A broadband digitizing rat detector: Simultaneous recording from all sound frequencies in the range of rat ultrasonic vocalizations

A system is described that digitizes rodent vocalizations after the signals have passed through a spectrum analyzer. The system’s capacity to record simultaneously from all frequencies in a range selected by the experimenter is demonstrated. In the graphic display, both single and simultaneous multiple vocalizations of rats ranging freely in large experimental rooms are presented. The capacity of this system to record simultaneous vocalizations in a form that permits rapid analysis of many of the parameters of the signals is especially useful in the analysis of rodent social behavior.     

Common Sense and the Natural Light in George Berkeley’s Philosophy

Philosophia - It is argued that George Berkeley’s term ‘common sense’ does not indicate shared conviction, but the shared capacity of reasonable judgement, and is therefore to be...     

Culture and beliefs about time: comparisons among black Americans, black Africans, and white Americans

The authors investigated the extent to which racial factors, cultural factors, or both influence a person's beliefs about physical time, personal time, and experienced and remembered duration. A total of 750 Black American, Black African, and White American students responded to a questionnaire on these beliefs about time. Factor analysis was used to compare belief structures. Pairwise comparisons, performed separately for each statement, tested the direction and strength of the reported beliefs. The groups showed many similarities, but they also showed some differences. All 3 groups differed in beliefs about physical and personal time, but they did not differ in beliefs about duration experiences. This evidence does not support simplistic views of racial or cultural influences. Culture may differentially influence beliefs about physical time and personal time. Beliefs about duration experiences may represent an ethnic factor that transcends cultures.