What is Interference?

The need for consistency in training, motor learning, technical preparation, and competition is well understood by coaches, athletes, and applied sport psychology  (SP)  consultants.  A  number  of  factors,  however,  can  interfere  with  athletes’  ability to  perform  or  learn  at  an  appropriate  level  during  training,  technical  preparation,  and  competition. The term interference addresses the decrease in performance due to conflicts between different cognitive  modules  or  motor  structures  within  the human  action  system  in  a  specific  environmental constellation.

Interference in Cognitive Learning and Verbal Memory

In  the  psychological  realm,  interference  is  mostly discussed in the context of memory and learning. Interference is addressed as a memory problem that occurs when a learning process is impaired because of  an  existing,  stabilized  memory  structure  or when the activation of consolidated memory representations  is  affected  because  of  newly  learned material. Interference in learning with verbal material has been observed and studied for more than

100 years. Notably, the studies of the German psychologist Georg Elias Müller opened up new perspectives  on  the  topic  of  memory  consolidation. While the studies of Hermann Ebbinghaus (1885) hypothesized  forgetting  as  a  function  of  time, Müller  and  his  student  Alfred  Pilzecker  provided evidence  for  interference-based  memory  loss  and an  interference-based  decrease  of  learning.  The term retroactive interference was coined by Müller and  describes  the  phenomenon  seen  in  memory in which newly learned material affects the recall performance  of  previously  learned  information. In  the  opposite  direction,  proactive  interference specifies  the  phenomena  that—depending  on  the task—previously  learned  information  potentially impairs the learning of new information. Proactive interference is commonly explained as competition between two learning processes that are based on the  same  cognitive  resources.  From  this  point  of view,  in  the  case  of  retroactive  interference,  the learning  of  new  material  influences  the  consolidation  of  previously  learned  material  in  memory. During proactive interference, consolidated memory information is challenged by new information and inhibits the consolidation of new information in  memory.  Subsequent  studies  have  found  that similarity between the information already stored in memory and the new material affects the learning process and causes interference.

Interference in Motor Learning and Motor Memory

In  motor  control  research,  interference  is  mostly discussed  in  the  context  of  motor  learning.  The learning  of  new  skills  is  based  on  previously learned  sensory-motor  patterns  that  are  stored  in memory. In general, there are two possible types of interactions between previously learned skills and recently acquired skills: (1) a positive and supportive interaction called transference or (2) a negative interaction called motor interference. Transference was   originally   addressed   by   researchers   like Nikolai A. Bernstein and is explained as the facilitation of learning as a result of similarity between the required motor pattern and the existing stored pattern,  while  conversely,  motor  interference  is mostly  hypothesized  as  a  negative  overlap  (i.e., dissimilarity)  between  the  coordination  patterns of previously learned motor actions and the structure  of  a  recently  acquired  skill.  From  this  point of  view,  learning  to  crawl  could  generally  facilitate  skills  like  canoeing  because  of  similarities  in motor  structures  (transference),  while  techniques in  sports  like  tennis  and  badminton  at  the  same time seem to be related at a surface level but suffer from interference because of significant differences between the relevant sensory-motor structures at a functional level.

Charles H. Shea and other researchers addressed the topic of contextual interference and compared performance during practice of a motor task under randomized  and  blocked  conditions.  They  found that practicing the task in a blocked order, repetitively and under stable conditions (low contextual interference),  resulted  in  better  performance  than did  practicing  the  task  under  randomized  conditions  (high  contextual  interference).  Interestingly, however, when the performance between random and  blocked  practice  was  compared,  these  and other  studies  revealed  that  the  random  practice  group  showed  superior  performance  to  the blocked  practice  group.  It  has  been  hypothesized that  in  the  short  term,  reduced  interference  supports  the  learning  process  of  simple  motor  skills, but in the long term, randomized practice supports the  establishment  of  more  stable  representations in motor memory and leads to better performance compared  to  the  more  artificial  (low  contextual interference) conditions.

Interference Between Motor Control and Verbal Memory

Until  now,  the  phenomenon  of  interference  has been mostly investigated in the area of verbal memory research, isolated from motor learning and vice versa. Interference in the context of motor learning has  often  been  discussed  as  it  relates  to  memory resources,  but  it  remains  unclear  whether  or  not motor planning and verbal working memory share common cognitive resources. In our daily life, verbal memorization and motor action are often performed together—for instance, remembering a list of consumables in a shop while walking along the shop floor and searching for the next product.

In the research area concerning the learning and storage of lists in working memory, the serial position effect is a stable finding. This effect is observed when subjects memorize and recall a sequence of items. Subjects are best able to memorize the items presented  at  the  beginning  of  the  list  (primacy effect) and the end of the list (recency effect). This recall paradigm has often been used to learn about interference in verbal memory. Combining a motor task and a verbal memory task could lead to two kinds  of  interference:  cognitive  interference  or motor  interference.  In  the  case  of  cognitive  interference,  the  memorization  of  verbal  lists  would decrease  the  motor  performance;  conversely,  the opposite  would  be  true  in  the  motor  interference scenario.  In  a  variety  of  tasks  such  as  replanning of motor actions and sequential motor planning in unimanual  and  bimanual  coordination,  researchers  like  Matthias  Weigelt,  Mark  G.  Fischman, and Marnie A. Spiegel have investigated in recent years the interference between motor planning and recall  performance.  In  multiple  experiments,  they found evidence for the so-called motor interference hypothesis—that  is,  that  motor  planning  reduces memory  performance  of  verbal  items  because  of the challenge between these two entities.


  1. Logan, S. W., & Fischman, M. G. (2011). The relationship between end-state comfort effects and memory performance in serial and free recall. Acta Psychologica, 137, 292–299.
  2. Shea, J. B., & Morgan, R. L. (1979). Contextual interference effects on the acquisition, retention, and transfer of a motor skill. Journal of Experimental Psychology: Human Learning & Memory, 5, 179–187.
  3. Spiegel, M. A., Koester, D., Weigelt, M., & Schack, T. (2012). The costs of changing an intended action: Movement planning, but not execution, interferes with verbal working memory. Neuroscience Letters, 509,82–86.

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