The Homophone Meaning Generation Test

  

When people are asked to supply as many meanings as they can for a word presented orally and out of context, they begin with the most frequent meanings, and once these are exhausted, turn to other, less common, meanings.  This process requires a strategic search in the knowledge base and mental flexibility, which are part of executive functions.

The homophone meaning generation test – HMGT , developed in Hebrew by Prof. Gitit Kave and her colleagues,   tests this process.  Homophones are words which have different meanings that "sound the same".  For instance, the word "right" has the meaning of "a direction (opposed to "left")" and the meaning of "appropriate, suitable".  

The test in its Hebrew form is made of 24 homophones, each having between three and ten possible meanings.  Half of the words are also homographs (all their meanings are spelled  the same way).  The words are presented orally, one by one.  The person is asked to think about as many meanings as he can to each word.  There is no time limit.  When the person is not able to think about any more meanings, the next word is presented.  Each different meaning is assigned a point.  The score in the test is the number of meanings given to all presented words.  The production of meanings requires strategic search and mental flexibility, thus the test is supposed to measure executive functions. 

Prof. Kave and her colleagues performed a few experiments with this test, in children and adults, two of them will be presented here, 

In the adult study, the relation between the homophone test and shifting and clustering in fluency tests was examined.

What are shifting and clustering?

Phonemic fluency tests (in which the person is asked to name as many words beginning with a specific letter within one minute as he can) and semantic fluency tests (in which a person is asked to say as many words belonging to a specific category within one minute as he can) measure the ability to search and retrieve information from long term memory (thus they belong to the broad ability "Long Term Storage and Retrieval").

In both of these tests, the memory search includes two aspects:  clusters and switches.  During test performance people usually produce clusters of words that are related to each other semantically (for instance, "horse, cow, donkey, goat, sheep" is a cluster of "farm animals") or phonetically (for example, "buy, bug, bus" is a cluster of words beginning with "bu").  When the subcategory from which the words were retrieved is exhausted (the person cannot think about more farm animals or more words beginning with "bu"), the person shifts to another subcategory (for instance, he will transfer to "sea animals" or to "be").

Clusters reflect the semantic organization of the crystallized knowledge.  Shifts reflect executive functions (strategic search in the fund of lexical knowledge, monitoring, the initiation of response, flexibility, an ability to shift set).

The phonemic fluency test is presumed to require executive functions more than the semantic fluency test.  This is because when we retrieve information by content (like in the semantic fluency test) we perform a familiar act which fits the way our knowledge is organized.  But when we retrieve words beginning with a specific letter, we perform a new and unfamiliar task.  In order to optimally perform this task we have to come up with a search strategy, monitor the search process and act flexibly.  These are executive functions.

One hundred volunteers aged 18-35 and with an average of 13.8 years of  education participated in the study.  All participants were healthy native Hebrew speakers.  Each participant was tested with the homophone test and the semantic and phonemic fluency tests.

Since the homophone test was built as an executive functioning test, requiring directed and flexible memory search, the assumption was that the homophone test will be correlated with phonemic fluency more than with semantic fluency.  In fact, a significant and equal correlation was found between the homophone test and both fluency tests.

The authors offer 2 kinds of explanations for this finding:  it may be that the lexical knowledge component existing in the homophone test and the semantic fluency test caused the correlation between these tests to be higher than expected.  Another possibility is that both fluency tests require a similar executive search.  The relation between all three tests can be resulting from a common executive component, which is necessary for successful performance in these tasks.

When we look at the shifts and clusters data we get a finer picture:

Performance in the homophone test was related more to the number of switches or the number of clusters that a person performed in both fluency tests, than to the average size of the cluster in these tests.  This strengthens the hypothesis, that the relation between the three tests is stronger in the executive component than in the lexical semantic component.  While members in a sematic cluster (for example, "dog, cat, hare, gerbil") belong to a similar conceptual field, this is not the case with homophone representations.    Thus performance in the homophone test cannot be attributed to the spread of activation within a sub category in the semantic lexicon 

Participants in this study produced more meanings for non-homographic homophones than for words that are both homophones and homographs.  The score of the homographs was more strongly related to the switching component in both fluency tests than the score on the non homographs.  This means that finding different meanings for homophones that are also homographs requires more executive functions than finding different meanings for homophones that are not homographs. 

How do children perform in the homophone test?  A child cannot retrieve meanings that do not yet exist in his lexicon.  But sometimes a child will find it hard to retrieve meanings he is familiar with since his retrieval skills may not be flexible enough.  Children's retrieval skills are affected by the development of their vocabulary and the development of controlled search processes in their existing lexical knowledge. 

Children's vocabulary is developing constantly, as the child is exposed to reading and literature.  At the end of 2^nd grade, English speaking children's vocabulary contains 6000 word meanings.  Their vocabulary increases in the next few years at a rate of 1000 meanings per year.  In addition to the growing lexicon, knowledge about word meanings also grows.  The meanings of new words are gradually refined in a process that continues into adolescence.

Efficient  search strategies also develop throughout childhood and into adolescence.  These search strategies are one of the manifestations of executive functions. 

In the children's study, changes in word retrieval throughout childhood were assessed by four tasks:  a picture naming task, a phonemic fluency task, a semantic fluency task and the homophone test.  These tasks differ in the amount of flexibility needed to perform the test. 

In the picture naming task (in which the child sees a picture of an object and is asked to name it) there is no need for flexibility in lexical search.  Each picture corresponds to one word only.  When this word is found, the search is over.

Semantic and phonemic fluency tests require a more flexible search in the lexicon, using clustering and switching strategies as was discussed earlier.  There is a developmental improvement in the performance on these tests up to the age of 12 and beyond.  The fluency component that improves the most throughout childhood is the shifting component.  As was said before, this is an executive component which reflects strategic search, response initiation, monitoring and flexibility.

In order to perform the homophone test optimally, the word search has to continue much after the first word has been retrieved.  Unlike the fluency tests in which the search is performed on a limited set of the lexical knowledge, the homophone test requires searching and retrieving from the whole lexicon.  Thus it may require a more flexible search strategy than is required for the other tests.

Two hundred and seven children participated in the study, 20 from each age group in the age range of 8-17 and in grades 3^rd to 12^th.  The children were born in Israel and speak Hebrew as a first language.  They don't have learning disabilities, neurological or developmental problems and their socioeconomic status is average.

The children's scores on all four tests rose steadily between age 8 and age 17.  Picture naming ability rose the least (although the test being used was probably too easy in its Hebrew version, since the youngest children succeeded in 83% of its items).    Scores on the homophone test showed the steepest rise.  Thus, performance on the homophone test changed the most during development.

Like the adults, children produced less meanings for homophones that are also homographs (all their meanings are spelled the same) than for homophones that are not homographs.  The rate of development in performance on the homographs was identical to the rate of development in performance on non homographs. 

To summarize, this test assesses executive functions in a verbal task.  High scores on the homophone test indicate that the person has a rich lexical network and that he is able to shift between meanings flexibly.

How would this test be classified in CHC abilities?

I've recently written about the place of executive functions in CHC theory – "between" fluid ability and short term memory. 

  

The homophone test does not fit any of the definitions of the Fluid  narrow abilities (induction, deduction, quantitative reasoning).  In Hoelzle's study, other tests measuring executive functions are classified under fluid ability.  Hoelzle did not classify the homophone test or similar tests.  Due to the nature of this test and the classification of other executive function tests to fluid ability, perhaps we can classify this test also to fluid ability, at least tentatively.

The homophone test does not fit any of the definitions of narrow abilities within Short Term Memory.

The narrow ability "Ideational fluency" (in "Long Term Storage and Retrieval") is defined as the "ability to rapidly produce a series of ideas, words, or phrases related to a specific condition or object.".  Because of the speed factor, the homophone test cannot be classified here.

The narrow ability "Lexical knowledge" (in "Comprehension  - Knowledge") is "knowledge of the definitions of words and the concepts that underlie them".  The homophone test does require such knowledge and seems to fit here.

So it seems that in CHC terms the test can be considered to test Fluid ability and Comprehension Knowledge (Lexical Knowledge).

References:

KavÉ, G., Avraham, A., Kukulansky-Segal, D., & Herzberg, O. (2007). How does the homophone meaning generation test associate with the phonemic and semantic fluency tests? A quantitative and qualitative analysis. Journal of the International Neuropsychological Society, 13(03), 424-432.‏  

Kavé, G., Kukulansky-Segal, D., Avraham, A., Herzberg, O., & Landa, J. (2010). Searching for the right word: Performance on four word-retrieval tasks across childhood. Child Neuropsychology, 16(6), 549-563.‏

Hoelzle, J. B. (2008). Neuropsychological assessment and the Cattell-Horn-Carroll (CHC) cognitive abilities model. ProQuest.‏    PAGE 114   http://utdr.utoledo.edu/cgi/viewcontent.cgi?article=2213&context=theses-dissertations

Executive functions – where do they fit within CHC terminology?

 

Executive functions are cognitive functions needed to deal with new and unfamiliar tasks.  Examples of executive functions would be identifying a goal or a problem, planning how to reach that goal or how to solve that problem, choosing an action plan among alternatives, initiating the plan, monitoring the plan's execution, responding flexibly when problems arise, and inhibiting automatic responses that are not conducive to reaching the solution. 

In Adele Diamond's conceptualization (4), executive functions are composed of three components:

Inhibition:  behavioral inhibition (self control and the ability to resist temptation) and cognitive inhibition (controlling internal and external distractions and inhibiting automatic responses).

Working memory – which enables planning and monitoring progress towards   goal attainment.

Flexible thinking – which enables us to think about new solutions and to change strategy if the chosen one doesn't  lead to the preferred results. 

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Where do executive functions fit within CHC terminology?

When we speak about "executive functions" and about "CHC abilities" we use two different languages.  The concept "Executive functions"  belongs to neuropsychological theories.  CHC abilities are concepts belonging to psychometric theory.  Thus, asking "Where do executive functions fit within CHC terminology?" is like asking "How do you say "caucus" in French"?  There probably is no French concept which exactly parallels the meaning of "caucus" in American English. 

Nevertheless, executive functions can be placed between Fluid Ability and Short Term Memory.  The relations between them are presented in the slide below:

  

 

The relation between Executive Functions and Fluid Ability:

Flanagan and her colleagues (1) define Fluid Ability as "mental operations that an individual may use when faced with a relatively novel task that cannot be performed automatically".  These thinking processes include identifying and constructing concepts and relations, deriving conclusions, understanding consequences, abstract thinking, problem solving, reorganizing or restructuring information, inductive and deductive reasoning, classifying, creating hypotheses and quantitative reasoning.

According to this conceptualization, the common element of Fluid Ability and Executive Functions is the Flexibility in reasoning.

McGrew, in the CHC version 2 definitions, defines Fluid Ability like this:  "The deliberate but flexible control of attention to solve novel “on the spot” problems that cannot be performed by relying exclusively on previously learned habits, schemas, and scripts".

  

This conceptualization emphasizes the control of attention, and through it, the inhibition component, as a common component of Fluid Ability and Executive Functions, along with the Flexibility component.

Thus, this conceptualization brings Fluid Ability and Executive Functions closer together.  According to this conceptualization, in order to solve new problems successfully, we must recruit attentional resources and inhibit automatic and well practiced responses.

Salthouse writes:  "Contextual analyses have … revealed very strong relations of fluid cognitive ability (Gf) to constructs hypothesized to represent executive functioning  and to assorted variables postulated to represent specific aspects of executive functioning.  These patterns suggest that Gf may reflect nearly the same dimension of individual differences as executive functioning".

 

What about the relation between Executive Functions and Short Term Memory?

Short Term Memory is "the ability to apprehend and hold information in immediate awareness and then use it within a few seconds" (1).  The broad ability Short Term Memory contains two narrow abilities:  Memory Span (the ability to attend to and immediately recall temporally ordered elements in the correct order after a single presentation) and Working Memory (the ability to temporarily store and perform a set of cognitive operations on information that requires divided attention and the management of the limited capacity of short term memory".

Thus, the common element of Executive functions and Short Term Memory is the Working Memory component (by Adele Diamond's conceptualization, according to which one of the components of Executive Functions is Working Memory).

"Executive function deficits may be most noticeable in the capacity of the individual to allocate and sustain attentional resources…Attentional capacity, and to some extent divided attention, are characteristic of working memory tasks that require an individual to keep two or more sets of elements "alive" in short term memory and alternate between performing operations on the two sets of information" (5).

 

We've discussed the relations between Executive Functions and Fluid Ability, and between Executive Functions and Short Term Memory.  Now we can come full circle and discuss the relations between Fluid Ability and Short Term Memory.

 

Researchers find high correlations (0.8-0.88) between measures of working memory and measures of Fluid Ability (2).

 Lohman and his colleagues (2) note that "critics complained that some tasks used to estimate working memory in … studies were indistinguishable from tasks used to estimate reasoning" (2).

"In part, this is a problem of words. The term working memory connotes too small a construct; reasoning connotes too large a construct—especially given the way each is typically measured. Consider first the reasoning construct. In the best of these studies, reasoning is estimated by performance on a series of short, puzzle-like tasks. More commonly, it is estimated by a single test such as the Raven Progressive Matrices that uses a single item format.  Indeed, figural reasoning tests such as the Raven are typically much poorer predictors of both real-world learning and academic achievement than measures of verbal and quantitative reasoning. Whether measured by one task or several short tasks, the reasoning construct is usually underrepresented. 

On the other hand, the construct measured by the series of working memory tests is much more complex than its label suggests. These tasks generally require participants to understand and follow a sometimes complex set of directions; to assemble and then revise a strategy for performing a difficult, attention-demanding task; to maintain a high level of effort across a substantial number of trials; and then to repeat the process for a new task with a new set of directions. In addition, many working memory tasks require individuals to process simultaneously one set of ideas while remembering another set. Although the individual tasks are generally thought to be easy, they are certainly not trivial, especially when performed under memory load. These tasks elicit executive functions such as the monitoring of processes, controlling their rate and sequence of operation, inhibiting inappropriate response processes, coordinating information from different domains, and integrating ideas into a coherent mental model. Such executive functions clearly overlap with many researchers’ conception of reasoning or even of general intelligence" (2).  

This is quite convincing, but studiesshow that even tasks that measure only Memory Span, without any manipulation, correlate significantly with Fluid Ability (3).

To summarize, from the point of view of CHC abilities, we see a great closeness between Fluid Ability and Short Term Memory.  We also see a great closeness between Executive functions,  Fluid Ability and Short Term Memory. 

It may be that these three concepts will merge in the future to form one psychometric ability.  Maybe this ability will be named "Executive Functions", and Fluid Ability and Short Term Memory will be narrow abilities within it.

References:

1.  Flanagan, Dawn p., Ortiz, Samuel O. and Alfonso, Vincent C.  Essentials of cross battery assessment.  Second edition, 2007, Wiley and sons

2.  Lohman, D. F., Lakin, J. M., Sternberg, R. J., & Kaufman, S. B. (2009).Reasoning and intelligence. Handbook of intelligence, 419-441.‏ 

3.  Fukuda, K., Vogel, E., Mayr, U., & Awh, E. (2010). Quantity, not quality: The relationship between fluid intelligence and working memory capacity.Psychonomic bulletin & review, 17(5), 673-679.‏

4.    Diamond, Adele.  Executive functions. Annu. Rev. Psychol. 2013. 64:135–68

http://www.iapsych.com/articles/diamond2013.pdf

5.  WJ3COG examiner's manual.

Intelligence and cognitive abilities part 3:  

Fluid ability and Executive Functions