Cognitive fatigue defined in the context of attention networks

We examined the effect of cognitive fatigue on the Attention Networks Test (ANT). Participants were 228 non-demented older adults. Cognitive fatigue was operationally defined as decline in alerting, orienting, and executive attention performance over the course of the ANT. Anchored in a theoretical model implicating the frontal basal ganglia circuitry as the core substrate of fatigue, we hypothesized that cognitive fatigue would be observed only in executive attention. Consistent with our prediction, significant cognitive fatigue effect was observed in executive attention but not in alerting or orienting. In contrast, orienting improved over the course of the ANT and alerting showed a trend, though insignificant, that was consistent with learning. Cognitive fatigue is conceptualized as an executive failure to maintain and optimize performance over acute but sustained cognitive effort resulting in performance that is lower and more variable than the individual's optimal ability.     

The effects of differential vowel prolongations on perceptions of speech naturalness

Prolongation of speech sounds is currently used to modify stuttering and enhance fluency. Prolonged speech (PS) (e.g., prolonged vowels, prolongation throughout utterances) is, however, often perceived as unnatural by listeners. This study examined at which durations and in which contexts 52 college students (primary language was American English) perceived PS to be unnatural. Stimuli were limited to controlled variation in prolongation of the vowel in the middle single-syllable word of a carrier phrase (i.e., say word again). The prolongation was effected by digital waveform manipulation within the Kay Elemetrics Computerized Speech Laboratory (CSL). The listeners judged if they strongly agreed, agreed, or disagreed that the phrases sounded natural. Results indicated that the extent of vowel duration (and possibly context) does influence listener's perception of speech naturalness, findings which can be applied to facilitate fluency therapy.

Educational objectives: (1) The reader will learn about and be able to summarize the digital waveform manipulation procedure in the study. (2) The reader will learn about and be able to describe the effects of differential vowel prolongation on listener's perception of speech naturalness. (3) The reader will learn about and evaluate how differential vowel prolongation can be used to enhance fluency.     

Effects of Control on the Stress Reactions of Commuters1

The effects of morning, rush hour commuting were examined in a quasi-experimental field study involving government-employed commuters (single and carpool drivers). Commuting stress was measured as a response to variations in how difficult it was for commuters to move from home to work. The mediation of these effects by two sources of control in the commuting situation also were assessed. Control was operationalized as control over the internal environment of the car (single versus carpool driver) and choice over routes taken to get to work. Among commuters with a high impedance route, driving to work was associated with significant increases in systolic and diastolic blood pressure and decreases in behavioral performance. The stress of commuting under high impedance conditions was reduced for single drivers relative to carpoolers. Under similar conditions of high impedance, however, having the option to select more than one route to get to work seemed to be more stressful than having only one route. The practical implications of these results are discussed.     

Some parameters affecting the distributional properties of operant-level running in rats

Six adult female albino rats were subjected to operations known to increase the frequency of wheel-running. Operations included limited access to wheel, food deprivation, and protracted maintenance on a 24-hr feeding schedule. A distributional analysis of response duration, burst duration, and inter-burst interval showed that the increased frequency in all cases arose mainly from a shortening of the interval between successive bursts. Only short-term food deprivation produced any notable increase in burst length, and even here changes in both speed of the individual responses and in number of responses per burst were slight compared to changes in inter-burst interval.     

Distributional properties of operant-level locomotion in the rat

Four rats had continuous access to activity wheels first, then access for 1 hr per day, and, subsequently, continuous access. Limiting S's access to the wheel substantially increased the total frequency of running. A distributional analysis of response duration, burst duration, and interburst interval showed that the increased frequency arose almost entirely from a shortening of the interval between successive bursts. In contrast, speed of the individual response and number of responses per burst changed only negligibly. If S were running, the probability that it would either stop or continue did not differ appreciably for the conditions of continuous or limited access to the wheel. But if S were not running, the probability that it would start running was appreciably greater for limited than for continuous access.     

CAREGIVING HISTORY AND PRENATAL DEPRESSIVE SYMPTOMS IN LOW-INCOME ADOLESCENT AND YOUNG ADULT WOMEN: MODERATING AND MEDIATING EFFECTS

Prenatal depressive symptoms have been linked to negative outcomes for mothers and children. Using attachment theory as a framework, this study examined developmental differences in the interpersonal context of prenatal depressive symptoms among adolescents (age 14 to 19 years; n = 352) and young adults (age 20 to 24 years; n = 348). Participants included low-income, single, predominantly African American and Latina women. Moderating and mediating factors were found in the relation between caregiving history (perceived unavailability and inconsistency of maternal and paternal figures during childhood) and depressive symptoms. For pregnant adolescents, maternal unavailability predicted depressive symptoms whereas maternal inconsistency did not. In contrast, for pregnant young women, only maternal inconsistency predicted depressive symptoms; and this association was mediated by perceptions of prenatal support. For both groups, paternal caregiving history had a small yet independent association with depressive symptoms. Results highlight the need to consider developmental differences in the interpersonal context of prenatal depressive symptoms in delivering mental health interventions to young women of color.     

The role of socio-communicative rearing environments in the development of social and physical cognition in apes

The cultural intelligence hypothesis (CIH) claims that humans’ advanced cognition is a direct result of human culture and that children are uniquely specialized to absorb and utilize this cultural experience ( Tomasello, 2000 ). Comparative data demonstrating that 2.5‐year‐old human children outperform apes on measures of social cognition but not on measures of physical cognition support this claim ( Herrmann et al., 2007 ). However, the previous study failed to control for rearing when comparing these two species. Specifically, the human children were raised in a human culture whereas the apes were raised in standard sanctuary settings. To further explore the CIH, here we compared the performance on multiple measures of social and physical cognition in a group of standard reared apes raised in conditions typical of zoo and biomedical laboratory settings to that of apes reared in an enculturated socio‐communicatively rich environment. Overall, the enculturated apes significantly outperformed their standard reared counterparts on the cognitive tasks and this was particularly true for measures of communication. Furthermore, the performance of the enculturated apes was very similar to previously reported data from 2.5‐year‐old children. We conclude that apes who are reared in a human‐like socio‐communicatively rich environment develop superior communicative abilities compared to apes reared in standard laboratory settings, which supports some assumptions of the cultural intelligence hypothesis.     

Modeling growth in boys' aggressive behavior across elementary school: links to later criminal involvement, conduct disorder, and antisocial personality disorder

The present study used general growth mixture modeling to identify pathways of antisocial behavior development within an epidemiological sample of urban, primarily African American boys. Teacher-rated aggression, measured longitudinally from 1st to 7th grade, was used to define growth trajectories. Three high-risk trajectories (chronic high, moderate, and increasing aggression) and one low-risk trajectory (stable low aggression) were found. Boys with chronic high and increasing trajectories were at increased risk for conduct disorder, juvenile and adult arrest, and antisocial personality disorder. Concentration problems were highest among boys with a chronic high trajectory and also differentiated boys with increasing aggression from boys with stable low aggression. Peer rejection was highest among boys with chronic high aggression. Interventions with boys with distinct patterns of aggression are discussed.