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. Author manuscript; available in PMC: 2019 Sep 1.
Published in final edited form as: Schizophr Res. 2018 Apr 26;199:83–89. doi: 10.1016/j.schres.2018.04.019

Figure 1. Study Procedures.

Figure 1

(A) Design. Participants were trained on three tasks in a fixed order during Training and were Tested 24h later. (B) Word Pair Task. During Initial Exposure, each word pair was displayed for 5s, with an interstimulus interval (ISI) of 100ms, and participants were instructed to “remember which words go together.” During subsequent phases, the middle 20 pairs were presented in a random order to avoid primacy and recency effects. During Feedback Training, participants were shown the first word of each pair (cue) and asked to verbally report its associate (target). The experimenter typed their response and it was displayed on the screen below the cue for 2s. If the response was incorrect, the correct target word was displayed in red above the incorrect response for 2s. This procedure was repeated until at least 12 of the targets (60%) were recalled correctly or until the list had been repeated 10 times. The Pre-Sleep Test started approximately 30m later, after training on the Tone Task. (C) Visual Discrimination Task. After a jittered interval (200–280ms), a target screen (Panels 1, 2) that contained a rotated “T” or “L” at the center and a horizontal or vertical array of three diagonal bars in the lower-left quadrant was presented for 16ms (fixation points and target arrays are displayed in bold for illustration purposes only). The array of diagonal bars was ~2.5° in length and was located ~5° from the center. The target screen was followed by a blank screen for an ISI of 20–400ms and then a mask for 16ms (Panel 3). Upon termination of the mask screen, the screen went black and participants indicated with button presses whether the diagonal lines were arranged horizontally (H) or vertically (V), and whether there was a T or an L at fixation. This was followed by the return of the fixation screen. (D) Tone Task. The task consisted of three phases: Exposure, Pre-Sleep Test and Post-Sleep Test. Exposure involved listening to a single structured stream of 1818 tones lasting 400s. Each tone lasted 200ms, with a 20ms gap between tones. Pre and Post-Sleep tests took place immediately and 24h after Exposure, respectively, and consisted of a forced-choice recognition test. Bottom: In each of 84 trials participants were presented with two 18-tone sequences (4s each) and asked to indicate which sequence sounded more familiar.