Recent Abstracts (Part 2 of 2)

By Darren Schreiber

This selection contains some critical new work on extinguishing fear (18, 19, 20) that will be crucial for treating the veterans returning from our many conflicts overseas and for reducing the huge social costs of PTSD. Elizabeth Phelps has been doing some truly impressive work over the years, but this might turn out to be one of her most interesting discoveries. I’m also fascinated by the possibility the treating depression with SSRI’s implicates changes in personality, not merely mental illness (6). Given the role of personality in both political behavior and in general well-being, this work has some interesting social implications. It is also heartening to find additional evidence that measures of subjective well-being correspond well to objective indicators (9). And, since I always relish a nice hike in one of San Diego’s many fantastic parks, I’m glad to know that it might be having a positive effect on my generosity and seeking out of intrinsic rewards (13). On a darker note, the idea that insurgency has some predictable elements to it is an intriguing possibility (3, 4).

I was also interested to read about a new book on the coming era of “big data” (8) and since it was free online I’ve already downloaded and read some of the chapters that looked interesting. On the topic of the future of science, Nature’s asked some scholars to speculate about where their fields will be in a decade (17) and some exciting examples for future work in observing behavior (16) and modeling (15) are presented. I was also fascinated to read more about the possibility that the role of a gene might depend on who you inherited it from (12). When a colleague at the Santa Fe Institute was telling me about this over the summer, I was incredulous.

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1) Wallis. Polar exploration. Nature Neuroscience (2010) vol. 13 (1) pp. 7-8
2) Tsujimoto et al. Evaluating self-generated decisions in frontal pole cortex of monkeys. Nature Neuroscience (2009) vol. 13 (1) pp. 120
3) Gilbert. Modellers claim wars are predictable. Nature (2009) vol. 462 (7275) pp. 836
4) Bohorquez et al. Common ecology quantifies human insurgency. Nature (2009) vol. 462 (7275) pp. 911-4
5) Ziv and Ahissar. Neuroscience: New tricks and old spines. Nature (2009) vol. 462 (7275) pp. 859-61
6) Tang et al. Personality change during depression treatment: a placebo-controlled trial. Arch Gen Psychiatry (2009) vol. 66 (12) pp. 1322-30
7) Editorial. Credit where credit is due. Nature (2009) vol. 462 (7275) pp. 825
8) Nielsen. A guide to the day of big data. Nature (2009) vol. 462 (10) pp. 722-723
9) Oswald and Wu. Objective Confirmation of Subjective Measures of Human Well-Being: Evidence from the U.S.A. Science (2009) pp.
10) Schurger et al. Reproducibility Distinguishes Conscious from Nonconscious Neural Representations. Science (2010) vol. 327 (5961) pp. 97-99
11) HUGO Pan-Asian SNP Consortium et al. Mapping human genetic diversity in Asia. Science (2009) vol. 326 (5959) pp. 1541-5
12) Kong et al. Parental origin of sequence variants associated with complex diseases. Nature (2009) vol. 462 (7275) pp. 868-74
13) Weinstein et al. Can Nature Make Us More Caring? Effects of Immersion in Nature on Intrinsic Aspirations and Generosity. Personality and social psychology bulletin (2009)
14) Raihani et al. Punishers benefit from third-party punishment in fish. Science (2010) vol. 327 (5962) pp. 171
15) Laursen. Computational biology: Biological logic. Nature (2009) vol. 462 (7272) pp. 408-10
16) Buchen. Behaviour: Flies on film. Nature (2009) vol. 462 (7273) pp. 562-4
17) Editorial. 2020 visions. Nature (2010) vol. 463 (7277) pp. 26-32
18) Quirk and Milad. Neuroscience: Editing out fear. Nature (2010) vol. 463 (7277) pp. 36-7
19) Schiller et al. Preventing the return of fear in humans using reconsolidation update mechanisms. Nature (2010) vol. 463 (7277) pp. 49-53
20) Phelps. Making the paper: Elizabeth Phelps. Nature (2010) vol. 463 (7277) pp. 8-8

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1) Wallis. Polar exploration. Nature Neuroscience (2010) vol. 13 (1) pp. 7-8

The frontal pole cortex is thought to be the most complex of all frontal cortex areas. Overcoming technical obstacles to direct recordings, a study in this issue finds that neurons in this area have unexpectedly simple response properties.

2) Tsujimoto et al. Evaluating self-generated decisions in frontal pole cortex of monkeys. Nature Neuroscience (2009) vol. 13 (1) pp. 120

The frontal pole cortex (FPC) expanded markedly during human evolution, but its function remains uncertain in both monkeys and humans. Accordingly, we examined single-cell activity in this area. On every trial, monkeys decided between two response targets on the basis of a ‘stay’ or ‘shift’ cue. Feedback followed at a fixed delay. FPC cells did not encode the monkeys’ decisions when they were made, but did so later on, as feedback approached. This finding indicates that the FPC is involved in monitoring or evaluating decisions. Using a control task and delayed feedback, we found that decision coding lasted until feedback only when the monkeys combined working memory with sensory cues to ‘self-generate’ decisions, as opposed to when they simply followed trial-by-trial instructions. A role in monitoring or evaluating self-generated decisions could account for FPC’s expansion during human evolution.

3) Gilbert. Modellers claim wars are predictable. Nature (2009) vol. 462 (7275) pp. 836

Seemingly random attacks and a shadowy, mysterious enemy are the hallmarks of insurgent wars, such as those being fought in Afghan- istan and Iraq. Many social scientists, as well as the military, hold that, like conventional civil wars, these conflicts can’t be understood with- out considering local factors such as geography and politics. But a mathematical model published today in Nature (see page 911) suggests that insurgencies have a common underlying pattern that may allow the timing of attacks and the number of casualties to be predicte

4) Bohorquez et al. Common ecology quantifies human insurgency. Nature (2009) vol. 462 (7275) pp. 911-4

Many collective human activities, including violence, have been shown to exhibit universal patterns. The size distributions of casualties both in whole wars from 1816 to 1980 and terrorist attacks have separately been shown to follow approximate power-law distributions. However, the possibility of universal patterns ranging across wars in the size distribution or timing of within-conflict events has barely been explored. Here we show that the sizes and timing of violent events within different insurgent conflicts exhibit remarkable similarities. We propose a unified model of human insurgency that reproduces these commonalities, and explains conflict-specific variations quantitatively in terms of underlying rules of engagement. Our model treats each insurgent population as an ecology of dynamically evolving, self-organized groups following common decision-making processes. Our model is consistent with several recent hypotheses about modern insurgency, is robust to many generalizations, and establishes a quantitative connection between human insurgency, global terrorism and ecology. Its similarity to financial market models provides a surprising link between violent and non-violent forms of human behaviour.

5) Ziv and Ahissar. Neuroscience: New tricks and old spines. Nature (2009) vol. 462 (7275) pp. 859-61

Imaging of brain structures in living mice reveals that learning new tasks leads to persistent remodelling of synaptic structures, with each new skill associated with a small and unique assembly of new synapses.

6) Tang et al. Personality change during depression treatment: a placebo-controlled trial. Arch Gen Psychiatry (2009) vol. 66 (12) pp. 1322-30

CONTEXT: High neuroticism is a personality risk factor that reflects much of the genetic vulnerability to major depressive disorder (MDD), and low extraversion may increase risk as well. Both have been linked to the serotonin system. OBJECTIVES: To test whether patients with MDD taking selective serotonin reuptake inhibitors (SSRIs) report greater changes in neuroticism and extraversion than patients receiving inert placebo, and to examine the state effect hypothesis that self-reported personality change during SSRI treatment is merely a change of depression-related measurement bias. DESIGN: A placebo-controlled trial. SETTING: Research clinics. Patients Adult patients with moderate to severe MDD randomized to receive paroxetine (n = 120), placebo (n = 60), or cognitive therapy (n = 60). OUTCOME MEASURES: NEO Five-Factor Inventory and Hamilton Rating Scale for Depression. RESULTS: Patients who took paroxetine reported greater personality change than placebo patients, even after controlling for depression improvement (neuroticism, P < .001; extraversion, P = .002). The advantage of paroxetine over placebo in antidepressant efficacy was no longer significant after controlling for change in neuroticism (P = .46) or extraversion (P = .14). Patients taking paroxetine reported 6.8 times as much change on neuroticism and 3.5 times as much change on extraversion as placebo patients matched for depression improvement. Although placebo patients exhibited substantial depression improvement (Hamilton Rating Scale for Depression score, -1.2 SD, P < .001), they reported little change on neuroticism (-0.18 SD, P = .08) or extraversion (0.08 SD, P = .50). Cognitive therapy produced greater personality change than placebo (P

7) Editorial. Credit where credit is due. Nature (2009) vol. 462 (7275) pp. 825

A proposed author ID system is gaining widespread support, and could help lay the foundation for an academic-reward system less heavily tied to publications and citations.

8) Nielsen. A guide to the day of big data. Nature (2009) vol. 462 (10) pp. 722-723

Book review of The Fourth Paradigm: Data-Intensive Scientific Discovery Edited by Tony Hey, Stewart Tansley and Kristin Tolle

9) Oswald and Wu. Objective Confirmation of Subjective Measures of Human Well-Being: Evidence from the U.S.A. Science (2009) pp.

A huge research literature, across the behavioral and social sciences, uses information on individuals’ subjective well-being. These are responses to questions-asked by survey interviewers or medical personnel-such as “how happy do you feel on a scale from 1 to 4?” Yet there is little scientific evidence that such data are meaningful. This study examines a 2005-2008 Behavioral Risk Factor Surveillance System random sample of 1.3 million United States citizens. Life-satisfaction in each U.S. state is measured. Across America, people’s answers trace out the same pattern of quality of life as previously estimated, using solely nonsubjective data, in a literature from economics (so-called “compensating differentials” neoclassical theory due originally to Adam Smith). There is a state-by-state match (r = 0.6, P < 0.001) between subjective and objective well-being. This result has some potential to help to unify disciplines.

10) Schurger et al. Reproducibility Distinguishes Conscious from Nonconscious Neural Representations. Science (2010) vol. 327 (5961) pp. 97-99

What qualifies a neural representation for a role in subjective experience? Previous evidence suggests that the duration and intensity of the neural response to a sensory stimulus are factors. We introduce another attribute-the reproducibility of a pattern of neural activity across different episodes-that predicts specific and measurable differences between conscious and nonconscious neural representations indepedently of duration and intensity. We found that conscious neural activation patterns are relatively reproducible when compared with nonconscious neural activation patterns corresponding to the same perceptual content. This is not adequately explained by a difference in signal-to-noise ratio.

11) HUGO Pan-Asian SNP Consortium et al. Mapping human genetic diversity in Asia. Science (2009) vol. 326 (5959) pp. 1541-5

Asia harbors substantial cultural and linguistic diversity, but the geographic structure of genetic variation across the continent remains enigmatic. Here we report a large-scale survey of autosomal variation from a broad geographic sample of Asian human populations. Our results show that genetic ancestry is strongly correlated with linguistic affiliations as well as geography. Most populations show relatedness within ethnic/linguistic groups, despite prevalent gene flow among populations. More than 90% of East Asian (EA) haplotypes could be found in either Southeast Asian (SEA) or Central-South Asian (CSA) populations and show clinal structure with haplotype diversity decreasing from south to north. Furthermore, 50% of EA haplotypes were found in SEA only and 5% were found in CSA only, indicating that SEA was a major geographic source of EA populations.

12) Kong et al. Parental origin of sequence variants associated with complex diseases. Nature (2009) vol. 462 (7275) pp. 868-74

Effects of susceptibility variants may depend on from which parent they are inherited. Although many associations between sequence variants and human traits have been discovered through genome-wide associations, the impact of parental origin has largely been ignored. Here we show that for 38,167 Icelanders genotyped using single nucleotide polymorphism (SNP) chips, the parental origin of most alleles can be determined. For this we used a combination of genealogy and long-range phasing. We then focused on SNPs that associate with diseases and are within 500 kilobases of known imprinted genes. Seven independent SNP associations were examined. Five-one with breast cancer, one with basal-cell carcinoma and three with type 2 diabetes-have parental-origin-specific associations. These variants are located in two genomic regions, 11p15 and 7q32, each harbouring a cluster of imprinted genes. Furthermore, we observed a novel association between the SNP rs2334499 at 11p15 and type 2 diabetes. Here the allele that confers risk when paternally inherited is protective when maternally transmitted. We identified a differentially methylated CTCF-binding site at 11p15 and demonstrated correlation of rs2334499 with decreased methylation of that site.

13) Weinstein et al. Can Nature Make Us More Caring? Effects of Immersion in Nature on Intrinsic Aspirations and Generosity. Personality and social psychology bulletin (2009) pp. 0146167209341649v1

Four studies examined the effects of nature on valuing intrinsic and extrinsic aspirations. Intrinsic aspirations reflected prosocial and other-focused value orientations, and extrinsic aspirations predicted self-focused value orientations. Participants immersed in natural environments reported higher valuing of intrinsic aspirations and lower valuing of extrinsic aspirations, whereas those immersed in non-natural environments reported increased valuing of extrinsic aspirations and no change of intrinsic aspirations. Three studies explored experiences of nature relatedness and autonomy as underlying mechanisms of these effects, showing that nature immersion elicited these processes whereas non-nature immersion thwarted them and that they in turn predicted higher intrinsic and lower extrinsic aspirations. Studies 3 and 4 also extended the paradigm by testing these effects on generous decision making indicative of valuing intrinsic versus extrinsic aspirations.

14) Raihani et al. Punishers benefit from third-party punishment in fish. Science (2010) vol. 327 (5962) pp. 171

In cases where uninvolved bystanders pay to punish defectors, this behavior has typically been interpreted in terms of group-level rather than individual-level benefits. Male cleaner fish, Labroides dimidiatus, punish their female partner if she cheats while inspecting model clients. Punishment promotes female cooperation and thereby yields direct foraging benefits to the male. Thus, third-party punishment can evolve via self-serving tendencies in a nonhuman species, and this finding may shed light on the evolutionary dynamics of more complex behavior in other animal species, including humans.

15) Laursen. Computational biology: Biological logic. Nature (2009) vol. 462 (7272) pp. 408-10

An intuitive approach to computer modelling could reveal paths to discovery, finds Lucas Laursen.

16) Buchen. Behaviour: Flies on film. Nature (2009) vol. 462 (7273) pp. 562-4

A unique collaboration is bringing automated screening to the study of fly behaviour and could change the way that machines see humans. Lizzie Buchen reports.

17) Editorial. 2020 visions. Nature (2010) vol. 463 (7277) pp. 26-32

For the first issue of the new decade, Nature asked a selection of leading researchers and policy-makers where their fields will be ten years from now. We invited them to identify the key questions their disciplines face, the major roadblocks and the pressing next steps.

18) Quirk and Milad. Neuroscience: Editing out fear. Nature (2010) vol. 463 (7277) pp. 36-7

Retrieving a memory initiates a window of vulnerability for that memory. Simple behavioural methods can modify distressing memories during this window, eliminating fear reactions to traumatic reminders.

19) Schiller et al. Preventing the return of fear in humans using reconsolidation update mechanisms. Nature (2010) vol. 463 (7277) pp. 49-53

Recent research on changing fears has examined targeting reconsolidation. During reconsolidation, stored information is rendered labile after being retrieved. Pharmacological manipulations at this stage result in an inability to retrieve the memories at later times, suggesting that they are erased or persistently inhibited. Unfortunately, the use of these pharmacological manipulations in humans can be problematic. Here we introduce a non-invasive technique to target the reconsolidation of fear memories in humans. We provide evidence that old fear memories can be updated with non-fearful information provided during the reconsolidation window. As a consequence, fear responses are no longer expressed, an effect that lasted at least a year and was selective only to reactivated memories without affecting others. These findings demonstrate the adaptive role of reconsolidation as a window of opportunity to rewrite emotional memories, and suggest a non-invasive technique that can be used safely in humans to prevent the return of fear.

20) Phelps. Making the paper: Elizabeth Phelps. Nature (2010) vol. 463 (7277) pp. 8-8

Training helps people forget some fearful memories.


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