[U1Q] At the beginning of the week, a preschool student’s in…

[U1Q] At the beginning of the week, a preschool student’s intervention team completed a preference assessment which illustrated a love of pretzel M & M’s. On Thursday, after 20 hours of instruction on a FR 2 schedule of reinforcement (getting reinforcement after every second response), the student started throwing the instructional materials and no longer ate the reinforcers that he received. This is likely due to: