designs, with special attention to problems arising in connection with repeated measures.     

Integration of spatial information across vision and language

Three experiments investigated whether spatial information acquired from vision and language is maintained in distinct spatial representations on the basis of the input modality. Participants studied a visual and a verbal layout of objects at different times from either the same (Experiments 1 and 2) or different learning perspectives (Experiment 3) and then carried out a series of pointing judgments involving objects from the same or different layouts. Results from Experiments 1 and 2 indicated that participants pointed equally fast on within- and between-layout trials; coupled with verbal reports from participants, this result suggests that they integrated all locations in a single spatial representation during encoding. However, when learning took place from different perspectives in Experiment 3, participants were faster to respond to within- than between-layout trials and indicated that they kept separate representations during learning. Results are compared to those from similar studies that involved layouts learned from perception only.     

Understanding intention from minimal displays of human activity

The impression of animacy from the motion of simple shapes typically relies on synthetically defined motion patterns resulting in pseudorepresentations of human movement. Thus, it is unclear how these synthetic motions relate to actual biological agents. To clarify this relationship, we introduce a novel approach that uses video processing to reduce full-video displays of human interactions to animacy displays, thus creating animate shapes whose motions are directly derived from human actions. Furthermore, this technique facilitates the comparison of interactions in animacy displays from different viewpoints-an area that has yet to be researched. We introduce two experiments in which animacy displays were created showing six dyadic interactions from two viewpoints, incorporating cues altering the quantity of the visual information available. With a six-alternative forced choice task, results indicate that animacy displays can be created via this naturalistic technique and reveal a previously unreported advantage for viewing intentional motion from an overhead viewpoint.     

Recognition of self-generated actions from kinematic displays of drawing

Five experiments addressed the question of whether individuals can distinguish between self-generated and other-generated actions when seeing their visual effects. Each experiment consisted of a recording session in which participants drew familiar and unfamiliar characters without receiving visual feedback and a recognition session in which they provided self-or-other judgments (SOJs) to indicate whether a kinematic display reproduced the visual effects of their own actions. The main results were that self-generated and other-generated drawing can be distinguished, that the familiarity of character shapes does not influence the accuracy of SOJs, and that velocity information is crucial for the identification of self-generated drawing. The ability to determine authorship from kinematic displays of drawing provides evidence for the contribution of action-planning structures to perception.