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.     

The representation of response effector and response location in episodic memory for newly acquired actions: Evidence from retrieval-induced forgetting

Information retrieval can cause forgetting for related but non-retrieved information. Such retrieval-induced forgetting (RIF) has been previously found for semantically and episodically related information. The current study used RIF to examine whether response effector and location are encoded explicitly in action memory. Participants learned unique touchscreen responses to ten novel objects. Correct actions to each object involved left-hand or right-hand pushing of one of four possible object buttons. After learning, participants practiced two of the ten object-specific sequences. Unpracticed actions could share hand only, button only, both hand and button, or neither hand nor button, with the practiced actions. Subsequent testing showed significant RIF (in retrieval accuracy and speed measures) for actions that shared hand only, button only, or both hand and button with the practiced action. The results have implications for understanding the representations mediating episodic action memory, and for the potential of RIF as a tool for elucidating feature-based representations in this and other domains.     

The association between maternal strategies and preschoolers' memory for location of objects

Using a Vygotskian theoretical framework and a social interaction design, we observed 30 middle-class North American mother–child dyads engaged in a location memory activity. The central aim of this investigation was to assess maternal and preschool strategy use employed during a memory for location task, and to determine which strategies are associated with preschooler accuracy of memory for location of objects. Results suggest that mothers are more apt to utilize labelling, encouragement, and guidance as opposed to location-specific assistance to their child during the task, and children are more apt to link the memory information to their real-life experiences, request help for assistance, and utilize self-regulatory speech. Implications of the research, suggestions for future research, and expansions of theoretical perspectives on the role of social interaction on preschool location memory performance, and educational implications are discussed.     

Verb semantic structures in memory for sentences: Evidence for componential representation

This research contrasts two hypotheses concerning componential storage of meaning. The Complexity Hypothesis assumed by Fodor (The language of thought, NY: Crowell, 1975), Kintsch (The representation of meaning in memory, Hillsdale, NJ: Erlbaum, 1974), and Thorndyke (Conceptual complexity and imagery in comprehension and memory. Journal of Verbal Learning and Verbal Behavior, 1975, 14, 359–369) states that a word with many semantic components will require more processing resources, comprehension time, and long-term memory space than a word with few components, and thus will interfere more with memory for surrounding words. This memory prediction was tested against an alternative prediction based on connectivity. The Connectivity Hypothesis views verb semantic structures as frames for sentence representation and states that memory strength between two nouns in a sentence increases with the number of underlying verb subpredicates that connect the nouns. Thus, the Complexity Hypothesis predicts that a verb with many subpredicates will lead to poorer memory strength between the surrounding nouns than a verb with few subpredicates, while the Connectivity Hypothesis predicts that verbs with many subpredicates will lead to greater memory strength between nouns in cases when the additional subpredicates provide semantic connections between the nouns.In three experiments, subjects recalled subject-verb-object sentences, given subject nouns as cues. General verbs, with relatively few subpredicates, were compared with more specific verbs whose additional subpredicates either did or did not provide additional connections between the surrounding nouns. The level of recall of the object noun, given the subject noun as cue, was predicted by the relative number of connecting subpredicates in the verb, but not by the relative number of subpredicates. This finding supports the Connectivity Hypothesis over the Complexity Hypothesis. These results are interpreted in terms of a model in which the verb conveys a structured set of subpredicates that provides a connective framework for sentence memory.     

Comparing objects in memory: Evidence suggesting an internal psychophysics

In this experiment, Ss were visually presented with the names of two animals and were required to throw a switch under the name of the larger animal. Although error rates were relatively low (4.5%), reaction time (RT) was largely an inverse linear function of the logarithm of the estimated difference in animal size. Since RT is similarly related to size differences when Ss make direct perceptual comparisons (e.g., of lengths of line),.it was argued that Ss compare animal names by making an “internal psychophysical judgment.” A more general model was then proposed for answering, from memory, questions of the form, “Which is /X/, /A/ or [B/?” where /X/ is any comparative adjective and /A/and /B/ are any concrete nouns.     

Visual working memory for dynamic objects: Impaired binding between object feature and location

In daily life, people frequently need to observe dynamic objects and temporarily maintain their representations in visual working memory (VWM). The present study explored the mechanism underlying the binding between perceptual features and locations of dynamic objects in VWM. In three experiments, we measured and compared the memory performance for feature-location binding of multiple dynamic and static objects. The results showed that the feature-location binding was impaired for the dynamic objects compared with the static objects. The impairment persisted when the global spatial configuration of the objects remained intact during the motion, as well as when the binding task was relatively easy, such as binding between single-feature objects and coarse locations. The results indicate that object features and locations are not maintained in VWM as well-integrated object files; rather, the formation of feature-location binding may require additional processes, which are disrupted by the constant change of locations in dynamic circumstances. We propose a consolidation process as possible underlying mechanism, and discuss factors that may influence the strength of feature-location binding in dynamic circumstances.     

The representation of nonstructural information in visual memory: Evidence from image combination

Two experiments investigated the differential representation of the figure and ground of a picture in visual short-term and long-term memory. It is known (Hitch, Brandimonte, & Walker, 1995) that subjects find it more difficult to combine mental images of two separately presented pictures in order to identify a novel form when the two pictures are incongruent in color (i.e., when a black-on-white line drawing has to be combined with a white-on-black drawing). In the present experiments, thefigures were depicted in solid form to allow color congruity to be varied independently for figure and ground. Results showed a clear impairment in image combination when the to-be-combined figures were incongruent in color (black-on-gray and white-on-gray) but not when theirgrounds were incongruently colored (gray-on-black and gray-on-white). In this way, image combination was seen to be supported by a representation of the object depicted in the picture rather than by a literal representation of the picture itself (i.e., a pictorial code). In line with previous findings, the same representation was seen to support image combination based on short-term memory (Experiment 1) and long-term memory (Experiment 2), provided that in the latter case verbal recoding was precluded. When verbal recoding was allowed, image combination based on long-term memory was insensitive to color congruity, implying the involvement of a more abstract structural representation.     

Cross-modal and intra-modal binding between identity and location in spatial working memory: The identity of objects does not help recalling their locations

In this study we tested incidental feature-to-location binding in a spatial task, both in unimodal and cross-modal conditions. In Experiment 1 we administered a computerised version of the Corsi Block-Tapping Task (CBTT) in three different conditions: the first one analogous to the original CBTT test; the second one in which locations were associated with unfamiliar images; the third one in which locations were associated with non-verbal sounds. Results showed no effect on performance by the addition of identity information. In Experiment 2, locations on the screen were associated with pitched sounds in two different conditions: one in which different pitches were randomly associated with locations and the other in which pitches were assigned to match the vertical position of the CBTT squares congruently with their frequencies. In Experiment 2 we found marginal evidence of a pitch facilitation effect in the spatial memory task. We ran a third experiment to test the same conditions of Experiment 2 with a within-subject design. Results of Experiment 3 did not confirm the pitch–location facilitation effect. We concluded that the identity of objects does not affect recalling their locations. We discuss our results within the framework of the debate about the mechanisms of “what” and “where” feature binding in working memory.     

Trade-off between memory for verbal items and their visual attributes.

Instructions to attend to the case and color in which words were presented led to improved retention of these visual attributes but depressed recognition performance. This trade-off between item and attribute memory occurred at three presentation rates (1.5, 5.5, and 10.5 sec/item), suggesting that visual attributes of verbal stimuli are rarely stored unless subjects expect that knowledge of physical form will be useful later. Visual attributes of high-imagery words were retained better than visual attributes of low imagery words by subjects instructed to attend to case and color, but not by subjects asked only to attend to word meaning. Implications of these findings for the hypothesis that visually presented verbal stimuli are stored as literal copies are discussed.     

The structure of memory: Evidence concerning the recall of surface and background colour of shapes

In the first of four experiments, two groups of subjects were shown a series of cards, each displaying a different shape. For one group the shapes were of different colours, and each was located on either a black or a white background. For the other group a shape was black or white, and its background was coloured. Subjects in both groups were instructed to memorize the colour and brightness (black or white) assigned to each shape. Recall of the colours, in response to the names of the shapes, was superior for the group for which the shapes themselves had been coloured. In the other three experiments the finding was extended, with the aim of limiting possible explanations of the effect. One of these experiments showed that the effect is obtained when the relevant stimuli are imagined rather than being physically shown to a subject. This suggests that the effect is not the result of processes of attention that are dependent upon the perceptual analysis of a display. In discussion, it is argued that the effect may shed light on the constraints that govern the process of association. One hypothesis that specifically accounts for the results is that the structure of memory for visually presented information is that of a network of propositions.     

Dual representation of item positions in verbal short-term memory: Evidence for two access modes

Memory sets of N=1 ~ 5 digits were exposed sequentially from left-to-right across the screen, followed by N recognition probes. Probes had to be compared to memory list items on identity only (Sternberg task) or conditional on list position. Positions were probed randomly or in left-to-right order. Search functions related probe response times to set size. Random probing led to ramped, “Sternbergian” functions whose intercepts were elevated by the location requirement. Sequential probing led to flat search functions—fast responses unaffected by set size. These results suggested that items in STM could be accessed either by a slow search-on-identity followed by recovery of an associated location tag, or in a single step by following item-to-item links in study order. It is argued that this dual coding of location information occurs spontaneously at study, and that either code can be utilised at retrieval depending on test demands.     

Object identification: The mental representation of physical and conceptual attributes

In two experiments, subjects indicated whether two pictures of familiar objects were equivalent. The picture pairs were identical, showed the same object in various perspectives and states, or showed different objects with varying degrees of conceptual relatedness. In Experiment 1, the equivalence criterion for judging the picture pairs was varied between subjects (identity of pictures; conceptual equivalence of objects at subordinate, basic, or superordinate level). The reaction times of the four subject groups suggest that a pictorial stimulus is not always mentally represented in the same way, and that the instructions given determine which attributes of the stimulus are represented. In Experiment 2, the visual similarity of the picture pairs was varied. The results indicate, at least with a basic-level equivalence instruction, that not only perceptual, but also non-perceptual, functional attributes are represented—namely, those that, according to Rosch et al. (1976), are common to the members of a superordinate category.     

Distinct roles for medial temporal lobe structures in memory for objects and their locations

The ability to learn and retain novel information depends on a system of structures in the medial temporal lobe (MTL) including the hippocampus and the surrounding entorhinal, perirhinal, and parahippocampal cortices. Damage to these structures produces profound memory deficits; however, the unique contribution to memory of each of these structures remains unclear. Here we have used functional magnetic resonance imaging (fMRI) to determine whether the perirhinal and parahippocampal cortices show differential memory-related activity. Based on the distinct patterns of cortical input to these two areas, we reasoned that these structures might show differential activity for spatial and object recognition memory. In each of 11 subjects, we found that the perirhinal cortex was active during both spatial and object memory encoding, while the anterior parahippocampal cortex was active only during spatial encoding. These data support the idea that MTL structures make distinct contributions to recognition memory performance.     

Searching for impossible objects: Processing form and attributes in early vision

In five experiments, we investigated the extent to which form (shape) and metric attributes (three-dimensional, 3-D, orientation), both defined by relations between une elements, are processed in early vision. Search for a target defined by an abstract property of form (i.e., impossibility) was slow and serial. In contrast, search for a 3-D orientation target was considerably easier. Subsequent experiments suggest that this difference reflects the fact that 3-D orientation is derivable from localized sets of lines, whereas impossibility is an idiosyncratic property of the complete set of relations between lines. We conclude that only “gross” aspects of form are available in early vision as the complete set of line relations is not processed preattentively. However, localized processing of line relations is sufficient to derive 3-D orientation.     

Differential ordering of objects and attributes

By reference to nominated attributes, a genus, being a population of objects of one specified kind, may be partitioned into species, being subpopulations of different kinds. A prototype is an object representative of its species within the genus. Using this framework, the paper describes how objects can be relatively differentiated with respect to attributes, and how attributes can be relatively differentiating with respect to objects. Methods and rationale for such differential ordering of objects and attributes are presented by example, formal development, and application.For a genus comprisingn species of object there is a subsetP ofn distinct prototypes. With respect tom nominated attributes, each object in has anm-element characterization. Together these determine ann ×m objects × attributes matrix, the rows of which are the characterizations of the prototypical objects. Over then species in , an associated relative frequency vector gives the distribution of objects (and of their characterizations). The matrix and vector associate the objects in with points in a metric space (P, ); and it is with respect to various sums of distances in this attribute space that one can differentially order objects and attributes.The definition of the distance function is generalized across kinds of difference, types of characterization, scale-types of measurement, Minkowskiindex 1, and any form of distribution of objects over species. Explanatory and taxonomic applications in psychology and other fields are discussed, with focus on classification, identification, recognition, and search. The Braille code and the identification of its characters provide illustration.An anticipation and some preliminary indications were given in Sutcliffe and Bristow (1966), Sutcliffe (1972, 1973), and Nowakowska (1975). Subsequently the ideas have been extended and their applications realized in a computer program which, in its development, has so far gone through many minor and three major revisions to its present form in Sutcliffe (1985). The foregoing provided the foundation for the empirical applications and for the presentation in this paper of the ideas in their general form. the research has been supported by funds from the University of Sydney Research Grant and from the Australian Research Grants Scheme. In the working out and exposition of the ideas I have very much benefited from constructive critical comment given by C. R. Latimer, J. B. Michell, G. Oliphant, and E. Seneta, and from the professional programming skills of Michael Wilson and David Shillito. I am grateful for the invitation and the facilities for writing extended during 1983 by Georges Noizet, Laboratoire de Psychologie Expérimentale, Université René Descartes, Paris V, and by Samuel Messick, Vice President for Research, E.T.S. Princeton, N.J. Finally, I acknowledge the improvements in presentation of this paper which have arisen from the editor's and reviewers' comments.