text: Reinforcement magnitude modulation of the rate-dependent effects of fluvoxamine is consistent with results in pigeons (Lamb and Ginsburg, 2008) and rats (Harper, 1999). In pigeons, rate-dependent effects of fluvoxamine diminished with increasing lengths of access to grain under a similar multiple fixed-interval schedule to the one used in this study (Lamb and Ginsburg, 2008). In rats, Harper (1999) reported that fluoxetine (which selectively inhibits serotonin reuptake like fluvoxamine) increased the response rate for the low-frequency reinforcement at a dose that had no effect on responding for the higher frequency reinforcement.