What are the effects of alcohol on muscle memory? Muscle memory (also referred to as "motor memories") is a form of procedural memory, which is a form of implicit memory. I'm particularly interested in trained tasks like throwing a dart, shooting a ball in foosball, or touch typing, which as far as I understand could be considered muscle memory.

Studies seem to have shown that alcohol has no significant effect on implicit memory.

From www.intropsych.com:


  Hashtroudi, Parker, DeLisi, Wyatt, and Mutter (1984) studied the
  effects of alcohol on implicit and explicit memory. Ninety-six male
  volunteers between the ages of 21 and 35 were recruited for the
  all-day experiment (they were kept at the lab until their blood
  alcohol returned to zero). The researchers found that alcohol
  intoxication had effects similar to brain injury. It damaged
  explicit memory but not implicit memory.


From wikipedia:


  While retrieval of explicit memory is severely impaired by alcohol,
  retrieval of implicit memory is not. (Nelson, T. et al. 1986)


From a later study by Lister, R. G. et al. (1991)


  [...] no impairment was observed if memory for the same material was
  assessed implicitly using a backwards-reading or word-completion task.


I was wondering whether any studies have been done which investigate the effects of alcohol on muscle memory specifically. Possible measures could be the speed of the executed motion, and its accuracy. The methodology followed could be along the lines of:


A task has been practiced. (on an 'expert' level, where the motion becomes unconscious)
Measure performance.
Drink alcohol.
Measure performance under second condition.



Hashtroudi, S., Parker, E. S., DeLisi, L. E., Wyatt, R. J., &amp; Mutter, S. A. (1984). Intact retention in acute alcohol amnesia. Journal of Experimental Psychology: Learning, Memory, and Cognition, 10(1), 156.
Nelson, T., McSpadden, M., Fromme, K., &amp; Marlatt, G. (1986). Effects of Alcohol Intoxication on Metamemory and on Retrieval from Long-Term Memory. Journal of Experimental Psychology, 115(3), 247-254.
Lister, R. G., Gorenstein, C., Risher-Flowers, D., Weingartner, H. J., &amp; Eckardt, M. J. (1991). Dissociation of the acute effects of alcohol on implicit and explicit memory processes. Neuropsychologia, 29(12), 1205-1212.
Alcohol consumption causes deficits in motor coordination by affecting the cerebellum, which is the main area involved in regulating finer adjustments in movement and motor learning. From Belmeguenai et. al (2008):


  It has previously been shown that ethanol modulates inhibitory transmission in the cerebellum and affects synaptic transmission and plasticity at excitatory climbing fiber (CF) to Purkinje cell synapses. However, it has not been examined thus far how acute ethanol application affects long-term depression (LTD) and long-term potentiation (LTP) at excitatory parallel fiber (PF) to Purkinje cell synapses, which are assumed to mediate forms of cerebellar motor learning.


The tasks you have outlined above are all considered 'fine motor skills', and are thus mediated in part by the cerebellum. It is certainly the case that alcohol consumption affects finer muscle coordination. It is also the case that hangover effect reduces athletic performance by up to 11.4% in trained athletes (who would fit the 'expert' level you have described above).

There aren't many studies on alcohol's effects on muscle memory specifically, though there are studies on how sleep affects motor learning. There is also evidence that alcohol consumption mimics the effects of sleep deprivation, and affects sleep quality directly.