fMRI Study Examining Effects of D-cycloserine in Specific Phobia

Regions of interest (ROIs) were specified based on previous research and included amygdala, insula, dorsal anterior cingulate cortex (ACC), dorsolateral PFC (dlPFC), and hippocampus. Multiple regression analyses were used to examine differences in response between experimental conditions (spider versus butterfly images). For significant clusters of activation within ROIs, the average max percent signal change is reported. For other regions, the average max percent signal change is reported within a sphere centered at coordinates identified via previous research.

Time frame: 2 Weeks

Population: There were 54 enrolled in the study. 8 subjects were excluded from fMRI analyses: 1 for claustrophobia, 3 for scanner artifact, 1 because of motion \>3mm; 3 of paradigm-consistent motion which could not be corrected for.

This test measures a person's emotional decision making. Participants are presented with virtual decks of cards on a computer. Participants are told that each card they draw will win them game money. However, sometimes cards result in losing game money. The task includes 100 trials and the total score represents the number of cards drawn from bad decks as compared to good or safe decks. Thus, the score ranges from -100 to +100, with higher sores representing better performance.

Time frame: 2 weeks

The RCFT assesses the a person's ability to use cues to retrieve information. The test measures visuospatial construction and memory. A person is asked to draw a figure. The figure is broken down into 18 elements. The score is based on their presence, completeness, and correct placement. Each element is scored from 0-2. The Copy, Immediate, and Delay results are scored on a 36 point scale. The higher the score, the better the person performed on the test with a 0 being the minimum and 36 being the maximum score. The organization score is scored according to whether the participant drew five cohesive units of the figure together, for a range of 0-6 and a higher score indicating better organizational performance.

Time frame: 2 weeks

This scale measures the learning and memory of functioning adults. Logical Memory I and II and Faces I and II subtests were administered to participants. The tasks measure verbal and visual memory, respectively. Scoring is based on the number of story details or faces correctly recalled during immediate (Logical Memory I, Faces I) and 30 minute delayed (Logical Memory II, Faces II) conditions. Total score ranges from 0-75 on Logical Memory I, 0-50 on Logical Memory II, 0-48 on Faces I, and 0-48 on Faces II. For all subtests, higher scores indicate better memory performance.

Time frame: 2 Weeks

The Wisconsin Card Sorting Task measures executive functioning and cognitive flexibility. The task uses a deck of 64 cards that the participant must sort according to specified rules. The test is stopped when when six sequences of 10 correct responses have been achieved, or after the deck has been completed twice, which provides a cumulative total of 128 trials. We report the number of errors on the task, which has a range of 0 -128, with a higher score representing worse performance.

Time frame: 2 weeks

Population: Two subjects did not complete the test because they had previous exposure to the test.