A Diagnostic Test in Which an X-Ray Is Obtained After

question 27

Multiple Choice

A diagnostic test in which an x-ray is obtained after injection of radiopaque contrast material into blood vessels is a(n)

• A)Doppler study
• B)venogram
• C)central venous pressure
• D)angiogram
• E)cardiac stress test

---

Definitions:

Variable-interval

A reinforcement schedule where a response is reinforced after a variable and unpredictable time interval has occurred.

Variable-ratio

A schedule of reinforcement where a response is reinforced after an unpredictable number of responses. This schedule creates a high steady rate of responding.

Fixed-ratio

A schedule of reinforcement where a response is only reinforced after a specific number of responses, common in behaviorist psychology.

Fixed-interval

A schedule of reinforcement where the first response is rewarded only after a specified amount of time has elapsed.