Papers by Carter Wendelken
Proceedings of the Annual Meeting of the Cognitive Science Society, 2000
A connectionist model capable of performing rapid inferences to establish explanatory and referen... more A connectionist model capable of performing rapid inferences to establish explanatory and referential coherence is described. The model's ability to perform such inferences arises from (i) its structure, (ii) its use of mutual inhibition among "sibling" types, entities, and rules, (iii) the use of temporal synchrony for representing dynamic bindings, and (iv) its ability to rapidly modify weights in response to convergent activity.
The influence of parental education and family in the development of reasoning skills and the lateral fronto-parietal network
Examining prospectively the influence of SES on the development of reasoning and the lateral fron... more Examining prospectively the influence of SES on the development of reasoning and the lateral fronto-parietal network (LFPN). Preregistration and supporting documents.
Proceedings of the Twenty-Fourth Annual Conference of the Cognitive Science Society, 2019
A connectionist model for emergent planning behavior is proposed. The model demonstrates that a s... more A connectionist model for emergent planning behavior is proposed. The model demonstrates that a simple planning schema, acting in concert with two general purpose cognitive functionalities, namely, episodic memory and perception, can solve a restricted class of planning problems by backchaining from the goal to the current state. In spite of its simple structure, the schema can search for and execute plans involving multiple steps. We discuss how this simple model can be extended into a more powerful and expressive planning system by incorporating additional control and memory structures.
Proceedings of the Twenty-Fourth Annual Conference of the Cognitive Science Society, 2019
Combining Belief and Utility in a Structured Connectionist Agent Architecture Carter Wendelken an... more Combining Belief and Utility in a Structured Connectionist Agent Architecture Carter Wendelken and Lokendra Shastri International Computer Science Institute 1947 Center Street, Suite 600 Berkeley, CA 94704 carterw,shastri @icsi.berkeley.edu type hierarchy Abstract The SHRUTI model demonstrates how a system of sim- ple, neuron-like elements can encode a large body of re- lational causal knowledge and provide the basis for rapid inference. Here we show how a representation of util- ity can be integrated with the existing representation of belief, such that the resulting architecture can be used to reason about values and goals and thereby contribute to decision-making and planning. +e fact type buy(Person,-,-) +v +e +v entity To understand how the brain creates the mind, one could work mainly from the top down, characterizing mental processes, or from the bottom up, trying to understand the capabilities of neurons and simple circuits. In devel- oping the SHRUTI model we have pursued b...
JAMA Psychiatry, 2020
Understanding the neurodevelopmental trajectory of psychiatric symptoms is important for improvin... more Understanding the neurodevelopmental trajectory of psychiatric symptoms is important for improving early identification, intervention, and prevention of mental disorders. OBJECTIVE To test whether the strength of the coupling of activation between specific brain regions, as measured by resting-state functional magnetic resonance imaging (fMRI), predicted individual children's developmental trajectories in terms of attentional problems characteristic of attention-deficit/hyperactivity disorder and internalizing problems characteristics of major depressive disorder (MDD). A community cohort of 94 children was recruited from Vanderbilt University between 2010 and 2013. They were followed up longitudinally for 4 years and the data were analyzed from 2016 to 2019. Based on preregistered hypotheses and an analytic plan, we examined whether specific brain connectivity patterns would be associated with longitudinal changes in scores on the Child Behavior Checklist (CBCL), a parental-report assessment used to screen for emotional, behavioral, and social problems and to predict psychiatric illnesses. MAIN OUTCOMES AND MEASURES We used the strength of resting-state fMRI connectivity at age 7 years to predict subsequent changes in CBCL measures 4 years later and investigated the mechanisms of change by associating brain connectivity changes with changes in the CBCL. We analyzed data from a longitudinal brain development study involving children assessed at age 7 years (n = 94; 41 girls [43.6%]) and 11 years (n = 54; 32 girls [59.3%]). As predicted, less positive coupling at age 7 years between the medial prefrontal cortex and dorsolateral prefrontal cortex (DLPFC) was associated with a decrease in attentional symptoms by age 11 years (t 49 = 2.38; P = .01; β = 0.32). By contrast, a less positive coupling between a region implicated in mood, the subgenual anterior cingulate cortex (sgACC), and DLPFC at age 7 years was associated with an increase in internalizing (eg, anxiety/depression) behaviors by age 11 years (t 49 = -2.4; P = .01; β = -0.30). Logistic regression analyses revealed that sgACC-DLPFC connectivity was a more accurate predictor than baseline CBCL measures for progression to a subclinical score on internalization (t 50 = -2.61; P = .01; β = -0.29). We then replicated and extended the sgACC-DLPFC result in an independent sample of children with (n = 25) or without (n = 18) familial risk for MDD. CONCLUSIONS AND RELEVANCE These resting-state fMRI metrics are promising biomarkers for the early identification of children at risk of developing MDD or attention-deficit/ hyperactivity disorder.
The Journal of Neuroscience, 2017
Prior research points to a positive concurrent relationship between reasoning ability and both fr... more Prior research points to a positive concurrent relationship between reasoning ability and both frontoparietal structural connectivity (SC) as measured by diffusion tensor imaging (Tamnes et al., 2010) and frontoparietal functional connectivity (FC) as measured by fMRI (Cocchi et al., 2014). Further, recent research demonstrates a link between reasoning ability and FC of two brain regions in particular: rostrolateral prefrontal cortex (RLPFC) and the inferior parietal lobe (IPL) (Wendelken et al., 2016). Here, we sought to investigate the concurrent and dynamic, lead-lag relationships among frontoparietal SC, FC, and reasoning ability in humans. To this end, we combined three longitudinal developmental datasets with behavioral and neuroimaging data from 523 male and female participants between 6 and 22 years of age. Cross-sectionally, reasoning ability was most strongly related to FC between RLPFC and IPL in adolescents and adults, but to frontoparietal SC in children. Longitudinal analysis revealed that RLPFC-IPL SC, but not FC, was a positive predictor of future changes in reasoning ability. Moreover, we found that RLPFC-IPL SC at one time point positively predicted future changes in RLPFC-IPL FC, whereas, in contrast, FC did not predict future changes in SC. Our results demonstrate the importance of strong white matter connectivity between RLPFC and IPL during middle childhood for the subsequent development of both robust FC and good reasoning ability.
Proceedings of the National Academy of Sciences, 2017
Metamemory monitoring, or the ability to introspect on the accuracy of one’s memories, improves c... more Metamemory monitoring, or the ability to introspect on the accuracy of one’s memories, improves considerably during childhood, but the underlying neural changes and implications for intellectual development are largely unknown. The present study examined whether cortical changes in key brain areas hypothesized to support metacognition contribute to the development of metamemory monitoring from late childhood into early adolescence. Metamemory monitoring was assessed among 7- to 12-y-old children (n = 145) and adults (n = 31). Children returned for up to two additional assessments at 8 to 14 y of age (n = 120) and at 9 to 15 y of age (n = 107) (n = 347 longitudinal scans). Results showed that metamemory monitoring continues to improve from childhood into adolescence. More pronounced cortical thinning in the anterior insula and a greater increase in the thickness of the ventromedial prefrontal cortex over the three assessment points predicted these improvements. Thus, performance bene...
Cerebral cortex (New York, N.Y. : 1991), Jan 23, 2016
Just as the ability to remember prior events is critical for guiding our decision-making, so too ... more Just as the ability to remember prior events is critical for guiding our decision-making, so too is the ability to recognize the limitations of our memory. Indeed, we hypothesize that neural signaling of retrieval failure promotes more accurate memory judgments over time. To test this hypothesis, we collected longitudinal functional magnetic resonance imaging data from 8 to 9 years olds, 10 to 12 years olds, and adults, with two time points spaced approximately 1.4 years apart (198 scan sessions in total). Participants performed an episodic memory retrieval task in which they could either select a response or report uncertainty about the target memory detail. Children who engaged anterior insula more strongly during inaccurate or uncertain responses exhibited greater longitudinal increases in anterior prefrontal cortex activation for decisions to report uncertainty; both of these neural variables predicted improvements in episodic memory. Together, the results suggest that the brain...
Developmental Science, 2017
In a large sample of children spanning ages 6-18 years, this study demonstrates pronounced age-re... more In a large sample of children spanning ages 6-18 years, this study demonstrates pronounced age-related improvements in analogical reasoning between ages 6 and 10, and continued improvement until mid-adolescence. • We used neuroimaging to distinguish among several plausible cognitive accounts of the development of analogical reasoning. • This work demonstrates that the development of analogical reasoning is associated with increased engagement of the left anterior inferior prefrontal cortex (BA 47/45), previously shown to be associated with the ability to select among competing semantic associations. • Improvements over this age range were not observed in brain regions linked to domain-general processes underlying response control or relational thinking. Analogical reasoning, or the ability to find correspondences between individual objects as well as their relationships
A Time and a Place for Everything: Building Blocks of Episodic Memory
Shruti-agent: A structured connectionist model of decision-making
Abstract A neurally plausible connectionist model,of decisionmaking, based on the SHRUTI architec... more Abstract A neurally plausible connectionist model,of decisionmaking, based on the SHRUTI architecture, is being devloped. Toward this end, issues of appropriate connectionist representations for belief and utility, necessary control mechanisms, and reinforcement-based learning are addressed.
Developmental Cognitive Neuroscience, 2016
The goal of the present study was to investigate whether hippocampal contribution to episodic mem... more The goal of the present study was to investigate whether hippocampal contribution to episodic memory retrieval varies as a function of age (8-9 versus 10-11 versus adults), performance levels (high versus low) and hippocampal sub-region (head, body, tail). We examined fMRI data collected during episodic retrieval from a large sample (N = 126). Participants judged whether a stimulus had been encoded previously, and, if so, which of three scenes it had been paired with (i.e., source judgment). For 8-to 9-years-olds as well as low-performing 10-to 11-year-olds, hippocampal activations did not reliably differentiate between trials on which item-scene associations were correctly recalled (correct source), incorrectly recalled (incorrect source), or trials on which the item was forgotten (miss trials). For high-performing 10-11-year olds and low-performing adults, selective hippocampal activation was observed for correct source relative to incorrect source and miss trials; this effect was observed across the entire hippocampus. For high-performing adults, hippocampal activation also distinguished between correct and incorrect source trialsl, but only in the hippocampal head, suggesting that good performance in adults is associated with more focal hippocampal recruitment. Thus, both age and performance are important factors for understanding the development of memory and hippocampal function.
Child development, Jan 23, 2015
This research investigated whether episodic memory development can be explained by improvements i... more This research investigated whether episodic memory development can be explained by improvements in relational binding processes, involved in forming novel associations between events and the context in which they occurred. Memory for item-space, item-time, and item-item relations was assessed in an ethnically diverse sample of 151 children aged 7-11 years and 28 young adults. Item-space memory reached adult performance by 9½ years, whereas item-time and item-item memory improved into adulthood. In path analysis, item-space, but not item-time best explained item-item memory. Across age groups, relational binding related to source memory and performance on standardized memory assessments. In conclusion, relational binding development depends on relation type, but relational binding overall supports episodic memory development.
A connectionist model capable of performing rapid inferences to establish explanatory and referen... more A connectionist model capable of performing rapid inferences to establish explanatory and referential coherence is described. The model's ability to perform such inferences arises from (i) its structure, (ii) its use of mutual inhibition among "sibling" types, entities, and rules, (iii) the use of temporal synchrony for representing dynamic bindings, and (iv) its ability to rapidly modify weights in response to convergent activity.
PLOS ONE, 2015
We have reported previously that intensive preparation for a standardized test that taxes reasoni... more We have reported previously that intensive preparation for a standardized test that taxes reasoning leads to changes in structural and functional connectivity within the frontoparietal network. Here, we investigated whether reasoning instruction transfers to improvement on unpracticed tests of reasoning, and whether these improvements are associated with changes in neural recruitment during reasoning task performance. We found behavioral evidence for transfer to a transitive inference task, but no evidence for transfer to a rule generation task. Across both tasks, we observed reduced lateral prefrontal activation in the trained group relative to the control group, consistent with other studies of practice-related changes in brain activation. In the transitive inference task, we observed enhanced suppression of task-negative, or default-mode, regions, consistent with work suggesting that better cognitive skills are associated with more efficient switching between networks. In the rule generation task, we found a pattern consistent with a training-related shift in the balance between phonological and visuospatial processing. Broadly, we discuss general methodological considerations related to the analysis and interpretation of training-related changes in brain activation. In summary, we present preliminary evidence for changes in brain activation associated with practice of high-level cognitive skills.
Understanding language is the quintessential soft-computing problem. In order to understand langu... more Understanding language is the quintessential soft-computing problem. In order to understand language,a hearer must integrate a wide array of fuzzy, incomplete, and common sense knowledge. Yet we understand language effortlessly, spontaneously, and with remarkable efficiency. This remarkable human ability poses a challenge for computational neuroscience: How can a system of slow neuron-like elements represent a large body of knowledge and perform a wide range of inferences with such speed? SHRUTI attempts to address this challenge by demonstrating how a neural network can encode a large body of (i) specific facts, (ii) rules involving variables, negation, quantification, multiple antecedents and consequents, and (iii) knowledge about entities and types, and yet perform a wide range of inferences within a few hundred milliseconds. This paper provides a brief overview of shruti with an emphasis on the encoding of soft (evidential) rules and facts, and the manner in which SHRUTI combine...
Luerssen SCAN2015 Supplement
Developmental Change in Relational Binding and Hippocampal Structure
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Papers by Carter Wendelken