Monday, October 5, 2020

Are there dedicated female neurons for saying no to sex? In the sophisticated fly Drosophila, there are.

Neuroscience: The Female Art of Saying No. Anne C.von Philipsborn. Current Biology, Volume 30, Issue 19, October 5 2020, Pages R1080-R1083.

Rolf Degen's take:

Refers to: Ovipositor Extrusion Promotes the Transition from Courtship to Copulation and Signals Female Acceptance in Drosophila melanogaster. Cecilia Mezzera, Margarida Brotas, Miguel Gaspar, Hania J. Pavlou, Stephen F. Goodwin, Maria LuĂ­sa Vasconcelos. Current Biology, Volume 30, Issue 19, October 5 2020, Pages 3736-3748.e5.

Summary: Females communicate sexual receptivity in various ways. Drosophila signal that they are mated and ovulating, and resistive to mating again, by extruding their egg-laying organ (ovipositor). Connectome-aided circuit analysis reveals how this break up message is computed and differs from an acceptance response in virgins.


Are there dedicated female neurons for saying no to sex? In the sophisticated fly Drosophila, there are.

From the Mezzera paper:

Summary: Communication between male and female fruit flies during courtship is essential for successful mating, but, as with many other species, it is the female who decides whether to mate. Here, we show a novel role for ovipositor extrusion in promoting male copulation attempts in virgin and mated females and signaling acceptance in virgins. We first show that ovipositor extrusion is only displayed by sexually mature females, exclusively during courtship and in response to the male song. We identified a pair of descending neurons that controls ovipositor extrusion in mated females. Genetic silencing of the descending neurons shows that ovipositor extrusion stimulates the male to attempt copulation. A detailed behavioral analysis revealed that during courtship, the male repeatedly licks the female genitalia, independently of ovipositor extrusion, and that licking an extruded ovipositor prompts a copulation attempt. However, if the ovipositor is not subsequently retracted, copulation is prevented, as it happens with mated females. In this study, we reveal a dual function of the ovipositor: while its extrusion is necessary for initiating copulation by the male, its retraction signals female acceptance. We thus uncover the significance of the communication between male and female that initiates the transition from courtship to copulation.

The transition from courtship to copulation is a critical moment for the reproductive success of animals. The exact steps leading to this transition in any species remain largely uncharacterized [41]. In our work, we showed that in fruit flies, male licking and female ovipositor extrusion are involved in this transition (schema in Figure 5G). An important feature of this interaction is that the female mating status determines whether this transition is complete. We observed that virgin females retract the ovipositor upon a male’s attempt, thus allowing copulation, whereas mated females do not, thus blocking copulation.

Virgin and mated females use a variation of the same behavior to stimulate and prevent copulation, respectively. This variation requires different descending neurons probably acting on common circuits. This could be a versatile and economic strategy to mediate opposite responses when the same individual uses one or the other variation depending on the circumstances.

Why would a mated female signal the male to attempt copulation while blocking intromission? In circumstances that we have not addressed in this study, mated females re-mate. For a few hours after mating, and given the appropriate context, mated females will eject the sperm and re-mate in an attempt to increase fecundity and offspring genetic diversity [25, 42]. In this case, prompting the male to attempt copulation makes sense, as it could lead to copulation. An additional role for full ovipositor extrusion in mated females, which we have not explored here, may be in announcing the female’s current pheromonal composition. Ovipositor extrusion would be an efficient way of exposing the anti-aphrodisiac pheromones 3-O-acetyl-1,3-dihydroxyoctacosa-11,19-diene [24] present in the tip of the ovipositor and cis-vaccenyl acetate, mostly in the reproductive system [25, 43], which, together with 7-tricosene [23] present in the cuticle, indicate to an approaching male that the female has mated, and, depending on the combination and intensity of the chemical cues, the male may or may not initiate courtship.

In this work, we identified a pair of descending neurons that control full ovipositor extrusion. Full ovipositor extrusion can be induced in the virgin female by DNp13 activation, but activity in these neurons is not necessary for ovipositor extrusion in virgins. Although full and partial ovipositor extrusions do not have a sharp distinction, ovipositor extrusion is commanded by different neurons and controlled differently in virgin and mated flies. It remains to be elucidated which are the descending neurons controlling virgin ovipositor extrusion and how they interact with DNp13 to control similar behavior in females in different mating states.

Our work shows that, during the interaction between the sexes, the female responds to the male courtship song with ovipositor extrusion. However, it is apparent in the videos that song does not always lead to ovipositor extrusion. This response pattern suggests that ovipositor extrusion is not a reflexive reaction to courtship song, but rather arises from a temporal or multimodal integration. Further experiments are required to elucidate the nature of this association. How does the male verify that the song was heard? Our results indicate that the male is sampling the female genitalia with the proboscis throughout courtship. Presumably, licking is intended to probe the chemical landscape of the female genitalia, which is likely to change when the ovipositor is extruded; in this way, the male could sense when the female is responding to the song. We show that licking of the ovipositor elicits a copulation attempt. In line with early suggestions that compounds are released during ovipositor extrusion to stimulate the male [11], we speculate that a chemical compound is presented with the ovipositor by the female and sensed by taste neurons on the male proboscis. A gustatory signal, yet unidentified and common to virgin and mated females, would stimulate the male to attempt copulation. Having established that licking an extruded ovipositor is the starting point for the male to attempt copulation allows us to use the same starting point to study how the transition from courtship to copulation is processed in the male brain.

In conclusion, our work highlights how both sexes contribute to continuous communication during courtship that culminates in copulation attempt gated by the female ovipositor extrusion. Moreover, our findings open new avenues of study of the neuronal regulation of behaviors that lead to the transition from courtship to copulation and how this transition regulates neuronal activity.

Contrary to the common impression, the U.S. public is largely uninformed rather than misinformed of a wide range of factual claims verified by journalists

The Value of Not Knowing: Partisan Cue-Taking and Belief Updating of the Uninformed, the Ambiguous, and the Misinformed. Jianing Li, Michael W Wagner. Journal of Communication, Volume 70, Issue 5, October 2020, Pages 646–669,

Abstract: The problem of a misinformed citizenry is often used to motivate research on misinformation and its corrections. However, researchers know little about how differences in informedness affect how well corrective information helps individuals develop knowledge about current events. We introduce a Differential Informedness Model that distinguishes between three types of individuals, that is, the uninformed, the ambiguous, and the misinformed, and establish their differences with two experiments incorporating multiple partisan cues and issues. Contrary to the common impression, the U.S. public is largely uninformed rather than misinformed of a wide range of factual claims verified by journalists. Importantly, we find that the success of belief updating after exposure to corrective information (via a fact-checking article) is dependent on the presence, the certainty, and the accuracy of one’s prior belief. Uninformed individuals are more likely to update their beliefs than misinformed individuals after exposure to corrective information. Interestingly, the ambiguous individuals, regardless of whether their uncertain guesses were correct, do not differ from uninformed individuals with respect to belief updating.


Sociotechnical changes in the communication environment and the concomitant concerns over the quality and content of information people consume have urged scholars to carefully theorize how persuasion takes place (Holbert, Garrett, & Gleason, 2010). Knowledge, a foundational factor in persuasion theories, is important for considering how people elaborate on and react to new information (Petty & Cacioppo, 1986). In this paper, we conceptualized differential types of informedness and tested how individuals with different states of informedness take up partisan cues and update beliefs about what is true.

First, and contrary to the impression that many citizens are misinformed, the majority of our respondents are uninformed of a wide range of claims important enough to be verified by journalists. Only a small group of respondents hold confident, inaccurate beliefs. This builds on work by Pasek et al. (2015) by distinguishing between the uninformed, who admit that they “don’t know,” the ambiguous, who take a guess with varying degrees of accuracy, and the misinformed, who hold steadfast false beliefs. In the current environment where concerns over misinformation often lead to heightened attention to belief accuracy, our findings highlight the necessity to bridge between work on political ignorance and misperception and the benefit of leveraging belief accuracy, belief presence and belief certainty to better assess public informedness.

Considering our Differential Informedness Model along with theories on information shortcuts (Popkin, 1991) and belief updating (Kunda, 1990) yields several important implications. Notably, the conceptual distinctions between types of political informedness are substantively meaningful in belief updating. Individuals engage in different levels of motivated reasoning depending on their prior informedness. In the immigration condition, the misinformed individuals held on to false beliefs even after reading the fact-checking article, while the uninformed and the ambiguous individuals were less likely to choose the incorrect answer. Interestingly, the ambiguous individuals, regardless of whether their uncertain guess was correct or not, did not differ from uninformed individuals with respect to belief updates. This gives hope that although the persuasive effects of fact-checks might be hindered by confident misperceptions, it is still useful to the much larger group of citizens who are uninformed or ambiguous of the facts. Of course, it is likely that these same citizens are less likely to participate in democratic politics, muting the persuasive effects of fact-checks on attitudes and behaviors.

Further, integrating the Differential Informedness Model with theories about the effects of information shortcuts on decision-making (Popkin, 1991), we find that what people believe is also influenced by who is doing the talking. Labeling the three U.S. political figures, Donald Trump, Mitch McConnell, and Chuck Schumer, as the source of a claim of fact influenced people’s factual beliefs to different extents. Unsurprisingly, Trump was the strongest cue of the three, resulting in a decreased number of “Don’t know” answers, an increased number of certain answers, and more partisan-congruent truthfulness evaluation. The McConnell cue resulted in increased partisan-congruent evaluation, while the Schumer cue leads to increased number of certain answers. These findings confirm that the influence of partisan cues on factual beliefs is not particular to a single partisan politician, although prominence in political discourse, or indeed, the elite in question’s partisanship itself, may influence the size of the effect.

Our findings also lay plain the likelihood that context will play important roles in conclusions about persuasive effects. With the divisive yet ubiquitous immigration issue, fact-checking helps the uninformed more than the misinformed, highlighting its role in accurate belief formation beyond belief debiasing (Graves & Amazeen, 2019). For marijuana legalization, fact-checking generally helps everyone. Is this due to fundamental differences in the nature of the issues, or is it because the immigration claim is rated false while the marijuana claim is rated true? Our study implies that the misinformed may have a harder time believing something they thought was true is actually false than the other way around (Wintersieck, 2017).

Taken together, our work points to fruitful directions in theorizing a more generalized process (Figure 3) of how prior states of differential informedness, interacting with message features, can trigger distinct types of processing motivations and ultimately produce pro- or anti-democratic changes as well as persistence regarding various persuasion outcomes. Our proposed framework suggests directions to theorize about message features—including but not limited to information shortcuts and issue contexts—such as argument strength, message frames, etc., to consider the role of differential informedness when estimating persuasive effects. Further, building on work that highlights outcomes beyond message-congruent response changing (Miller, 2002), our work suggests that individuals may engage in accurate belief formation or hold on to persistent ones. Future research should explore if backfire, or reinforcement of responses, depends upon differential informedness (Nyhan & Reifler, 2010Wood & Porter, 2019) and consider attitudinal and behavior outcomes beyond belief responses (Thorson, 2016).

Figure 3
A simple model of informedness, message features, motivation, and persuasive outcomes.

A simple model of informedness, message features, motivation, and persuasive outcomes.

What can journalists learn from our analysis? Fact-checking stands as an attractive remedy for the public to navigate a complicated media ecosystem rife with misinformation and a focus on the horse race (Amazeen, 2015). However, we offered a nuanced account of the ability of fact-checking to help citizens learn about the truth. Of course, reporters do not control their audiences’ prior states of informedness; but taking caution with partisan cues when presenting facts can facilitate more accurate beliefs. Fact-checkers might consider focusing on the evidence regarding the veracity of the claims they check and give less attention to who made the claim. A downside of this approach is that the partisan source is usually a key element of what makes the factual claim newsworthy and perhaps the most crucial factor in the size of the audience the fact-check earns. Finally, given that the majority of the public is uninformed rather than misinformed, journalists might consider focusing on presenting verifiable facts rather than repeating a false claim, which may lead audience to erroneously remember it as true (Peter & Koch, 2016).

While we analyzed beliefs about claims of fact for 60 claims across two studies, we only provided fact-check reporting on two of the claims. More work on representative samples across countries is necessary before meaningful generalizations about belief updating based upon informedness is possible. Of course, we randomly assigned the politicians we used in our studies to the claims we selected for analysis. In the political information ecology, these claims are not random nor is the attention they receive from fact-checkers. The nature of the political environment will also likely impact our findings on partisan cues and belief updating. People tend to adopt partisan frames, regardless of quality, when the environment is polarized, while non-polarized environments tend to encourage individuals to seek the best argument before adopting a position on an issue (Druckman, Peterson, & Slothuus, 2013). Future research should replicate our findings with considerations of contextual or ecological variances.

We have made the case that it is important to differentiate among types of informedness to assess the quality of citizens’ knowledge and persuade them to believe what is verifiably true. Persuasive effects of corrective information can be strong for those who are aware of their own ignorance but may fail when individuals do not know the biases they carry that cause unearned certainty about their beliefs. We examined 60 factual claims, partisan cues regarding three political elites, and two-issue contexts for a granularity of data that has allowed us to advance knowledge on an important question in political communication. Our framework on differential informedness is applicable to other subject areas such as health and science where knowledge measurement is increasingly crucial and useful in theorizing a general process of the interplay of informedness, message features, and motivations on persuasive outcomes.