Noise increment detection in children 1 to 3 years of age

Studies using burst comparison procedures to examine age-related changes in intensity discrimination have reported that the ability to discriminate differences in intensity does not reach maturity until late childhood. In the present study, developmental changes in intensity discrimination were examined in 1- to 3-year-old children, using an increment detection paradigm. Children and adults detected increments in a continuous standard presented at three levels ranging from 35 to 55 dB SPL. Adults were also tested at lower levels of the standard in order to permit age comparisons at equivalent sensation levels. Standard stimuli were two-octave bands of noise centered at either 400 or 4000 Hz, and increments were 200 msec in duration. Discrimination performance improved significantly with both age and level of the standard. For all age groups, performance was significantly better for high- than for low-frequency stimuli, but frequency-dependent differences in increment thresholds did not vary reliably with age. Age differences were largest at low levels of the standard. At the highest level (approximately 30 dB nHL), children's difference limens for both low- and high-frequency noise bands were adultlike by 3 years of age. These results suggest that the developmental time course of increment detection is more rapid than that previously reported in burst comparison studies.     

The structure of the self-concept and its relation to psychological adjustment

Research on the relation between the structure of the self-concept and psychological adjustment has produced seemingly inconsistent findings. Some research suggests that greater pluralism in self-concept structure enhances adjustment, whereas other research suggests that greater unity in the structure enhances adjustment. Four studies examined the relations among measures of self-concept structure and their relations with adjustment. The measures of self-concept structure included two that we viewed as reflecting self-concept pluralism (self-complexity and self-concept compartmentalization) and four that we viewed as reflecting self-concept unity (self-concept differentiation, self-concept clarity, self-discrepancies, and the average correlation among participants' self-aspects). The measures of self-concept pluralism were unrelated to one another, were unrelated to the measures of self-concept unity, and were unrelated to the measures of adjustment. The measures of self-concept unity were moderately related to one another and were moderately related to the measures of adjustment.     

Brain imaging of tongue-twister sentence comprehension: twisting the tongue and the brain

This study used fMRI to investigate the neural basis of the tongue-twister effect in a sentence comprehension task. Participants silently read sentences equated for the syntactic structure and the lexical frequency of the constituent words, but differing in the proportion of words that shared similar initial phonemes. The manipulation affected not only the reading times and comprehension performance, but also the amount of activation seen in a number of language-related cortical areas. The effect was not restricted to cortical areas known to be involved in articulatory speech programming or rehearsal processes (the inferior frontal gyrus and anterior insula), but also extended to areas associated with other aspects of language processing (inferior parietal cortex) associated with phonological processing and storage.     

Hot dogs and zavy cats: preschoolers' and adults' expectations about familiar and novel adjectives

In recent years, a growing body of research has begun to examine the processes that underlie young children's acquisition of adjectival meanings. In the present studies, we examined whether preschoolers' willingness to extend adjectives was influenced by the type of property labeled by familiar adjectives (Experiment 1) and by semantic information conveyed in the sentence used to introduce novel adjectives (Experiment 2). In Experiment 1, we examined preschoolers' and adults' expectations about the generalizability of familiar adjectives of three different types: emotional state terms, physiological state terms, and stable trait terms. On each trial, we labeled a target animal with one of the three different types of adjectives and asked whether these terms could apply to a subordinate-level match, a basic-level match, a superordinate-level match, or an inanimate object. Results indicated that 4-year-olds and adults extended the trait terms, but not the emotional or physiological terms, to members of the same basic-level category. In Experiment 2, we presented 4-year-olds and adults with novel adjectives in one of two verb frames: stable ("This X is very daxy") or transient ("This X feels very daxy"). Participants were more likely to extend the novel adjective to subordinate matches if they were in the Stable frame group than if they were in the Transient frame group. These findings are discussed in terms of implications for young children's expectations about familiar and novel adjectives.     

Ambiguity in the brain: what brain imaging reveals about the processing of syntactically ambiguous sentences

Two fMRI studies investigated the time course and amplitude of brain activity in language-related areas during the processing of syntactically ambiguous sentences. In Experiment 1, higher levels of activation were found during the reading of unpreferred syntactic structures as well as more complex structures. In Experiments 2A and 2B higher levels of brain activation were found for ambiguous sentences compared with unambiguous sentences matched for syntactic complexity, even when the ambiguities were resolved in favor of the preferred syntactic construction (despite the absence of this difference in previous reading time results). Although results can be reconciled with either serial or parallel models of sentence parsing, they arguably fit better into the parallel framework. Serial models can admittedly be made consistent but only by including a parallel component. The fMRI data indicate the involvement of a parallel component in syntactic parsing that might be either a selection mechanism or a construction of multiple parses.     

Evaluating the interdependence of aging-related changes in visual and auditory acuity,balance, and cognitive functioning

High proportions of shared age-related variance are found among measures of perceptual acuity, balance, muscle strength, and cognitive capabilities in age-heterogeneous, cross-sectional studies. Reliance on cross-sectional studies is problematic, however, because associations may arise from age-related mean trends. Narrow age-cohort samples provide an alternative basis for testing hypotheses regarding associations among rates of change. Cross-domain associations were evaluated in combined 75-year-old cohort samples from Denmark, Finland, and Sweden. In general, no consistent associations were found across sensory, balance, strength, and cognitive domains. These findings indicate that the effects of aging on sensory acuity, balance, and cognitive functioning are likely to be largely independent, multidimensional, and complex at the level of the individual.     

The PIG in sPrInG: Evidence on letter grouping from the reading of buried words

We introduce a novel procedure for investigating factors that determine selective attention to letters in words. Participants were presented with words (in Experiments 1 and 3) and nonwords (in Experiment 2) that contained a buried word whose letters differed in color relative to the other letters present (e.g.,pig, in spring). The strings were presented in single case or mixed case, keeping the letters of the buried words in one case (SpRiNg). The time in which the whole stimulus was named was shorter for same-case than for mixed-case strings (forspring: spring < SpRiNg). In contrast, the time in which buried words were named was shorter in mixed- than in same-case strings (forpig: spring > SpRiNg). Across items, the effects of case mixing were negatively correlated across the two tasks. The positive effect of case mixing for buried words also occurred irrespective of whether the whole string was a word or a nonword, and there were contributions from similarity of both letter size and case. The results suggest that case mixing can facilitate selective attention to letters, which is otherwise disrupted by size- and case-based grouping across letter strings. The study provides evidence for letter grouping using size and case information.     

Developmental changes in eyeblink conditioning and neuronal activity in the pontine nuclei

Neuronal activity was recorded in the pontine nuclei of developing rats during eyeblink conditioning on postnatal days 17–18 (P17–P18) or P24–P25. A pretraining session consisted of unpaired presentations of a 300-msec tone conditioned stimulus (CS) and a 10-msec periorbital shock unconditioned stimulus (US). Five paired training sessions followed the unpaired session, consisting of 100 trials of the CS paired with the US. The rats trained on P24–P25 exhibited significantly more conditioned responses (CRs) than the rats trained on P17–P18, although both groups produced CRs by the end of training. Ontogenetic increases in pre-CS and stimulus-elicited activity in the pontine nuclei were observed during the pretraining session and after paired training. The activity of pontine units was greater on trials with CRs relative to trials without CRs in rats trained on P24–P25, but almost no CR-related modulation was observed in the pontine units of rats trained on P17–P18. The findings indicate that pontine neuronal responses to the CS and modulation of pontine activity by the cerebellum and red nucleus undergo substantial postnatal maturation. The developmental changes in pontine neuronal activity might play a significant role in the ontogeny of eyeblink conditioning.     

"Automatism" and the emergence of dynamic psychiatry

This article is about the clash of two explanatory paradigms, each attempting to account for the same data of human experience. In the first half of the nineteenth century, physiologists investigated reflex actions and applied a recently coined word, "automatism," to describe actions which, although seeming to arise from higher centers, actually result from automatic reaction to sensory stimuli. Experiments with spinal reflexes led to the investigation of the reflex action of the brain or "cerebral automatisms." Reflex actions of this kind were used to explain everything from acting compulsively to composing symphonies. Physiological explanations of phenomena of this kind seemed insufficient to some and, in the 1880s, Frederic Myers and Pierre Janet developed psychological frameworks for understanding these phenomena, positing hidden centers of intelligence at work in the individual, outside ordinary awareness, which produce what came to be called "psychological automatisms." Their attempts to unify this psychological framework with the existing physiological one failed. Nevertheless, their work played a crucial role in paving the way for what Ellenberger called dynamic psychiatry, which accepts the reality of an unconscious dynamic of the psyche.