Developmental cognitive neuroscience: progress and potential

Developmental cognitive neuroscience is an evolving field that investigates the relations between neural and cognitive development. Lying at the intersection of diverse disciplines, work in this area promises to shed light on classic developmental questions, mechanisms subserving developmental change, diagnosis and treatment of developmental disorders, and cognitive and neuroscientific topics traditionally considered outside the domain of development. Fundamental questions include: What are the interrelations between developmental changes in the brain (e.g. in connectivity, chemistry, morphology) and developmental changes in children's behavior and cognitive abilities (e.g. representational complexity, ability to sustain selective attention, speed of processing)? Why, and how, is learning enhanced during certain periods in development? How is our knowledge organized, and how does this change with development? We discuss preliminary investigations of such questions and directions for future work.     

The race model inequality: interpreting a geometric measure of the amount of violation

An inequality by J. O. Miller (1982) has become the standard tool to test the race model for redundant signals reaction times (RTs), as an alternative to a neural summation mechanism. It stipulates that the RT distribution function to redundant stimuli is never larger than the sum of the distribution functions for 2 single stimuli. When many different experimental conditions are to be compared, a numerical index of violation is very desirable. Widespread practice is to take a certain area with contours defined by the distribution functions for single and redundant stimuli. Here this area is shown to equal the difference between 2 mean RT values. This result provides an intuitive interpretation of the index and makes it amenable to simple statistical testing. An extension of this approach to 3 redundant signals is presented.     

Conditions under which young children can hold two rules in mind and inhibit a prepotent response

The day-night task requires saying "night" to a picture of the sun and "day" to a picture of the moon. In this investigation of why young children fail at this task, systematic variations of the task were administered to 96 children, half 4 years old and half 4 1/2 years old. Training children on the strategy of chunking the 2 rules into I ("say the opposite"), thus reducing memory load, did not help their performance. What helped was reducing the inhibitory demand by instructing them to say "dog" and "pig" (not "night" and "day") even though memory of 2 rules and inhibiting saying what the pictures represented were still required. Here the response to be activated and the response to be inhibited were unrelated. When the correct response was semantically related to, and the direct opposite of, the to-be-inhibited response, children performed poorly. Inserting a delay between stimulus and response helped even though that delay was filled with distraction. Young children apparently need several seconds to compute the answer on this task. Often they do not take the needed time; when forced to do so, they do well.     

Modeling spatial effects in visualtactile saccadic reaction time

Saccadic reaction time (SRT) to visual targets tends to be shorter when nonvisual stimuli are presented in close temporal or spatial proximity, even when subjects are instructed to ignore the accessory input. Here, we investigate visualtactile interaction effects on SRT under varying spatial configurations. SRT to bimodal stimuli was reduced by up to 30 msec, in comparison with responses to unimodal visual targets. In contrast to previous findings, the amount of multisensory facilitation did not decrease with increases in the physical distance between the target and the nontarget but depended on (1) whether the target and the nontarget were presented in the same hemifield (ipsilateral) or in different hemifields (contralateral), (2) the eccentricity of the stimuli, and (3) the frequency of the vibrotactile nontarget. The time-window-of-integration (TWIN) model for SRT (Colonius & Diederich, 2004) is shown to yield an explicit characterization of the observed multisensory spatial interaction effects through the removal of the peripheral-processing effects of stimulus location and tactile frequency.     

Responses of dairy heifers to the visual cliff formed by a herringbone milking pit: evidence of fear of heights in cows (Bos taurus)

The ability of cows (Bos taurus) to perceive depth has never been experimentally investigated. If cows can perceive depth, the milking pit in commercial milking facilities may be fear provoking for dairy cows, as past research has shown that most land-dwelling species possess an instinctive fear of heights. In the current study, 12 dairy heifers (1-year-old cows) were exposed to a milking pit (depth-exposed group) and 13 heifers (control group) were exposed to a standard change in the environment while they moved through a milking facility over a 5-day treatment period. Heifers in the depth-exposed group showed a higher heart rate (p < .05) and stopped more often (p < .05) than did those in the control group; persistence of heart rate but not of behavioral responses on repeated exposures indicated that some habituation to the depth stimulus had occurred. Depth exposure had no effect on cortisol concentrations or on ease of handling. These results indicate that heifers responded differently to a change in depth than they did to a standard change in the environment and provide evidence of both depth perception and acute fear of heights in cows.     

Stigma and the delegitimation experience: An interpretative phenomenological analysis of people living with chronic fatigue syndrome

Individual in-depth interviews with 14 people with chronic fatigue syndrome (CFS) were conducted, focusing on the experience of living with CFS. The interviews were transcribed verbatim and were analysed for recurrent themes using interpretative phenomenological analysis (IPA). Here we present two inter-related themes: “Negotiating a diagnosis” and “Negotiating CFS with loved ones”. Participants reported delay, negotiation and debate over diagnosis: further, they perceived their GPs to be sceptical, disrespectful and to be lacking in knowledge and interpersonal skills. However, participants found delegitimising encounters with their partners more difficult to deal with. Participants viewed such delegitimation as a form of personal rejection; they were hurt by their loved ones’ reactions and subsequently pondered the price of love, respect and friendship. The findings are discussed in relation to extant literature, and recommendations for future research are suggested.     

The Panel Study on American Religion and Ethnicity: Background, Methods, and Selected Results

Surveying 2,610 respondents, the Panel Study of American Religion and Ethnicity is a nationally representative in-home survey of the noninstitutionalized U.S. adult population. The survey is designed to (a) focus primarily on religion and spirituality (with over 200 questions on these topics), (b) include multiple other modules (such as health, family relationships, and social ties), (c) oversample African Americans, Asians, and Hispanics, and (d) follow the same respondents over time. We describe the main design features of the survey, present some characteristics of the sample, and provide basic findings. It is our hope that these data will foster more research and contribute to a better understanding of the role and meaning of religion in the contemporary United States .