Long-term memory and retrieval at ages 2, 3, 4

Two experiments are reported examining the contents and accessibility of a subset of the knowledge represented in long-term memory by very young children. In Experiment 1, children aged 2 to 4 were asked in a production task to name items commonly found in particular rooms in a house, and then to verify the appropriate locations of a set of miniature replicas of household items in a dollhouse. In Experiment 2, object context was manipulated to observe if further external context improves or changes production. Children 3 and 4 years old were asked to produce appropriate room items under one of three conditons: either presented no room objects as in the first experiment, or given room objects highly- or less-frequently associated in the first study.Very young children revealed considerable knowledge in this domain, and even at the youngest ages, core defining information was retrieved. It was equally clear, however, that young children know much more than they can produce, that there is noticeable improvement in ability to retrieve information over this age range, and that additional external object context does not necessarily facilitate retrieval from long-term memory.     

Masking disrupts recovery of location information

In two experiments, we tested subjects’ ability to localize a letter in a character string with identification controlled by varying the delay of a mask, dimming the display, or deleting some of the dots used to define the letters on the cathode-ray screen. The first experiment involved two tasks. In the first task, subjects indicated whether or not a letter named verbally had been present in an eight-letter target string. In the second task, they localized a letter named verbally in the target string; the target string was presented by using display parameters shown in the first task to hold character identification between 70% and 75% correct. In the second experiment, we tallied errors in a partial-report bar-probe study after equating performance across the manipulations of display quality. Masking disrupted subjects’ ability to recover location information more than either a manipulation of stimulus luminance or a manipulation of its visual form.     

Performance or capacity, the model still requires definitions and boundaries it doesn't have

Siegel is correct that, in its current form, the specific constructs underlying the Demands and Capacities Model cannot be adequately defined. However, substituting observable behavior (performance) for presumed underlying weaknesses in the speech production systems of those who stutter (capacity) does not appear to solve the problem of circularity identified. Rather, demands have not been adequately defined, either.

There is much to agree with in Siegel's note. However, it is not clear to me that the Demands and Capacities Model is salvaged by substituting the term “Performance” for “Capacity.” Rather, the problem with the Model is one of defining terms precisely enough so that the Model is not circular (as Ingham & Cordes (1997) have noted), or the logical inverse of Procruste's bed, as I have stated elsewhere (Bernstein Ratner, 1997), a model that fits all interpretations simply because it stretches to fit all possibilities.     

Harnessing the Power of a Novel Program for Dynamic Balance Perturbation with Supported Body Weight

Abstract

Self-initiated postural adjustments commonly occur in daily life. To accessibly measure this type of dynamic balance, we developed a simple computer program to induce virtual perturbations and combined it with a commercially available balance board and portable EMG system to measure resulting self-initiated postural adjustments. When performing perturbed balance tests, safety harness with body weight support (BWS) is often used. However, influences of these harnesses on postural reactions are not well known. This study investigated the sensitivity of our assessment tool under different BWS conditions and muscle responses during postural adjustments following perturbation at different directions. Fifteen neurologically intact participants performed self-initiated postural adjustments under conditions with: (1) no harness; (2) harness with no BWS; and (3) harness with 10% BWS. Postural adjustment time and muscle activities of the lower leg were measured. We observed significant increases in postural adjustment time in the harness with no BWS condition and differneces in lower leg muscles response to virtual perturbation. Our findings suggest that the combination of our customized program with EMG is a sensitive and convenient tool to measure postural adjustments that approximate real-world scenarios. This method can be used with light body weight support to ensure safety without influencing muscle synergies.     

Mental health assessment of infants,toddlers, and preschoolers in a service program and a treatment outcome research program

This article describes the mental health assessment in preparation for treatment conducted in two University-based clinical programs that offer dyadic child-parent psychotherapy as the treatment modality. The Infant-Parent Program is a mental health program serving children between birth and 3 years of age and their families when the parent-child relationship is jeopardized by risk factors in the parent, child, or family circumstances. The Child Trauma Research Project is an intervention outcome research program serving preschool- aged children and their mothers when the child witnessed domestic violence. The programs share a similar assessment approach emphasizing the importance of a working alliance, spontaneous parental reports, and observation of child-parent interaction in a variety of settings. However, their different functions in terms of clinical service and research dictate appropriate modifications in their respective assessment procedures. The two assessment protocols and their rationale will be described in the context of the clinical and research goals of the programs. © 1997 Michigan Association for Infant Mental Health     

Non-symbolic arithmetic in adults and young children

Five experiments investigated whether adults and preschool children can perform simple arithmetic calculations on non-symbolic numerosities. Previous research has demonstrated that human adults, human infants, and non-human animals can process numerical quantities through approximate representations of their magnitudes. Here we consider whether these non-symbolic numerical representations might serve as a building block of uniquely human, learned mathematics. Both adults and children with no training in arithmetic successfully performed approximate arithmetic on large sets of elements. Success at these tasks did not depend on non-numerical continuous quantities, modality-specific quantity information, the adoption of alternative non-arithmetic strategies, or learned symbolic arithmetic knowledge. Abstract numerical quantity representations therefore are computationally functional and may provide a foundation for formal mathematics.     

Lexical and Metrical Stress in Word Recognition: Lexical or Pre-lexical Influences?

The influence of lexical stress and/or metrical stress on spoken word recognition was examined. Two experiments were designed to determine whether response times in lexical decision or shadowing tasks are influenced when primes and targets share lexical stress patterns (JUVenile–BIBlical [Syllables printed in capital letters indicate those syllables receiving primary lexical stress.]). The results did not support an effect of lexical stress on the organization of lexical memory. In Experiment 3 primes and targets whose first syllables shared lexical stress only (MUDdy–PASta), metrical stress only (alTHOUGH–PASta), both cues (LECtern–PASta), or neither cue (conTROL–PASta) revealed no priming effect. However, targets whose first syllables were strong were responded to faster than targets whose first syllables were weak. Experiment 4 manipulated the metrical stress patterns of bi-syllabic primes and targets. Targets with strong–weak metrical stress patterns were responded to more quickly than those with strong–strong or weak–strong patterns. Although the priming paradigm did not reveal an influence of lexical and metrical stress on the organization of lexical memory, the data do support an influence of strong syllables on the processing of auditorily presented words.     

Novel metaphors appear anomalous at least momentarily: evidence from N400

This study addresses a central question in perception of novel figurative language: whether it is interpreted intelligently and figuratively immediately, or only after a literal interpretation fails. Eighty sentence frames that could plausibly end with a literal, truly anomalous, or figurative word were created. After validation for meaningfulness and figurativeness, the 240 sentences were presented to 11 subjects for event related potential (ERP) recording. ERP's first 200 ms is believed to reflect the structuring of the input; the prominence of a dip at around 400 ms (N400) is said to relate inversely to how expected a word is. Results showed no difference between anomalous and metaphoric ERPs in the early window, metaphoric and literal ERPs converging 300-500 ms after the ending, and significant N400s only for anomalous endings. A follow-up study showed that the metaphoric endings were less frequent (in standardized word norms) than were the anomalous and literal endings and that there were significant differences in cloze probabilities (determined from 24 new subjects) among the three ending types: literal > metaphoric > anomalous. It is possible that the low frequency of the metaphoric element and lower cloze probability of the anomalous one contributed to the processes reflected in the early window, while the incongruity and near-zero cloze probability of the anomalous endings produced an N400 effect in them alone. The structure or parse derived for metaphor during the early window appears to yield a preliminary interpretation suggesting anomaly, while semantic analysis reflected in the later window renders a plausible figurative interpretation.