Pupillary Responses Reflect Dynamic Changes in Multiple Cognitive Factors During Associative Learning in Primates.

Associative learning involves complex interactions of multiple cognitive factors. While adult subjects can articulate these factors verbally, for model animals such as macaques, we rely on behavioral outputs. In our study, we used pupillary responses as an alternative measure to capture these underlying cognitive changes. We recorded the dynamic changes in the pupils of three male macaques when they learned the associations between visual stimuli and reward sizes under the classical Pavlovian experimental paradigm. We found that during the long-term learning process, the gradual changes in the pupillary response reflect the changes in the cognitive state of the animals. The pupillary response can be explained by a linear combination of components corresponding to multiple cognitive factors. These components reflect the impact of visual stimuli on the pupils, the prediction of reward values associated with the visual stimuli, and the macaques' understanding of the current experimental reward rules. The changing patterns of these factors during interday and intraday learning clearly demonstrate the enhancement of current reward-stimulus association and the weakening of previous reward-stimulus association. Our study shows that the dynamic response of pupils can serve as an objective indicator to characterize the psychological changes of animals, understand their learning process, and provide important tools for exploring animal behavior during the learning process.

Predicting Cued and Oddball Visual Search Performance from fMRI, MEG, and DNN Neural Representational Similarity.

Capacity limitations in visual tasks can be observed when the number of task-related objects increases. An influential idea is that such capacity limitations are determined by competition at the neural level: two objects that are encoded by shared neural populations interfere more in behavior (e.g., visual search) than two objects encoded by separate neural populations. However, the neural representational similarity of objects varies across brain regions and across time, raising the questions of where and when competition determines task performance. Furthermore, it is unclear whether the association between neural representational similarity and task performance is common or unique across tasks. Here, we used neural representational similarity derived from fMRI, MEG, and a deep neural network (DNN) to predict performance on two visual search tasks involving the same objects and requiring the same responses but differing in instructions: cued visual search and oddball visual search. Separate groups of human participants (both sexes) viewed the individual objects in neuroimaging experiments to establish the neural representational similarity between those objects. Results showed that performance on both search tasks could be predicted by neural representational similarity throughout the visual system (fMRI), from 80 ms after onset (MEG), and in all DNN layers. Stepwise regression analysis, however, revealed task-specific associations, with unique variability in oddball search performance predicted by early/posterior neural similarity and unique variability in cued search task performance predicted by late/anterior neural similarity. These results reveal that capacity limitations in superficially similar visual search tasks may reflect competition at different stages of visual processing.

Shared thoughts and practices on some modifiable cancer risk factors.

OBJECTIVE: Numerous cancer-causing factors are inversely correlated with health literacy. The current study's objective was to evaluate the Saudi community's knowledge, attitude, and behavior regarding certain carcinogens. SUBJECTS AND METHODS: To perform this descriptive study, a cross-sectional survey was carried out in Hail City, Northern Saudi Arabia, between September 2020 and November 2020. In the city of Hail, about 450 volunteers have expressed interest in taking part in the study. RESULTS: A total of 165 individuals smoked cigarettes and drank alcohol, respectively (67%) and 42 (9%). Negative attitudes toward cigarette smoking, alcohol consumption, radiation exposure, genetic predisposition, some viruses, some bacterial infection, some parasites, and fungi were 85/450 (19%), 209/450 (46.4%), 206/450 (45.8%), 322/450 (71.6%), 297/450 (66%), 375/450 (83.3%), 403/450 (89.6%), and 405/450 (90%), in that order. CONCLUSIONS: Some cancer-causing substances are widely used in the Saudi community. Lack of understanding and a negative attitude toward some carcinogens are widespread, necessitating immediate interventions at the community and health affairs levels.

Corrigendum to: IDH knockdown alters foraging behavior in the termite Odontotermes formosanus in different social contexts.

[This corrects the article DOI: 10.1093/cz/zoab032.].

Gold(I) Catalysis Applied to the Stereoselective Synthesis of Indeno[2,1-b]thiochromene Derivatives and Seleno Analogues.

A gold(I)-catalyzed cascade reaction for the stereoselective synthesis of sulfur- or selenium-containing indeno[1,2-b]chromene derivatives from o-(alkynyl)styrenes substituted at the triple bond with a thio- or seleno-aryl group is described. The reaction involves a double cyclization process through a proposed key gold-cyclopropyl carbene intermediate that evolves by the intramolecular addition of an aromatic to the cyclopropane ring, affording polycyclic structures. The enantioselective version was studied using gold(I) complexes bearing chiral ligands.