Biomedical subjects

H Intraub

Publications and source records attributed to H Intraub.

12 recordsLinked to original sources

PubMed1999

Wide-angle memories of close-up scenes: a demonstration of boundary extension.

Boundary extension refers to a tendency to remember seeing a greater expanse of a scene than was shown in a photograph. It is hypothesized that the view shown in the stimulus activates expectations about the scene's layout just outside the picture's borders. Following presentation, the viewer remembers having seen this expected information, and this yields boundary extension. We provide photographs and instructions for conducting two brief demonstrations of the phenomenon and provide materials for a related class experiment on the journal's World-Wide Web site. These demonstrations of boundary extension provide graphic illustrations of the role of schematic expectancies in the representation of scenes and help to illustrate the role of real-world knowledge in cognition.

Education, Medical↗

PubMed1998

Effects of perceiving and imagining scenes on memory for pictures.

Boundary extension is the tendency to remember having seen a greater expanse of a scene than was shown. Four experiments tested whether a picture must depict a partial view of a scene for the distortion to occur. The premise was that partial views activate a perceptual schema, a representation of the expected scene structure outside the view. Participants were 473 undergraduates. Experiments 1 and 2 tested recognition memory and recall of 16 outline-objects presented in outline-scenes versus presentation on blank backgrounds. Experiments 3 and 4 compared memory for outline-objects when scene context was or was not imagined. Boundary errors consistent with the perceptual schema hypothesis only occurred for partial views (perceived or imagined). Results suggest that scene perception and imagination activate the same schematic representation.

Female↗

PubMed1997

Vertical biases in scene memory.

In a recent theoretical paper (Behavioral and Brain Sciences, 1990, 13, 519-542), Previc argued that vertical asymmetries in perception may largely result from the biases of the lower and upper visual fields toward proximal and distal space, respectively. The present study examined whether this same relationship may exist for visual scene memory, by re-analyzing data from Intraub and Richardson (Journal of Experimental Psychology: Learning, Memory, and Cognition, 1989, 15, 179-187). In that study, subjects remembered photographs of scenes as being farther away than was actually the case and extended the boundaries of the scenes accordingly; in some cases, the remembered scenes were also shifted vertically. This study formally examined whether prominent landmarks in Intraub and Richardson's close-up and wide-angle photographs were displaced vertically in subjects' reproductions of them from memory. A total of 475 measurements in 210 drawings by 41 subjects were made. The results were that 64% of the original landmark points were shifted downward in the drawings made from memory, whereas only 36% were shifted upward. Although most of the original points were located in the upper-field and would have been expected to be shifted downward as the original image contracted in memory, a chi-square analysis showed that more upper-field points were shifted downward than were lower-field points shifted upward in the remembered scenes. The downward shift could reflect an expansion of the upper-field in memory, consistent with the scene being placed farther away, or it could reflect an elevation of the assumed viewing (head) position in memory.

Adult↗

PubMed1993

Boundary extension: fundamental aspect of pictorial representation or encoding artifact?

Viewers remember seeing more of a scene than was actually depicted in a photograph, a phenomenon called boundary extension (H. Intraub & M. Richardson, 1989). We tested whether prior warning would eliminate this distortion, by having 81 Ss view 12 photographs of simple scenes for 15 s each after receiving 1 of 3 encoding instructions. All subjects were told to remember each picture in detail. Control Ss received no additional information. Test-informed Ss received prior warning about the type of tests. Demo Ss experienced a demonstration of the phenomenon and were instructed to guard against it. After presentation, a drawing task and a boundary recognition test were administered. Prior warning sometimes reduced, but never eliminated, boundary extension. We suggest the phenomenon reflects activation of scene expectations during perception.

Female↗

PubMed1992

Looking at pictures but remembering scenes.

Ss tend to remember close-up photographs as having had extended boundaries (Intraub & Richardson, 1989). Three alternate explanations were tested: object completion, distortion toward a perceptual schema, and normalization toward a prototypic view. In three experiments, 55-130 undergraduates viewed 16 close-up, prototypic, or wide-angle views of objects for 15 s each. Immediately or 48 hr later, they rated test pictures on a 5-point scale as "same", "closer up", or "father away." Results ruled out object completion because boundary extension occurred when the picture contained no incomplete objects. Immediate tests supported the perceptual schema hypothesis because all unidirectional distortions involved boundary extension. Delayed tests were more suggestive of a memory schema effect because wide-angle pictures yielded boundary restriction. A two-component model of picture processing is proposed.

Adult↗

PubMed1992

Reading and visual memory: remembering scenes that were never seen.

In Experiment 1 (N = 16), under conditions of high memory load (60 pictures and 50 paragraphs) and a 1-week retention interval, undergraduate subjects reported their memory for photographs of scenes (cued recall and free-recall tasks). Subjects frequently reported memory for photographs that they had actually never seen, but had read about in a brief paragraph. In Experiment 2 (N = 40), the same pattern of results was obtained with immediate testing. Experiment 2 also demonstrated that the likelihood of subjects falsely attributing scene memory (based on reading) to actually having viewed a photograph was reduced when metacognitive awareness of imaging during reading was made salient. Awareness of image creation was induced by requiring subjects to rate the paragraphs with respect to imagery vividness. Although other measures of memory remained the same, subjects in the induced-imagery condition made 50% fewer confusion errors than subjects who read the paragraphs without imagery instructions. The results are discussed in the context of Johnson and Raye's (1981) reality monitoring model.

Adult↗

PubMed1989

Illusory conjunctions of forms, objects, and scenes during rapid serial visual search.

"Temporal migration" describes a situation in which subjects viewing rapidly presented stimuli (e.g., 9-20 items/s) confidently report a target element as having been presented in the same display as a previous or following stimulus in the sequence. Four experiments tested a short-term buffer model of this phenomenon. Experiments 1 and 4 tested the hypothesis that subjects' errors are due to the demands of the verbal report procedure rather than to perceptual integration. In Experiment 1, 12 color objects were presented at a rate of 9/s. Prior to each sequence, an object was named and subjects responded "yes" or "no" to indicate whether the target element (a black frame) occurred with that object. Consistent with the perceptual hypothesis, the yes/no procedure yielded the same results as the verbal report procedure. Experiment 2 tested the hypothesis that the direction of migration depends on "frame" detection time. Results showed that reaction time to frame detection was significantly faster in trials in which subjects reported the frame on a preceding rather than a following picture. Experiments 3 and 4 used the standard naming procedure and the yes/no procedure to test temporal migration using more complex, interrelated stimuli (objects and scenes). Implications for the use of the temporal migration effect to study visual integration within eye fixations are discussed.

Attention↗

PubMed1989

Wide-angle memories of close-up scenes.

We report a picture-memory phenomenon in which subjects' recall and recognition of photographed scenes reveal a pronounced extension of the pictures' boundaries. After viewing 20 pictures for 15 s each, 37 undergraduates exhibited this striking distortion; 95% of their drawings included information that had not been physically present but that would have been likely to have existed just outside the camera's field of view (Experiment 1). To determine if boundary extension is limited to recall and drawing ability, Experiment 2 tested recognition memory for boundaries. Eighty-five undergraduates rated targets and distractors on a boundary-placement scale. Subjects rated target pictures as being closer up than before and frequently mistook extended-boundary distractors as targets. Results are discussed in terms of picture comprehension and memory. In addition to its theoretical value, discovery of the phenomenon demonstrates the importance of more widespread use of open-ended tests in picture-memory methodology.

Adult↗

PubMed1985

Visual dissociation: an illusory conjunction of pictures and forms.

Undergraduates viewed rapidly presented series of color photographs (9/s) and were required to indicate which photograph appeared within a black outline rectangle (the "frame"). Experiment 1 demonstrated that subjects were often confident and wrong, reporting the immediately preceding or following picture in the sequence. Experiment 2 showed that migration of the frame to other pictures cannot be attributed to spatial separation, because the same effect occurred when a small frame was presented in the center of the picture itself. Experiment 3 ruled out masking of the "framed" picture as the cause of the illusion by showing that the framed picture is indeed identified on those trials where the frame appears to be elsewhere. Experiment 4 showed that when simpler, more familiar stimuli (numbers) were presented, a more rapid presentation rate (18/s) was required to obtain the effect. It is proposed that the illusion reflects the action of integrative processes in a very short-term buffer and that it may provide a new tool with which to study the integration of features within scenes.

Adolescent↗

PubMed1985

Levels of processing and picture memory: the physical superiority effect.

Six experiments studied the effect of physical orienting questions (e.g., "Is this angular?") and semantic orienting questions (e.g., "Is this edible?") on memory for unrelated pictures at stimulus durations ranging from 125-2,000 ms. Results ran contrary to the semantic superiority "rule of thumb," which is based primarily on verbal memory experiments. Physical questions were associated with better free recall and cued recall of a diverse set of visual scenes (Experiments 1, 2, and 4). This occurred both when general and highly specific semantic questions were used (Experiments 1 and 2). Similar results were obtained when more simplistic visual stimuli--photographs of single objects--were used (Experiments 5 and 6). As in the case of the semantic superiority effect with words, the physical superiority effect for pictures was eliminated or reversed when the same physical questions were repeated throughout the session (Experiments 4 and 6). Conflicts with results of previous levels of processing experiments with words and nonverbal stimuli (e.g., faces) are explained in terms of the sensory-semantic model (Nelson, Reed, & McEvoy, 1977). Implications for picture memory research and the levels of processing viewpoint are discussed.

Attention↗

PubMed1984

Conceptual masking: the effects of subsequent visual events on memory for pictures.

Three experiments studied the effects of voluntary and involuntary focus of attention on recognition memory for pictures. Experiments 1 and 3 tested the conceptual-masking hypothesis, which holds that a visual event will automatically disrupt processing of a previously glimpsed picture if that event is new and meaningful. Memory for 112-ms pictures was tested under conditions where the to-be-ignored 1.5-s interstimulus interval contained a blank field; a repeating picture; a new picture; a new, nonsense picture; or a new, inverted picture each time. The blank field, repeating picture, and new, nonsense picture did not disrupt memory as much as a new, meaningful picture, supporting the conceptual-masking hypothesis. Experiment 2 studied voluntary attentional control of encoding by instructing subjects to focus attention on the brief pictures, all pictures, or the long pictures in a sequence. Recognition memory for pictures of both durations showed a striking ability of observers to process pictures selectively. The possible role of these effects in visual scanning are discussed.

Adult↗

PubMed1980

Presentation rate and the representation of briefly glimpsed pictures in memory.

Four experiments on memory for briefly presented complex pictures showed the following: (a) Pictures shown in a sequence for 110 msec each with a blank 5,890-msec interstimulus interval (ISI) were later recognized almost as well as pictures shown for 6 sec each with no ISI; (b) when the ISI was deleted, recognition memory for the briefly presented pictures dropped almost to chance; (c) however, filling a 5-sec ISI with a to-be-ignored picture that was the same on all trials had little or no effect on memory for the briefly presented pictures; (d) when the time between 110-msec pictures was decreased from 4,890 to 1,390, 620, 385, or 0 msec, the ability to detect that they were mirror reversed in the recognition test decreased more rapidly than did recognition accuracy. Evidently, incidental visuospatial properties of a picture can be encoded for at least 1 sec after a brief presentation unless another to-be-remembered picture is presented during that time.

Attention↗