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Nov 07

Midwestern Psychological Association 2012 (Chicago, IL)

Title: Coordinated action and timing responses separated across hands are integrated in sequence learning. (PDF)

Area: Cognitive Neuroscience of Learning and Memory.

Problem or Major Purpose: Skill learning relies on a flexible explicit set of actions to perform which provides scaffolding for the relatively inflexible implicit representation supporting performance improvements through practice. A key question regarding implicit knowledge is to what extent the timing and order of sequential movements is specific and inflexible to what was practiced. Sanchez, Gobel, & Reber (2010) previously used the Serial Interception Sequence Learning (SISL) task to demonstrate implicit learning in healthy patients with little trace of associated explicit knowledge. In the SISL task, participants’ attempt to make a precisely-timed motor response to cues scrolling down a monitor toward one of four target zones. The cues follow a covertly-embedded repeating sequence of cue order and inter-cue timing. Other work examining the integration of sequential response order and timing with the SISL task has shown that these two sources of information are integrated during learning (Gobel, Sanchez, & Reber, 2011). This produces a surprisingly inflexible knowledge representation which resists transfer to very similar motor sequences.

Procedure: To test the hypothesis that sequence inflexibility arose from the need to combine order and timing information into a single keypress response, SISL learning was examined with a guitar-shaped manipulandum that separated action selection and response timing across hands and required a bimanually-coordinated response on each trial. Twenty-eight Northwestern University undergraduates (17 F, Mean Age = 21.3 years) participated for course credit. Participants completed 2880 trials of training on the SISL task, followed by a test where the order of cue responses and inter-cue timing were separately manipulated from the trained sequence in order to assess transfer to sequences with novel timing or novel order.

Results: Participants exhibited sequence-specific performance improvements for only the trained sequence and performance was equivalent to an unpracticed sequence if either timing or order was disrupted. Separate examination of each hand individually also failed to show any evidence of partial transfer from the trained sequence.

Conclusions and Implications: When response timing and order are both necessary for coordinated sequence performance, they become integrated in the motor plan that is necessary for expression even when expressed largely through different hands. These results have broader implications to educational training whereby rote practice of cognitive or motor skills may result in a hyper-specific, inflexible knowledge representation.

Mini-Abstract: Skill learning was examined with a guitar-shaped manipulandum that separated action selection and response timing across hands and required a bimanually-coordinated response on each trial. Participants exhibited sequence-specific performance improvements for only the trained sequence and performance was equivalent to an unpracticed sequence if either timing or order was disrupted.