The mental representation of ordinal sequences is spatially organized

In the domain of numbers the existence of spatial components in the representation of numerical magnitude has been convincingly demonstrated by an association between number magnitude and response preference with faster left- than right-hand responses for small numbers and faster right- than left-hand responses for large numbers (Dehaene, S., Bossini, S., & Giraux, P. (1993) The mental representation of parity and number magnitude. Journal of Experimental Psychology: General, 122, 371-396). Because numbers convey not only real or integer meaning but also ordinal meaning, the question of whether non-numerical ordinal information is spatially coded naturally follows. While previous research failed to show an association between ordinal position and spatial response preference, we present two experiments involving months (Experiment 1) and letters (Experiment 2) in which spatial coding is demonstrated. Furthermore, the response-side effect was obtained with two different stimulus-response mappings. The association occurred both when ordinal information was relevant and when it was irrelevant to the task, showing that the spatial component of the ordinal representation can be automatically activated.     

The effects of classification structure on organized free recall in children

A sorting presentation procedure was used to study the effects of three classification schemes (self-generated, thematic, or taxonomic) on the organized free recall of second and fifth graders. Recall and clustering were significantly higher for subjects who used self-generated organizations than for subjects given the experimenter-prescribed taxonomic classification. The results indicated that memory performance benefitted when the organization of stimulus materials was consonant with children's personal classification structures.     

The memorial consequences of multiple-choice testing

The present article addresses whether multiple-choice tests may change knowledge even as they attempt to measure it. Overall, taking a multiple-choice test boosts performance on later tests, as compared with nontested control conditions. This benefit is not limited to simple definitional questions, but holds true for SAT II questions and for items designed to tap concepts at a higher level in Bloom’s (1956) taxonomy of educational objectives. Students, however, can also learn false facts from multiple-choice tests; testing leads to persistence of some multiple-choice lures on later general knowledge tests. Such persistence appears due to faulty reasoning rather than to an increase in the familiarity of lures. Even though students may learn false facts from multiplechoice tests, the positive effects of testing outweigh this cost.     

The development of organized rehearsal

The purpose of this research was to evaluate the development or organization strategies in rehearsal processes. First-grade (age 7 years), third-grade (age 9 years), and fifth-grade (age 11 years) children were exposed to a memory task which involved multiple overt rehearsal and recall phases. The children were either free to rehearse any words from a taxonomically structured list or they were taught to rehearse in categories. The recall phase was either free or categorically cued. The number of repetitions in rehearsal increased only as a function of age. All of the independent variables facilitated the amount of organized rehearsal and the amount of retention. Children at all ages were able to maximize the relative amount of organized rehearsal when rehearsal was cued. The correlational analysis of the dependent variables indicated that for young children the quantity of rehearsal was linked to retention, but for older children the quality of rehearsal was related to retention. The results were interpreted as demonstrating the bases for production inefficiencies.     

The development of organized visual search

Visual search plays an important role in guiding behavior. Children have more difficulty performing conjunction search tasks than adults. The present research evaluates whether developmental differences in children's ability to organize serial visual search (i.e., search organization skills) contribute to performance limitations in a typical conjunction search task. We evaluated 134 children between the ages of 2 and 17 on separate tasks measuring search for targets defined by a conjunction of features or by distinct features. Our results demonstrated that children organize their visual search better as they get older. As children's skills at organizing visual search improve they become more accurate at locating targets with conjunction of features amongst distractors, but not for targets with distinct features. Developmental limitations in children's abilities to organize their visual search of the environment are an important component of poor conjunction search in young children. In addition, our findings provide preliminary evidence that, like other visuospatial tasks, exposure to reading may influence children's spatial orientation to the visual environment when performing a visual search.     

Learning the structure of event sequences

How is complex sequential material acquired, processed, and represented when there is no intention to learn? Two experiments exploring a choice reaction time task are reported. Unknown to Ss, successive stimuli followed a sequence derived from a "noisy" finite-state grammar. After considerable practice (60,000 exposures) with Experiment 1, Ss acquired a complex body of procedural knowledge about the sequential structure of the material. Experiment 2 was an attempt to identify limits on Ss ability to encode the temporal context by using more distant contingencies that spanned irrelevant material. Taken together, the results indicate that Ss become increasingly sensitive to the temporal context set by previous elements of the sequence, up to 3 elements. Responses are also affected by priming effects from recent trials. A connectionist model that incorporates sensitivity to the sequential structure and to priming effects is shown to capture key aspects of both acquisition and processing and to account for the interaction between attention and sequence structure reported by Cohen, Ivry, and Keele (1990).     

The perception of 3-dimensional affine structure from minimal apparent motion sequences

The research described in the present article was designed to identify the minimal conditions for the visual perception of 3-dimensional structure from motion by comparing the theoretical limitations of ideal observers with the perceptual performance of actual human subjects on a variety of psychophysical tasks. The research began with a mathematical analysis, which showed that 2-frame apparent motion sequences are theoretically sufficient to distinguish between rigid and nonrigid motion and to identify structural properties of an object that remain invariant under affine transformations, but that 3 or more distinct frames are theoretically necessary to adequately specify properties of euclidean structure such as the relative 3-dimensional lengths or angles between nonparallel line segments. A series of four experiments was then performed to verify the psychological validity of this analysis. The results demonstrated that the determination of structure from motion in actual human observers may be restricted to the use of first order temporal relations, which are available within 2-frame apparent motion sequences. That is to say, the accuracy of observers' judgments did not improve in any of these experiments as the number of distinct frames in an apparent motion sequence was increased from 2 to 8, and performance on tasks involving affine structure was of an order of magnitude greater than performance on similar tasks involving euclidean structure.     

John Lind memorial symposium

John Lind, Professor of Pediatrics at the Karolinska Institute, emphasized that “the family is born in the maternity hospital.” He had a warm concern for all parents and infants and was extremely influential in both pediatric and child-rearing practices in Sweden and in the promotion of infant and caregiver-infant interaction research. Lind initiated and/or stimulated the scientific study of the infant's cry, parent-infant interactions, the role of the father in the perinatal environment, fetal and neonatal perception, and perinatal hospital practices. In many respects, his work predated contemporary emphases on perinatal coaching programs, social support (doula) during labor and delivery, parent education on childrearing, the use of ethnographic data for contemporary perinatal practices, interdisciplinary team approaches to study of infant care and development, changes in newborn nursery practices, and, above all, care and sensitivity to the initial synchronization of the parent-infant interaction system. This paper honors John Lind's contributions to our knowledge of infant development and parent-infant interaction, his influences on the field of pediatrics and the interdisciplinary study of infancy, and his commitment to enhancement of the quality of life for infants and their families. Although his life has ended, his ideas will continue to inspire and challenge the study of early human development for many years to come.     

Preferences for scale structure in melodic sequences

Most Western music is tonal; that is, pitch organization can largely be described in terms of scales or keys. A considerable amount of research has been conducted on the role played by scale in perceiving notes and melodies. The present article points out a potentially important distinction between scale structure (the set permitted pitch intervals between notes) and mode (the assignment of a special salience or centrality to particular notes within the scale structure). Four experiments are described that investigated the judgment of adult Western listeners for melodies that approximated to scale structure in differing degrees but that were random in other respects. We found that musicians and nonmusicians gave higher ratings of preference and adjudged musicality to melodies containing increased numbers of consecutive notes conforming to scale structure. A significant exception to this rule was the least scalar type of sequence, which received ratings as high as the fully scalar sequences. This exception occurred because subjects identified scale structure not only in groups of contiguous notes but also in groups of discontiguous notes that formed a coherent "stream" as long as the number of notes intervening corresponded to a standard temporal grouping, or meter, such as is commonly found in Western music.     

The effects of uncontrollable failure and depression on memorial processes

Many investigators have argued that exposure to uncontrollable failure and depressed mood affect learning processes. However, little has been done to explore how information processing is affected by such events. Two experiments revealed that prior failure (Experiment 1) and depressed mood (Experiment 2) have similar effects on a simple free-recall task. These data are interpreted to suggest that the experience of uncontrollable failure and depression disrupt the transfer or retrieval of new information from a transient to a more permanent storage format. The implications of these data are discussed.     

Associative relations in instrumental learning: The eighteenth Bartlett memorial lecture

Instrumental learning involves three primary events: a stimulus (S), a response (R), and an outcome (O). Evidence is reviewed indicating the presence of binary associations among those events, as well as a hierarchical structure of the form S-(R-O). Experiments examining the conditions that produce learning, the content of the learning once it has occurred, and the way learning maps into performance all suggest the presence of such a hierarchical structure.     

Domain-specific learning of grammatical structure in musical and phonological sequences

Artificial grammar learning depends on acquisition of abstract structural representations rather than domain-specific representational constraints, or so many studies tell us. Using an artificial grammar task, we compared learning performance in two stimulus domains in which respondents have differing tacit prior knowledge. We found that despite grammatically identical sequence structures, learning was better for harmonically related chord sequences than for letter name sequences or harmonically unrelated chord sequences. We also found transfer effects within the musical and letter name tasks, but not across the domains. We conclude that knowledge acquired in implicit learning depends not only on abstract features of structured stimuli, but that the learning of regularities is in some respects domain-specific and strongly linked to particular features of the stimulus domain.     

Statistical learning of higher-order temporal structure from visual shape sequences

In 3 experiments, the authors investigated the ability of observers to extract the probabilities of successive shape co-occurrences during passive viewing. Participants became sensitive to several temporal-order statistics, both rapidly and with no overt task or explicit instructions. Sequences of shapes presented during familiarization were distinguished from novel sequences of familiar shapes, as well as from shape sequences that were seen during familiarization but less frequently than other shape sequences, demonstrating at least the extraction of joint probabilities of 2 consecutive shapes. When joint probabilities did not differ, another higher-order statistic (conditional probability) was automatically computed, thereby allowing participants to predict the temporal order of shapes. Results of a single-shape test documented that lower-order statistics were retained during the extraction of higher-order statistics. These results suggest that observers automatically extract multiple statistics of temporal events that are suitable for efficient associative learning of new temporal features.     

Cross-octave masking of single tones and musical sequences: The effects of structure on auditory recognition

A series of experiments explored the role of structural information in the auditory recognition process, within the context of a backward recognition masking paradigm. A masking tone presented after a test tone has been found to interfere with the perceptual processing of the test tone, the degree of interference decreasing with increased durations of the silent intertone interval between the test and masking tones. In the current studies, the task was modified to utilize three-tone sequences as the test stimuli. Six test sequences were employed (LMH, LHM, MLH, MHL, HLM, HML), where L, M, and H represent the lowest, middle, and highest frequencies in the melody. The observers identified these six possible sequences when the three tones of the test sequence were interleaved with three presentations of a single masking tone. All three tones of the test sequence were drawn from the same octave, while the masking tones could be drawn from any of three octaves, symmetrical around the octave containing the test tones. Under these conditions, interference occurred primarily from masking tones drawn from the same octave as the test tones. Masking tones drawn from other octaves were found to produce little, if any, interference with perception of the test tones. This effect was found to occur only for the identification of tonal sequences. Substantial masking of single-tone targets occurred with masking tones drawn from octaves other than that containing the targets. The results make apparent the use of structural information during auditory recognition. A theoretical interpretation was advanced which suggests that, while single tones are perceived on the basis of absolute pitch, the presence of auditory structure may allow relational information, such as exact pitch intervals or melodic contour, to facilitate perception of the tonal sequence.