Friday, May 14, 2021

Two promising post-traumatic stress disorder treatments

I want to pass on references to two new approaches to relieving the symptoms of post-traumatic stress disorder (PTSD). Nuwer describes a new study showing that MDMA (known as the party drug Ecstasy, or Molly) can bring relief to PTSD when used in conjunction with talk therapy. Ressler et al. address the problem that human patients cannot be directly re-exposed to trauma-cues of the sort that have been used in animal studies to induce and then disrupt reconsolidation of traumatic memories. They devise a procedure for covertly capturing and attenuating a hippocampu-dependent fear memory in male rats, a procedure that might prove to be useful in human therapy. Here is their abstract:
Reconsolidation may be a viable therapeutic target to inhibit pathological fear memories. In the clinic, incidental or imaginal reminders are used for safe retrieval of traumatic memories of experiences that occurred elsewhere. However, it is unknown whether indirectly retrieved traumatic memories are sensitive to disruption. Here we used a backward (BW) conditioning procedure to indirectly retrieve and manipulate a hippocampus (HPC)-dependent contextual fear engram in male rats. We show that conditioned freezing to a BW conditioned stimulus (CS) is mediated by fear to the conditioning context, activates HPC ensembles that can be covertly captured and chemogenetically activated to drive fear, and is impaired by post-retrieval protein synthesis inhibition. These results reveal that indirectly retrieved contextual fear memories reactivate HPC ensembles and undergo protein synthesis-dependent reconsolidation. Clinical interventions that rely on indirect retrieval of traumatic memories, such as imaginal exposure, may open a window for editing or erasure of neural representations that drive pathological fear.

Wednesday, May 12, 2021

Social isolation makes us stupid.

The summary of an open source article from Ingram et al. in the Journal of Applied Cognitive Psychology:
Studies examining the effect of social isolation on cognitive function typically involve older adults and/or specialist groups (e.g., expeditions). We considered the effects of COVID‐19‐induced social isolation on cognitive function within a representative sample of the general population. We additionally considered how participants ‘shielding’ due to underlying health complications, or living alone, performed. We predicted that performance would be poorest under strictest, most‐isolating conditions. At five timepoints over 13 weeks, participants (N = 342; aged 18–72 years) completed online tasks measuring attention, memory, decision‐making, time‐estimation, and learning. Participants indicated their mood as ‘lockdown’ was eased. Performance typically improved as opportunities for social contact increased. Interactions between participant sub‐groups and timepoint demonstrated that performance was shaped by individuals' social isolation levels. Social isolation is linked to cognitive decline in the absence of ageing covariates. The impact of social isolation on cognitive function should be considered when implementing prolonged pandemic‐related restrictive conditions.

Monday, May 10, 2021

Tribe trumps truth.

I've been trying to cut down on the number of posts on politics, but with the republican party now requiring a loyalty test that is the modern equivalent the firewalking rituals of Polynesia, Spain, and Greece I want to pass on a few articles relevant to their transition into a white anglo-saxon tribe that seeks to establish an autocratic regime that will preserve their minority ruling status. First, Brooks notes that
...Since the election, large swaths of the Trumpian right have decided America is facing a crisis like never before and they are the small army of warriors fighting with Alamo-level desperation to ensure the survival of the country as they conceive it...When asked in late January if politics is more about “enacting good public policy” or “ensuring the survival of the country as we know it,” 51 percent of Trump Republicans said survival; only 19 percent said policy...The level of Republican pessimism is off the charts. A February Economist-YouGov poll asked Americans which statement is closest to their view: “It’s a big, beautiful world, mostly full of good people, and we must find a way to embrace each other and not allow ourselves to become isolated” or “Our lives are threatened by terrorists, criminals and illegal immigrants, and our priority should be to protect ourselves.”...Over 75 percent of Biden voters chose “a big, beautiful world.” Two-thirds of Trump voters chose “our lives are threatened.”
Douthat describes the two crises of conservatism:
The normal crisis is a party crisis, the sort that afflicts all political coalitions. The Republican Party 40 years ago coalesced around a set of appeals that enabled its leaders to win large presidential majorities and set the national agenda. At a certain point the issue landscape changed, so did the country’s demographics, and the G.O.P. has struggled to adapt — cycling through compassionate conservatism, Tea Party conservatism and Trumpist populism without reproducing Ronald Reagan’s success.
But beneath this party crisis there is the deeper one, having to do with what conservatism under a liberal order exists to actually conserve...One powerful answer is that conservatism-under-liberalism should defend human goods that are threatened by liberal ideas taken to extremes. The family, when liberal freedom becomes a corrosive hyper-individualism. Traditional religion, when liberal toleration becomes a militant and superstitious secularism. Local community and local knowledge, against expert certainty and bureaucratic centralization. Artistic and intellectual greatness, when democratic taste turns philistine or liberal intellectuals become apparatchiks. The individual talent of the entrepreneur or businessman, against the leveling impulses of egalitarianism and the stultifying power of monopoly...
but,
What does it mean to conserve the family in an era when not just the two-parent household but childbearing and sex itself are in eclipse? What does it mean to defend traditional religion in a country where institutional faith is either bunkered or rapidly declining? How do you defend localism when the internet seems to nationalize every political and cultural debate? What does the conservation of the West’s humanistic traditions mean when pop repetition rules the culture, and the great universities are increasingly hostile to even the Democratic-voting sort of cultural conservative?
A further Douthat piece suggests that it is capitalism itself that is killing conservatism:
...the social trends American conservatives most dislike, the rise of expressive individualism and the decline of religion, marriage and the family, are driven by socioeconomic forces the right’s free-market doctrines actively encourage. “America’s moral traditionalists are wedded to an economic system that is radically anti-traditional,” he writes, and “Republicans can neither wage war on capitalism nor make peace with its social implications.”
...it’s not that capitalist dynamism inevitably dissolves conservative habits. It’s more that the wealth this dynamism piles up, the liberty it enables and the technological distractions it invents, let people live more individualistically — at first happily, with time perhaps less so — in ways that eventually undermine conservatism and dynamism together. At which point the peril isn’t markets red in tooth and claw, but a capitalist endgame that resembles Aldous Huxley’s “Brave New World,” with a rich and technologically proficient world turning sterile and dystopian.
...let’s not let liberals off the hook. If capitalist churn isn’t what it used to be, if taming its excesses in the style of France or Sweden isn’t enough to restore family and community, if the combination of welfare-state liberalism and personal emancipation trends toward a Huxleyan dystopia, do liberals have any resources besides complaints about capitalism that might help pull us off that course?...Because if conservatism’s responses are incoherent and insufficient, I fear that liberalism has no response at all.

Friday, May 07, 2021

Structural Whitening

I pass on this summary by Rai of a study by Anicich et al. in J. Exp. Soc. Psychol:
As the US population becomes more racially diverse, it is unclear how ethnic white populations will respond to these demographic changes. Anicich et al. found experimentally that when white Americans were given the opportunity to populate fictional cities, they imposed greater racial segregation in areas that they frequented more often, such as work or school, because they feel greater anxiety around non-whites. In a follow-up study, the authors examined policies at tennis and golf clubs across the United States, and found that in areas with higher racial diversity, clubs engaged in more exclusionary behavior, such as enacting strict dress codes. These findings suggest that as racial diversity increases, white Americans may respond by trying to structure their environment in more segregated ways.
And here is the abstract of the article:
The current research explores how local racial diversity affects Whites' efforts to structure their local communities to avoid incidental intergroup contact. In two experimental studies (N = 509; Studies 1a-b), we consider Whites' choices to structure a fictional, diverse city and find that Whites choose greater racial segregation around more (vs. less) self-relevant landmarks (e.g., their workplace and children's school). Specifically, the more time they expect to spend at a landmark, the more they concentrate other Whites around that landmark, thereby reducing opportunities for incidental intergroup contact. Whites also structure environments to reduce incidental intergroup contact by instituting organizational policies that disproportionately exclude non-Whites: Two large-scale archival studies (Studies 2a-b) using data from every U.S. tennis (N = 15,023) and golf (N = 10,949) facility revealed that facilities in more racially diverse communities maintain more exclusionary barriers (e.g., guest policies, monetary fees, dress codes) that shield the patrons of these historically White institutions from incidental intergroup contact. In a final experiment (N = 307; Study 3), we find that Whites' anticipated intergroup anxiety is one driver of their choices to structure environments to reduce incidental intergroup contact in more (vs. less) racially diverse communities. Our results suggest that despite increasing racial diversity, White Americans structure local environments to fuel a self-perpetuating cycle of segregation.

Wednesday, May 05, 2021

Evidence that monkeys have conscious awareness of self - they know what they saw.

Ben-Haim et al. Disentangle perceptual awareness from nonconscious processing in rhesus monkeys  

Significance

Many animals perform complex intelligent behaviors, but the question of whether animals are aware while doing so remains a long debated but unanswered question. Here, we develop a new approach to assess whether nonhuman animals have awareness by utilizing a well-known double dissociation of visual awareness—cases in which people behave in completely opposite ways when stimuli are processed consciously versus nonconsciously. Using this method, we found that a nonhuman species—the rhesus monkey—exhibits the very same behavioral signature of both nonconscious and conscious processing. This opposite double dissociation of awareness firstly allows stripping away the long inherent ambiguity when interpreting the processes governing animal behavior. Collectively, it provides robust support for two distinct awareness modes in nonhuman animals.
Abstract
Scholars have long debated whether animals, which display impressive intelligent behaviors, are consciously aware or not. Yet, because many complex human behaviors and high-level functions can be performed without conscious awareness, it was long considered impossible to untangle whether animals are aware or just conditionally or nonconsciously behaving. Here, we developed an empirical approach to address this question. We harnessed a well-established cross-over double dissociation between nonconscious and conscious processing, in which people perform in completely opposite ways when they are aware of stimuli versus when they are not. To date, no one has explored if similar performance dissociations exist in a nonhuman species. In a series of seven experiments, we first established these signatures in humans using both known and newly developed nonverbal double-dissociation tasks and then identified similar signatures in rhesus monkeys (Macaca mulatta). These results provide robust evidence for two distinct modes of processing in nonhuman primates. This empirical approach makes it feasible to disentangle conscious visual awareness from nonconscious processing in nonhuman species; hence, it can be used to strip away ambiguity when exploring the processes governing intelligent behavior across the animal kingdom. Taken together, these results strongly support the existence of both nonconscious processing as well as functional human-like visual awareness in nonhuman animals.
(Note: Establishing double dissociation of awareness used a nonverbal spatial-cueing paradigm. Motivated readers can email me to obtain a PDF of the article which describes this paradigm.)

Monday, May 03, 2021

People have shaped most of terrestrial nature for at least 12,000 years

From Ellis et al.

Significance

The current biodiversity crisis is often depicted as a struggle to preserve untouched habitats. Here, we combine global maps of human populations and land use over the past 12,000 y with current biodiversity data to show that nearly three quarters of terrestrial nature has long been shaped by diverse histories of human habitation and use by Indigenous and traditional peoples. With rare exceptions, current biodiversity losses are caused not by human conversion or degradation of untouched ecosystems, but rather by the appropriation, colonization, and intensification of use in lands inhabited and used by prior societies. Global land use history confirms that empowering the environmental stewardship of Indigenous peoples and local communities will be critical to conserving biodiversity across the planet.
Abstract
Archaeological and paleoecological evidence shows that by 10,000 BCE, all human societies employed varying degrees of ecologically transformative land use practices, including burning, hunting, species propagation, domestication, cultivation, and others that have left long-term legacies across the terrestrial biosphere. Yet, a lingering paradigm among natural scientists, conservationists, and policymakers is that human transformation of terrestrial nature is mostly recent and inherently destructive. Here, we use the most up-to-date, spatially explicit global reconstruction of historical human populations and land use to show that this paradigm is likely wrong. Even 12,000 y ago, nearly three quarters of Earth’s land was inhabited and therefore shaped by human societies, including more than 95% of temperate and 90% of tropical woodlands. Lands now characterized as “natural,” “intact,” and “wild” generally exhibit long histories of use, as do protected areas and Indigenous lands, and current global patterns of vertebrate species richness and key biodiversity areas are more strongly associated with past patterns of land use than with present ones in regional landscapes now characterized as natural. The current biodiversity crisis can seldom be explained by the loss of uninhabited wildlands, resulting instead from the appropriation, colonization, and intensifying use of the biodiverse cultural landscapes long shaped and sustained by prior societies. Recognizing this deep cultural connection with biodiversity will therefore be essential to resolve the crisis.
Motivated readers can obtain a PDF of the article by emailing me.