A file extension is the set of three or four characters at the end of a filename; in this case, .obj. File extensions tell you what type of file it is, and tell Windows what programs can open it. Windows often associates a default program to each file extension, so that when you double-click the file, the program launches automatically.
A sensory threshold is the level of strength a stimulus must reach to be detected. Psychologists study sensory thresholds to learn how humans and animals process sensory information.An absolute threshold is the lowest level of strength necessary for detection.For example, when sounds are just loud enough to hear (but no louder), they occur at the absolute threshold.Absolute thresholds vary according to sensory adaptation (diminished sensitivity to stimulus after prolonged exposure).Animals often have different absolute thresholds than people. The differential threshold is the point of lowest intensity at which one can tell that a stimulus has strengthened.n absolute threshold is the lowest level of strength necessary for detection. For example, when sounds are just loud enough to hear (but no louder), they occur at the absolute threshold. Absolute thresholds vary according to sensory adaptation (diminished sensitivity to stimulus after prolonged exposure).
Object permanence. Object permanence is the understanding that objects continue to exist even when they cannot be observed. This is a fundamental concept studied in the field of developmental psychology, the subfield of psychology that addresses the development of infants' and children's social and mental capacities. There is not yet scientific consensus on when the understanding of object permanence emerges in human development. Some researchers contend that it is acquired within the first two years of life, while others believe that it is an innate or built-in understanding present at birth.