Memory for objects and parts

Performance on whole comparisons of two whole objects was compared to that for partial comparisons of a whole object and a part. In particular, same-different comparisons were measured for sequential displays of two-dimensional line figures. The comparisons were analogous to those in the word priority paradigm (Johnson, 1975). The whole comparisons were found to be more accurate and faster than the partial comparisons. This whole advantage was also found for accuracy using a two-alternative forced-choice procedure. This effect was found for brief displays of a single object and for longer duration displays of two objects. It was also found for three different sets of line figures. In contrast, the whole advantage was not found for unconnected figures. These findings were interpreted in the context of hierarchical representations of objects and parts.     

Memory for objects and parts

Performance on whole comparisons of two whole objects was compared to that for partial comparisons of a whole object and a part. In particular,same-different comparisons were measured for sequential displays of two-dimensional line figures. The comparisons were analogous to those in the word priority paradigm (Johnson, 1975). The whole comparisons were found to be more accurate and faster than the partial comparisons. This whole advantage was also found for accuracy using a two-alternative forced-choice procedure. This effect was found for brief displays of a single object and for longer duration displays of two objects. It was also found for three different sets of line figures. In contrast, the whole advantage was not found for unconnected figures. These findings were interpreted in the context of hierarchical representations of objects and parts.     

Infants’ recognition of objects using canonical color

We explored infants’ ability to recognize the canonical colors of daily objects, including two color-specific objects (human face and fruit) and a non-color-specific object (flower), by using a preferential looking technique. A total of 58 infants between 5 and 8 months of age were tested with a stimulus composed of two color pictures of an object placed side by side: a correctly colored picture (e.g., red strawberry) and an inappropriately colored picture (e.g., green-blue strawberry). The results showed that, overall, the 6- to 8-month-olds showed preference for the correctly colored pictures for color-specific objects, whereas they did not show preference for the correctly colored pictures for the non-color-specific object. The 5-month-olds showed no significant preference for the correctly colored pictures for all object conditions. These findings imply that the recognition of canonical color for objects emerges at 6 months of age.     

An unforgettable apple: Memory and attention for forbidden objects

Are we humans drawn to the forbidden? From jumbo-sized soft drinks to illicit substances, the influence of prohibited ownership on subsequent demand has made this question a pressing one. We know that objects that we ourselves own have a heightened psychological saliency, relative to comparable objects that are owned by others, but do these kinds of effects extend from self-owned to “forbidden” objects? To address this question, we developed a modified version of the Turk shopping paradigm in which “purchased” items were assigned to various recipients. Participants sorted everyday objects labeled as “self-owned”, “other-owned,” and either “forbidden to oneself” (Experiment 1) or “forbidden to everyone” (Experiment 2). Subsequent surprise recognition memory tests revealed that forbidden objects with high (Experiment 1) but not with low (Experiment 2) self-relevance were recognized as well as were self-owned objects, and better than other-owned objects. In a third and final experiment, we used event-related potentials (ERPs) to determine whether self-owned and self-forbidden objects, which showed a common memory advantage, are in fact treated the same at a neurocognitive–affective level. We found that both object types were associated with enhanced cognitive analysis, relative to other-owned objects, as measured by the P300 ERP component. However, we also found that self-forbidden objects uniquely triggered an enhanced response preceding the P300, in an ERP component (the N2) that is sensitive to more rapid, affect-related processing. Our findings thus suggest that, whereas self-forbidden objects share a common cognitive signature with self-owned objects, they are unique in being identified more quickly at a neurocognitive level.     

Recognizing objects seen from novel viewpoints: effects of view similarity and time

View combination refers to a process that allows generalization to novel views of an object by the combination of object views represented in memory. The present experiments examined whether the perceived similarity between views or the temporal separation of views poses constraints on the view combination process. The results indicated that, although similar views are mapped onto the same object more easily than dissimilar views, dissimilar views, when experienced contiguously in time, produce greater generalization after view combination than similar views. These findings suggest that although the mapping of dissimilar views to the same object is difficult, exposure to temporally contiguous dissimilar views produces better generalization than does exposure to similar views, presumably because they provide more structural information about the object. However, view combination appears to be constrained to views experienced contiguously in time.     

Memory for objects in real scenes: The development of recognition and recall

Subjects examined crowded semirealistic layouts of toy objects, or photographs of these layouts, and then tried to identify added, moved or deleted items. The main study, involving 1st-, 3rd, 6th-graders, and adults, showed that although successful recognition of added items was superior to both recall of deleted items and recognition of moved ones, all three scores improved with age. In addition, false reports of “new” items decreased markedly in the older groups. The results argue against the widely held view that recognition memory undergoes little or no developmental improvement. No significant difference between real layouts and photographs appeared either in the main experiment or in replications involving shorter exposure (Experiment 2) or retarded subjects (Experiment 3).     

Memory for curvature of objects: Haptic touch vs. vision

The present study examined the role of vision and haptics in memory for stimulus objects that vary along the dimension of curvature. Experiment 1 measured haptic‐haptic (T‐T) and haptic‐visual (T‐V) discrimination of curvature in a short‐term memory paradigm, using 30‐second retention intervals containing five different interpolated tasks. Results showed poorest performance when the interpolated tasks required spatial processing or movement, thereby suggesting that haptic information about shape is encoded in a spatial‐motor representation. Experiment 2 compared visual‐visual (V‐V) and visual‐haptic (V‐T) short‐term memory, again using 30‐second delay intervals. The results of the ANOVA failed to show a significant effect of intervening activity. Intra‐modal visual performance and cross‐modal performance were similar. Comparing the four modality conditions (inter‐modal V‐T, T‐V; intra‐modal V‐V, T‐T, by combining the data of Experiments 1 and 2), in a global analysis, showed a reliable interaction between intervening activity and experiment (modality). Although there appears to be a general tendency for spatial and movement activities to exert the most deleterious effects overall, the patterns are not identical when the initial stimulus is encoded haptically (Experiment 1) and visually (Experiment 2).     

The verbal nature of representations of the canonical colors of objects

In selecting the canonical colors of color-specific objects, children may use verbal mediation, a cognitive process whereby an object and its color are matched using verbal rather than pictorial representation [British Journal of Developmental Psychology 14 (1996) 339]. To investigate this process, 108 2- to 5-year-old children were asked to identify 11 colors and to choose crayons to color pictures of color-specific objects. Canonical color choice was significantly predicted by color-labeling skill above the variance portion predicted by age alone. Children were also asked to explain their color choices. Children who knew their colors and who colored canonically provided explanations for their color choices consistent with verbal mediation. However, a high proportion of children who did not know a color, and thus could not use verbal mediation, also gave sophisticated explanations for their color choices if they colored the objects canonically. These findings provide modest support for the idea that identification of canonical colors of objects is a verbal process.     

Infant search tasks reveal early concepts of containment and canonical usage of objects

It is difficult to gain unambiguous evidence on the use of concepts by infants. Many results can be accounted for in terms of action-based strategies. The evidence reported here fulfils the minimal criteria for the operation of working concepts in infants. Search tasks are used with a filled interval which forces memory-search, and the object is hidden in containers which fulfil their customary job or violate it. Infants treat an upright cup as a more reliable location marker than an inverted one. A series of experiments probes the phenomenon. The results indicate that the infants have a working concept of containment which can be triggered by the provision of containers in their canonical orientation. Even “object permanence tasks” lead infants to access their knowledge of the relationships into which things typically enter in the world outside the laboratory.     

Transfer between vision and haptics: Memory for 2-D patterns and 3-D objects

Explicit memory tests such as recognition typically access semantic, modality-independent representations, while perceptual implicit memory tests typically access presemantic, modality-specific representations. By demonstrating comparable cross- and within-modal priming using vision and haptics with verbal materials (Easton, Srinivas, & Greene, 1997), we recently questioned whether the representations underlying perceptual implicit tests were modality specific. Unlike vision and audition, with vision and haptics verbal information can be presented in geometric terms to both modalities. The present experiments extend this line of research by assessing implicit and explicit memory within and between vision and haptics in the nonverbal domain, using both 2-D patterns and 3-D objects. Implicit test results revealed robust cross-modal priming for both 2-D patterns and 3-D objects, indicating that vision and haptics shared abstract representations of object shape and structure. Explicit test results for 3-D objects revealed modality specificity, indicating that the recognition system keeps track of the modality through which an object is experienced.     

The Structural Memory: A network model for human perception of serial objects

Summary The Structural Memory, a network model for human perception of serial objects, such as series, is presented. Our theoretical assumptions originate from the Structural Information (Theory (SIT) (Buffart & Leeuwenberg, 1983; Leeuwenberg, 1969), a theory concerning the perceptible structures in an object and the human preference for one of these structures. A symbolic notation of such a perceptible structure in an object is called a representation. For a given maximum number of symbols we can generate all representations automatically. From this procedure we define G(eneration)-relations between the representations. We also define S(tructure)-relations based upon the structures described by the representations. The representations and relations can be seen as respectively the nodes and links in a network. This network is the basis for the Structural Memory. We therefore assign an activation value to each representation in the network, expressing the strength of the preference for the described structure at a certain moment. By means of a process model we are able to make predictions for the strength of the preference for a perceptible structure in an object. The process is only based upon the network structure, because of a relation found between the preference measure, used in SIT, for a perceptible structure in an object and the number of G- and S-relations of the corresponding representation in the network. It is shown that with two of these process models some experiments by Van Leeuwen and Buffart can be simulated.     

Memory for objects and their locations: the role of the hippocampus in retention of object-place associations

Computational models of hippocampal function have suggested that the hippocampus is involved in the formation and storage of arbitrary associations. Previous studies have shown that rats with hippocampal lesions are impaired in object-place associative learning. However, few studies have examined the role of the hippocampus in the retention of previously learned arbitrary associations. In the present study, male Long-Evans rats with either cortical control or hippocampal lesions were tested on a task measuring the retention of previously learned arbitrary associations using an object-place paired-associate task. To assess retention, each animal was trained on the paired-associate task for 360 trials, then received a lesion, and was retested to examine retention of the previously learned associations. The results indicate that all rats learned the task prior to surgery. Following surgery, rats with cortical control lesions were not impaired in the retention of object-place associations. In contrast, hippocampal lesions resulted in an initial deficit in retention of the paired-associate task followed by recovery. Therefore, the hippocampus may play a role in the retrieval of previously learned arbitrary association.     

Memory of action events: the role of objects in memory of self- and other-performed tasks.

Encoding action phrases by enactment produces better recall than hearing or reading the action phrase. This study examined whether enactment enhances memory relative to observing another perform the same action. Theories of the enactment effect suggest that the complexity of the action, here manipulated by varying the number of objects involved in an action, may determine whether enactment enhances memory relative to observation. The results revealed a consistent subject-performed task advantage across all object conditions; the size of the effect did not vary with increasing task complexity. Additionally, items that included the use of an object were recalled better than those without objects. The results are consistent with the views of Engelkamp and Zimmer (1997) and Backman, Nilsson, & Kormi-Nouri (1993), who argued that the SPT effect is due to motor and/or sensory encoding.     

Perceiving circular heading in noncanonical flow fields

Five experiments examined circular heading perception with optical flows that departed from the canonical form. Noncanonicity was achieved through nonrigidity of the environment (Experiments 1 and 2), oscillations of the point of observation (Experiment 3), and the bending of light (Experiments 4 and 5). In Experiments 1 and 2, perception was impaired more by nonrigidity of the ground plane than by nonrigidity of the medium. In Experiment 3, perception was unimpaired by noncanonical flows induced by the bounce and sway of observer locomotion. In Experiments 4 and 5, perception was not impaired when light paths were distorted by a spherical projection, but perception was impaired when they were distorted by a sine function. Results are discussed in relation to the hypothesis that the information for perceiving heading is the ordinal pattern of optical flow.     

Memory for common objects: brief intentional study is sufficient to overcome poor recall of US coin features

Prior studies have explained the very poor recall for the features of a coin in terms of visual characteristics. Two experiments compared incidental exposure and intentional study of US coins on recall of their features. In Experiment 1, recall performance for a rarely seen Mercury dime after a 1-min study period was better than that for an unstudied penny, even when the test on the dime was delayed 1 week. In Experiment 2, participants studied the dime for 15, 30, 45, or 60 s. Recall of the dime was greater than that of the unstudied penny even with the shortest study interval. Thus, a high level of recall of a coin's features can be obtained with brief intentional study, and that level can be maintained across a long delay interval. These findings suggest that poor retention of coin features is due to incidental exposure rather than to visual characteristics. Copyright © 2004 John Wiley & Sons, Ltd.     

Endpoints and viewpoints on spatial neglect

In this issue of the Journal of Neuropsychology, Abe and Ishiai (2022) report an experiment designed to probe the subjective experience of line bisection in neglect. A re-analysis of their data can also offer insights into how best to characterise neglect performance for this and other tasks. We show that sensitive measures of neglect can be obtained by quantifying the difference in the influence (or ‘weighting’) that each endpoint has on the response. The right endpoint is dramatically more influential than the left in people with neglect performing line bisection and endpoint reproduction tasks. This supports the view that neglect may limit the ability to simultaneously represent two locations, so that the response is determined primarily with respect to the right endpoint. We also discuss Abe and Ishiai's conclusion that bisection responses in neglect are accompanied by the subjective experience of a complete line extending equally to either side of the chosen midpoint.     

Contrasting Memory for Temporal-Source and Memory for Content in Children's Discrimination of Repeated Events

The current studies examined the separate roles that memory of temporal-source and memory of content play in children's discrimination of occurrences of a repeated event. The studies were also designed to determine the impact of age and retention interval on each of these components. In Experiment One, 4- to 5- versus 6- to 8-year-old children experienced six occurrences of a repeated event; each occurrence had the same underlying structure; however, a different version or instantiation of each item was included in each occurrence of the event. At either 1 or 6 week delay, the children were asked to recall which instantiation of the item was included in the final occurrence. In Experiment Two, children were required to recall as many instantiations as they could, prior to making a decision about which instantiation was included in the final occurrence. The results indicated that: (a) children's capacity to correctly identify the final instantiation declined over time and increased with age; (b) children's capacity to provide an instantiation that was temporally close to the final occurrence declined over time and increased with age; and (c) children's ability to remember the source of an instantiation decreased over time irrespective of any loss of memory for content. The results were discussed in relation to current theories of memory and children's eyewitness memory. © 1997 John Wiley & Sons, Ltd.     

Shape-from-shading for matte and glossy objects

We wanted to find out whether the presence of specular highlights on the otherwise matte objects would make a difference to the perceived surface relief. Six different, globally convex objects were displayed on a computer screen. The depicted objects were either matte or glossy and were illuminated from one of the two different directions. Shape-from-shading was evaluated with two different paradigms. In Experiment 1 observers were asked to set a number of local surface attitude probes such that the probes looked as if they were tangent to the objects' surfaces. In Experiment 2, observers were instructed to make traces of the contours of the depicted objects in the horizontal and vertical planes. Although the two tasks target different aspects of the perceived surface, they give essentially similar results here. In both tasks we found differences that were induced by changing the illumination direction. Surprisingly, no systematic difference was found between the results for matte and glossy objects. We must, therefore, conclude that there is no evidence from the current study that glossiness influences shape perception although to the observer matte and glossy objects look quite different.     

Memory for position and

Memory for the position of an object is biased. When asked to judge whether an object has changed its position with respect to a position shown a few milliseconds before, observers tend to detect the displacement more often when the displacement is not in the expected direction (downward for a falling object). The hypothesis proposed by Freyd (1983, 1987) states that the internal representation of an object is intrinsically dynamic. Therefore, the forces perceived as acting on the object affect the representation. Quantitative predictions of this model were tested in three experiments by measuring memory distortion for the position of an object on an inclined plane. Angle of inclination and retention interval were varied. The results for different inclinations support the physical model. The time course of the memory distortion suggests a new view about the relation between this phenomenon and very short-term memory.