Printer friendly version
Our cognitive system processes vowels and consonants at a different speed
14 April 2009
Through a study carried out at the Universities of La Laguna and Valencia, it has been verified that the brain distinguishes between vowels and consonants. Neuronal mechanisms change when they are processed and, when it comes to lexical access; both have a different status in our mind, thus contributing differently to this basic process of visual word recognition.
The group of researchers led by Manuel Carreiras wanted to research the neuronal bases of an activity involving daily cognition such as the processing of vowels and consonants. The result was published in the last edition of Journal of Cognitive Neuroscience, which is published in the USA by the prestigious Massachusetts Institute of Technology (MIT).
Manuel Carreiras, who also acts as director of the new Basque Centre on Cognition Brain and Language (BCBL), observed that conclusions from previous studies already suggested that consonants and vowels contribute differently to lexical access, something that this study wants to examine in detail.
During the new research, the researchers submitted 31 students from La Laguna (23 women and 8 men, all native speakers of Spanish who had no neurological or psychiatric problems) to experimental situations that involved showing a word twice for only 50 milliseconds on its first appearance: the first relay of words were identical and followed the pattern "CHOCOLATE - CHOCOLATE"; during the second, two consonants were removed on the first appearance and followed the pattern "CHO O LATE - CHOCOLATE", and during the third, the same was done with two non-adjacent vowels, as in "CHO L TE - CHOCOLATE.
"We chose 120 words of between seven and eleven letters that, on average, appeared 26 times per million in the Lexesp Spanish database", Carreiras explains to SINC. The participants were placed in a dark, soundproof cubicle to see the stimuli on a monitor. There they were asked to press one of two buttons, "yes" or "no" to answer the following question: "Is this a legitimate Spanish word or not?"
The scientists assessed the error percentages and response times. Data were also recorded with an electroencephalogram, as well as eye movements and blinking.
The results of this approach show that omitting two letters within each word for 50 milliseconds also slowed down identification of the word, but even more important is the fact that this delay was greater when consonants were hidden rather than vowels.
For Carreiras and his team, there is "an alternative vision regarding the differences observed between consonants and vowels", which is related to frequency. "Vowels tend to be more frequent than consonants". In most languages there are more consonants, but vowels are more frequent, which opens the door to the debate of whether consonant-vowel status is more important than the frequency of the letter in question.
Computerized Spanish lexicon (Lexesp)
Lexesp-corco is a database of Spanish words made up of two parts. In the first, a collection of sloganized words is used as the database, which allows for searches to be made of appearances and co-appearances of words, slogans, and categories of words, within a given context. In the second, lists of previously indexed words are used for the creation of studies that make it possible to search for word characteristics.