Studies related to Processing Speed and L-Tyrosine

Tyrosine Improves Working Memory in a Multitasking Environment
Effect None
Values Correct latency (s). Placebo: 3.1 ± 0.2 Tyrosine: 3.2 ± 0.2 Error latency (s). Placebo: 3.5 ± 0.2 Tyrosine: 3.3 ± 0.4 Average latency (s). Placebo: 3.3 ± 0.2 Tyrosine: 3.2 ± 0.2
Trial Design Non-randomized controlled trial
Trial Length 24 hours
Number of Subjects 20
Sex Both Genders
Notes for this study:
In a double-blind, crossover trial with unclear randomization, 20 participants took 150 mg/kg of tyrosine or placebo 60 minutes before cognitive testing.

The tyrosine group had more correct answers on the complex Sternberg memory task, while there wasn't a difference for the simple task. There wasn't a statistically significant difference for latency on correct or erroneous answers. Overall, when taking tyrosine, participants scored more points on the complex tasks but not simple tasks. There wasn't a statistically significant difference in arithmetic or tone detection.

There weren't statistically significant differences between treatments for the change in mean arterial pressure, heart rate, cortisol or adrenocorticotropic hormone.