Effects of the periodic administration of odor or vibration on a 3-hr. vigilance task

The present study examined performance during 3 hr. of simulated sentry duty with and without the intermittent administration of low-level sensory stimuli (odor or vibration). For odor and control conditions, target-detection latency increased steadily over the course of the 3-hr. session. Administration of a tactile stimulus reduced the increase in detection latency compared to that found in odor and control conditions. For all conditions, there were no significant differences in target-detection frequency, shot accuracy, or friend-foe discrimination. Across all conditions, restlessness (motor activity) increased significantly the first hour and remained elevated for the rest of the session. Subjective measures of workload (NASA-TLX) indicated that the 3-hr. task rated high on physical demand, mental demand, frustration, and overall workload. These findings suggest that the intermittent delivery of a clearly detectable tactile stimulus can reduce reaction-time decrements that occur as time on task increases.     

Spatial representation by young infants: Categorization of spatial relations or sensitivity to a crossing primitive?

The spatial representation abilities of 3- to 4-month-old infants were examined in four experiments. Experiments 1 and 2 showed that infants familiarized with a diamond appearing in distinct locations to the left or right of a vertical bar subsequently preferred a stimulus depicting the diamond on the opposite side of the bar over a stimulus depicting the diamond in a novel location on the same side of the bar. Experiment 3 was a replication of Experiment 1, except that the bar was oriented at 45 degrees. In this instance, infants divided their attention between the stimulus depicting the diamond on the opposite side of the bar and the stimulus depicting the diamond in a novel location on the same side of the bar. Experiment 4 demonstrated that the results of Experiment 3 were not a consequence of a failure to process the diagonal bar. When considered with previous reports that infants can represent the categories of above and below (Quinn, 1994), the present results suggest that (1) infants can also represent the categories of left and right, and (2) performance cannot be interpreted as a response to an arbitrary crossing of one object relative to another. Although recent discussions of the relation between language and cognition have pointed to the ways in which spatial language influences spatial cognition (Bowerman & Levinson, 2001), the present findings are consistent with an influence in the opposite direction: Spatial cognition may in some instances shape spatial language.     

Advantages and disadvantages of phonological similarity in serial recall and serial recognition of nonwords

The phonological similarity effect (PSE) was studied with lists of nonwords in one task of serial recall and one task of serial recognition. PSE was critically affected by the scoring procedure and the type of phonological similarity involved, and the effect diverged in several ways from the findings of previous studies on words. PSE was absent in serial recall, regardless of scoring procedure, when phonologically similar items that shared the midvowel were compared with phonologically distinct items. PSE was reversed when serial recall and item recall scores of rhyme items and consonant frame items were compared with distinct items, but it was present in the position accuracy score of rhyme lists. In serial recognition, PSE was absent when rhyme lists were compared with distinct lists. Recognition was better for consonant frame lists than for rhyme lists, and there was a marginally significant reversal of PSE when consonant frame lists were compared with distinct lists. In the view of Fallon, Groves, and Tehan's (1999) study and the present study, rhyming improves item recall and serial recall but diminishes position accuracy, regardless of lexicality. But consonant frame lists with differing midvowels have higher item recall, serial recall, and position accuracy scores than do rhyme lists.     

Developmental outcomes after early prefrontal cortex damage

The neuropsychological bases of cognitive, social, and moral development are minimally understood, with a seemingly wide chasm between developmental theories and brain maturation models. As one approach to bridging ideas in these areas, we review 10 cases of early prefrontal cortex damage from the clinical literature, highlighting overall clinical profiles and real life developmental outcomes. Based on these cases, there is preliminary evidence to support distinctive developmental differences after: (1) dorsolateral, (2) mesial, and (3) orbital-polar prefrontal lesions, for more profound impairments after bilateral damage, and possibly for recovery differences after very early vs. later childhood lesion onset. Further case and group studies are needed to confirm reliable effects of specific lesion locations, the influence of age of lesion onset, and related experiential and treatment variables in determining adult outcomes. Rather than a single underlying deficit associated with early prefrontal cortex damage, we interpret the findings to suggest that it is the altered integration and interplay of cognitive, emotional, self-regulatory, and executive/metacognitive deficits that contribute to diverse developmental frontal lobe syndromes. The findings support the fundamental importance of prefrontal cortex maturation in protracted cognitive, social-emotional, and moral development.     

Temporal variation in Irish suicide rates

Using Irish suicide data for the period 1990-1998, the independent effects of month and day adjusting for age, gender, and calendar year effects and distinguishing between holiday and working Mondays were assessed. The male suicide rate was significantly higher on working Mondays (+31%) and Saturdays (+14%), and during April, June, and August (+17%), after adjustment for the other variables. In contrast, female suicide rates were higher only in August (+35%) and exhibited no day effect. Teenage men had a greater elevation of risk on Saturdays, Sundays, and both working and holiday Mondays than any other group. The study findings should be taken into account in the planning of specialized health care services and helplines for suicidal people. Furthermore, the findings provide support for Gabennesch's (1988) broken promise theory and the relationship between dysfunctions of the serotonergic system and suicidal behavior.     

Learning at a distance II. Statistical learning of non-adjacent dependencies in a non-human primate

In earlier work we have shown that adults, infants, and cotton-top tamarin monkeys are capable of computing the probability with which syllables occur in particular orders in rapidly presented streams of human speech, and of using these probabilities to group adjacent syllables into word-like units. We have also investigated adults' learning of regularities among elements that are not adjacent, and have found strong selectivities in their ability to learn various kinds of non-adjacent regularities. In the present paper we investigate the learning of these same non-adjacent regularities in tamarin monkeys, using the same materials and familiarization methods. Three types of languages were constructed. In one, words were formed by statistical regularities between non-adjacent syllables. Words contained predictable relations between syllables 1 and 3; syllable 2 varied. In a second type of language, words were formed by statistical regularities between non-adjacent segments. Words contained predictable relations between consonants; the vowels varied. In a third type of language, also formed by regularities between non-adjacent segments, words contained predictable relations between vowels; the consonants varied. Tamarin monkeys were exposed to these languages in the same fashion as adults (21 min of exposure to a continuous speech stream) and were then tested in a playback paradigm measuring spontaneous looking (no reinforcement). Adult subjects learned the second and third types of language easily, but failed to learn the first. However, tamarin monkeys showed a different pattern, learning the first and third type of languages but not the second. These differences held up over multiple replications, using different sounds instantiating each of the patterns. These results suggest differences among learners in the elementary units perceived in speech (syllables, consonants, and vowels) and/or the distance over which such units can be related, and therefore differences among learners in the types of patterned regularities they can acquire. Such studies with tamarins open interesting questions about the perceptual and computational capacities of human learners that may be essential for language acquisition, and how they may differ from those of non-human primates.     

Difficulties in comprehending causal relations among children with ADHD: the role of cognitive engagement

The present study examined whether time spent in long looks (i.e., >or=15 s), an index of cognitive engagement, would account for differences between children with attention deficit hyperactivity disorder (ADHD) and comparison children in understanding causal relations. Children viewed two televised stories, once in the presence of toys and once in their absence. Dependent variables were visual attention and questions tapping factual information and causal relations. Comparison children answered significantly more causal relations questions than did the children with ADHD, but only in the toys-present condition. Four lines of evidence revealed that the difficulties children with ADHD had in answering causal relations questions in the toys-present condition could be linked specifically to this group's decreased time spent in long looks.     

Contextual moderation of racial bias: the impact of social roles on controlled and automatically activated attitudes

Three experiments tested the hypothesis that the social roles implied by specific contexts can attenuate or reverse the typical pattern of racial bias obtained on both controlled and automatic evaluation measures. Study 1 assessed evaluations of Black and Asian faces in contexts related to athlete or student roles. Study 2 compared evaluations of Black and White faces in 3 role-related contexts (prisoner, churchgoer, and factory worker). Study 3 manipulated role cues (lawyer or prisoner) within the same prison context. All 3 studies produced significant reversals of racial bias as a function of implied role on measures of both controlled and automatic evaluation. These results support the interpretation that differential evaluations based on Race x Role interactions provide one way that context can moderate both controlled and automatic racial bias.     

The relationship among expressions, labels, and descriptions of contempt

This article reports 4 studies that demonstrate that the contempt expression is reliably associated with situations that elicit contempt and that the inability to label the contempt expression reflects a problem with its label or concept and not with the relationship between its expression and emotion. In Study I, the labeling of contempt in fixed-choice judgment tasks did not occur because of a process of elimination. In Studies 2 and 3, the contempt expression was associated with situations that elicit contempt, but participants did not label the situations in an open-ended response. In Study 3, participants also more reliably labeled the contempt expression with situations rather than with labels and did not generate contempt situations from labels. In Study 4, participants reported using, hearing, and reading about contempt the least among 7 emotions tested.     

NEO-PI-R neuroticism scores in substance-dependent outpatients: internal consistency and self-partner agreement

We evaluated internal consistency reliabilities and self-partner agreement on Revised NEO Personality Inventory (Costa & McCrae, 1992) Neuroticism (N) domain and facet scores (anxiety, angry hostility, depression, self-consciousness, impulsiveness, vulnerability) in a sample of 48 substance-dependent outpatients. Low internal consistency was seen for self-rated impulsiveness (alpha =.36). Agreement between self and partner reports was low for impulsiveness (.22) and vulnerability (.24) and was modest for the remaining facets of N (.31 to.34) and the N domain score (.31).