Figure 2.

Comparison of difference limen (DL; with s.e. bars) between the control group and the DXM group for amplitude discrimination with dual-site adaptation at times T_0, T₁, and T₂ (see Methods for description). DLs are shown for two conditions of adapting stimulus duration: 500 and 2000 msec. Note that at T₁, performance was significantly degraded for the DXM group under both conditions of adapting stimulus duration (p < 0.01). DLs show signs of recovering to baseline levels at T₂, although they remain significantly elevated at that time (p < 0.01).