In Two Minds: Dual-Process Accounts of Reasoning

Evans, J.S. (2003). In two minds: dual-process accounts of reasoning. TRENDS in Cognitive Sciences, Volume 7 (10), 454-459.

Sometimes we take action before we’ve even realized we’re thinking about it. We hold our hand out to catch a ball; we produce a well-formed sentence. At other times, we use our brains to work out a problem like the answer to a difficult math equation, or to form an opinion on a particular issue. In this review paper, Evans (2003) describes these two distinct forms of reasoning, and argues that they are supported by separate cognitive systems in the brain.

System 1 is sometimes called our implicit reasoning, or unconscious system. It is thought to be the universal cognition that is shared between humans and other animals. Even though the brain goes through many steps using this type of reasoning, we’re usually only aware of the end product (in Evan’s terms, ‘only the final product is posted to consciousness’). System 1 processes are based on associative learning that activates specific neural networks. As a result, System 1 knowledge is based on prior experiences and beliefs. When we experience a flame and the sensation of heat together repeatedly, we begin to associate fire with heat and pull away from fire even without thinking about it. Evan’s argues that the learning mechanisms of this system are domain-general, but that the function is domain-specific.

System 2 is thought to have evolved more recently and to be unique to humans. Its processes are slower, operate in sequence, and are under voluntary control. This system requires the use of working memory (WM) and is therefore restricted to the limitations of WM (e.g., how much you can hold in mind at one time). The purpose of System 2 is for abstract, hypothetical thinking. Consider the example of how I decided to get to campus today: System 1 instinctively reaches for the car keys as this is how I have travelled to campus all winter long; however, System 2 constructs a mental model of possibilities, such as taking into account it is now Spring, the temperature is warmer, and the roads are clear, therefore I could dust of my bicycle and get some exercise while I travel to school, which has health benefits compared to sitting in a car driving. System 2 would also take into consideration the fact that my bicycle will require a tune up in order to use it and I unfortunately do not have enough time to do the work if I am to arrive on time, therefore I should drive to campus today in my car and make some time on the weekend to get my bicycle ready. It is clear from this example that the two processes interact with one another depending on what is being reasoned.

One technique used to investigate these two systems is a deductive reasoning paradigm. The participant judges whether an argument is true or false requiring reasoning using System 2. Sometimes the argument uses familiar information in a believable or unbelievable way. Judgments influenced by this prior knowledge reflect the influence of System 1.  Neuropsychological studies employing functional magnetic resonance imaging (fMRI) provides additional evidence for the distinction between System 1 and 2 processes because separate brain areas are activated on tasks tapping System 1 and/or 2.

Of interest to our lab is how these systems might influence language learning.

Blogger: Ian Gallant is about to graduate from the Masters of Clinical Science degree in Speech Language Pathology. He hangs out in the LWM lab on a regular basis. 

Morpheme Learning of Children With Specific Language Impairment Under Controlled Instructional Conditions

Connell, P. & Stone, C. (1992). Morpheme learning of children with specific language impairment under controlled instructional conditions. Journal of Speech and Hearing Research, Volume 35, 844-852.

Connell and Stone (1992) examined how children with Specific Language Impairment (SLI) learn differently than Typically Developing (TD) children. The study investigated language learning in children with SLI under controlled experimental teaching conditions. According to Connell’s previous work (1986), children with SLI do not differ from children with TD in learning language rules during teaching sessions under an imitation condition that requires imitating and producing language rules. In comparison, children with SLI showed poorer learning of language rules under a modeling condition that required only listening to the input.    

The 1992 study compared the comprehension and production performance of children with SLI, and either age or language - matched groups. Specifically, it examined children’s mastery of learning the new morphemes under modeling and imitation instruction conditions. Using a computerized language- teaching program, children were taught a set of invented morphemes over a two-week period. The results indicated that for morpheme comprehension, there was no difference between children with SLI and the control groups under modeling or imitation conditions. On the other hand, for morpheme production, children with SLI scored significantly lower than the other groups in the modeling, but not the imitation condition. In sum, children with SLI produced the invented new morphemes more reliably under imitation trials than modeling trials. However, TD children showed no such preferences regarding either the molding or imitation instruction.

These results suggest that children with SLI may fail to learn language simply from hearing language models. Rather, children with SLI may benefit from learning in a richer context involving production and comprehension.

Blogger: Areej Balilah

Learning Non-Adjacent Regularities at Age 0;7

Gervain, J., & Werker, J.F. (In press). Learning non-adjacent regularities at age 0;7. Journal of Child Language, DOI:10.1017/S0305000912000256

The ability to learn rules is an important part of language learning. Infants have been found to be able to learn certain regularities involving both adjacent repetitions (e.g., ‘wo fe fe’) and non-adjacent repetitions (e.g., ‘wo fe wo’). This study compared learning of adjacent and non-adjacent repetitions in 7-month old infants to examine evidence that these patterns are processed differently in the brain.

In each of two experiments, infants completed a test phase: the infant heard a ‘word’ that either followed a pattern (e.g., adjacent repetition) or had no pattern (e.g., ‘wo fe  ga’) at the same time they looked to a light. If the infant noticed, or was familiar with, the pattern of the word being played, the infant would look away quickly. If the word being played was novel, the infant would look longer. A ‘looking time difference’ would show that the infant discriminated the pattern from the novel words. In Experiment 1, there was a familiarization phase: the infants heard words that followed the pattern (e.g., adjacent repetition) for 2 minutes prior to the test phase. In Experiment 2, the infant completed the test phase only with no familiarization phase.

Infants showed a ‘looking time difference’ for both adjacent and non-adjacent repetitions in Experiment 1 with the familiarization phase, but not Experiment 2. There were no differences in learning across trials for adjacent or non-adjacent repetitions.  These results indicate that the infants learned the relevant rule during the familiarization phase in Experiment 1. There was no evidence of a different learning mechanism for adjacent vs. non-adjacent repetitions, though more research at other stages of development is needed.

The findings provide further evidence of the importance of pattern learning in language acquisition. Children with language impairment may need more explicit (‘meta’) strategies to notice/learn linguistics patterns/rules.

Blogger: Lisa Archibald

Sentence Repetition as a Measure of Early Grammatical Development in Italian

Devescovi, A., & Caselli, M.C. (2007). Sentence repetition as a measure of early grammatical development in Italian. International Journal of Language & Communication Disorders, 42(2), 187–208. 

Early identification of language impairment is essential in order to provide timely intervention, however, few standardized measures exist for children under four years of age. Devescovi and Caselli suggest that the Sentence Repetition Test (SRT) could serve as a suitable assessment of language development for young children based on the premise that a child’s ability to repeat a sentence is representative of her spontaneous language abilities. Consensus has not been reached on whether the SRT is an accurate measure of language ability; some say it overestimates ability, while others argue it underestimates it. Most significantly though, SRT has been recognized as a tool for identifying language impairment (e.g., Conti-Ramsden et al., 2001).

In the first of two studies, Devescovi and Caselli examine test-retest reliability of SRT in 100 Italian-speaking children aged 2;0 to 4;0. The authors find that calculating the mean length of utterance in words is sensitive to linguistic development between the ages of 2;0 and 2;6, and that number of sentences repeatedly correctly better discriminates the older age bands. It is important to note that MLU is calculated in words in this study by counting not morphemes, but whole words, which is common in studies of the development of Italian. Perhaps calculation of MLU using morphemes would offer better discrimination beyond 2;6.

In the second study, Devescovi and Caselli examine the correlation between SRT performance, verbal memory span (VMS), and spontaneous speech (structured conversation and picture description), noting that verbal memory span has been shown to predict MLU in spontaneous speech (Blake et al., 1994). SRT responses and spontaneous utterances are analyzed for three factors: number of verbs, omitted articles, and MLU (in words). Analysis revealed no correlation between any of these measures and VMS after controlling for age. Article omission and number of verbs in SRT were both related to spontaneous speech, while correlation between MLU (in words) of SRT and spontaneous speech was not significant.

The sentences used in the SRT included simple sentence structure and only those morphemes expected to develop by 4;0. While it is important to include sentences that could be repeated by the youngest children in the age span, it is possible that limiting the complexity of the stimuli may have limited the performance of the older children, causing a ceiling effect. Despite limitations of the task, positive correlations shown in the findings suggest that some form of SRT may be beneficial in assessing language of young children.

Blogger: Laura Pauls

Variability and Detection of Invariant Structure

Variability and Detection of Invariant Structure. Gomez, R. L. (2002). Psychological Science, 13, 5.

Recent theories of language learning suggest that language learners are particularly adept at tracking the statistical regularities that exist within natural language. For example, learners are able to sensitive to “adjacent dependencies”, that is, the higher probabilities that occur between adjacent syllables within words than between words. However, a key aspect of language learning involves learning patterns between “non-adjacent dependencies”. Some examples of nonadjacent dependencies experienced in everyday language use are the dependencies between auxiliaries and inflectional morphemes (e.g.: is running), and dependencies involving agreement (e.g.: the kids in the park are playing). What is of interest to researchers is how humans learn to track these nonadjacent relationships.

In an experimental task involving learning nonadjacent dependencies, subjects listen to a string of syllables and must learn that a particular non-adjacent pattern – for example, that a first element always occurs with a third element in the string. A key hypothesis in this learning regards the middle element. If the middle element varies more, the pattern between the first and third element becomes more salient and the learner shows greats sensitivity to learning the nonadjacent dependency.

In this study, adults and infants were exposed to an artificial language containing nonadjacent dependencies between words (e.g.: aXd, bXe, cXf). The set size of X varied between conditions, drawing X from a set size of either 2, 6, 12, or 24 elements. Learning was greater for when the set size from which X was drawn was highly variable (set size = 24). These results demonstrate that learning is adaptable may be dynamically guided by the statistical structure in their linguistic environment. It should be noted that these results have not been replicated in all subsequent studies.

Statistical learning in children with language impairment has been investigated only recently (see blogpost from Evans et al., 2009). It may be that these children have more difficulty recognizing such patterns in language. Current interventions involving explicitly teaching linguistic rules may facilitate this learning.

Blogger: Nicolette Noonan

Relationships Among Linguistic Processing Speed, Phonological Working Memory, and Attention in Children Who Stutter

Anderson, J. D., & Wagovich, S. A. (2010). Relationships among linguistic processing speed, phonological working memory, and attention in children who stutter. Journal of Fluency Disorders, 35, 216-234. 

Studies of speech reaction time (SRT) are thought to examine the efficiency with which a person processes and responds to language-based stimuli. The few studies that have examined SRT in groups of children who stutter (CWS) and their typically developing peers have revealed mixed findings.

One finding is that longer SRT’s correspond with higher receptive vocabulary scores in children who do not stutter, but that for CWS, there appears to be no relationship between vocabulary and SRT. It is proposed that the relationship between vocabulary scores and SRT’s in typically fluent groups is mediated by lexical competition, such that individuals with larger vocabularies take longer to select a word and thus have slower reaction times than children with poorer vocabularies. Anderson and Wagovich hypothesized that factors related to lexical processing, such as phonological working memory, may correlate with SRT’s in children who stutter.  These researchers also investigated whether attentional processes may affect SRT’s in CWS.

In this study, groups of children who do or do not stutter completed nonword repetition, picture naming, and their parents completed a temperament questionnaire about them. These measures were used to evaluate phonological working memory, SRT, and attention, respectively. Results revealed that performance on tests of nonword repletion related to SRT in the children who stuttered but not the typically fluent group. Anderson and Wagovich concluded that for CWS, phonological working memory is associated with SRT.

Nonword repetition is typically considered to be a measure of phonological short-term memory because it involves immediate repetition only, rather than additionally requiring information processing as in working memory tasks. More broadly, nonword repetition taps several processes involved in phonological processing (discrimination, encoding, storage, output). Further work is needed to understand what underlying process may account for the associations between nonword repetition and SRT in the CWS in this study.

Blogger: Alexandra Smith

Grammatical Difficulties in Children with SLI: Is Learning Deficient?

Grammatical Difficulties in Children with SLI: Is Learning Deficient? Hsu, H. J., & Bishop, D. (2011). Hum Dev. 53(5): 264-277.

One view of language learning suggests that children (and humans generally) are sensitive to the patterns of sounds that they hear in language. This statistical learning is based on the frequencies or probabilities of sounds in the language. First, young children store heard sentences in an exemplar-by-exemplar fashion (Ellis, 2002), memorizing individual items. In time, children develop more  abstract (syntactic) patterns of different types, and these frames allow them to produce correct grammatical sentences (Ellis, 2002).

Hsu and Bishop discuss the viewpoint that the grammatical deficits in SLI are due to an impairment in the ability to extract these statistical patterns from the input. As a result, children with SLI may require more exposure to learn abstract syntactic patterns. Indeed, Bishop, Adams, and Rosen (2006) found that even after daily training with a particular construction type, children with SLI did not achieve fluent automatic comprehension. It may be that the poor statistical learning in SLI results from other deficits, however. Limitations in short-term memory (Coady & Evans, 2008) or speech perception (Joanisse et al., 2000) may negatively impact statistical learning abilities in SLI.

Children with SLI may have difficulty identifying patterns in the language they hear. Isolating particular patterns to increase the frequency of exposure and highlight the form are approaches that would be consistent with this viewpoint.

Blogger: Areej Balilah. 

Cognitive Profiling and Preliminary Subtyping in Chinese Developmental Dyslexia

Ho, C. S. H., Chan, D. W. O., Lee, S. H., Tsang, S. M., & Luan, V. H. (2004). Cognition, 91, 43-75.

Even though reading impairment is thought to be just as common among children in China as it is in other countries, most of the pioneering research on dyslexia has been conducted in English with the English alphabet. As a result, the leading theories of dyslexia account for reading impairment in languages like English, but it is unclear whether they apply to languages like Chinese with logographic written symbols. According to one theory called the phonological deficit hypothesis, children with reading impairment may have difficulty mapping (or matching) print and sound due to noisy representations of words in their brains (or underspecified phonological representations).

Ho and colleagues suggest that in Chinese, the nature of the deficits underlying dyslexia might be different. This is because of the nature of Chinese script, as parts of the written symbols in Chinese don’t directly map onto sounds in the word in the same way they do in English. The authors tested 147 Cantonese-speaking children with dyslexia in Hong Kong. Measures included the ability to rapidly name pictures (rapid naming), manipulate sounds in words (phonological processing), read symbols (orthographic processing), and other visual-perceptual skills. Ho and colleagues found that more children had problems with rapid naming (57% of children) and orthographic processing (42%) than with phonological processing (29%) and visual processing (27%). In other analyses involving step-wise regression, results suggested that rapid naming and orthographic processing are related to reading impairment in Chinese. Unlike findings for English speakers, phonological processing was not importantly related to dyslexia in Chinese. These results have implications for the types of intervention strategies that might be used to help children in China improve their reading.

A final note: it is worth mentioning that the phonological processing tasks used in this study were rather simple, and children performed very well on them (even those classified with reading impairment). These tasks asked children to indicate which of two syllables out of a group of three shared sounds. It might be that phonology would have been found to play a larger role in Chinese dyslexia if other tasks had been included. This remains an ongoing debate.

Guest blogger: Jeff Malins from the Language, Reading and Cognitive Neuroscience Lab. Jeff is a PhD student in Neuroscience, and has used measures such as eyetracking, ERPs, and fMRI to study spoken word recognition in adult native speakers of Mandarin Chinese. He is also currently collaborating with researchers in Beijing on a project looking at Mandarin spoken word recognition in children with reading impairments

Guiding Principles and Clinical Applications for Speech-Language Pathology Practice in Early Intervention

Paul, D., & Roth, F.P. (2011). Guiding Principles and Clinical Applications for Speech-Language Pathology Practice in Early Intervention. Language, Speech, and Hearing Services in Schools, 42, 320-330.

This clinical forum note describes four guiding principles in early intervention. Early intervention is defined as services provided to those from birth to 3 years who have, or are at risk for, communication, speech, language, hearing, feeding, swallowing, and/or emergent literacy problems. The services encompass screening/assessment, goal setting/intervention, consultation, service coordination, transition planning, and advocacy. SLPs play a central role in early intervention.

Principle 1 encompasses the idea that services are family centred, and culturally and linguistically responsive. Such services support family involvement in the child’s development, and positive interactions. Principle 2 highlights the need for services to be developmentally supportive and promote children’s participation in their natural environments. Principle 3 refers to services that are comprehensive, coordinated, and team based. Domains of development are interdependent during early childhood requiring comprehensive and coordinated services. Finally, Principle 4 says that services are based on the highest quality evidence available. This evidence may be external and drawn from published research findings or internal including policy, informed clinical opinion, and patient preferences.

There is much to agree with in these principles. Optimal implementation remains a challenge in many settings, but is a good target!

Incidental language learning: Listening (and learning) out of the corner of your ear

Saffran, J. R., Newport, E. L., Aslin, R. N., Tunick, R. A., & Barrueco, S. (1997). Psychological Science, 8, 101-105.

Language learning is incidental; that is, children learn language without being aware that they’re learning it. Humans are sensitive to the patterns they hear in language. Frequency patterns across a broad range of natural experiences are encoded incidentally, and support language learning. One way to study language learning is to teach someone an artificial language, a language they could never have learned before.

One important key to language learning is knowing when one word ends and another begins. There are lots of statistical cues available in the language that can help new language learners figure out where the words are. In particular, there is a relationship between sounds that tend to occur within or between words. For example, some sounds are more likely to occur within a word. If infants are sensitive to these patterns, they may be better at learning language.

In this study, participants listened to a stream of artificial language while focused on something else for 21 minutes. Even though the participants were not told to attend to the language, both adults and children performed above chance level at selecting items from the artificial language. After 42 minutes of exposure, performance was significantly improved and significantly greater than chance.

Despite mere minutes of listening, the complex stimuli, and importantly, the absence of instructions to attend to the artificial language, both adults and children demonstrated statistically-based learning of word boundaries. These findings suggest that incidental learning is a robust phenomenon that may play a role in natural language acquisition. The fact that children and adults did not differ in their learning of words in the artificial language gives support to the idea that early-acquired aspects of language are learned equally well by younger and older learners. Further research is needed to address questions related to the development of this ability.

Nicolette Noonan is an incoming Masters student in the Speech and Language Sciences field.