22q11.2 Deletion Syndrome Is Associated With Impaired Auditory Steady-State Gamma Response

Figures

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  Fig. 1.. Temporal structure of the auditory stimulation paradigm to evoke 40 Hz auditory steady-state responses. Regular (run 1) and irregular (run 2) 40 Hz click trains were given in separate experimental blocks. Each click train had duration of 1 s, followed by a pause of 2 s. Clicks were applied every 25 ms at a constant frequency of 40 Hz in the regular condition and randomly jittered from 11 to 37 ms in the irregular condition. An epoch covered the period of 40 Hz stimulation and a peristimulus window of −1000 to 2000 ms.

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  Fig. 2.. Group time frequency plots of the ASSR within the 10–60 Hz range from electrode Cz. (A) Group ITPC of the ASSR for the regular (top) and irregular (bottom), for both noncarriers (left) and 22q11.2 carriers (right). (B) Group power of the ASSR, again shown for both conditions and groups. In both (A) and (B), the time stamp 0 indicates the onset of the click train. Duration of the click train is illustrated by the grey box. In the time-frequency response a cut-off can be seen (ie, white area without data in the color plots) due to the length of the wavelet being longer for the lower frequencies as compared to higher frequencies. Consequently, not all time point values can be estimated. (C) Topographical maps for ITPC presented for controls, 22q11.2 and both conditions as in A in the time window 300–700 ms and frequency window 36–44 Hz. (D) Topographical maps for power presented for controls, 22q11.2 and both conditions as in B in the time window 300–700 ms and frequency window 36–44 Hz.

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  Fig. 3.. Group data of the ASSR. Mean ITPC (A) and mean gamma power (B) of the ASSR evoked by regular or irregular 40 Hz click trains in 22q11.2 carriers (light gray) and healthy noncarriers (dark gray). Asterisks indicate significant between-group difference (*P < .05, **P < .01). Error bars equal SEM (standard error of the mean). (C) and (D) shows ITPC and power as a function of SIPS negative subscale scores, respectively. Since the nonparametric spearman rank correlation was used, there is no regression line.