Influence of consonantal context on the pronunciation of vowels: a comparison of human readers and computational models

In two experiments, we found that college students' pronunciations of vowels in nonwords are influenced both by preceding and following consonants. The predominance of rimes in previous studies of reading does not appear to arise because readers are unable to pick up associations that cross the onset-rime boundary, but rather because English has relatively few such associations. Comparisons between people's vowel pronunciations and those produced by various computational models of reading showed that no model provided a good account of human performance on nonwords for which the vowel shows contextual conditioning. Possible directions for improved models are suggested.     

Assessing the factorial invariance of Harter's self-concept measures: comparing preadolescents with and without spina bifida using child,parent, and teacher report

The purpose of this study was to determine whether the structure of children's self-concept, as rated by children themselves on the Self-Perception Profile for Children (SPPC; Harter, 1985), and the structure of children's competence, as rated by their parents on the Rating Scale of Child's Actual Behavior (PRS) and teachers on the Rating Scale of Child's Actual Behavior (TRS; Harter, 1985), are similar across samples of children with and without spina bifida (children were 8 and 9 years of age; n = 68 in each sample). Using confirmatory factor analyses, results revealed that a multidimensional model for the SPPC and the TRS fit the data well for both samples. On the other hand, the model for both mothers' and fathers' PRS ratings did not fit the data for the spina bifida sample. Further tests of factorial invariance conducted on the SPPC and TRS revealed that the spina bifida and able-bodied samples tended to have the same pattern and magnitude of factor loadings for both instruments. There was some invariance, however, in the amount of unique error variance accounted for across samples. These results bolster our confidence in using the SPPC and TRS to compare children with and without spina bifida.     

Children's working-memory processes: a response-timing analysis

Recall response durations were used to clarify processing in working-memory tasks. Experiment 1 examined children's performance in reading span, a task in which sentences were processed and the final word of each sentence was retained for subsequent recall. Experiment 2 examined the development of listening-, counting-, and digit-span task performance. Responses were much longer in the reading-and listening-span tasks than in the other span tasks, suggesting that participants in sentence-based span tasks take time to retrieve the semantic or linguistic structure as cues to recall of the sentence-final words. Response durations in working-memory tasks helped to predict academic skill and achievement, largely separate from the contributions of the memory spans themselves. Response durations thus are important in the interpretation of span task performance.     

Sex differences among five sources of motivation in the motivation sources inventory: preliminary findings

Paper reports sex differences among five sources of motivation for a sample of 208 undergraduate students who completed the Motivation Sources Inventory. t tests yielded few statistically significant sex differences for the five sources of motivation; however, Instrumental Motivation was higher among men than women, while the remaining four motives showed no sex difference. Implications and research opportunities are discussed.     

Developments in long-term explicit memory late in the first year of life: behavioral and electrophysiological indices

Coincident with developments in the temporal-cortical explicit memory network, long-term recall abilities are newly emergent late in the first year of human life. We recorded event-related potentials (ERPs) in 9-month-olds as an index of the integrity of the neural substrate underlying a task thought to reflect explicit memory, namely, deferred imitation. ERP measures of recognition memory 1 week after unique laboratory experiences predicted whether and how much infants recalled of the experiences 1 month later. The findings further imply that memory storage and consolidation processes are a major source of variability in long-term recall memory late in the first year of life.     

Modeling unipolar depression as a chaotic process

This study inspected the deterministic structure of unipolar depression. Two women self-monitored sadness hourly 10 times a day for 6 months. One woman had a recurrent history of unipolar depression, and the other did not. Data were analyzed by visual inspection, examination of the Fourier transforms of the time plots, and the correlation dimension. Results suggested that in addition to a strong periodic component that existed only within the depressed subject's mood time series, a low-dimensional chaotic process might have been operating. In the nondepressed control subject, no such periodicity or process could be identified. The findings support maladaptive deterministic theories of mood disorders and have implications for the assessment of unipolar depression.     

Respect for the developmentally disabled and forgoing life-sustaining treatment

A developmentally disabled person should be treated at all times as a unique individual and not as some anonymous "disabled person." The developmentally disabled should not be subjected to invasive medical treatment that is unduly burdensome or nonbeneficial, or be forced to endure a quality of life not meaningful to them as individuals. They have a right to refuse or accept treatment that a surrogate must exercise on behalf of each individual in a responsible and careful manner. Three cases and a preliminary approach to the ethical analysis of decisions to allow developmentally disabled persons to die by forgoing medical treatment are offered. The "best interests" of a developmentally disabled individual, properly understood, can serve as a useful and ethically defensible standard for determining the ethical propriety of surrogate decision making about forgoing life-sustaining medical treatment of the disabled.     

The neural basis of autobiographical and semantic memory: new evidence from three PET studies

A novel, neuropsychologically informed paradigm (extended retrieval of events in response to a cue word) was used to investigate the neural basis of autobiographical and semantic memory. Contrasting retrieval of autobiographical memories with retrieval of semantic facts (ABM-SEM) in 24 subjects across three PET studies revealed bilateral involvement of the middle temporal gyrus (BA 21) and medial frontal cortex (BA 9/10). The opposite contrast, SEM-ABM, resulted in increased regional cerebral blood flow in left posterior temporal regions (BA 37) and left prefrontal cortex (BA 45/46). Laterality maps suggest that the bilateral pattern seen in our studies, but not often in other neuroimaging investigations, reflects the use of a task stressing retrieval of specific personal events. Further comparisons revealed that the activation in the right anterior temporal lobe during autobiographical recall was virtually identical to that seen during retrieval of information about famous people or events in contrast with retrieval of general semantic facts. These findings suggest that the retrieval of an autobiographical event requires participation from conceptual knowledge, and that this type of knowledge is bilaterally distributed in the temporal lobes.