| 41. |
- Liu, Xueping, et al.
(författare)
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Variants in the fetal genome near pro-inflammatory cytokine genes on 2q13 associate with gestational duration.
- 2019
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Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- The duration of pregnancy is influenced by fetal and maternal genetic and non-genetic factors. Here we report a fetal genome-wide association meta-analysis of gestational duration, and early preterm, preterm, and postterm birth in 84,689 infants. One locus on chromosome 2q13 is associated with gestational duration; the association is replicated in 9,291 additional infants (combined P=3.96×10-14). Analysis of 15,588 mother-child pairs shows that the association is driven by fetal rather than maternal genotype. Functional experiments show that the lead SNP, rs7594852, alters the binding of the HIC1 transcriptional repressor. Genes at the locus include several interleukin 1 family members with roles in pro-inflammatory pathways that are central to the process of parturition. Further understanding of the underlying mechanisms will be of great public health importance, since giving birth either before or after the window of term gestation is associated with increased morbidity and mortality.
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| 42. |
- Lowe, Robert, et al.
(författare)
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A Dynamic Field Theoretic Model of Iowa Gambling Task Performance
- 2010
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Ingår i: 2010 IEEE 9th International Conference on Development and Learning (ICDL). - : IEEE conference proceedings. - 9781424469024 - 1424469023 - 9781424469000 - 1424469007 ; , s. 297-304
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Konferensbidrag (refereegranskat)abstract
- Choice behaviour where outcome-contingencies vary or are prohabilistic has been the focus of many benchmark tasks of infant to adult development in the psychology literature. Dynamic field theoretic (DFT) investigations of cognitive and behavioural competencies have been used in order to identify parameters critical to infant development. In this paper we report the findings of a DFT model that is able to replicate normal functioning adult performance on the Iowa gambling task (IGT). The model offers a simple demonstration proof of the parsimonious reversal learning alternative to Damasio’s somatic marker explanation of IGT performance. Our simple model demonstrates a potentially important role for reinforcement/reward learning to generating behaviour that allows for advantageous performance. We compare our DFT modelling approach to one used on the A-not-B infant paradigm and suggest that a critical aspect of development lies in the ability to flexibly trade off perseverative versus exploratory behaviour in order to capture statistical choice-outcome contingencies. Finally, we discuss the importance of an investigation of the IGT in an embodied setting where reward prediction learning may provide critical means by which adaptive behavioural reversals can be enacted.
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| 43. |
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| 44. |
- Lowe, Robert, et al.
(författare)
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Affective-Associative Two-Process theory: A neural network investigation of adaptive behaviour in differential outcomes training
- 2017
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Ingår i: Adaptive Behavior. - : SAGE Publications. - 1059-7123 .- 1741-2633. ; 25:1, s. 5-23
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Tidskriftsartikel (refereegranskat)abstract
- In this article we present a novel neural network implementation of Associative Two-Process (ATP) theory based on an Actor-Critic-like architecture. Our implementation emphasizes the affective components of differential reward magnitude and reward omission expectation and thus we model Affective-Associative Two-Process theory (Aff-ATP). ATP has been used to explain the findings of differential outcomes training (DOT) procedures, which emphasize learning differentially valuated outcomes for cueing actions previously associated with those outcomes. ATP hypothesizes the existence of a prospective' memory route through which outcome expectations can bring to bear on decision making and can even substitute for decision making based on the retrospective' inputs of standard working memory. While DOT procedures are well recognized in the animal learning literature they have not previously been computationally modelled. The model presented in this article helps clarify the role of ATP computationally through the capturing of empirical data based on DOT. Our Aff-ATP model illuminates the different roles that prospective and retrospective memory can have in decision making (combining inputs to action selection functions). In specific cases, the model's prospective route allows for adaptive switching (correct action selection prior to learning) following changes in the stimulus-response-outcome contingencies.
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| 45. |
- Lowe, Robert, et al.
(författare)
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Affective-associative two-process theory: a neurocomputational account of partial reinforcement extinction effects
- 2017
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Ingår i: Biological Cybernetics. - : Springer Science and Business Media LLC. - 0340-1200 .- 1432-0770. ; 111:5-6, s. 365-388
-
Tidskriftsartikel (refereegranskat)abstract
- The partial reinforcement extinction effect (PREE) is an experimentally established phenomenon: behavioural response to a given stimulus is more persistent when previously inconsistently rewarded than when consistently rewarded. This phenomenon is, however, controversial in animal/human learning theory. Contradictory findings exist regarding when the PREE occurs. One body of research has found a within-subjects PREE, while another has found a within-subjects reversed PREE (RPREE). These opposing findings constitute what is considered the most important problem of PREE for theoreticians to explain. Here, we provide a neurocomputational account of the PREE, which helps to reconcile these seemingly contradictory findings of within-subjects experimental conditions. The performance of our model demonstrates how omission expectancy, learned according to low probability reward, comes to control response choice following discontinuation of reward presentation (extinction). We find that a PREE will occur when multiple responses become controlled by omission expectation in extinction, but not when only one omission-mediated response is available. Our model exploits the affective states of reward acquisition and reward omission expectancy in order to differentially classify stimuli and differentially mediate response choice. We demonstrate that stimulus-response (retrospective) and stimulus-expectation-response (prospective) routes are required to provide a necessary and sufficient explanation of the PREE versus RPREE data and that Omission representation is key for explaining the nonlinear nature of extinction data.
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| 46. |
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| 47. |
- Lowe, Robert, et al.
(författare)
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Bridging Connectionism and Relational Cognition through Bi-directional Affective-Associative Processing
- 2019
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Ingår i: Open Information Science. - : Walter de Gruyter GmbH. - 2451-1781. ; 3:1, s. 235-260
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Tidskriftsartikel (refereegranskat)abstract
- Connectionist architectures constitute a popular method for modelling animal associative learning processes in order to glean insights into the formation of cognitive capacities. Such approaches (based on purely feedforward activity) are considered limited in their ability to capture relational cognitive capacities. Pavlovian learning value-based models, being not based purely on fully connected feedforward structure, have demonstrated learning capabilities that often mimic those of ‘higher’ relational cognition. Capturing data using such models often reveals how associative mechanisms can exploit structure in the experimental setting, so that ‘explicit’ relational cognitive capacities are not, in fact, required. On the other hand, models of relational cognition, implemented as neural networks, permit formation and retrieval of relational representations of varying levels of complexity. The flexible processing capacities of such models are, however, are subject to constraints as to how offline relational versus online (real-time, real-world) processing may be mediated. In the current article, we review the potential for building a connectionist-relational cognitive architecture with reference to the representational rank view of cognitive capacity put forward by Halford et al. Through interfacing system 1-like (connectionist/associative learning) and system 2-like (relational-cognition) computations through a bidirectional affective processing approach, continuity between Halford et al’s cognitive systems may be operationalized according to real world/online constraints. By addressing i) and ii) in this manner, this paper puts forward a testable unifying framework for system 1-like and system 2-like cognition.
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| 48. |
- Lowe, Robert, 1975-, et al.
(författare)
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Designing for a Wearable Affective Interface for the NAO Robot : A Study of Emotion Conveyance by Touch
- 2018
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Ingår i: Multimodal Technologies and Interaction. - : M D P I AG. - 2414-4088. ; 2:1
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Tidskriftsartikel (refereegranskat)abstract
- We here present results and analysis from a study of affective tactile communication between human and humanoid robot (the NAO robot). In the present work, participants conveyed eight emotions to the NAO via touch. In this study, we sought to understand the potential for using a wearable affective (tactile) interface, or WAffI. The aims of our study were to address the following: (i) how emotions and affective states can be conveyed (encoded) to such a humanoid robot, (ii) what are the effects of dressing the NAO in the WAffI on emotion conveyance and (iii) what is the potential for decoding emotion and affective states. We found that subjects conveyed touch for longer duration and over more locations on the robot when the NAO was dressed with WAffI than when it was not. Our analysis illuminates ways by which affective valence, and separate emotions, might be decoded by a humanoid robot according to the different features of touch: intensity, duration, location, type. Finally, we discuss the types of sensors and their distribution as they may be embedded within the WAffI and that would likely benefit Human-NAO (and Human-Humanoid) interaction along the affective tactile dimension.
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| 49. |
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| 50. |
- Lowe, Robert
(författare)
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Embodiment in Emotional Learning, Decision Making and Behaviour : The ‘What’ and the ‘How’ of Action
- 2014
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Ingår i: Universal Access in Human-Computer Interaction. Aging and Assistive Environments. - Cham : Springer International Publishing Switzerland. - 9783319074450 - 9783319074467 ; , s. 672-679
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Konferensbidrag (refereegranskat)abstract
- Connectionist and bio-inspired approaches to the study of emotional learning and decision making often emphasize, or imply, an executive role for the brain whilst paying only lip service to the role of the non-neural body. In this short paper I will discuss approaches to modelling emotions that have attempted to take into account, in one form or another, the role of the body in emotional learning and decision making. More specifically, I will argue that the ‘how’ of behavioural responding and not just the ‘what’ must be factored into any learning algorithm that purports to be emotional. Furthermore, I will refer to research that has utilized abstract artificial environments designed to explore the relevance of how behaviours are carried out with a view to scaling performance to more complex, including human-based, environments.
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