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Biomedical subjects

K Pezdek

Publications and source records attributed to K Pezdek.

14 recordsLinked to original sources
PubMed2001

The effect of exposure to multiple lineups on face identification accuracy.

This study examines the conditions under which an intervening lineup affects identification accuracy on a subsequent lineup. One hundred and sixty adults observed a photograph of one target individual for 60 s. One week later, they viewed an intervening target-absent lineup and were asked to identify the target individual. Two days later, participants were shown one of three 6-person lineups that included a different photograph of the target face (present or absent), a foil face from the intervening lineup (present or absent), plus additional foil faces. The hit rate was higher when the foil face from the intervening lineup was absent from the test lineup and the false alarm rate was greater when the target face was absent from the test lineup. The results suggest that simply being exposed to an innocent suspect in an intervening lineup, whether that innocent suspect is identified by the witness or not, increases the probability of misidentifying the innocent suspect and decreases the probability of correctly identifying the true perpetrator in a subsequent test lineup. The implications of these findings both for police lineup procedures and for the interpretation of lineup results in the courtroom are discussed.

Adolescent↗
PubMed2001

Imagination inflation: a statistical artifact of regression toward the mean.

In the imagination inflation procedure of Garry, Manning, Loftus, and Sherman (1996), subjects rated a list of events in terms of how likely each was to have occurred in their childhood. Two weeks later, some of the events were imagined; control events were not. The subjects then rated the likelihood of occurrence for each event a second time. Garry et al. (1996) reported that the act of imagining the target events led to increased ratings of likelihood. This finding has been interpreted as indicating that false events can be suggestively planted in memory by simply having people imagine them. The present study tests and confirms the hypothesis that the results that have been attributed to imagination inflation are simply a statistical artifact of regression toward the mean. The experiment of Garry et al. (1996) was reproduced (with some procedural changes), using younger and older adults. The results of Garry et al. (1996) were replicated; likelihood ratings for events initially rated low in likelihood did increase from Time 1 to Time 2. However, ratings for events initially rated high in likelihood decreased under the same conditions, and these results were consistent with the imagined target events, the target events not imagined, and the nontarget events.

Adolescent↗
PubMed1999

The effect of the cognitive interview on face identification accuracy: release from verbal overshadowing.

Three experiments tested the effect of verbal description on face identification accuracy. Based on verbal overshadowing research, it was predicted that enhancing verbal description of a face would reduce subsequent face identification accuracy. Experiment 1 tested and confirmed this hypothesis using the cognitive interview to enhance verbal description; face identification accuracy was reduced significantly following the cognitive interview, compared with a standard police interview. Experiments 2 and 3 tested and confirmed the hypothesis that verbal overshadowing would be reduced when a delay is inserted between verbal description and face identification, hence resulting in "release from verbal overshadowing." These results suggest that in the verbal overshadowing task, the verbal description does not overwrite the visually based representation of the face in memory but rather makes it less accessible at the time of face identification. The cognitive interview reduces face identification accuracy only when the identification follows description immediately--a rare situation in real criminal cases.

Adult↗
PubMed1997

The suggestibility of children's memory for being touched: planting, erasing, and changing memories.

Investigates recent claims that it is relatively easy to suggestively plant false memories in children, by comparing the relative vulnerability to suggestibility of changed, planted, and erased memories. 80 4-year-olds and 80 10-year-olds either were touched in a specific way or were not touched at all, and it was later suggested that a different touch, a completely new touch, or no touch at all had occurred. The suggestibility effect occurred only in the changed memory condition; the difference between the experimental changed condition and the corresponding control condition was significant. In the planted and erased memory conditions no suggestibility effect occurred; there was no significant reduction in the experimental groups relative to the corresponding control conditions. Thus, although it is relatively easy to suggest to a child a change in an event that was experienced, it is less likely that an event can be planted in or erased from memory. It is thus inappropriate to provide courtroom testimony regarding the probability of suggestively planting false memories based on the classic suggestibility research, which has largely been restricted to the study of suggestively changing memories.

Child↗
PubMed1988

Picture memory: recognizing added and deleted details.

When people are presented simple and complex pictures and then tested in a same-changed recognition test with a simple or complex form of each, d' is greater for the simple than the complex picture (Pezdek & Chen, 1982). The results of three experiments confirm the robustness of this "asymmetric confusability effect" and test a model of the processes underlying this effect. According to the model, pictures are schematically encoded such that the memory representation of both simple and complex pictures is similar to the simple form of each. In Experiment 1, a sentence was presented that described the central schema in the picture prior to subjects' viewing each picture. This manipulation exaggerated the asymmetric confusability effect; schematic processing thus underlies the effect. Results of Experiment 2 refute the hypothesis that the effect results from subjects erroneously anticipating a recall test rather than a recognition test. Furthermore, although some of the nonschematic elaborative information in complex pictures is stored in memory, it is difficult to retrieve to verify that something is missing when complex presentation pictures are changed to simple test pictures (Experiment 3). Thus, although people are able to distinguish large sets of old pictures from new distractor pictures, their ability to detect missing elaborative visual details is more limited.

Attention↗
PubMed1987

Memory for pictures: a life-span study of the role of visual detail.

This experiment assessed the effect of the amount of physical detail in pictures on picture recognition memory for 7-year-olds, 9-year-olds, young adults, and older adults over 68. Subjects were presented simple and complex line drawings, factorially combined in a "same-different" recognition test with simple or complex forms of each. For each age group, recognition accuracy was significantly higher for pictures presented in the simple than in the complex form. This effect was due to differences between simple and complex pictures in the correct rejection rate but not the hit rate; subjects were less accurate detecting deletions from changed complex pictures than additions to changed simple pictures. The older adults were no better than chance at correctly rejecting changed complex pictures. Although increasing the presentation duration from 5 sec to 15 sec increased overall accuracy, it did not increase subjects' ability to correctly reject changed complex pictures. Results are interpreted in terms of schematic encoding and storage of pictures. Accordingly, visual information that communicates the central schema of each picture is more likely to be encoded and retained in memory than information that does not communicate this schema.

Adolescent↗
PubMed1983

Children's television viewing: attention and comprehension of auditory versus visual information.

This study examines the relationship between children's attention and comprehension of auditory and visual information on television. 60 5-year-olds viewed a videotape of "Sesame Street" and were then asked comprehension questions. Equal numbers of children viewed the television with (a) toys available to play with (the visual attention manipulation); (b) a record playing in the room (the auditory attention manipulation); or (c) no toys or record available (the control condition). All children viewed the same television sequence, which consisted of (a) visual segments, (b) auditory segments, and (c) mixed modality segments. The major results were that the children effectively distributed their attention such that they could process auditory and visual information from television while performing other activities. Further, the children were sensitive to which segments required visual attention and which did not, and they were able to spontaneously adjust their pattern of visual attention appropriately. These results indicate that children utilize a fairly sophisticated cognitive processing strategy while watching television.

Attention↗
PubMed1980

Cognitive mapping: knowledge of real-world distance and location information.

A series of experiments investigated how information about geographic environments is processed. In the first experiment, response time to decide which of two pairs of states or buildings were physically closer in the real world increased as the ratio of the interpair distances approached one. The second experiment examined spatial memory for the interrelationships among states and buildings. Subjects' reaction time to determine the accuracy of relative spatial positions of triads of states was a linear function of the degree of triad rotation from the 0 degrees Cartesian plane of a standard U.S. map. No linear rotation function was reported for triad rotations of buildings. In Experiment 3 a group of subjects unfamiliar with the campus tested in Experiments 1 and 2 learned the location of the buildings from a map only. This group's data reflected a linear trend of reaction time with degree of building triad rotation, similar to results with states in Experiment 2. Perhaps when an environment is primarily learned by a map, knowledge of the interpositions of items in the environment is formed in the single perspective of the map. When the environment is primarily learned through direct experience, knowledge of interpositions of items is more flexible and is processed from many perspectives.

Cognition↗
PubMed1980

Life-span differences in semantic integration of pictures and sentences in memory.

This study examined life-span developmental differences in spontaneous integration of semantically relevant material presented in pictures and sentences. 45 third graders, 45 sixth graders, 45 high school students, and 30 adults over 60 were presented a sequence of 24 pictures and sentences, followed by 24 intervening items. Each intervening item corresponded to, but was in the opposite modality from, one of the original items and was either semantically relevant or irrelevant to the corresponding original. In a "same-different" recognition test, data suggested that the sixth-grade and high school subjects semantically integrated original items with relevant intervening items that were in the opposite modality and made subsequent recognition responses on the basis of the integrated memory. Third graders and older adults, however, showed no evidence of spontaneous, cross-modality semantic integration. Further, increasing the temporal delay between presenting the to-be-integrated items, from 5 min to 1 day, decreased overall response sensitivity but did not alter the patterns of integration results. The findings are discussed in terms of age differences in the spontaneous use of strategies for effective memory processing, with the extreme age groups processing more formal characteristics of the stimuli in memory, and the middle 2 groups processing deeper, more semantic information.

Adolescent↗
PubMed1979

Visual and verbal memory for objects and their spatial locations.

Four experiments assessed the role of verbal and visual processing in memory for aspects of a simulated, real-world spatial display. Subjects viewed a three-dimensional model of a city with 16 bulidings that were placed on the display. The buildings were represented on the model with or without an accompanying name label on each buliding. After studying the display, subjects were tested on recall and recognition of the building names, picture recognition of the buildings, and spatial memory for where the bulidings had been located. Overall picture recognition accuracy was low, and the presence of a name label on each building significantly reduced picture recognition accuracy but improved relocation accuracy. Spatial location information was not encoded independently of verbal and visual identity information. However, location information was more accurately retained with memory for verbal than visual aspects of the stimuli. The results are discussed in terms of the theoretical importance of differentiating memory for the identity of visual stimuli from descriptive memory for their physical characteristics in "visual memory" research.

Discrimination, Psychological↗