Rebellious teens? Genetic and environmental influences on the social attitudes of adolescents

Genetic and environmental influences in social attitudes were investigated in adopted and nonadopted children (N = 654) and their biological and adoptive relatives in the Colorado Adoption Project. Conservatism and religious attitudes were measured in the children annually from ages 12 to 15 and in the parents during the 12-year-old visit. Multivariate genetic model fitting indicated that both conservatism and religious attitudes are strongly influenced by shared-family environmental factors throughout adolescence. In contrast to previous findings from twin studies, which suggest that genetic influence on social attitudes does not emerge until adulthood, the present study detected significant genetic influence in conservatism as early as age 12. There was no evidence of genetic influence, however, on religious attitudes during adolescence.     

Processing of temporal duration information in working memory after frontodorsal tumour excisions

This study aimed to test the hypothesis that impairments of temporal duration processing after frontal lobe lesions reflect deficits in executive monitoring functions rather than a domain-specific deficit in the maintenance of duration information in working memory. Patients with frontodorsal lesions, clinical controls with post-central lesions, and healthy controls performed recognition and classification tasks, which should allow for testing maintenance and monitoring functions, respectively. Results showed mild non-selective impairments of the frontal patients on both temporal and spatial recognition tasks, but a marked selective degradation on temporal classification while performance on spatial classification was unimpaired. This suggests that maintenance of duration information in working memory after frontal lesions is basically preserved but that, depending on executive task characteristics, there is a specific deficit in the strategic organization of this type of information.     

Priming visual face-processing mechanisms: electrophysiological evidence

Accumulated evidence from electrophysiology and neuroimaging suggests that face perception involves extrastriate visual mechanisms specialized in processing physiognomic features and building a perceptual representation that is categorically distinct and can be identified by face-recognition units. In the present experiment, we recorded event-related brain potentials in order to explore possible contextual influences on the activity of this perceptual mechanism. Subjects were first exposed to pairs of small shapes, which did not elicit any face-specific brain activity. The same stimuli, however, elicited face-specific brain activity after subjects saw them embedded in schematic faces, which probably primed the subjects to interpret the shapes as schematic eyes. No face-specific activity was observed when objects rather than faces were used to form the context. We conclude that the activity of face-specific extrastriate perceptual mechanisms can be modulated by contextual constraints that determine the significance of the visual input.     

Index to Volume 23

Other Index

Index to Volume 23     

Word naming times and psycholinguistic norms for Italian nouns

The present study describes normative measures for 626 Italian simple nouns. The database (LEXVAR. XLS) is freely available for down-loading on the Web site http://wwwistc.ip.rm.cnr.it/material/ database/. For each of the 626 nouns, values for the following variables are reported: age of acquisition, familiarity, imageability, concreteness, adult written frequency, child written frequency, adult spoken frequency, number of orthographic neighbors, mean bigram frequency, length in syllables, and length in letters. A classification of lexical stress and of the type of word-initial phoneme is also provided. The intercorrelations among the variables, a factor analysis, and the effects of variables and of the extracted factors on word naming are reported. Naming latencies were affected primarily by a factor including word length and neighborhood size and by a word frequency factor. Neither a semantic factor including imageability, concreteness, and age of acquisition nor a factor defined by mean bigram frequency had significant effects on pronunciation times. These results hold for a language with shallow orthography, like Italian, for which lexical nonsemantic properties have been shown to affect reading aloud. These norms are useful in a variety of research areas involving the manipulation and control of stimulus attributes.     

The Roles of Ethnicity and School Context in Predicting Children's Victimization by Peers

This study examines the prevalence, stability, and contextual correlates of peer victimization in a sample of African-American, Hispanic, and non-Hispanic White urban elementary school-age children. A total of 1956 children (40% African-American, 42% Hispanic, and 18% White) attending any 1 of 14 public elementary schools located in one large and one mid-sized Midwestern city participated in this study. Peer ratings of victimization were obtained at two points in time, separated by a 2-year period. Findings revealed that risk for being victimized by peers varied by ethnicity and by school context. Hispanic children had lower victimization scores than did either African-American or White children. These findings, however, were moderated by school context, such that attending ethnically integrated schools was associated with a significantly higher risk of victimization for White children and a slightly lower risk of victimization for African-American children and did not affect the risk of victimization for Hispanic children. In addition, African-American children were less likely than Hispanic and White children to be repeatedly victimized by peers over time. The importance of considering ethnicity and context in explaining peer victimization is discussed and suggestions for preventive interventions and future research are provided.     

Implicit motor sequence learning is represented in response locations

Previous work (Willingham, 1999) has indicated that implicit motor sequence learning is not primarily perceptual; that is, what is learned is not a sequence of stimuli. Still other work has indicated that implicit motor sequence learning is not specific to particular muscle groups or effectors. In the present work, we tested whether implicit motor sequence learning would be represented as a sequence of response locations. In Experiment 1, learning showed very poor transfer when the response locations were changed, even though the stimulus positions were unchanged. In Experiment 2, participants switched their hand positions at transfer, so that one group of participants pushed the same sequence of keys but used a different sequence of finger movements to do so, whereas another group pushed a different sequence of keys but used the same sequence of finger movements used at training. Knowledge of the sequence was shown at transfer only if the sequence of response locations was maintained, not the sequence of finger movements.     

Auditory language comprehension: an event-related fMRI study on the processing of syntactic and lexical information

The functional specificity of different brain regions recruited in auditory language processing was investigated by means of event-related functional magnetic resonance imaging (fMRI) while subjects listened to speech input varying in the presence or absence of semantic and syntactic information. There were two sentence conditions containing syntactic structure, i.e., normal speech (consisting of function and content words), syntactic speech (consisting of function words and pseudowords), and two word-list conditions, i.e., real words and pseudowords. The processing of auditory language, in general, correlates with significant activation in the primary auditory cortices and in adjacent compartments of the superior temporal gyrus bilaterally. Processing of normal speech appeared to have a special status, as no frontal activation was observed in this case but was seen in the other three conditions. This difference may point toward a certain automaticity of the linguistic processes used during normal speech comprehension. When considering the three other conditions, we found that these were correlated with activation in both left and right frontal cortices. An increase of activation in the planum polare bilaterally and in the deep portion of the left frontal operculum was found exclusively when syntactic processes were in focus. Thus, the present data may be taken to suggest an involvement of the left frontal and bilateral temporal cortex when processing syntactic information during comprehension.