Cross language learning disabilities and verbal versus spatial memory

The research reported in this talk involves comparisons of verbal and spatial memory tasks across groups of children (and adults) with different types of learning difficulties. The research focuses on children with literacy acquisition problems and investigates whether such problems are related to specific areas of deficit. In the first piece of research, children with dyslexia (literacy learning problems) and dyspraxia (motor deficits) were contrasted on measures of memory (for example, tasks that required the retention of sequences of verbal material or spatial movements) and additional measures of literacy (reading and spelling), phonological (awareness of sounds within words) and motor (fine and gross motor tasks) functioning. The data were consistent with a dissociation between tasks/groups such that dyslexics showed weak phonological processing but intact visuo-spatial processing, whereas children with dyspraxia showed weaknesses on task involving visuo-spatial information, but average levels of performance on tasks that required phonological processing. Similar results were identified amongst adult groups, consistent with a deviant level of functioning rather than a developmental delay. A second line of research contrasted children with or without literacy problems across language backgrounds (English, Arabic, Chinese and bilingual children). Consistent with the dyslexia data, children with poor English literacy skills showed weaknesses in verbal/phonological memory tasks but not in visuo-spatial memory. However, for Chinese-language children, visuo-spatial memory differed between good and poor literacy learners, but there was little evidence for verbal memory differences. In contrast, the Arabic and bilingual children showed differences in both verbal and visuo-spatial areas, although the evidence was consistent with enhanced visual/spatial skills amongst the good literacy groups, rather than poor literacy children showing weaknesses in those tasks. These data suggest that the influence of memory skills on learning may vary with the language of instruction. A final line of enquiry considers whether teaching strategies to children with learning difficulties may overcome some of the identified memory deficits and lead to better levels of learning. English language children with learning difficulties were taught visual and verbal strategies to support retention of materials in short-term memory tasks. In the majority of cases, learning was improved when it focused on visuo-spatial strategies but not when verbal strategies were used. These data support the relationship between learning difficulties and different aspects of short-term memory that may lead to poor levels of learning. It also presents evidence that memory (particularly those related to visuo-spatial) processes are influenced by the context within which learning is taking place, both in terms of the language of instruction and the strategies used to support learning. For some children with educational difficulties based around language-related deficits, visuo-spatial strategies may support acquisition.     

Psychotropic placebos create resistance to the misinformation effect

Can a placebo for a psychotropic drug help participants resist the misinformation effect? To answer this question, we gave participants a mixture of baking soda and water and told half of them that the mixture was a cognition-enhancing drug called R273 and told the other half that it was an inactive version of the drug. Shortly thereafter, all participants took part in a three-stage misinformation experiment. Compared with participants who were told that they had taken the placebo, the participants who were told that they had taken the drug reported improved cognitive abilities and were less susceptible to the misinformation effect. We provide sourcemonitoring and mindfulness accounts of our findings.     

Imagination inflation is a fact, not an artifact: A reply to Pezdek and Eddy

Pezdek and Eddy (2001) claim to prove that imagination inflation is a spurious effect caused by regression to the mean (RTM). They make four predictions about what patterns of data would demonstrate a genuine effect for imagination versus those that would be explainable by RTM. We review each of those predictions, and demonstrate significant problems with them. We conclude that imagination inflation is a genuine effect, and that Pezdek and Eddy’s work has contributed to the growing research showing that when people imagine fictitious events from long ago, they become more confident that those false events were genuine experiences.     

False memories for end-of-life decisions

OBJECTIVE: To examine people's false memories for end-of-life decisions. DESIGN: In Study 1, older adults decided which life-sustaining treatments they would want if they were seriously ill. They made these judgments twice, approximately 12 months apart. At Time 2, older adults and their self-selected surrogate decision makers tried to recall the older adults' Time 1 decisions. In Study 2, younger adults made treatment decisions twice, approximately 4 months apart. At Time 2, younger adults tried to recall their Time 1 decisions. MAIN OUTCOME MEASURES: Percentage of participants who falsely remembered that their original treatment decisions were the same as their current decisions. RESULTS: In Study 1, older adults falsely remembered that 75% of their original decisions were the same as their current decisions; surrogates falsely thought that 86% of older adults' decisions were the same. In Study 2, younger adults falsely remembered that 69% of their original decisions were the same as their current decisions. CONCLUSION: Age alone cannot account for people's false memories of their end-of-life decisions; we discuss other mechanisms. The results have practical implications for policies that encourage people to make legal documents specifying their end-of-life treatment decisions.     

Brain hyper‐connectivity and operation‐specific deficits during arithmetic problem solving in children with developmental dyscalculia

Developmental dyscalculia (DD) is marked by specific deficits in processing numerical and mathematical information despite normal intelligence (IQ) and reading ability. We examined how brain circuits used by young children with DD to solve simple addition and subtraction problems differ from those used by typically developing (TD) children who were matched on age, IQ, reading ability, and working memory. Children with DD were slower and less accurate during problem solving than TD children, and were especially impaired on their ability to solve subtraction problems. Children with DD showed significantly greater activity in multiple parietal, occipito‐temporal and prefrontal cortex regions while solving addition and subtraction problems. Despite poorer performance during subtraction, children with DD showed greater activity in multiple intra‐parietal sulcus (IPS) and superior parietal lobule subdivisions in the dorsal posterior parietal cortex as well as fusiform gyrus in the ventral occipito‐temporal cortex. Critically, effective connectivity analyses revealed hyper‐connectivity, rather than reduced connectivity, between the IPS and multiple brain systems including the lateral fronto‐parietal and default mode networks in children with DD during both addition and subtraction. These findings suggest the IPS and its functional circuits are a major locus of dysfunction during both addition and subtraction problem solving in DD, and that inappropriate task modulation and hyper‐connectivity, rather than under‐engagement and under‐connectivity, are the neural mechanisms underlying problem solving difficulties in children with DD. We discuss our findings in the broader context of multiple levels of analysis and performance issues inherent in neuroimaging studies of typical and atypical development.     

Intentional and automatic processing of numerical information in mathematical anxiety: testing the influence of emotional priming

ABSTRACT

Current theoretical approaches suggest that mathematical anxiety (MA) manifests itself as a weakness in quantity manipulations. This study is the first to examine automatic versus intentional processing of numerical information using the numerical Stroop paradigm in participants with high MA. To manipulate anxiety levels, we combined the numerical Stroop task with an affective priming paradigm. We took a group of college students with high MA and compared their performance to a group of participants with low MA. Under low anxiety conditions (neutral priming), participants with high MA showed relatively intact number processing abilities. However, under high anxiety conditions (mathematical priming), participants with high MA showed (1) higher processing of the non-numerical irrelevant information, which aligns with the theoretical view regarding deficits in selective attention in anxiety and (2) an abnormal numerical distance effect. These results demonstrate that abnormal, basic numerical processing in MA is context related.     

Comparative judgments of symbolic and non-symbolic stimuli yield different patterns of reaction times

Are different magnitudes, such as Arabic numerals, length and area, processed by the same system? Answering this question can shed light on the building blocks of our mathematical abilities. A shared representation theory suggested that discriminability of all magnitudes complies with Weber's law. The current work examined this suggestion. We employed comparative judgment tasks to investigate different types of comparisons — conceptual comparison of numbers, physical comparison of numbers and physical comparison of different shapes. We used 8 different size ratios and plotted reaction time as a function of these ratios. Our findings suggest that the relationship between discriminability and size ratio is not always linear, as previously suggested; rather, it is modulated by the type of comparison and the type of stimuli. Hence, we suggest that the representation of magnitude is not as rigid as previously suggested; it changes as a function of task demands and familiarity with the compared stimuli.     

Postulates for revising BDI structures

The process of rationally revising beliefs in the light of new information is a topic of great importance and long-standing interest in artificial intelligence. Moreover, significant progress has been made in understanding the philosophical, logical, and computational foundations of belief revision. However, very little research has been reported with respect to the revision of other mental states, most notably propositional attitudes such as desires and intentions. In this paper, we present a first attempt to formulate a general framework for understanding the revision of mental states. We develop an abstract belief-desire-intention model of agents, and introduce a notion of rationality for this model. We then present a series of formal postulates characterizing the processes of adding beliefs, desires, and intentions, updating costs and values, and removing beliefs, desires, and intentions. We also investigate the computational complexity of several problems involving the abstract model and comment on algorithms for revision.