Distortions in immediate memory

A series of five pairs of abstract geometrical figures were presented to each subject. Unknown to the subjects, the members of each pair were identical. The second member was presented 10 seconds after the first member and the subject then judged whether a specified feature of the figure had changed in one of two possible directions. One group of 32 subjects were not told which feature of the figure would be critical until presentation of the second member: a further group of 32 subjects were given this information before presentation of the first member. Subjects in both groups were significantly consistent with one another in some of their judgements, thus indicating that distortions in remembering had occurred. It is argued that memory distortions of this type (for which previous evidence has been unsatisfactory) are of particular interest since, unlike other memory changes, they are difficult to ascribe to the constructive or inferential character of recognition and recall.     

Distortions in memory for maps

Evidence is presented for systematic errors in memory for real and artificial maps, local environments, and visual forms. These errors are attributed to two heuristics that are derived from principles of perceptual organization. Maps of countries or localities are conceived of as figures in backgrounds. Remembering the absolute location of figures is difficult, and is facilitated by remembering locations relative to other figures and/or relative to the natural directions of the figure. In alignment, figures are lined up relative to one another, a phenomenon related to perceptual grouping by proximity. In rotation, the natural axes induced by a figure converge with frame axes (north-south, east-west, or horizontal, vertical), a phenomenon related to perceptual organization by common fate. Heuristic-induced errors occur in a variety of tasks, and even when subjects are explicitly forewarned. These heuristics may be invoked in forming representations as well as in inference, and function analogously to syntax in locating smaller elements in larger units.     

Distortions and fluctuations in topographic memory

Two experiments dealing with, the learning of a space by map or by navigation approached the questions of equivalency of the cognitive processes involved in spatial information and of response fluctuation. In the first experiment, 11 subjects were asked to situate, six times, 18 lo-cations on a blank map. In the second experiment, the subjects were first given 3 min to learn a map with 12 locations marked, and then asked to reproduce it. The task was repeated six times, using three different maps. This gave us several trials per subject, so that distortion could be distinguished from response fluctuation. In Experiment 1, the range of values was the same for response inaccuracy and response, fluctuation; in Experiment 2, the range was greater for response inaccuracy than for response fluctuation. The results showed that space learning by navigation and space learning by map involve different cognitive processes.     

Distortions in the memory of the pitch of speech

Corneille, Huart, Becquart, & Brédart (2004) found that people remember ambiguous race faces as closer to a race prototype than they actually are. In three studies, we examined whether this memory bias generalizes to voice memory. In Studies 1 and 2, participants listened to synthesized male and female speech samples (high, moderate, or low pitch) and were asked to identify a voice target when paired against distracters higher or lower in pitch. The results showed that pitch distortions occurred, with the pattern consistent with assimilation toward low and high ends of the pitch continuum. Study 3 replicated this result with a wider voice pitch range. The results parallel those of Corneille et al. (2004). The implications of this work are discussed.     

Early declarative memory for location

The abilities of 7.5-month-old infants to recall the location of hidden objects after delays averaging 90 seconds were investigated in three experiments. Various kinds of events were introduced during the delays in order to examine the stability of early location memory. Recall, as shown by reaching towards the correct location, was most clearly found when the infants were allowed either to remain seated facing the hiding locations (Expt 1) or were turned around and immediately re-seated (Expt 2) during the delays. In both experiments, the infants’ attention was diverted from the hiding places, but during all or most of the delay the infants were facing the locations. Recall was dampened when infants were removed from the immediate location of the hiding and engaged in other activities such as looking at a picture during the delay (Expt 3). Further analyses indicated an effect for age that coincides with other research on location memory: evidence for recall was more clearly found for the older, but not the younger, 7-month-olds.     

Testing the exclusivity effect in location memory

There is growing literature exploring the possibility of parallel retrieval of location memories, although this literature focuses primarily on the speed of retrieval with little attention to the accuracy of location memory recall. Baguley, Lansdale, Lines, and Parkin (2006) found that when a person has two or more memories for an object's location, their recall accuracy suggests that only one representation can be retrieved at a time (exclusivity). This finding is counterintuitive given evidence of non-exclusive recall in the wider memory literature. The current experiment explored the exclusivity effect further and aimed to promote an alternative outcome (i.e., independence or superadditivity) by encouraging the participants to combine multiple representations of space at encoding or retrieval. This was encouraged by using anchor (points of reference) labels that could be combined to form a single strongly associated combination. It was hypothesised that the ability to combine the anchor labels would allow the two representations to be retrieved concurrently, generating higher levels of recall accuracy. The results demonstrate further support for the exclusivity hypothesis, showing no significant improvement in recall accuracy when there are multiple representations of a target object's location as compared to a single representation.     

Adaptive memory: enhanced location memory after survival processing

Two experiments investigated whether survival processing enhances memory for location. From an adaptive perspective, remembering that food has been located in a particular area, or that potential predators are likely to be found in a given territory, should increase the chances of subsequent survival. Participants were shown pictures of food or animals located at various positions on a computer screen. The task was to rate the ease of collecting the food or capturing the animals relative to a central fixation point. Surprise retention tests revealed that people remembered the locations of the items better when the collection or capturing task was described as relevant to survival. These data extend the generality of survival processing advantages to a new domain (location memory) by means of a task that does not involve rating the relevance of words to a scenario.     

Shape effects on memory for location

The participants were 40 students who were briefly presented 32 dot locations, one at a time, and attempted to reproduce each location after a short delay. Half of the participants completed the task with the surrounding shapes being a circle, a horizontal ellipse, and a vertical ellipse; for the other half, the surrounding shapes were a square, a triangle, and a pentagon. Elongation of the task field along an axis led to exaggerated bias along that axis, but the pattern of bias was fairly constant across the shapes. The data were modeled by assuming that bias in estimation was due to the weighting of spatial category prototypes. Modeling indicated that shape affected spacing of prototypes, but there was no evidence that it affected the number of prototypes. These results were consistent with use of a viewer-based frame of reference, with prototypes reflecting four spatial quadrants generated by left—right and up—down distinctions from the viewer’s perspective.     

Biases in long-term location memory in the real world

The category adjustment (CA) approach to distortions in location memory has been largely documented in simplified lab-created spaces but minimally in navigable real-world environments. In the current paper, we extend the approach to a navigable real-world environment and specifically evaluate the assumption that long-term location memory may be retrievable despite errors in recall. Memory for the location of a fountain in a heavily navigated square on a university campus was tested by reproduction on a photograph of the square and then by a forced-choice recognition test. While the recall data showed the standard bias, the recognition data revealed chance-level performance. The pattern of results suggests a possible difference between accessibility of working memories for locations within laboratory-created spaces and long-term memories for locations within complex navigable spaces. The results are discussed in terms of the CA model.     

Visuospatial processing in memory for word location in writing

Two experiments examined how visuospatial processing engaged during text composition intervenes in memory for word location. Experiment 1 showed that in contrast to participants who performed a spatial task concurrently with composing a text, participants who performed a concurrent visual task recalled fewer word locations after the composition. Consequently, it is hypothesized that writers process the written text in order to visually represent its physical layout, and that this representation is then used when locating words. Experiment 2 tested this hypothesis by comparing a standard composition condition (with the written trace) with a condition in which the written trace was suppressed during composition, and with a condition without written trace and with added visual noise. Memory for word location only decreased with visual noise, indicating that construction of the visual representation of the text does not rely on the written trace but involves visual working memory.     

Developmental aspects of memory for spatial location

The purpose was to show whether or not the encoding of location met criteria defining an automatic process (L. Hasher & R. T. Zacks, 1979, Journal of Experimental Psychology: General, 108, 356-388; 1984, American Psychologist, 39, 1372-1388). Among other criteria, automatic processes are not expected to show developmental changes beyond an early age, to be unrelated to intelligence level, and to be unaffected by instructions. In the first experiment preschool through sixth-grade children were compared on a 40-picturebook task following incidental (remember the names of pictures) or intentional (remember location) instruction. Subjects viewed and named pictures in sets of four, arranged in quadrants in the opened book, and then attempted to recall names of the objects pictured and to relocate pictures on blank pages. In the second experiment, second and sixth graders, college students, elderly persons, and mentally retarded persons were compared on a 60-picturebook task following either incidental or semantic incidental instructions (give the function of objects pictured). Memory for location was invariant across age groups and intelligence level. The only exception was that 3 and 4 year olds were more accurate following intentional instructions. Otherwise there were no differences between intentional and incidental instructions. Semantic instructions resulted in slightly more accurate locations. The results were interpreted as supportive of the Hasher and Zacks' automaticity hypothesis.     

The role of experience in location estimation: Target distributions shift location memory biases

Research based on the Category Adjustment model concluded that the spatial distribution of target locations does not influence location estimation responses [Huttenlocher, J., Hedges, L., Corrigan, B., & Crawford, L. E. (2004). Spatial categories and the estimation of location. Cognition, 93, 75–97]. This conflicts with earlier results showing that location estimation is biased relative to the spatial distribution of targets [Spencer, J. P., & Hund, A. M. (2002). Prototypes and particulars: Geometric and experience-dependent spatial categories. Journal of Experimental Psychology: General, 131, 16–37]. Here, we resolve this controversy by using a task based on Huttenlocher et al. (Experiment 4) with minor modifications to enhance our ability to detect experience-dependent effects. Results after the first block of trials replicate the pattern reported in Huttenlocher et al. After additional experience, however, participants showed biases that significantly shifted according to the target distributions. These results are consistent with the Dynamic Field Theory, an alternative theory of spatial cognition that integrates long-term memory traces across trials relative to the perceived structure of the task space.     

The privileged role of location in visual working memory

Reports have conflicted about the possible special role of location in visual working memory (WM). One important question is: Do we maintain the locations of objects in WM even when they are irrelevant to the task at hand? Here we used a continuous response scale to study the types of reporting errors that participants make when objects are presented at the same or at different locations in space. When several objects successively shared the same location, participants exhibited a higher tendency to report features of the wrong object in memory; that is, they responded with features that belonged to objects retained in memory but not probed at retrieval. On the other hand, a similar effect was not observed when objects shared a nonspatial feature, such as color. Furthermore, the effect of location on reporting errors was present even when its manipulation was orthogonal to the task at hand. These findings are consistent with the view that binding together different nonspatial features of an object in memory might be mediated through an object’s location. Hence, spatial location may have a privileged role in WM. The relevance of these findings to conceptual models, as well as to neural accounts of visual WM, is discussed.     

Gender differences in object location memory: A meta-analysis

The goal of the present study was to quantify the magnitude of gender differences in object location memory tasks. A total of 123 effect sizes (d) drawn from 36 studies were included in a meta-analysis using a hierarchical approach. Object identity memory (37 effect sizes) and object location memory (86 effect sizes) tasks were analyzed separately. Object identity memory task showed significant gender differences that were homogeneous and in favor of women. For the object location memory tasks, effect sizes had to be partitioned by age (younger than 13, between 13 and 18, older than 18), object type (common, uncommon, gender neutral, geometric, masculine, feminine), scoring method (accuracy, time, distance), and type of measure (recall, recognition) to achieve homogeneity. Significant gender differences in favor of females were obtained in all clusters above the age of 13, with the exception of feminine, uncommon, and gender-neutral objects. Masculine objects and measures of distance produced significant effects in favor of males. Implications of these results for future work and for theoretical interpretations are discussed.     

Recognition memory and the recall of spatial location

It is argued that memory for events should depend on the ability to recall their attributes. Two experiments suggest that this is so for the attribute of spatial location. When words presented in spatial arrays were later re-presented in a joint test of recognition memory and location recall, it was found that the surer one’s recognition, the greater the accuracy of location recall. Instructions to attend to a word’s location resulted in poorer recognition memory and marginally poorer location recall than were obtained when location was “incidentally” learned. Finally, when words were presented in color as well as in space, recognition memory was best when both attributes were recalled, was better when only location, was recalled than when only color was recalled, and was poorest when neither attribute was recalled.     

Cue usage in memory for location when orientation is fixed

In previous research, it was demonstrated that including one or three cues surrounding a circular field had no effect on spatial memory for dot locations when the field's orientation was fixed, but that there were very large effects when orientation varied across trials (Fitting, Wedell, & Allen, 2007). In four new experiments, we explored the use of external cues in the fixed orientation environment, using 0, 4, 8, or 24 cues and manipulating task difficulty. In Experiments 1-3, the angular bias data supported the use of four quadrant-based prototypes regardless of cue condition, but there were clear cue effects on radial prototype locations. Increasing the number of cues enhanced accuracy of spatial memory for targets closer to cues. In Experiment 4, we severely challenged memory by using multiple targets and a filled delay before estimation. Doing so demonstrated an effect of cues on the categorical structuring of memory. Collectively, findings indicate that when orientation is fixed, cues bolster fine-grain memory, but that they only alter the default categorical scheme when memory demands are high.     

The representation of objects and their attributes in memory: Evidence concerning memory for location

The general principle is advanced that different attributes of objects (e.g. shape and colour) are more readily associated when they are attributes of the same object than when they are attributes of different objects. Previous studies provide support for the principle, for they have shown that a shape is more readily associated with its own colour than, for example, with the colour of its background. In the present experiments, the principle was applied to the attributes of shape and location. In four experiments it was shown that a shape was more readily associated with its own location than with the location of another object. Differences in contiguity between the presentation of the shape and the location with which the shape was to be associated were controlled for, as were other factors. The results were interpreted as providing support for the general principle stated above. It was suggested that the general principle could be explained by supposing that memory is propositional in format.     

The representation of time and location in memory for sentences

Two theoretical approaches to the representation of Time and Location Markers in Memory were contrasted. According to predictions derived from one approach, the amount of forgetting will be the same for two-proposition sentences and sentences with a single proposition and a Time or a Location marker. According to the other approach, the amount of forgetting will be the same for one-proposition sentences and sentences with a Time or a Location Marker. Propositional structure and the level of within-sentence associations were orthogonally varied to create eight within-subject experimental conditions. Ninety subjects studied 40 sentences and were required to recall then. Four dependent variables were used: number of sentences completely recalled, number of sentences partially recalled, number of sentences where information was lost from within the proposition, and number of sentences where a complete proposition was lost. The results suggest that Time and Location markers are represented in memory as arguments in a proposition rather than as separate propositions. Level of associations within the sentence seems to have a different effect when the sentence is composed of one or two propositions. The results also suggest that there may be differences between the representations of Time and Location markers.