ScientificbackgroundLong-term procedural memory (LTPM) refers to the process oflearning motor skills that can be used throughout our life (Lum andConti-Ramsden, 2013).
LTPM has been found to be affected by a number offactors, two of which being interference from learning a second motor skill andretroactive interference. Retroactive interference refers to novel informationoverwriting existing memory traces (Rasch and Born, 2013). Therefore, as aperson cannot be exposed to new information when asleep, LTPMs can beconsolidated at the highest level (more robust) after a night of sleep. As aresult, the same level of consolidation cannot take place if someone is sleepdeprived due to the presence of retroactive interference (Alhola andPolo-Kantola, 2007). Generally, research has found consistency with the respectof sleep leading to better LTPM, however, there is a debate to the extent towhich LTPM is influenced by learning a second skill.
The role of sleep in the robustness of LTPM was seen in Holz,Piosczyk, Landmann, Feige, Spiegelhalder, Riemann, Nissen, and Voderholzer’s research(2012). They found that there was a significantly higher recall of fingertapping (LTPM) in participants who went to sleep shortly after initialtraining, compared to those who were trained earlier on in the day (exposed toretroactive interference). Moreover, a wide scope of research(Prehn-Kristensen, Molzow, Munz, Wilhelm, Muller, Freytag, Wiesner, and Baving(2011), Borragan, Urbain, Schmitz, Mary, Peigneux (2015), Allen (2012), and Yan(2017)) has replicated previous findings which support the role of sleepleading to more robust LTPM. These pieces of research were conducted on childand adult populations, with different motor skills being studied, ranging fromthe rehearsal of a finger tapping sequence to a 13 note melody on a piano.
Consequently,a consistency within research can be seen surrounding the role of sleep andLTPM. The issue within research lies with the role of learning a secondskill. Holz et al (2012) reported that the LTPM of an initial motor skill canbe compromised as a result of learning a second motor kill, however, thisfinding was not replicated within their own research (if training of the secondmotor skill took place 4 hours after initial learning). Additionally, both Yan(2017) and Borragan et al (2015) found that learning a new sequence prior totesting of the initial skill did not lead to a difference in recall betweengroups.
Alternatively, Urbain, Hououx, Ve Albouy, and Peigeneux (2013) foundthat when a second skill was presented, the interference effects wassignificantly higher than that of staying awake. These findings are alsosupported by Allen (2012) who found that when a second melody on the piano waslearned, performance of the first melody was impacted. Due to the discrepanciespresent in research, this study will be important not only due to it providingan extension of previous research, but it will also help to clarify someinconsistencies that are present within the current literature. Aims and hypotheses We hope to provide greater depth surrounding the roleof sleep in LTPM and also provide clarification involving the role of learninga second skill in the ability to accurately recall the initial skill learnt.Subsequently, we hypothesise that our research will show that the robustness ofLTPM will be significantly greater for those who receive a night of sleep,compared to those who are sleep deprived. This is hypothesised on the basis ofprevious research (Rasch and Born, 2013) which has shownthat receiving a night of sleep means that a person will not be affected byretroactive interference (existing memory trace of the initial skill will notbe overwritten).
Additionally, we hypothesise that learning a second skillprior to testing of the initial skill will result in a significant decrease inLTPM (finger tapping score) compared to the baseline measurement (role oflearning a second skill). This is because the learning of the second skill willtake place 3 hours prior to the testing of the initial skill. Thus, as Holz etal (2012) found that an effect is seen if secondary skill learning takes place4 hours before testing of the initial skill, a 3 hour period should be asufficient time period to see a significant effect. MethodsWe will aim to get an equal sample of male and femaleparticipants due to prior research (Holzet al (2012)) having been limited to the female population.
Thus, we will use astratified sampling method to find a representative sample of male and femalepopulations. Upon gaining an equal sample of male and female participants, halfof each gender will be randomly allocated to either the sleep or sleep deprivedgroup. The study will commence at 9 pm, whereby participants will be exposed to100 trials of a finger tapping task that they will attempt to learn. The taskwill involve using a laptop, in which, the letters on the keyboard will be usedto represent numbers; V(1), B(2), N(3), and M(4) (Yan, 2017). Participants willthen be asked to learn the sequence ‘31423’ by tapping the appropriate letterswith their dominant hand over the 100 trials.
In order to ease the learningprocess, accuracy feedback will be shown on the laptop screen (Yan, 2017).Additionally, participants will be given a two-minute rest after every 25trials so that they remain focused at all times. Upon the completion of thetrials, one half of the group will receive a night of sleep, whilst the otherhalf of the group will be sleep deprived. Participants in the sleep conditionwill wake at 7 am and both groups will then be tested in order to gain abaseline measurement of finger tapping performance.
After a baselinemeasurement has been recorded, participants will be told that they are free toleave. Six days later participants will return to the location for midday.Shortly after arrival participants will be given a second finger tapping task,with the sequence being ‘34123’. After the 100 trials have been completed ofthis new task, participants will be asked to wait for a period of 3 hours. Whenthe time has elapsed, participants will then be tested on the initial fingertapping task. During this testing, participants will not be given accuracyfeedback on the laptop screen, but will still be given a two-minute break tokeep the participants focused.
The final trial will mark the end ofparticipation. In terms of analysis, the independent variables will consist ofthe amount of sleep and the second finger tapping task, whilst the dependentvariables will be compromised of the accuracy and speed of finger tapping.Consequently, in order to analyse the data we will need to run a 2 x 2 mixedANOVA on SPSS due to there being a baseline and experimental measurement offinger tapping, additionally, there are two groups (sleep/sleep deprived).Whilst it may be argued that there are ethical concerns surrounding the use ofsleep deprivation, every participant will have the choice to consent to takepart in the research, moreover, we will aim to conduct the sleep deprivation ona Thursday night so that their remaining working week will be minimallyaffected, and participants will then have the weekend to recover. Expected resultsWe previously hypothesised that the accuracy and speedof LTPM (finger tapping) will be significantly greater for those who receive anight of sleep (compared to those who are sleep deprived) and that learning asecond skill prior to testing of the initial skill will result in a significantdecrease in accuracy and speed of finger tapping (compared to the baselinemeasurement). Therefore, if our results support our hypotheses, we will expectto see a similar outcome to Urbain et al (2013) who found that there was a significantlyreduced recall of the initial skill due to exposure of a second motor skill.Additionally, if our results support our hypothesis regarding the role of sleepand LTPM, it will add reliability to the plethora of research that existsshowing the positive effect that sleep has on the robustness of LTPM. Overallsupport could prove to have an important impact on society, especially for sportand music.
This is because Allen (2012) found that when a second melody is learned on the piano, theperformance of the first melody is impacted. As a result, if someone isattempting to learn a new piece of music, it may be best to focus on one at a time.We believe that our findings would show that this could be generalised to othersporting activities such as learning a certain skill in football which would,for example, allow an attacker player to become better in their role.