A developmental approach to robotic pointing via human-robot interaction

The ability of pointing is recognised as an essential skill of a robot in its communication and social interaction. This paper introduces a developmental learning approach to robotic pointing, by exploiting the interactions between a human and a robot. The approach is inspired through observing the process of human infant development. It works by first applying a reinforcement learning algorithm to guide the robot to create attempt movements towards a salient object that is out of the robot's initial reachable space. Through such movements, a human demonstrator is able to understand the robot desires to touch the target and consequently, to assist the robot to eventually reach the object successfully. The human-robot interaction helps establish the understanding of pointing gestures in the perception of both the human and the robot. From this, the robot can collect the successful pointing gestures in an effort to learn how to interact with humans. Developmental constraints are utilised to drive the entire learning procedure. The work is supported by experimental evaluation, demonstrating that the proposed approach can lead the robot to gradually gain the desirable pointing ability. It also allows that the resulting robot system exhibits similar developmental progress and features as with human infants

FRN results during outcome evaluation.

<p>For illustrative purpose, grand-averaged ERP waveforms of FRN from 2 midline frontal electrodes (Fz, FCz) were shown over outcome (reciprocity vs. non-reciprocity) and commitment (promise vs. non-promise).</p

Anchors as Semantic Primes in Value Construction: An EEG Study of the Anchoring Effect

<div><p>Previous research regarding anchoring effects has demonstrated that human judgments are often assimilated to irrelevant information. Studies have demonstrated that anchors influence the economic valuation of various products and experiences; however, the cognitive explanations of this effect remain controversial, and its neural mechanisms have rarely been explored. In the current study, we conducted an electroencephalography (EEG) experiment to investigate the anchoring effect on willingness to accept (WTA) for an aversive hedonic experience and the role of anchors in this judgment heuristic. The behavioral results demonstrated that random numbers affect participants’ WTA for listening to pieces of noise. The participants asked for higher pay after comparing their WTA with higher numbers. The EEG results indicated that anchors also influenced the neural underpinnings of the valuation process. Specifically, when a higher anchor number was drawn, larger P2 and late positive potential amplitudes were elicited, reflecting the anticipation of more intensive pain from the subsequent noise. Moreover, higher anchors induced a stronger theta band power increase compared with lower anchors when subjects listened to the noises, indicating that the participants felt more unpleasant during the actual experience of the noise. The levels of unpleasantness during both anticipation and experience were consistent with the semantic information implied by the anchors. Therefore, these data suggest that a semantic priming process underlies the anchoring effect in WTA. This study provides proof for the robustness of the anchoring effect and neural evidence of the semantic priming model. Our findings indicate that activated contextual information, even seemingly irrelevant, can be embedded in the construction of economic value in the brain.</p></div

Grand-average LPP waveforms from channels CPz, Pz, POz and Oz in two anchor conditions (high, low) time-locked to anchor onset.

<p>Grand-average LPP waveforms from channels CPz, Pz, POz and Oz in two anchor conditions (high, low) time-locked to anchor onset.</p

Comparisons of the theta band ERS when the noise was played between the high and low anchor conditions on the left, middle and right hemispheres.

<p>Data were collapsed within five caudalities (F, FC, C, CP and P). Asterisks indicate significant (*<i>p</i> < 0.05) differences between the high and low anchor conditions.</p

Theta band ERS differences.

<p>(A) The time-frequency map shows the subtraction of the ERS of the low anchor condition from that of the high anchor condition over time (x-axis; 0 is onset of the noise stimulus) and frequency (y-axis) at Cz where ERS reached its maximum. The dotted contour corresponds to the window of 80–280 ms, 4–8 Hz from which the topographical map data in (B), (C) and (D) were obtained. (B) Average theta band ERS (high and low anchors) scalp map. (C) Difference in the theta band ERS (high anchor minus low anchor) scalp map. (D) Scalp map of the <i>p</i>-value of the one-tail t-test (high anchor > low anchor) for the theta band ERS. Blue colors indicate <i>p</i> < 0.05.</p

Catanionic Surfactant-Assisted Mineralization and Structural Properties of Single-Crystal-like Vaterite Hexagonal Bifrustums

Crystalline vaterite is the most thermodynamically unstable polymorph of anhydrous calcium carbonate (CaCO₃), and various morphologies can be controlled in the presence of organic additives. Constructing vaterite with minimal defects, determining its distinctive properties, and understanding the formation mechanism behind a biomimetic process are the main challenges in this field. In this paper, a unique single-crystal-like vaterite hexagonal bifrustum with two hexagonal and 12 trapezoidal faces has been fabricated through a catanionic surfactant-assisted mineralization approach for the first time. Compared with the polycrystalline vaterite aggregates, these bifrustums clearly present a doublet for Raman <i>v</i>₁ symmetric stretching mode, a low depolarizaiton ratio for carbonate molecular symmetry, and a high structural stability. These indicate a dominant position of hexagonal phase in each crystallite and confirm the Raman <i>v</i>₁ doublet characteristics of synthetic and biomineral-based vaterites. Our finding may provide evidence to distinguish vaterite with different structures and shed light on a possible formation mechanism of vaterite single crystals

Panc-1 CSCs lysates modified DCs stimulated proliferation of lymphocyte.

<p>Different DCs (Panc-1 CSC DC, DC) were cocultured with lymphocyte (reactors) in 96-well plates at different ratios (1∶10, 1∶20). The lymphocytes cultured alone were set as controls. After 96 h, the relative cell number was calculated as absorbance by MTT methods. The experiments were performed in triplicate. A. The relative number of lymphocyte after stimulation can be reflected by absorbance. Panc-1 CSCs modified DC stimulated stronger proliferation of lymphocyte compared with DC groups. B. The activating effects of DCs on lymphocyte can be reflected by lymphocyte proliferation rate. The Panc-1 CSCs lysates modified DC achieved a significant high lymphocyte proliferation rate compared with DC groups.</p

Panc-1 CSCs inhibited lymphocyte proliferation.

<p>Lymphocytes were stimulated to proliferate with PHA or anti-CD3 monoclonal antibodies. Panc-1 CSCs were co-cultured with lymphocyte at a ratio of 1∶10 in the presence of PHA or anti-CD3 monoclonal antibodies. Lymphocytes stimulated with PHA or anti-CD3 monoclonal antibodies solely were set as control. MTT assay indicated that lymphocyte proliferation promoted by PHA or anti-CD3 monoclonal antibodies was inhibited in the presence of Panc-1 CSCs.</p

Pancreatic CSCs lysates modified DCs provoked the secretion of IFN-γ, IL-2 and IL-10 on lymphocyte.

<p>Different DCs were co-cultured with 1×10⁶/ml lymphocyte in 96-well plates. The supernatants of the lymphocyte were collected 72 h after being stimulated with DC, and the concentrations of IFN-γ, IL-2, IL-10 were measured by ELISA assay. Pancreatic CSCs lysates modified DC provoked significant secretion of IFN-γ, IL-2 and IL-10 on lymphocyte.</p