Saturday, May 23, 2020

Long‐term potentiation serves as one of the mechanisms affording learning and memory storage in neuronal circuits

The history of long‐term potentiation as a memory mechanism: Controversies, confirmation, and some lessons to remember. Hans C. Dringenberg. Hippocampus, May 22 2020.

ABSTRACT: The discovery of long‐term potentiation (LTP) provided the first, direct evidence for long‐lasting synaptic plasticity in the living brain. Consequently, LTP was proposed to serve as a mechanism for information storage among neurons, thus providing the basis for the behavioral and psychological phenomena of learning and long‐term memory formation. However, for several decades, the LTP‐memory hypothesis remained highly controversial, with inconsistent and contradictory evidence providing a barrier to its general acceptance. This review summarizes the history of these early debates, challenges, and experimental strategies (successful and unsuccessful) to establish a link between LTP and memory. Together, the empirical evidence, gathered over a period of about four decades, strongly suggests that LTP serves as one of the mechanisms affording learning and memory storage in neuronal circuits. Notably, this body of work also offers some important lessons that apply to the broader fields of behavioral and cognitive neuroscience. As such, the history of LTP as a learning mechanism provides valuable insights to neuroscientists exploring the relations between brain and psychological states.

Investment in stocks led to a more right‐leaning outlook merit & deservingness, personal responsibility, & equality, & a shift to the right on policy questions, driven by decreasing distrust of markets

How Markets Shape Values and Political Preferences: A Field Experiment. Yotam Margalit  Moses Shayo. American Journal of Political Science, May 22 2020.

Abstract: How does engagement with markets affect socioeconomic values and political preferences? A long line of thinkers has debated the nature and direction of such effects, but claims are difficult to assess empirically because market engagement is endogenous. We designed a large field experiment to evaluate the impact of financial markets, which have grown dramatically in recent decades. Participants from a national sample in England received substantial sums they could invest over a 6‐week period. We assigned them into several treatments designed to distinguish between different theoretical channels of influence. Results show that investment in stocks led to a more right‐leaning outlook on issues such as merit and deservingness, personal responsibility, and equality. Subjects also shifted to the right on policy questions. These results appear to be driven by growing familiarity with, and decreasing distrust of markets. The spread of financial markets thus has important and underappreciated political ramifications.


Financial markets have an increasing presence in countries throughout the world. From the stock market tickers on the TV screens at the local store, through the ups and downs in people's pension savings, to the torrent of tweets of the current U.S. president about the Dow Jones' performance, more and more people are exposed to financial markets. However, little is known about the political ramifications of this trend. This article presents the first experimental analysis of how mass exposure to financial markets affects social values and preferences over economic policies. We find that engagement with financial markets brings about a rightward shift in values and attitudes. This effect is quite general and, if anything, appears to be stronger among voters on the left. Furthermore, the effect is most pronounced when individuals invest in actual stocks rather than in nonfinancial assets, a pattern consistent with an Exposure Channel. The most likely mechanism underlying these shifts is growing familiarity with and decreasing distrust of markets. This is reflected in growing confidence in people's ability to successfully invest in the market.
These results suggest a rather inconspicuous effect of the growing financial sector on politics, an effect that goes beyond the visible and widely discussed channels of influence, such as large campaign contributions, lobbying activity, or the prominence of Goldman Sachs executives in the U.S. government. By encouraging a pro‐market social and political outlook, markets may engender a self‐sustaining dynamic whereby their growing reach leads to wider support for their further expansion.
Our findings suggest a link between growing trust in financial markets and more right‐leaning socioeconomic values. A pertinent question is whether the opposite effects also hold true. Put differently, would growing distrust in financial (or other) markets lead to a leftward shift? Exploiting instances when markets were tainted by scandals (e.g., Barclays' Libor manipulation, Enron, Madoff), future research may be able to isolate the effect of trust in markets on socioeconomic preferences.
This is a first attempt at evaluating experimentally the impact of exposure to investing in the stock market on social values. The volatility of the market during the experimental treatment was higher than average because of the Brexit. While of course both treatment and control groups experienced the same external conditions, it is an open question whether lower market volatility would have produced weaker or stronger effects. Assuming that greater market uncertainty tends to decrease trust in markets, it seems reasonable to conjecture that the results we report underestimate the magnitude of the general effect. Future replications of this type of study will help shed light on this conjecture.
The interpretation and policy implications of our results depend, to some extent, on one's ideological dispositions. Some might find it troubling, for example, that engagement in financial markets decreases participants' appreciation of the need for a social safety net and for regulation of markets. Others, however, may applaud the effect of market participation on the way people think about personal responsibility for individual choices and achievements. Some may also celebrate the reduced support for market regulation. Similarly, people may disagree in how they interpret the finding that exposure to investment activity generates confidence (or, perhaps, overconfidence) in financial markets as a savings vehicle for the masses, including for people's pensions.
This latter point speaks to a growing policy trend of governments encouraging citizens to invest in the stock market via subsidies and tax breaks. The United States, for example, seeks to encourage savings by allowing tax‐deferred retirement funds for those making investments in Roth IRAs. In 2017, the Israeli government replaced some of the traditional child‐rearing assistance funds with a savings plan for every child. Rather than receiving cash, parents receive funds that they can invest in various savings vehicles, such as mutual funds. To date, these policies were assessed and debated with respect to their economic effects. Our findings suggest that such policies may also have meaningful political repercussions.

Suicide terrorists may have been subject to over-theorization: Countries with higher share of deaths from suicide displayed higher incidences of suicide attacks but similar incidences of non- suicide ones

Varaine, Simon. 2020. “The Statistical Logic of Suicide Terrorism.” PsyArXiv. May 22. doi:10.31234/

Abstract: The self-sacrifice of suicide terrorists is subject to sophisticated models of altruistic sacrifice. Yet, a simpler account is that it reflects common suicidal tendencies. This paper offers new micro and macro evidence supportive of this hypothesis. Study 1 compared a sample of suicide and non-suicide terrorists in the United States from 1948 to 2017. Results indicated that suicide terrorists were more likely to display various established suicidal risk factors including history of child abuse, absent parent/s and relationship troubles. Study 2 took advantage of the cross-national variations in suicidal tendencies to explain the incidence of suicide and non-suicide terrorist attacks worldwide from 1991 to 2014. Results revealed that countries with higher share of deaths from suicide displayed higher incidences of suicide attacks but similar incidences of non- suicide attacks. The decision of some terrorists to sacrifice their life may well have been subject to over-theorization.

Demonstrate Values: Behavioral Displays of Moral Outrage as a Cue to Long-term Mate Potential

Brown, Mitch, Lucas A. Keefer, Donald F. Sacco, and Faith L. Brown. 2020. “Demonstrate Values: Behavioral Displays of Moral Outrage as a Cue to Long-term Mate Potential.” PsyArXiv. May 22. doi:10.31234/

Abstract: Recent findings suggest that moral outrage serves an interpersonal function of signaling trustworthiness to others and such perceptions play a uniquely important role in identifying social opportunities. We conducted four studies investigating how behavioral displays of moral outrage are perceived in the specific context of mating. Results indicated participants (particularly women) found prospective mates espousing outrage more desirable for long-term mating (Study 1), and this perception of desirability was similarly inferred among same-sex raters (Study 2). We further replicated findings in Study 1, while additionally considering the basis of women’s attraction toward outraged behavior through candidate mediators (Studies 3 and 4). Although we found consistent evidence for the long-term desirability of outraged behavior, in addition, to trustworthiness, evidence remained mixed on the extent to which evaluations of a prospective mate’s outrage was the basis of effects. We frame results from complementary perspectives of trust signaling and sexual strategies theory.

Statistical occurrence of words about body parts in very different languages, nearly 4 billion native speakers: The body as extracted from language resembles the distorted human-like sensory homunculus

Guenther, Fritz, and Luca Rinaldi. 2020. “Cortical Maps Recovered from Language Statistics.” PsyArXiv. May 22. doi:10.31234/

Abstract: Large-scale linguistic data is nowadays available in abundance. Here, we demonstrate that the surface-level statistical structure of language alone opens a window into how our brain represents the world. To this end, we examine the statistical occurrence of words referring to body parts in very different languages, covering nearly 4 billions of native speakers. Our findings indicate that the human body as extracted from language resembles the distorted human-like figure known as the sensory homunculus, whose form depicts the amount of cortical area dedicated to somatosensory functions of each body part. This links the way conceptual knowledge is represented and communicated in language to how the brain processes information from the sensory systems.