Effect of Extended-release Oxymorphone Taken With or Without Food on Cognitive Functioning

RVP is a test of sustained attention. It is a sensitive measure of general cognitive performance. A white box appears in the center of the computer screen, inside which digits, from 2 to 9, appear in a pseudorandom order, at the rate of 100 digits per minute. The subject is requested to detect target sequences of three digits (for example, 2-4-6, 3-5-7, 4-6-8) and to register responses using the response box. The two main outcome measures are the probability to detect the predefined sequence (sensitivity [A']) and the speed at which the sequence is registered (response latency [ms]).

RVP is a test of sustained attention. It is a sensitive measure of general cognitive performance. A white box appears in the center of the computer screen, inside which digits, from 2 to 9, appear in a pseudorandom order, at the rate of 100 digits per minute. The subject is requested to detect target sequences of three digits (for example, 2-4-6, 3-5-7, 4-6-8) and to register responses using the response box. The two main outcome measures are the probability to detect the predefined sequence (sensitivity [A']) and the speed at which the sequence is registered (response latency [ms]).

SRM tests visual spatial recognition memory in a two-choice forced discrimination paradigm. The subject is presented with a white square, which appears in sequence at five different locations on the screen. In the recognition phase, the subject sees a series of five pairs of squares, one of which is in a place previously seen in the presentation phase. The other square is in a location not seen in the presentation phase. Locations are tested in the reverse of the presentation order. The two main outcome measures are the percentage of correct trials (correct hits [%]) and the speed of the subject's response (response latency [ms]).

SRM tests visual spatial recognition memory in a two-choice forced discrimination paradigm. The subject is presented with a white square, which appears in sequence at five different locations on the screen. In the recognition phase, the subject sees a series of five pairs of squares, one of which is in a place previously seen in the presentation phase. The other square is in a location not seen in the presentation phase. Locations are tested in the reverse of the presentation order. The two main outcome measures are the percentage of correct trials (correct hits [%]) and the speed of the subject's response (response latency [ms]).

SWM is a test of the subject's ability to retain spatial information and to manipulate remembered items in working memory. It is a self-ordered task, which also assesses heuristic strategy. The test is a sensitive measure of executive function. It begins with a number of colored squares (boxes) being shown on the screen. By touching the boxes and using a process of elimination, the subject finds blue tokens in a number of boxes and uses them to fill up an empty column on the screen. The number of boxes is gradually increased, until it is necessary to search a total of eight boxes. The color and position of the boxes are changed from trial to trial to discourage the use of stereotyped search strategies. The two main outcome measures are errors (touching boxes that have been found to be empty and revisiting boxes that have already been found to contain a token - total errors) and a measure of strategy (strategy score).

SWM is a test of the subject's ability to retain spatial information and to manipulate remembered items in working memory. The test is a sensitive measure of executive function. It begins with a number of colored squares (boxes) being shown on the screen. By touching the boxes and using a process of elimination, the subject finds blue tokens in a number of boxes and uses them to fill up an empty column on the screen. The number of boxes is gradually increased, until it is necessary to search a total of eight boxes. The color and position of the boxes are changed from trial to trial to discourage the use of stereotyped search strategies. The two main outcome measures are errors (touching boxes that have been found to be empty and revisiting boxes that have already been found to contain a token - total errors) and a measure of strategy (For assessed problems with six boxes or more, the number of distinct boxes used by the subject to begin a new search for a token)