Cristina Sampaio

Category-based errors and the accessibility of unbiased spatial memories: a retrieval model.

Studies have consistently shown a spatial memory bias such that a target location is remembered toward the prototypical location of the region to which the target belongs, indicating a blending between the targets specific information and the generic information of its region. The authors investigated whether people retain a veridical representation of a target location after a delay by determining the locus of the blending (during encoding, delay, or retrieval). To examine accessibility to the original target location, they used a recognition task, which is less demanding than the traditional reproduction procedure. The results showed that participants were able to recognize the original position of a target over their own biased recalled position after both a short (1,500 ms) and a longer (5,000 ms) delay. These findings reveal that spatial memories can be undistorted despite distorted recall responses. Results are discussed in terms of J. Huttenlocher, L. V. Hedges, and S. Duncans (1991) category adjustment model.

The role of unconscious memory errors in judgments of confidence for sentence recognition.

The present experiment tested the hypothesis that unconscious reconstructive memory processing can lead to the breakdown of the relationship between memory confidence and memory accuracy. Participants heard deceptive schema-inference sentences and nondeceptive sentences and were tested with either simple or forced-choice recognition. The nondeceptive items showed a positive relation between confidence and accuracy in both simple and forced-choice recognition. However, the deceptive items showed a strong negative confidence/accuracy relationship in simple recognition and a low positive relationship in forced choice. The mean levels of confidence for erroneous responses for deceptive items were inappropriately high in simple recognition but lower in forced choice. These results suggest that unconscious reconstructive memory processes involved in memory for the deceptive schema-inference items led to inaccurate confidence judgments and that, when participants were made aware of the deceptive nature of the schema-inference items through the use of a forced-choice procedure, they adjusted their confidence accordingly.

The temporal locus of the categorical bias in spatial memories

People often use the region of a targets location to make judgements about its exact position. Although there is general agreement that this category-based effect is due to a blending of the specific coding of a targets location and the categorical coding of its region, there is little agreement on when the blending occurs. The current paper examines whether the systematic bias is the result of combining separate undistorted mental representations at the time of retrieval or a result of using a category-distorted mental representation. Participants studied a dot within a circle and reproduced its location from memory after a short or long delay, and new categorical information was introduced during target retrieval. The results showed a larger increase over time in the biases caused by the new category introduced at retrieval than in the biases caused by the originally encoded category. The findings are consistent with retrieval models, providing evidence that category biasing processes operate at the time of memory retrieval.

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.

Overcoming Default Categorical Bias in Spatial Memory

In the present study, we investigated whether a strong default categorical bias can be overcome in spatial memory by using alternative membership information. In three experiments, we tested location memory in a circular space while providing participants with an alternative categorization. We found that visual presentation of the boundaries of the alternative categories (Experiment 1) did not induce the use of the alternative categories in estimation. In contrast, visual cuing of the alternative category membership of a target (Experiment 2) and unique target feature information associated with each alternative category (Experiment 3) successfully led to the use of the alternative categories in estimation. Taken together, the results indicate that default categorical bias in spatial memory can be overcome when appropriate cues are provided. We discuss how these findings expand the category adjustment model (Huttenlocher, Hedges, & Duncan, 1991) in spatial memory by proposing a retrieval-based category adjustment (RCA) model.

The cause of category-based distortions in spatial memory: A distribution analysis

Recall of remembered locations reliably reflects a compromise between a target’s true position and its region’s prototypical position. The effect is quite robust, and a standard interpretation for these data is that the metric and categorical codings blend in a Bayesian combinatory fashion. However, there has been no direct experimental evidence that the 2 codings are actually combined. That is, at least 2 mechanisms can produce biased mean responses: (a) people may in fact take a weighted average of the metric and categorical representations, but (b) these 2 codings may instead compete for response, each winning with a certain probability. The present work investigated these 2 hypotheses for the cause of category-based distortions using a new distribution analysis. Participants viewed a target within a blank circle and reproduced its location after a short delay. The error data for individual participants were fit with a kernel curve, which provides a distribution without the assumption of normality. Almost all individual distributions displayed a clear biased main peak, indicating a weighted average between the representations, not an alteration between the 2 representations.

A systematic spatial bias in remembering eye positions

ABSTRACT Categorical bias in location memory in geometric spaces is well established. The present study assessed the presence of the bias in locating eyes in images of human faces. Participants were presented with digital faces and indicated the position of one of the eyes in both upright and inverted orientations. Biases resulted from participants using multiple sources of accessible information. No differences were found for upright vs. inverted face images. Overall, the data were consistent with the retrieval category adjustment model. These distortions may be considered within the forensic context, when eyewitnesses work with a sketch artist or use a computer program to generate an image of the culprit.

High Confidence in Falsely Recognizing Prototypical Faces.

We applied a metacognitive approach to investigate confidence in recognition of prototypical faces. Participants were presented with sets of faces constructed digitally as deviations from prototype/base faces. Participants were then tested with a simple recognition task (Experiment 1) or a multiple-choice task (Experiment 2) for old and new items plus new prototypes, and they showed a high rate of confident false alarms to the prototypes. Confidence and accuracy relationship in this face recognition paradigm was found to be positive for standard items but negative for the prototypes; thus, it was contingent on the nature of the items used. The data have implications for lineups that employ match-to-suspect strategies.

Memory for non-native language: The role of lexical processing in the retention of surface form

Research on memory for native language (L1) has consistently shown that retention of surface form is inferior to that of gist (e.g., Sachs, 1967). This paper investigates whether the same pattern is found in memory for non-native language (L2). We apply a model of bilingual word processing to more complex linguistic structures and predict that memory for L2 sentences ought to contain more surface information than L1 sentences. Native and non-native speakers of English were tested on a set of sentence pairs with different surface forms but the same meaning (e.g., “The bullet hit/struck the bulls eye”). Memory for these sentences was assessed with a cued recall procedure. Responses showed that native and non-native speakers did not differ in the accuracy of gist-based recall but that non-native speakers outperformed native speakers in the retention of surface form. The results suggest that L2 processing involves more intensive encoding of lexical level information than L1 processing.