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Biomedical subjects

Andrew P King

Publications and source records attributed to Andrew P King.

6 recordsLinked to original sources
PubMed2006

Developmental origins of sociality in brown-headed cowbirds (Molothrus ater).

Five variables were studied relating to the emergence of sociality in hand-reared cowbirds (Molothrus ater): proximity, sex assortment, reactions to adults, head-down displays, and vocalizations. The authors were especially interested in female sociality because adult female birds influence male courtship, song content, and use through proximity, attention, and displays. The authors found that young female birds failed to show same-sex affiliation typical of the species at any point in the study. Brief introduction of adults did not affect social patterns. Adults used more head-down displays than juveniles, who used more displays with familiar peers. Directed and undirected singing emerged concurrently; directed singing was positively correlated with earlier hatching. This is the first demonstration of the need for early learning in the development of female sociality.

Age Factors↗
PubMed2005

Alignment of sparse freehand 3-D ultrasound with preoperative images of the liver using models of respiratory motion and deformation.

We present a method for alignment of an interventional plan to optically tracked two-dimensional intraoperative ultrasound (US) images of the liver. Our clinical motivation is to enable the accurate transfer of information from three-dimensional preoperative imaging modalities [magnetic resonance (MR) or computed tomography (CT)] to intraoperative US to aid needle placement for thermal ablation of liver metastases. An initial rigid registration to intraoperative coordinates is obtained using a set of US images acquired at maximum exhalation. A preprocessing step is applied to both the preoperative images and the US images to produce evidence of corresponding structures. This yields two sets of images representing classification of regions as vessels. The registration then proceeds using these images. The preoperative images and plan are then warped to correspond to a single US slice acquired at an unknown point in the breathing cycle where the liver is likely to have moved and deformed relative to the preoperative image. Alignment is constrained using a patient-specific model of breathing motion and deformation. Target registration error is estimated by carrying out simulation experiments using resliced MR volumes to simulate real US and comparing the registration results to a "bronze-standard" registration performed on the full MR volume. Finally, the system is tested using real US and verified using visual inspection.

Algorithms↗
PubMed2003

Social interaction shapes babbling: testing parallels between birdsong and speech.

Birdsong is considered a model of human speech development at behavioral and neural levels. Few direct tests of the proposed analogs exist, however. Here we test a mechanism of phonological development in human infants that is based on social shaping, a selective learning process first documented in songbirds. By manipulating mothers' reactions to their 8-month-old infants' vocalizations, we demonstrate that phonological features of babbling are sensitive to nonimitative social stimulation. Contingent, but not noncontingent, maternal behavior facilitates more complex and mature vocal behavior. Changes in vocalizations persist after the manipulation. The data show that human infants use social feedback, facilitating immediate transitions in vocal behavior. Social interaction creates rapid shifts to developmentally more advanced sounds. These transitions mirror the normal development of speech, supporting the predictions of the avian social shaping model. These data provide strong support for a parallel in function between vocal precursors of songbirds and infants. Because imitation is usually considered the mechanism for vocal learning in both taxa, the findings introduce social shaping as a general process underlying the development of speech and song.

Animals↗
PubMed2002

The presumption of sociality: social learning in diverse contexts in brown-headed cowbirds (Molothrus ater).

Data are presented on social and vocal learning in cowbirds (Molothrus ater) housed in large aviaries and given more degrees of freedom than in conventional experimental studies. The studies show that social and vocal outcomes are facultative responses to social contexts. Several findings are reviewed: First, cowbirds quickly self-organize into groups by age and sex; second, opportunities to interact across age and sex do exist and affect courtship competence; third, female cowbirds organize themselves differently in the presence and absence of male competition; and fourth, young, naive cowbirds show rapid and differential sensitivity to group dynamics. Taken as a whole, the data show that social Umwelten are dynamic, developmental ecologies.

Age Factors↗
PubMed2002

Voice recognition technology as a tool for behavioral research.

Behavioral research often requires the acquisition and processing of large volumes of data. Most current techniques for recording behavior constrain the amount and type of data that can be measured. We developed and tested a system that uses voice recognition technology to collect data on the social interactions and singing patterns of cowbirds (Molothrus ater) living outdoors in a semi-natural environment. We spoke observation data into a wireless microphone that transmitted the data to a computer in the laboratory. After collection, the data were automatically checked for errors and then were entered into a database. Overall, the system performed at extremely high levels of accuracy. Furthermore, owing to the removal of constraints on observers such as breaking visual contact with subjects and manual data entry into a database, we were able to increase the amount of data collected and to collect new measures of social interactions that have not been available to us in the past. We tested the system under the challenging circumstances of field observation, and it performed above our expectations. In a laboratory setting, if transmission difficulties are removed, voice recognition could be even more accurate. We recommend voice recognition as a powerful new tool for the variety of research fields in which measuring behavior is involved.

Animals↗