Even a 10 minute walk can boost your brain

From Suwabe et al.:

Significance

Our previous work has shown that mild physical exercise can promote better memory in rodents. Here, we use functional MRI in healthy young adults to assess the immediate impact of a short bout of mild exercise on the brain mechanisms supporting memory processes. We find that this brief intervention rapidly enhanced highly detailed memory processing and resulted in elevated activity in the hippocampus and the surrounding regions, as well as increased coupling between the hippocampus and cortical regions previously known to support detailed memory processing. These findings represent a mechanism by which mild exercise, on par with yoga and tai chi, may improve memory. Future studies should test the long-term effects of regular mild exercise on age-related memory loss.

Abstract

Physical exercise has beneficial effects on neurocognitive function, including hippocampus-dependent episodic memory. Exercise intensity level can be assessed according to whether it induces a stress response; the most effective exercise for improving hippocampal function remains unclear. Our prior work using a special treadmill running model in animals has shown that stress-free mild exercise increases hippocampal neuronal activity and promotes adult neurogenesis in the dentate gyrus (DG) of the hippocampus, improving spatial memory performance. However, the rapid modification, from mild exercise, on hippocampal memory function and the exact mechanisms for these changes, in particular the impact on pattern separation acting in the DG and CA3 regions, are yet to be elucidated. To this end, we adopted an acute-exercise design in humans, coupled with high-resolution functional MRI techniques, capable of resolving hippocampal subfields. A single 10-min bout of very light-intensity exercise (30%V˙O2peak) results in rapid enhancement in pattern separation and an increase in functional connectivity between hippocampal DG/CA3 and cortical regions (i.e., parahippocampal, angular, and fusiform gyri). Importantly, the magnitude of the enhanced functional connectivity predicted the extent of memory improvement at an individual subject level. These results suggest that brief, very light exercise rapidly enhances hippocampal memory function, possibly by increasing DG/CA3−neocortical functional connectivity.

An average person can recognize 5,000 faces.

Jenkins et al. recruited 25 undergraduate or postgraduate students at the University of Glasgow and the University of Aberdeen (15 female, 10 male; mean age 24, age range 18–61 years). They were given 1 hour to list as many faces from their personal lives as possible, and then another hour to do the same with famous faces, like those of actors, politicians, and musicians. To figure out how many additional faces people recognized but were unable to recall without prompting, they showed the participants photographs of 3441 celebrities, including Barack Obama and Tom Cruise. To qualify as “knowing” a face, the participants had to recognize two different photos of each person. Here is a video done by Science Magazine to describe the work:
 

Digital media and developing minds

I want to point to the Oct. 2 issue of PNAS, which free online access to a Sackler Colloquium on Digital Media and Developing Minds. The place to start is the introductory article by David Meyer, "From savannas to blue-phase LCD screens: Prospects and perils for child development in the Post-Modern Digital Information Age." Some clips from his article:

The Sackler Colloquium “Digital Media and Developing Minds” was an interdisciplinary collaborative endeavor to promote joint interests of the National Academy of Sciences, the Arthur M. Sackler Foundation, and the Institute of Digital Media and Child Development.‡‡ At the colloquium, a select group of media-savvy experts in diverse disciplines assembled to pursue several interrelated goals: (i) reporting results from state-of-the art scientific research; (ii) establishing a dialogue between medical researchers, social scientists, communications specialists, policy officials, and other interested parties who study media effects; and (iii) setting a future research agenda to maximize the benefits, curtail the costs, and minimize the risks for children and teens in the Post-Modern Digital Information Age.

Christakis et al. (36) report on “How early media exposure may affect cognitive function: A review of results from observations in humans and experiments in mice,” reviewing relevant results from empirical studies of humans and animal models that concern how intense environmental stimulation influences neural brain development and behavior.

Lytle et al. (37) report on “Two are better than one: Infant language learning from video improves in the presence of peers,” showing that social copresence with other same-aged peers facilitates 9-mo-old infants’ learning of spoken phonemes through interactions with visual touch screens.

Kirkorian and Anderson (38) report on “Effect of sequential video shot comprehensibility on attentional synchrony: A comparison of children and adults,” using temporally extended eye-movement records to investigate how “top-down” cognitive comprehension processes for interpreting video narratives develop over an age-range from early childhood (4-y-old) to adulthood.

Beyens et al. (39) report on “Screen media use and ADHD-related behaviors: Four decades of research,” systematically surveying representative scientific literature that suggests a modest positive correlation—moderated by variables such as gender and chronic aggressive tendencies—between media use and ADHD-related behaviors, thereby helping pave the way toward future detailed theoretical models of these phenomena.

Prescott et al. (40) report on “Metaanalysis of the relationship between violent video game play and physical aggression over time,” applying sophisticated statistical techniques to assess data from a large cross-cultural sample of studies (n = 24; aggregated participant sample size > 17,000) about associations between video game violence and prospective future physical aggression, which has yielded evidence of small but reliable direct relationships that are largest among Whites, intermediate among Asians, and smallest (unreliable) among Hispanics.

Uncapher and Wagner (41) report on “Minds and brains of media multitaskers: Current findings and future directions,” evaluating whether intensive media multitasking (i.e., engaging simultaneously with multiple media streams; for example, texting friends on smart phones while answering email messages on laptop computers and playing video games on other electronic devices) leads to relatively poor performance on various cognitive tests under single-tasking conditions, which might happen because chronic media multitasking diminishes individuals’ powers of sustained goal-directed attention.

Finally, Katz et al. (42) report on “How to play 20 questions with nature and lose: Reflections on 100 years of brain-training research,” analyzing how and why past research based on various laboratory and real-world approaches to training basic mental processes (e.g., selective attention, working memory, and cognitive control)—including contemporary video game playing (also known as “brain training”)—have yet to yield consistently positive, practically significant, outcomes, such as durable long-term enhancements of general fluid intelligence.

Sans Forgetica

A fascinating piece from Taylor Telford in The Washington Post describes a new font devised by psychology and design researchers at RMIT Univ. in Melbourne...

...designed to boost information retention for readers. It’s based on a theory called “desirable difficulty,” which suggests that people remember things better when their brains have to overcome minor obstacles while processing information. Sans Forgetica is sleek and back-slanted with intermittent gaps in each letter, which serve as a “simple puzzle” for the reader...The back-slanting in Sans Forgetica would be foreign to most readers...The openings in the letters make the brain pause to identify the shapes.

It may be my imagination, but I feel my brain perking up, working harder, to take in theis graphic:

The team tested the font’s efficacy along with other intentionally complicated fonts on 400 students in lab and online experiments and found that “Sans Forgetica broke just enough design principles without becoming too illegible and aided memory retention.

Details of how a fear response is unlearned.

Learning requires the formation of new nerve connections. When that learning is extinguished are those connections inhibited or lost? Wan Lai et al. provide evidence for the latter:

Significance

Whether learning-induced changes in neuronal circuits are inhibited or erased during the process of unlearning remains unclear. In this study, we examined the impact of auditory-cued fear conditioning and extinction on the remodeling of synaptic connections in the living mouse auditory cortex. We found that fear conditioning leads to cue-specific formation of new postsynaptic dendritic spines, whereas fear extinction preferentially eliminates these new spines in a cue-specific manner. Our findings suggest that learning-related changes of synaptic connections in the cortex are at least partially reversed after unlearning.

Abstract

Fear conditioning-induced behavioral responses can be extinguished after fear extinction. While fear extinction is generally thought to be a form of new learning, several lines of evidence suggest that neuronal changes associated with fear conditioning could be reversed after fear extinction. To better understand how fear conditioning and extinction modify synaptic circuits, we examined changes of postsynaptic dendritic spines of layer V pyramidal neurons in the mouse auditory cortex over time using transcranial two-photon microscopy. We found that auditory-cued fear conditioning induced the formation of new dendritic spines within 2 days. The survived new spines induced by fear conditioning with one auditory cue were clustered within dendritic branch segments and spatially segregated from new spines induced by fear conditioning with a different auditory cue. Importantly, fear extinction preferentially caused the elimination of newly formed spines induced by fear conditioning in an auditory cue-specific manner. Furthermore, after fear extinction, fear reconditioning induced reformation of new dendritic spines in close proximity to the sites of new spine formation induced by previous fear conditioning. These results show that fear conditioning, extinction, and reconditioning induce cue- and location-specific dendritic spine remodeling in the auditory cortex. They also suggest that changes of synaptic connections induced by fear conditioning are reversed after fear extinction.

How exercise slows Alzheimer’s disease.

Wow…if I ever needed more encouragement to keep up my exercise routines (mainly swimming, biking, and a few weights) Choi et al. provide it by demonstrating that in a mouse model of Alzheimer's disease, exercise improves memory through a combination of encouraging the generation of new nerve cells in the hippocampus and increasing the levels of brain-derived neurotrophic factor (BDNF) that supports neuronal growth and survival. Their abstract:

Adult hippocampal neurogenesis (AHN) is impaired before the onset of Alzheimer’s disease (AD) pathology. We found that exercise provided cognitive benefit to 5×FAD mice, a mouse model of AD, by inducing AHN and elevating levels of brain-derived neurotrophic factor (BDNF). Neither stimulation of AHN alone, nor exercise, in the absence of increased AHN, ameliorated cognition. We successfully mimicked the beneficial effects of exercise on AD mice by genetically and pharmacologically inducing AHN in combination with elevating BDNF levels. Suppressing AHN later led to worsened cognitive performance and loss of preexisting dentate neurons. Thus, pharmacological mimetics of exercise, enhancing AHN and elevating BDNF levels, may improve cognition in AD. Furthermore, applied at early stages of AD, these mimetics may protect against subsequent neuronal cell death.

More evidence against the transferable benefits of online brain training on cognitive function

From Stojanoski et al.:

There is strong incentive to improve our cognitive abilities, and brain training has emerged as a promising approach for achieving this goal. While the idea that extensive ‘training’ on computerized tasks will improve general cognitive functioning is appealing, the evidence to support this remains contentious. This is, in part, because of poor criteria for selecting training tasks and outcome measures resulting in inconsistent definitions of what constitutes transferable improvement to cognition. The current study used a targeted training approach to investigate whether training on two different, but related, working memory tasks (across two experiments, with 72 participants) produced transferable benefits to similar (quantified based on cognitive and neural profiles) untrained test tasks. Despite significant improvement on both training tasks, participants did not improve on either test task. In fact, performance on the test tasks after training were nearly identical to a passive control group. These results indicate that, despite maximizing the likelihood of producing transferable benefits, brain training does not generalize, even to very similar tasks. Our study calls into question the benefit of cognitive training beyond practice effects, and provides a new framework for future investigations into the efficacy of brain training.

Enhanced brain activity associated with highly superior memory.

Santangelo et al. show that people with superior memory have enhanced connectivity of their prefrontal cortex with their hippocampus and temporoparietal junction:

Significance

Recent research has identified human subjects who have highly superior autobiographical memory (HSAM). Here, we investigated, using fMRI, the neural activation induced by retrieval of autobiographical memories (AMs) and semantic memories (SMs) in subjects with HSAM and control subjects. While their brains were being scanned, subjects had to retrieve AMs as well as SMs (e.g., examples of animals). The subjects with HSAM displayed a superior ability to retrieve details of AMs, supported by enhanced activation of several brain regions, including the medial prefrontal cortex and temporoparietal junction, as well as increased connectivity of the prefrontal cortex with the hippocampus, a region well known to be involved in memory representation. These findings suggest that activation of these systems may play a critical role in enabling HSAM.

Abstract

Brain systems underlying human memory function have been classically investigated studying patients with selective memory impairments. The discovery of rare individuals who have highly superior autobiographical memory (HSAM) provides, instead, an opportunity to investigate the brain systems underlying enhanced memory. Here, we carried out an fMRI investigation of a group of subjects identified as having HSAM. During fMRI scanning, eight subjects with HSAM and 21 control subjects were asked to retrieve autobiographical memories (AMs) as well as non-AMs (e.g., examples of animals). Subjects were instructed to signal the “access” to an AM by a key press and to continue “reliving” it immediately after. Compared with controls, individuals with HSAM provided a richer AM recollection and were faster in accessing AMs. The access to AMs was associated with enhanced prefrontal/hippocampal functional connectivity. AM access also induced increased activity in the left temporoparietal junction and enhanced functional coupling with sensory cortices in subjects with HSAM compared with controls. In contrast, subjects with HSAM did not differ from controls in functional activity during the reliving phase. These findings, based on fMRI assessment, provide evidence of interaction of brain systems engaged in memory retrieval and suggest that enhanced activity of these systems is selectively involved in enabling more efficient access to past experiences in HSAM.

Crows make mental templates.

Weintraub points to further studies from the University of Aukland School of Psychology on the extraordinary New Caledonian crows that have been shown to learn tool use. They also appear to use “mental template matching” - forming an image in their heads of tools they have seen used by others, and then copying them.

 

An optimistic outlook creates a rosy past.

From Devitt and Schacter in the Harvard Psychology department, a study recruiting the usual gaggle of psychology undergraduate students as subjects:

People frequently engage in future thinking in everyday life, but it is unknown how simulating an event in advance changes how that event is remembered once it takes place. To initiate study of this important topic, we conducted two experiments in which participants simulated emotional events before learning the hypothetical outcome of each event via narratives. Memory was assessed for emotional details contained in those narratives. Positive simulation resulted in a liberal response bias for positive information and a conservative bias for negative information. Events preceded by positive simulation were considered more favorably in retrospect. In contrast, negative simulation had no impact on subsequent memory. Results were similar across an immediate and delayed memory test and for past and future simulation. These results provide novel insights into the cognitive consequences of episodic future simulation and build on the optimism-bias literature by showing that adopting a favorable outlook results in a rosy memory.

Electrical brain stimulation enhances visual memory performance

Kucewicz et al. study patients with epilepsy undergoing evaluation for resective surgery to show that stimulation of the lateral temporal cortex, but not the hippocampus, parahippocampal neocortex or prefrontal cortex, increases the number of words that patients can remember.:

Direct electrical stimulation of the human brain can elicit sensory and motor perceptions as well as recall of memories. Stimulating higher order association areas of the lateral temporal cortex in particular was reported to activate visual and auditory memory representations of past experiences (Penfield and Perot, 1963). We hypothesized that this effect could be used to modulate memory processing. Recent attempts at memory enhancement in the human brain have been focused on the hippocampus and other mesial temporal lobe structures, with a few reports of memory improvement in small studies of individual brain regions. Here, we investigated the effect of stimulation in four brain regions known to support declarative memory: hippocampus, parahippocampal neocortex, prefrontal cortex and temporal cortex. Intracranial electrode recordings with stimulation were used to assess verbal memory performance in a group of 22 patients (nine males). We show enhanced performance with electrical stimulation in the lateral temporal cortex (paired t-test, P = 0.0067), but not in the other brain regions tested. This selective enhancement was observed both on the group level, and for two of the four individual subjects stimulated in the temporal cortex. This study shows that electrical stimulation in specific brain areas can enhance verbal memory performance in humans.

Sitting is bad for your brain...

It is well known that sitting for long periods each day correlates with higher risk of heart disease, diabetes, and mortality rate. Siddarth et al. at UCLA now show a correlation of sedentary behavior with reduced thickness of the medial temporal lobe of our brains, which contains the hippocampus and is central to learning and memory. Their abstract:

Atrophy of the medial temporal lobe (MTL) occurs with aging, resulting in impaired episodic memory. Aerobic fitness is positively correlated with total hippocampal volume, a heavily studied memory-critical region within the MTL. However, research on associations between sedentary behavior and MTL subregion integrity is limited. Here we explore associations between thickness of the MTL and its subregions (namely CA1, CA23DG, fusiform gyrus, subiculum, parahippocampal, perirhinal and entorhinal cortex,), physical activity, and sedentary behavior. We assessed 35 non-demented middle-aged and older adults (25 women, 10 men; 45–75 years) using the International Physical Activity Questionnaire for older adults, which quantifies physical activity levels in MET-equivalent units and asks about the average number of hours spent sitting per day. All participants had high resolution MRI scans performed on a Siemens Allegra 3T MRI scanner, which allows for detailed investigation of the MTL. Controlling for age, total MTL thickness correlated inversely with hours of sitting/day (r = -0.37, p = 0.03). In MTL subregion analysis, parahippocampal (r = -0.45, p = 0.007), entorhinal (r = -0.33, p = 0.05) cortical and subiculum (r = -0.36, p = .04) thicknesses correlated inversely with hours of sitting/day. No significant correlations were observed between physical activity levels and MTL thickness. Though preliminary, our results suggest that more sedentary non-demented individuals have less MTL thickness. Future studies should include longitudinal analyses and explore mechanisms, as well as the efficacy of decreasing sedentary behaviors to reverse this association.

Locus Coeruleus integrity and memory in aging adults

The locus coeruleus is a deep brain nucleus whose cells synthesize noradrenaline that is sent via its axonal projections to other parts of the brain. Hämmerer et al. show that its integrity is critical in maintaining memory performance:

Significance

Locus coeruleus (LC) integrity in cognitively normal older adults is a potentially important preclinical marker in dementia. Our study establishes a link between variability in LC integrity and cognitive decline related to noradrenergic modulation in old age. We find that in older adults, reduced LC integrity explains lower memory performance. This effect was more pronounced for memory related to negative events, and accompanied by increased pupil diameter size in response to negative events. The study provides a strong motivation for future research investigating the role of LC integrity in healthy, as well as in pathological, aging.

Abstract

The locus coeruleus (LC) is the principal origin of noradrenaline in the brain. LC integrity varies considerably across healthy older individuals, and is suggested to contribute to altered cognitive functions in aging. Here we test this hypothesis using an incidental memory task that is known to be susceptible to noradrenergic modulation. We used MRI neuromelanin (NM) imaging to assess LC structural integrity and pupillometry as a putative index of LC activation in both younger and older adults. We show that older adults with reduced structural LC integrity show poorer subsequent memory. This effect is more pronounced for emotionally negative events, in accord with a greater role for noradrenergic modulation in encoding salient or aversive events. In addition, we found that salient stimuli led to greater pupil diameters, consistent with increased LC activation during the encoding of such events. Our study presents novel evidence that a decrement in noradrenergic modulation impacts on specific components of cognition in healthy older adults. The findings provide a strong motivation for further investigation of the effects of altered LC integrity in pathological aging.

How to goose your memory.

The abstract from Inman et al., "Direct electrical stimulation of the amygdala enhances declarative memory in humans." They show that stimulation of the amygdala that does not elicit an emotional response during a neutral event enhances memory of that event. :

Significance

Memories for emotional events tend to persist, raising a fundamental question about how the brain prioritizes significant memories. Past studies have pointed to a central role for the amygdala in mediating this endogenous memory enhancement. However, the premise that the amygdala can causally enhance declarative memory has not been directly tested in humans. Here we show that brief electrical stimulation to the human amygdala can enhance declarative memory for specific images of neutral objects without eliciting a subjective emotional response, likely by engaging other memory-related brain regions. The results show the human amygdala has a general capacity to initiate enhancement of specific declarative memories rather than a narrower role limited to indirectly mediating emotional effects on memory.

Abstract

Emotional events are often remembered better than neutral events, a benefit that many studies have hypothesized to depend on the amygdala’s interactions with memory systems. These studies have indicated that the amygdala can modulate memory-consolidation processes in other brain regions such as the hippocampus and perirhinal cortex. Indeed, rodent studies have demonstrated that direct activation of the amygdala can enhance memory consolidation even during nonemotional events. However, the premise that the amygdala causally enhances declarative memory has not been directly tested in humans. Here we tested whether brief electrical stimulation to the amygdala could enhance declarative memory for specific images of neutral objects without eliciting a subjective emotional response. Fourteen epilepsy patients undergoing monitoring of seizures via intracranial depth electrodes viewed a series of neutral object images, half of which were immediately followed by brief, low-amplitude electrical stimulation to the amygdala. Amygdala stimulation elicited no subjective emotional response but led to reliably improved memory compared with control images when patients were given a recognition-memory test the next day. Neuronal oscillations in the amygdala, hippocampus, and perirhinal cortex during this next-day memory test indicated that a neural correlate of the memory enhancement was increased theta and gamma oscillatory interactions between these regions, consistent with the idea that the amygdala prioritizes consolidation by engaging other memory regions. These results show that the amygdala can initiate endogenous memory prioritization processes in the absence of emotional input, addressing a fundamental question and opening a path to future therapies.

Old brains come uncoupled in sleep.

From Helfrich et al.:

Highlights

•Precise coupling of NREM (Non-rapid-eye-movement) slow waves and spindles dictates memory consolidation 

•Aging impairs slow wave-spindle coupling, leading to overnight forgetting 

•Age-related atrophy in mPFC (medial prefrontal cortex) predicts the failure of such coupling and thus memory

Summary

The coupled interaction between slow-wave oscillations and sleep spindles during non-rapid-eye-movement (NREM) sleep has been proposed to support memory consolidation. However, little evidence in humans supports this theory. Moreover, whether such dynamic coupling is impaired as a consequence of brain aging in later life, contributing to cognitive and memory decline, is unknown. Combining electroencephalography (EEG), structural MRI, and sleep-dependent memory assessment, we addressed these questions in cognitively normal young and older adults. Directional cross-frequency coupling analyses demonstrated that the slow wave governs a precise temporal coordination of sleep spindles, the quality of which predicts overnight memory retention. Moreover, selective atrophy within the medial frontal cortex in older adults predicted a temporal dispersion of this slow wave-spindle coupling, impairing overnight memory consolidation and leading to forgetting. Prefrontal-dependent deficits in the spatiotemporal coordination of NREM sleep oscillations therefore represent one pathway explaining age-related memory decline.

Memories are stored by the extracellular matrix surrounding brain cells.

Fascinating work from Thompson et al., who show that degrading the extracellular matrix structure with local injections into visual cortex area 2L of bacterial enzyme chondroitinase ABC can abolish a remote visual fear memory:

Significance

Perineuronal nets (PNNs), a type of extracellular matrix only found in the central nervous system, wraps tightly around the cell soma and proximal dendrites of a subset of neurons. The PNNs are long-lasting structures that restrict plasticity, making them eligible candidates for memory processing. This work demonstrates that PNNs in the lateral secondary visual cortex (V2L) are essential for the recall of a remote visual fear memory. The results suggest a role of extracellular molecules in storage and retrieval of memories.

Abstract

Throughout life animals learn to recognize cues that signal danger and instantaneously initiate an adequate threat response. Memories of such associations may last a lifetime and far outlast the intracellular molecules currently found to be important for memory processing. The memory engram may be supported by other more stable molecular components, such as the extracellular matrix structure of perineuronal nets (PNNs). Here, we show that recall of remote, but not recent, visual fear memories in rats depend on intact PNNs in the secondary visual cortex (V2L). Supporting our behavioral findings, increased synchronized theta oscillations between V2L and basolateral amygdala, a physiological correlate of successful recall, was absent in rats with degraded PNNs in V2L. Together, our findings suggest a role for PNNs in remote memory processing by stabilizing the neural network of the engram.

Improving brain function by shocking it.

This post points to three recent articles on non-invasive electrical brain stimulation of various types that enhance brain brain function.

Krause et al. show that Transcranial Direct Current Stimulates associative learning and alters functional connectivity in the macaque monkey brain:

Highlights

• tDCS improves animals’ behavior on an associative learning task 

• Stimulation has local effects on LFP power and coherence. 

• It also causes frequency-specific changes in connectivity between brain areas 

• Inter-area coherence in gamma frequencies is linked to behavioral improvement 

Summary

There has been growing interest in transcranial direct current stimulation (tDCS), a non-invasive technique purported to modulate neural activity via weak, externally applied electric fields. Although some promising preliminary data have been reported for applications ranging from stroke rehabilitation to cognitive enhancement, little is known about how tDCS affects the human brain, and some studies have concluded that it may have no effect at all. Here, we describe a macaque model of tDCS that allows us to simultaneously examine the effects of tDCS on brain activity and behavior. We find that applying tDCS to right prefrontal cortex improves monkeys’ performance on an associative learning task. While firing rates do not change within the targeted area, tDCS does induce large low-frequency oscillations in the underlying tissue. These oscillations alter functional connectivity, both locally and between distant brain areas, and these long-range changes correlate with tDCS’s effects on behavior. Together, these results are consistent with the idea that tDCS leads to widespread changes in brain activity and suggest that it may be a valuable method for cheaply and non-invasively altering functional connectivity in humans.

Grossman et al. (Open Access) describe the use of multiple external high frequency electric fields to generate electric field envelopes inside the brain that can stimulate neurons. This could potentially substitute for current stimulation therapies for Parkinson’s disease, depression, and obsessive-compulsive disorder that require implanting electrodes in the brain.

And, an opinion article by Diana et al. discusses rehabilitation of the addicted brain with transcranial magnetic stimulation.

Like apes and small children, ravens plan ahead.

The notion that animal cognition outside of the primate lineage is locked into the present has to be tossed. It appears that cognitive evolution of the ability to plan ahead proceeded independently in the (Corvid) lineage that lead to modern Ravens. Kabadayi and Osvath now show that ravens anticipate the nature, time, and location of a future event based on previous experiences. The ravens' behavior is not merely prospective, anticipating future states; rather, they flexibly apply future planning in behaviors not typically seen in the wild. From the summary by Boeckle and Clayton:

Kabadayi and Osvath test ravens' abilities to plan for future tool use and trading, rather than for food caching (a behavior that might be considered as an adaptive specialization to gather food in order to eat it at a future date)...The authors presented five ravens with a choice of objects. Only one of these objects was a functional tool, which could be used to retrieve food from a puzzle box. The ravens chose correctly not only when they were offered the box but also when they had to store the tool and plan for the next day. In another experiment, the ravens were trained to exchange tokens for food. When the ravens knew that trading would only happen on the next day, they chose and stored these tokens as soon as they were offered to them. By manipulating tool choice, time, and trading opportunities, the authors controlled the value of the items at choice in relation to current as well as future interactions.

The results from the two experiments show that ravens take temporal distance between item choice and reward into account, exercise self-control, and make decisions for predicted futures rather than arbitrary ones. Thus, the birds opt for a more distant but higher gratification rather than an immediate but lower gratification and do so flexibly across behaviors.

Exposure to and recall of violence reduce short-term memory and cognitive control

From Bogliacino et al.:

Significance

Research on violence has mainly focused on its consequences on individuals’ health and behavior. This study establishes the effects of exposure to violence on individuals’ short-term memory and cognitive control. These are key factors affecting individual well-being and societal development. We sampled Colombian civilians who were exposed either to urban violence or to warfare. We found that higher exposure to violence significantly reduces short-term memory and cognitive control only in the group actively recalling emotional states linked with such experiences. This finding demonstrates and characterizes the long-lasting effects of violence. Existing studies have found effects of poverty on cognitive control similar to those that we found for violence. This set of findings supports the validity of the cognitive theory underpinning these studies.

Abstract

Previous research has investigated the effects of violence and warfare on individuals' well-being, mental health, and individual prosociality and risk aversion. This study establishes the short- and long-term effects of exposure to violence on short-term memory and aspects of cognitive control. Short-term memory is the ability to store information. Cognitive control is the capacity to exert inhibition, working memory, and cognitive flexibility. Both have been shown to affect positively individual well-being and societal development. We sampled Colombian civilians who were exposed either to urban violence or to warfare more than a decade earlier. We assessed exposure to violence through either the urban district-level homicide rate or self-reported measures. Before undertaking cognitive tests, a randomly selected subset of our sample was asked to recall emotions of anxiety and fear connected to experiences of violence, whereas the rest recalled joyful or emotionally neutral experiences. We found that higher exposure to violence was associated with lower short-term memory abilities and lower cognitive control in the group recalling experiences of violence, whereas it had no effect in the other group. This finding demonstrates that exposure to violence, even if a decade earlier, can hamper cognitive functions, but only among individuals actively recalling emotional states linked with such experiences. A laboratory experiment conducted in Germany aimed to separate the effect of recalling violent events from the effect of emotions of fear and anxiety. Both factors had significant negative effects on cognitive functions and appeared to be independent from each other.

Default mode network and the wandering mind.

The respective roles of attentional and default mode networks in our brains has been the subject of numerous MindBlog posts (enter 'default mode' in the search box in the left column). Here is a further installment from Poerio et al.:

Experiences such as mind-wandering illustrate that cognition is not always tethered to events in the here-and-now. Although converging evidence emphasises the default mode network (DMN) in mind-wandering, its precise contribution remains unclear. The DMN comprises cortical regions that are maximally distant from primary sensory and motor cortex, a topological location that may support the stimulus-independence of mind-wandering. The DMN is functionally heterogeneous, comprising regions engaged by memory, social cognition and planning; processes relevant to mind-wandering content. Our study examined the relationships between: (i) individual differences in resting-state DMN connectivity, (ii) performance on memory, social and planning tasks and (iii) variability in spontaneous thought, to investigate whether the DMN is critical to mind-wandering because it supports stimulus-independent cognition, memory retrieval, or both. Individual variation in task performance modulated the functional organization of the DMN: poor external engagement was linked to stronger coupling between medial and dorsal subsystems, while decoupling of the core from the cerebellum predicted reports of detailed memory retrieval. Both patterns predicted off-task future thoughts. Consistent with predictions from component process accounts of mind-wandering, our study suggests a 2-fold involvement of the DMN: (i) it supports experiences that are unrelated to the environment through strong coupling between its sub-systems; (ii) it allows memory representations to form the basis of conscious experience.