Robert G. Morrison

A Neurocomputational Model of Analogical Reasoning and its Breakdown in Frontotemporal Lobar Degeneration

Analogy is important for learning and discovery and is considered a core component of intelligence. We present a computational account of analogical reasoning that is compatible with data we have collected from patients with cortical degeneration of either their frontal or anterior temporal cortices due to frontotemporal lobar degeneration (FTLD). These two patient groups showed different deficits in picture and verbal analogies: frontal lobe FTLD patients tended to make errors due to impairments in working memory and inhibitory abilities, whereas temporal lobe FTLD patients tended to make errors due to semantic memory loss. Using the Learning and Inference with Schemas and Analogies model, we provide a specific account of how such deficits may arise within neural networks supporting analogical problem solving.

Relational integration, inhibition, and analogical reasoning in older adults.

The difficulty of reasoning tasks depends on their relational complexity, which increases with the number of relations that must be considered simultaneously to make an inference, and on the number of irrelevant items that must be inhibited. The authors examined the ability of younger and older adults to integrate multiple relations and inhibit irrelevant stimuli. Young adults performed well at all but the highest level of relational complexity, whereas older adults performed poorly even at a medium level of relational complexity, especially when irrelevant information was presented. Simulations based on a neurocomputational model of analogical reasoning, Learning and Inference with Schemas and Analogies (LISA), suggest that the observed decline in reasoning performance may be explained by a decline in attention and inhibitory functions in older adults.

Distraction during relational reasoning: The role of prefrontal cortex in interference control

We compared the reasoning performance of patients with frontal-variant frontotemporal lobar degeneration (FTLD) with that of patients with temporal-variant FTLD and healthy controls. In a picture analogy task with a multiple-choice answer format, frontal-variant FTLD patients performed less accurately than temporal-variant FTLD patients, who in turn performed worse than healthy controls, when semantic and perceptual distractors were present among the answer choices. When the distractor answer choices were eliminated, frontal-variant patients showed relatively greater improvement in performance. Similar patient groups were tested with a relational-pattern reasoning task that included manipulations of one or two relations and both perceptual and semantic extraneous information. Frontal-variant patients showed performance deficits on all tasks relative to the other subject groups, especially when distracted. These results demonstrate that intact prefrontal cortex (PFC) is necessary for controlling interference from perceptual and semantic distractors in order to reason from relational structure.

Analogical priming via semantic relations.

Research on semantic memory has often tacitly treated semantic relations as simple conduits for spreading activation between associated object concepts, rather than as integral components of semantic organization. Yet conceptual relations, and the role bindings they impose on the objects they relate, are central to such cognitive tasks as discourse comprehension, inference, problem solving, and analogical reasoning. The present study addresses the question of whether semantic relations and their bindings can influence access to semantic memory. The experiments investigated whether, and under what conditions, presenting a prime pair of words linked by 1 of 10 common semantic relations would facilitate processing of a target pair of words linked by the same relation. No effect was observed when participants merely read the prime; however, relational priming was observed under instructions to note and use the semantic relations. Participants were faster at making a lexical decision or naming a word on a related pair of target words when that pair was primed with an analogously related pair of words than when the prime pair consisted of either two unrelated words or two words linked by some other relation. This evidence of analogical priming suggests that under an appropriate strategic set, lexical decisions and naming latencies can be influenced by a process akin to analogical mapping.

A computational account of children's analogical reasoning: balancing inhibitory control in working memory and relational representation

Theories accounting for the development of analogical reasoning tend to emphasize either the centrality of relational knowledge accretion or changes in information processing capability. Simulations in LISA (Hummel & Holyoak, 1997, 2003), a neurally inspired computer model of analogical reasoning, allow us to explore how these factors may collaboratively contribute to the development of analogy in young children. Simulations explain systematic variations in United States and Hong Kong childrens performance on analogies between familiar scenes (Richland, Morrison & Holyoak, 2006; Richland, Chang, Morrison & Au, 2010). Specifically, changes in inhibition levels in the models working-memory system explain the developmental progression in US childrens ability to handle increases in relational complexity and distraction from object similarity during analogical reasoning. In contrast, changes in how relations are represented in the model best capture cross-cultural differences in performance between children of the same ages (3-4 years) in the United States and Hong Kong. We use these results and simulations to argue that the development of analogical reasoning in children may best be conceptualized as an equilibrium between knowledge accretion and the maturation of information processing capability.

Young Children's Analogical Reasoning across Cultures: Similarities and Differences.

A cross-cultural comparison between U.S. and Hong Kong preschoolers examined factors responsible for young childrens analogical reasoning errors. On a scene analogy task, both groups had adequate prerequisite knowledge of the key relations, were the same age, and showed similar baseline performance, yet Chinese children outperformed U.S. children on more relationally complex problems. Children from both groups were highly susceptible to choosing a perceptual or semantic distractor during reasoning when one was present. Taken together, these similarities and differences suggest that (a) cultural differences can facilitate better knowledge representations by allowing more efficient processing of relationally complex problems and (b) inhibitory control is an important factor in explaining the development of childrens analogical reasoning.

Role of Gamma-Band Synchronization in Priming of Form Discrimination for Multiobject Displays

Previous research has shown that synchronized flicker can facilitate detection of a single Kanizsa square. The present study investigated the role of temporally structured priming in discrimination tasks involving perceptual relations between multiple Kanizsa-type figures. Results indicate that visual information presented as temporally structured flicker in the gamma band can modulate the perception of multiple objects in a subsequent display. For judgments of both relative orientation and relative position of 2 rectangles, response time to identify and discriminate relations between the objects was consistently decreased when the vertices corresponding to distinct Kanizsa-type rectangles were primed asynchronously. Implications are discussed for models of the perception of objects and their interrelations.

Neurocognitive Process Constraints on Analogy: What Changes to Allow Children to Reason like Adults?

Analogy employs a neurocognitive working-memory (WM) system to activate and bind relational representations, integrate multiple relations, and suppress distracting information. Analogy experiments exploring these processes have used a variety of methodologies including dual tasks, neuropsychology, and functional neuroimaging, as well as experiments with children and older adults. Collectively, these experiments provide a rich set of results useful in evaluating any model of analogy and its development.

Mental health risk factors associated with childhood language brokering

Serving as a language translator (broker) for family members during childhood can affect cognitive and emotional functions in both beneficial and detrimental ways. Child language brokers translate in a variety of contexts including conversations between their parents and financial, legal and medical professionals. Pressure to be involved in these activities may negatively affect mental health by placing undue stress on child language brokers, while also distracting them from other responsibilities such as school. In this study, the relationship between language brokering during childhood and adolescence and the mental health of bilingual young adults was examined. Overall, language brokers had higher levels of depression. Young adults who previously served as language brokers, particularly during their preadolescent years, had higher levels of anxiety than their bilingual non-brokering counterparts. It is important for parents, educators and mental health professionals to become more aware of the mental health consequences that may arise from language brokering duties, particularly how symptoms vary depending on whether brokering began in childhood or adolescence.

Cool, callous and in control: superior inhibitory control in frequent players of video games with violent content

Abstract Research on the effects of media violence exposure has shown robust associations among violent media exposure, increased aggressive behavior, and decreased empathy. Preliminary research indicates that frequent players of violent video games may have differences in emotional and cognitive processes compared to infrequent or nonplayers, yet research examining the amount and content of game play and the relation of these factors with affective and cognitive outcomes is limited. The present study measured neural correlates of response inhibition in the context of implicit attention to emotion, and how these factors are related to empathic responding in frequent and infrequent players of video games with graphically violent content. Participants completed a self-report measure of empathy as well as an affective stop-signal task that measured implicit attention to emotion and response inhibition during electroencephalography. Frequent players had lower levels of empathy as well as a reduction in brain activity as indicated by P100 and N200/P300 event related potentials. Reduced P100 amplitude evoked by happy facial expressions was observed in frequent players compared to infrequent players, and this effect was moderated by empathy, such that low levels of empathy further reduced P100 amplitudes for happy facial expressions for frequent players compared to infrequent players. Compared to infrequent players, frequent players had reduced N200/P300 amplitude during response inhibition, indicating less neural resources were recruited to inhibit behavior. Results from the present study illustrate that chronic exposure to violent video games modulates empathy and related neural correlates associated with affect and cognition.