Inferring the decision rules that drive co-foraging affiliations in wild mixed-species parrot groups.

Animals gathered around a specific location or resource may represent mixed-species aggregations or mixed-species groups. Patterns of individuals choosing to join these groups can provide insight into the information processing underlying these decisions. However, we still have little understanding of how much information these decisions are based upon. We used data on 12 parrot species to test what kind of information each species may use about others to make decisions about which mixed-species aggregations to participate in. We used co-presence and joining patterns with categorization and model fitting methods to test how these species could be making grouping decisions. Species generally used a simpler lower-category method to choose which other individuals to associate with, rather than basing these decisions on species-level information. We also found that the best-fit models for decision-making differed across the 12 species and included different kinds of information. We found that not only does this approach provide a framework to test hypotheses about why individuals join or leave mixed-species aggregations, it also provides insight into what features each parrot could have been using to make their decisions. While not exhaustive, this approach provides a novel examination of the potential features that species could use to make grouping decisions and could provide a link to the perceptive and cognitive abilities of the animals making these minute-by-minute decisions. This article is part of the theme issue 'Mixed-species groups and aggregations: shaping ecological and behavioural patterns and processes'.

Ideology, communication and polarization.

Ideologically committed minds form the basis of political polarization, but ideologically guided communication can further entrench and exacerbate polarization depending on the structures of ideologies and social network dynamics on which cognition and communication operate. Combining a well-established connectionist model of cognition and a well-validated computational model of social influence dynamics on social networks, we develop a new model of ideological cognition and communication on dynamic social networks and explore its implications for ideological political discourse. In particular, we explicitly model ideologically filtered interpretation of social information, ideological commitment to initial opinion, and communication on dynamically evolving social networks, and examine how these factors combine to generate ideologically divergent and polarized political discourse. The results show that ideological interpretation and commitment tend towards polarized discourse. Nonetheless, communication and social network dynamics accelerate and amplify polarization. Furthermore, when agents sever social ties with those that disagree with them (i.e. structure their social networks by homophily), even non-ideological agents may form an echo chamber and form a cluster of opinions that resemble an ideological group. This article is part of the theme issue 'The political brain: neurocognitive and computational mechanisms'.

Quality and readability of online patient information on treatment for erectile dysfunction.

Objectives: To investigate the quality and readability of online patient information on treatment for erectile dysfunction using a Google search. Materials and methods: The results of a Google search for "erectile dysfunction treatment" were reviewed. Webpages that contained written information on erectile dysfunction except those containing scientific publications and paywall protected webpages were included in further analysis. Typographic and treatment information were recorded. Readability was assessed using the Fleisch-Kincaid grade level, the Gunning-Fog index, the Coleman-Liau index, and Simple Measure of Gobbledygook. Website quality was assessed using the DISCERN instrument, Journal of the American Medical Association (JAMA) benchmark criteria, and presence of Health on the net (HON) code certification. Website typography, discussed treatment types, readability scores, and quality measures were reported. Parametric and nonparametric statistical tests were used to compare the data as appropriate dependent on the normality of data. Results: Eighty-one webpages were included. Urologists and hospitals were the most common producers with 15 (18%) each. Seventy-four (91%) webpages contained specific information on treatment for erectile dysfunction and 15 (19%) contained advertisements. Seventeen (21%) webpages were HON code certified. The median DISCERN score was 35 (IQR 26.5-44) out of 80. The mean combined readability score was 12.32 (SD 1.91). The median JAMA benchmark score was 1 (IQR 1-2) out of 4. Google rank had a small negative correlation with DISCERN score (τ = -0.16, P = .036). HON code certified webpages had higher DISCERN scores (median of 44 [IQR 35-58.5] vs 32.5 [IQR 25.25-42.25], U = 832, Z = 6561, P < .001). A linear regression was used to predict DISCERN score based on meeting each JAMA benchmark criterion (F(2, 78) = 22.7, P < .001) R 2 = 0.368, P < .001. Within this model the effects of meeting attribution (ß = 11.09) and currency (ß = 8.79) criterion were significant. Conclusions: The quality of online information on treatment for erectile dysfunction is generally poor. However, easy to identify markers of quality like HON code certification, or meeting JAMA benchmark criterion for attribution and currency may help patients to navigate to better quality online information on treatment for erectile dysfunction. Webpages are written at senior high school level, above any recommendations for patient medical information. Health professionals should use validated instruments to assess the quality of online information on treatment for erectile dysfunction prior to publication to improve their utility for patients.