Procedural learning is the acquisition of
a series of processes for the performance of a certain task. The ability to learn sequences of actions
helps us learn how to ride a bike, produce and perceive phoneme sequences, tie
shoelaces, drive, play music and perform any activity with a serial
aspect. All these skills are acquired
through lots of practice.
The interesting thing about procedural
learning and memory is that they can happen out of awareness. That means that we learn to perceive
regularities and sequences in the stimuli surrounding us, even when we are not
aware of it and certainly don't pay attention and effort to it.
In this study done by Yafit Gabay , Rachel Schiff and Eli Vakil of Bar Ilan university in Israel, procedural
learning was examined with adults with dyslexia.
Dissociation between the procedural
learning of letter names and motor sequences in developmental dyslexia. Yafit
Gabay , Rachel Schiff , Eli Vakil.
Neuropsychologia 50 (2012) 2435–2441
The researchers used a procedure called serial search task. University students with and without dyslexia
saw four letters presented on a computer screen, and heard the name of one of
the letters. Upon hearing the letter
name, they pressed one of four possible keys – the one that was in a
corresponding position to the visual representation of the letter that was
named. This was repeated again and again.
The order of letters presented on the screen changed each trial, and so
did the letter that was named. For half
of the participants, the order of key presses created a specific recurrent
motor sequence. For the other half, the
order of the letters named created a specific pattern. The participants were not aware of the
existence of a motor sequence or a letter sequence.
Both student groups, with and without dyslexia, implicitly learned
the motor sequence.
How did the researchers know this?
During performance, the participant's reaction times for the motor
sequence became shorter. This was one of the signs that they were learning the
sequence even though they were not aware of it.
But when the specific motor sequence was changed to a random motor
sequence, the participant's reaction times became longer. When the motor sequence was reinstated, the
reaction times became shorter again.
But students with dyslexia
could not learn the letter name sequence! Their reaction
time for the letter name sequence did not become shorter, while the reaction
time of students without dyslexia did. When the letter sequence was altered to a
random sequence, the reaction time of the students without dyslexia became
longer, while the reaction time of the students with dyslexia did not change.
What does that mean? The authors interpret the results
as showing that people with dyslexia have difficulties learning procedures with
linguistic components. This argument
was supported in this study by a learning task that is outside awareness
(implicit learning). This finding is
joined by findings from explicit learning tasks: children with specific
language disability have a severe difficulty to repeat nonwords. The difficulty mounts as the number of syllables in a word
rises. Repeating nonwords is a task that
requires serial processing with a linguistic component. Learning to pronounce a new word is a
procedural learning task.
Difficulty with serial learning impacts the ability to acquire
grammar. This argument is also supported
by an interesting procedural learning task:
artificial grammar learning. In this
task, a person memorizes sets of letter sequences that appear random, but are
formed by a complicated set of rules (an "artificial grammar"). After the memorizing phase, the person is
presented with new sets of letter sequences.
Some of the sequences are built by the "grammar" rules and
some are not. The person is asked to
sort the new "words" into "grammatical" words and
"nongrammatical" words. Although
people are usually unable to describe the sorting rule, and often say they are
only guessing, they do succeed in sorting above chance level. That means they have implicitly learned the
"grammar". It appears that children with
dyslexia are not able to perform this sorting task.
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