EEG Activity during Pursuit and Saccade Visual Strategies to Predict the Arrival Position of a Target

Background: In this study, we used electroencephalogram (EEG) to investigate the activity pattern of the cerebral cortex related to visual pursuit and saccade strategies to predict the arrival position of a visual target. In addition, we clarified the differences in the EEG of those who could predict the arrival position well using the saccade strategy compared to those who were not proficient. Methods: Sixteen participants performed two tasks: the “Pursuit Strategy Task (PST)” and the “Saccade Strategy Task (SST)” while undergoing EEG. For the PST, the participants were instructed to follow the target with their eyes throughout its trajectory and indicate when it reached the final point. For the SST, the participants were instructed to shift their gaze to the end point of arrival once they had predicted it. Results: Low beta EEG activity at the Oz, Cz, and CP2 electrodes was significantly higher during the SST than during the PST. In addition, low beta EEG activity at P7 electrode was significantly higher in the group showing a small position error (PE) than in the group showing a large PE at response. Conclusions: EEG activity at the Oz, Cz, and CP2 electrodes during the SST may reflect visuospatial attention to the moving target, the tracking of moving targets, and the focus on the final destination position. In addition, EEG activity at P7 electrode may more accurately detect the speed and direction of the moving target by the small PE group at response

A fluorous synthetic receptor that recognizes perfluorooctanoic acid (PFOA) via fluorous interaction obtained by molecular imprinting. Analyst 2012

A polymeric sorbent selective for perfluorooctanoic acid (PFOA) was synthesized by a molecular imprinting technique using a fluorous monomer and cross-linker, and assessed chromatographically, suggesting that the fluorous imprinted polymer recognizes PFOA via hydrogen bonding and fluorine-fluorine interaction. Fluorous compounds have attracted increasing attention in various fields of chemistry ranging from materials chemistry to pharmaceutical chemistry. 1 In accordance with the growing attention to fluorous compounds, the demand for fluorous compound-selective affinity media is increasing because such media are potentially useful in the synthesis, isolation and analysis of fluorous compounds. In particular, it is of significant interest to develop affinity media selective for some hazardous fluorous compounds, such as perfluorooctanoic acid (PFOA), which are reported to be accumulated in the environment and biological systems. 2 To our knowledge, however, no synthetic receptor selective for a specific fluorous compound is currently available, although fluorinated materials that exhibit group selectivity for general fluorous compounds are commercially obtainable, such as fluorous stationary phases for high performance liquid chromatography (HPLC) and solid-phase extraction. 3 These commercial products exhibit retention ability for fluorous compounds via fluorine-fluorine interaction, which is generally observed between fluorous molecules. Recently, the interaction has also been utilized in synthetic tags for the purification of products and the construction of microarrays. 4 On the basis of these properties, we envisage that fluorous compound-selective synthetic receptors can be realized by the design and formation of interaction points within a fluorous material for specific recognition of a given fluorous compound. Molecular imprinting, a synthesis methodology for obtaining polymeric artificial receptors, 5 was expected to be suitable for this purpose because the methodology can locate plural functional moieties around a given template molecule to construct a selective binding site as follows: (i) a template molecule is mixed with monomers to form polymerizable complexes, (ii) the complexes are polymerized in the presence of cross-linkers to produce a network polymer with the complexes immobilized and (iii) the template molecule is extracted from the network polymer, which results in a binding site complementary to the template molecule ( Four different PFOA-imprinted polymers were examined: IP(RR), IP(FR), IP(RF) and IP(FF) (Table 1) which were synthesized using methacrylic acid (MA) or 2-(trifluoromethyl)acrylic acid (TFMA) as a functional monomer and ethylene glycol dimethacrylate (EDMA) or 2,2,3,3,4,4-hexafluoropentan-1,5-diyl dimethacrylate (HFPDMA) as a cross-linker. TFMA and HFPDMA possess fluorine atoms, whereas MA and EDMA do not. Therefore, selection of the functional monomer and cross-linker would result in different fluorine atom contents in the product polymers. MA and TFMA also differ in their acidity; TFMA is more acidic than MA due to the electronwithdrawing effects of the trifluoromethyl group. This difference could influence the interaction mode of the resultant polymers; TFMA is a stronger proton donor and tends to be present as a carboxylate anion, which makes TFMA more useful than MAA for the imprinting of a compound with proton-accepting functionality. 7 Another difference between EDMA and HFPDMA is their length; HFPDMA possesses a longer spacer, and accordingly results i