Spatial Memory

A Canadian study involving 40 older adults (59-81), none of whom were aware of any major memory problems, has found that those scoring below 26 on the Montreal Cognitive Assessment (MoCA) dementia screening test also showed shrinking of the anterolateral entorhinal cortex. This brain region is the first affected in the development of Alzheimer's disease. The study found specifically that this area of the brain is involved in configural processing — that is, processing the spatial arrangement of an object's elements. Accordingly, this task provides a very early indicator of developing Alzheimer's.

You can do a preliminary assessment of your memory using Baycrest's scientifically-validated, online brain health assessment tool, Cogniciti at http://www.cogniciti.com.

https://www.eurekalert.org/pub_releases/2017-05/bcfg-dbc051117.php

A small study involving 50 younger adults (18-35; average age 24) has found that those with a higher BMI performed significantly worse on a computerised memory test called the “Treasure Hunt Task”.

The task involved moving food items around complex scenes (e.g., a desert with palm trees), hiding them in various locations, and indicating afterward where and when they had hidden them. The test was designed to disentangle object, location, and temporal order memory, and the ability to integrate those separate bits of information.

Those with higher BMI were poorer at all aspects of this task. There was no difference, however, in reaction times, or time taken at encoding. In other words, they weren't slower, or less careful when they were learning. Analysis of the errors made indicated that the problem was not with spatial memory, but rather with the binding of the various elements into one coherent memory.

The results could suggest that overweight people are less able to vividly relive details of past events. This in turn might make it harder for them to keep track of what they'd eaten, perhaps making overeating more likely.

The 50 participants included 27 with BMI below 25, 24 with BMI 25-30 (overweight), and 8 with BMI over 30 (obese). 72% were female. None were diagnosed diabetics. However, the researchers didn't take other health conditions which often co-occur with obesity, such as hypertension and sleep apnea, into account.

This is a preliminary study only, and further research is needed to validate its findings. However, it's significant in that it adds to growing evidence that the cognitive impairments that accompany obesity are present early in adult life and are not driven by diabetes.

The finding is also consistent with previous research linking obesity with dysfunction of the hippocampus and the frontal lobe.

http://www.eurekalert.org/pub_releases/2016-02/uoc-bol022616.php

https://www.theguardian.com/science/neurophilosophy/2016/mar/03/obesity-linked-to-memory-deficits

[4183] Cheke LG, Simons JS, Clayton NS. Higher body mass index is associated with episodic memory deficits in young adults. The Quarterly Journal of Experimental Psychology [Internet]. 2015 :1 - 12. Available from: http://dx.doi.org/10.1080/17470218.2015.1099163

Evidence against an evolutionary explanation for male superiority in spatial ability coves from a review of 35 studies covering 11 species: cuttlefish, deer mice, horses, humans, laboratory mice, meadow voles, pine voles, prairie voles, rats, rhesus macaques and talastuco-tucos (a type of burrowing rodent). In eight species, males demonstrated moderately superior spatial skills to their female counterparts, regardless of the size of their territories or the extent to which males ranged farther than females of the same species.

The findings lend support to an alternative theory: that the tendency for males to be better at spatial navigation may just be a "side effect" of testosterone.

http://phys.org/news/2013-02-males-superior-spatial-ability-evolutionary.html

[3315] Clint EK, Sober E, GarlandJr. T, Rhodes JS. Male Superiority in Spatial Navigation: Adaptation or Side Effect?. The Quarterly Review of Biology [Internet]. 2012 ;87(4):289 - 313. Available from: http://www.jstor.org/stable/10.1086/668168

Full text available at http://www.jstor.org/stable/10.1086/668168

A study into how well students understand specific diagrams reminds us that, while pictures may be worth 1000 words, even small details can make a significant difference to how informative they are.

The study focused on variously formatted cladograms (also known as phylogenetic trees) that are commonly used in high school and college biology textbooks. Such diagrams are hierarchically branching, and are typically used to show the evolutionary history of taxa.

Nineteen college students (most of whom were women), who were majoring in biology, were shown cladograms in sequential pairs and asked whether the second cladogram (a diagonal one) depicted relationships that were the same or different as those depicted in the first cladogram (a rectangular one). Taxa were represented by single letters, which were either in forward or reverse alphabetical order. Each set (diagonal and rectangular) had four variants: up to the right (UR) with forward letters; UR with reverse letters; down to the right (DR), forward letters; DR, reverse. Six topologies were used, creating 24 cladograms in each set. Eye-tracking showed how the students studied the diagrams.

The order of the letters turned out not to matter, but the way the diagrams were oriented made a significant difference to how well students understood them.

In line with our training in reading (left to right), and regardless of orientation, students scanned the diagrams from left to right. The main line of the cladogram (the “backbone”) also provided a strong visual cue to the direction of scanning (upward or downward). In conjunction with the left-right bias, this meant that UR cladograms were processed from bottom to top, while DR cladograms were processed from top to bottom.

Put like that, the results are less surprising. Diagonal cladograms going up to the right were significantly harder for students to match to the rectangular format (63% correct vs 70% for cladograms going down to the right).

Moreover, this was true even for experts. Of the two biology professors included in the study, one showed the same pattern as the students in terms of accuracy, while the other managed the translations accurately enough, but took significantly longer to interpret the UR diagrams than the DR ones.

Unfortunately, the upward orientation is the more widely used (82% of diagonal cladograms in a survey of 27 high school & college biology textbooks; diagonal cladograms comprised 72% of all diagrams).

The findings suggest that teachers need to teach their students to go against their own natural inclinations, and regardless of orientation, scan the tree in a downward direction. This strategy applies to rectangular cladograms as well as diagonal ones.

It’s worth emphasizing another aspect of these findings: even the best type of diagonal cladogram was only translated at a relatively poor level of accuracy. Previous research has suggested that the diagonal cladogram is significantly harder to understand than the rectangular format. Note that the only difference between them is the orientation.

All this highlights two points:

Even apparently minor aspects of a diagram can make a significant difference to how easily it’s understood.

Teachers shouldn’t assume that students ‘naturally’ know how to read a diagram.

Novick, L., Stull, A. T., & Catley, K. M. (2012). Reading Phylogenetic Trees: The Effects of Tree Orientation and Text Processing on Comprehension. BioScience, 62(8), 757–764. doi:10.1525/bio.2012.62.8.8

Catley, K., & Novick, L. (2008). Seeing the wood for the trees: An analysis of evolutionary diagrams in biology textbooks. BioScience, 58(10), 976–987. Retrieved from http://www.jstor.org/stable/10.1641/B581011
 

Spatial abilities have been shown to be important for achievement in STEM subjects (science, technology, engineering, math), but many people have felt that spatial skills are something you’re either born with or not.

In a comprehensive review of 217 research studies on educational interventions to improve spatial thinking, researchers concluded that you can indeed improve spatial skills, and that such training can transfer to new tasks. Moreover, not only can the right sort of training improve spatial skill in general, and across age and gender, but the effect of training appears to be stable and long-lasting.

One interesting finding (the researchers themselves considered it perhaps the most important finding) was the diversity in effective training — several different forms of training can be effective in improving spatial abilities. This may have something to do with the breadth covered by the label ‘spatial ability’, which include such skills as:

  • Perceiving objects, paths, or spatial configurations against a background of distracting information;
  • Piecing together objects into more complex configurations, visualizing and mentally transforming objects;
  • Understanding abstract principles, such as horizontal invariance;
  • Visualizing an environment in its entirety from a different position.

The review compared three types of training. Those that used:

  • Video games (24 studies)
  • Semester-long instructional courses on spatial reasoning (42 studies)
  • Practical training, often in a lab, that involved practicing spatial tasks, strategic instruction, or computerized lessons (138 studies).

The first two are examples of indirect training, while the last involves direct training.

On average, taken across the board, training improved performance by well over half a standard deviation when considered on its own, and still almost one half of a standard deviation when compared to a control group. This is a moderately large effect, and it extended to transfer tasks.

It also conceals a wide range, most of which is due to different treatment of control groups. Because the retesting effect is so strong in this domain (if you give any group a spatial test twice, regardless of whether they’ve been training in between the two tests, they’re going to do better on the second test), repeated testing can have a potent effect on the control group. Some ‘filler’ tasks can also inadvertently improve the control group’s performance. All of this will reduce the apparent effect of training. (Not having a control group is even worse, because you don’t know how much of the improvement is due to training and how much to the retesting effect.)

This caution is, of course, more support for the value of practice in developing spatial skills. This is further reinforced by studies that were omitted from the analysis because they would skew the data. Twelve studies found very high effect sizes — more than three times the average size of the remaining studies. All these studies took place in poorly developed countries (those with a Human Development Index above 30 at the time of the study) — Malaysia, Turkey, China, India, and Nigeria. HDI rating was even associated with the benefits of training in a dose-dependent manner — that is, the lower the standard of living, the greater the benefit.

This finding is consistent with other research indicating that lower socioeconomic status is associated with larger responses to training or intervention.

In similar vein, when the review compared 19 studies that specifically selected participants who scored poorly on spatial tests against the other studies, they found that the effects of training were significantly bigger among the selected studies.

In other words, those with poorer spatial skills will benefit most from training. It may be, indeed, that they are poor performers precisely because they have had little practice at these tasks — a question that has been much debated (particularly in the context of gender differences).

It’s worth noting that there was little difference in performance on tests carried out immediately after training ended, within a week, or within a month, indicating promising stability.

A comparison of different types of training did find that some skills were more resistant to training than others, but all types of spatial skill improved. The differences may be because some sorts of skill are harder to teach, and/or because some skills are already more practiced than others.

Given the demonstrated difficulty in increasing working memory capacity through training, it is intriguing to notice one example the researchers cite: experienced video game players have been shown to perform markedly better on some tasks that rely on spatial working memory, such as a task requiring you to estimate the number of dots shown in a brief presentation. Most of us can instantly recognize (‘subitize’) up to five dots without needing to count them, but video game players can typically subitize some 7 or 8. The extent to which this generalizes to a capacity to hold more elements in working memory is one that needs to be explored. Video game players also apparently have a smaller attentional blink, meaning that they can take in more information.

A more specific practical example of training they give is that of a study in which high school physics students were given training in using two- and three-dimensional representations over two class periods. This training significantly improved students’ ability to read a topographical map.

The researchers suggest that the size of training effect could produce a doubling of the number of people with spatial abilities equal to or greater than that of engineers, and that such training might lower the dropout rate among those majoring in STEM subjects.

Apart from that, I would argue many of us who are ‘spatially-challenged’ could benefit from a little training!

Grasp of fractions and long division predicts later math success

One possible approach to improving mathematics achievement comes from a recent study finding that fifth graders' understanding of fractions and division predicted high school students' knowledge of algebra and overall math achievement, even after statistically controlling for parents' education and income and for the children's own age, gender, I.Q., reading comprehension, working memory, and knowledge of whole number addition, subtraction and multiplication.

The study compared two nationally representative data sets, one from the U.S. and one from the United Kingdom. The U.S. set included 599 children who were tested in 1997 as 10-12 year-olds and again in 2002 as 15-17-year-olds. The set from the U.K. included 3,677 children who were tested in 1980 as 10-year-olds and in 1986 as 16-year-olds.

You can watch a short video of Siegler discussing the study and its implications at http://youtu.be/7YSj0mmjwBM.

Spatial skills improve children’s number sense

More support for the idea that honing spatial skills leads to better mathematical ability comes from a new children’s study.

The study found that first- and second-graders with the strongest spatial skills at the beginning of the school year showed the most improvement in their number line sense over the course of the year. Similarly, in a second experiment, not only were those children with better spatial skills at 5 ½ better on a number-line test at age 6, but this number line knowledge predicted performance on a math estimation task at age 8.

Hasty answers may make boys better at math

A study following 311 children from first to sixth grade has revealed gender differences in their approach to math problems. The study used single-digit addition problems, and focused on the strategy of directly retrieving the answer from long-term memory.

Accurate retrieval in first grade was associated with working memory capacity and intelligence, and predicted a preference for direct retrieval in second grade. However, at later grades the relation reversed, such that preference in one grade predicted accuracy and speed in the next grade.

Unlike girls, boys consistently preferred to use direct retrieval, favoring speed over accuracy. In the first and second grades, this was seen in boys giving more answers in total, and more wrong answers. Girls, on the other hand, were right more often, but responded less often and more slowly. By sixth grade, however, the boys’ practice was paying off, and they were both answering more problems and getting more correct.

In other words, while ability was a factor in early skilled retrieval, the feedback loop of practice and skill leads to practice eventually being more important than ability — and the relative degrees of practice may underlie some of the gender differences in math performance.

The findings also add weight to the view being increasingly expressed, that mistakes are valuable and educational approaches that try to avoid mistakes (e.g., errorless learning) should be dropped.

Infants can’t compare big and small groups

Our brains process large and small numbers of objects using two different mechanisms, seen in the ability to estimate numbers of items at a glance and the ability to visually track small sets of objects. A new study indicates that at age one, infants can’t yet integrate those two processes. Accordingly, while they can choose the larger of two sets of items when both sets are larger or smaller than four, they can’t distinguish between a large (above four) and small (below four) set.

In the study, infants consistently chose two food items over one and eight items over four, but chose randomly when asked to compare two versus four and two versus eight.

The researchers suggest that educational programs that claim to give children an advantage by teaching them arithmetic at an early age are unlikely to be effective for this reason.

I talked recently about how the well-established difference in spatial ability between men and women apparently has a lot to do with confidence. I also mentioned in passing that previous research has shown that training can close the gender gap. A recent study suggests that this training may not have to be specific to spatial skills.

In the German study, 120 students were given a processing speed test and a standard mental rotation test. The students were evenly divided into three groups: musicians, athletes, and education students who didn’t participate in either sports or music.

While the expected gender gap was found among the education students, the gap was smaller among the sports students, and non-existent in the music students.

Among the education students, men got twice as many rotation problems correct as women. Among the sports students, both men and women did better than their peers in education, but since they were both about equally advantaged, a gender gap was still maintained. However, among the musicians, it was only women who benefited, bringing them up to the level of the men.

Thus, for males, athletes did best on mental rotation; for females, musicians did best.

Although it may be that those who went into music or sports had relevant “natural abilities”, the amount of training in sports/music did have a significant effect. Indeed, analysis found that the advantage of sports and music students disappeared when hours of practice and years of practicing were included.

Interestingly, too, there was an effect of processing speed. Although overall the three groups didn’t differ in processing speed, male musicians had a lower processing speed than female musicians, or male athletes (neither of which groups were significantly different from each other).

It is intriguing that music training should only benefit females’ spatial abilities. However, I’m reminded that in research showing how a few hours of video game training can help females close the gender gap, females benefited from the training far more than men. The obvious conclusion is that the males already had sufficient experience, and a few more hours were neither here nor there. Perhaps the question should rather be: why does sports practice benefit males’ spatial skills? A question that seems to point to the benefits for processing speed, but then we have to ask why sports didn’t have the same effect on women. One possible answer here is that the women had engaged in sports for a significantly shorter time (an average of 10.6 years vs 17.55), meaning that the males tended to begin their sports training at a much younger age. There was no such difference among the musicians.

(For more on spatial memory, see the aggregated news reports)

Pietsch, S., & Jansen, P. (2012). Different mental rotation performance in students of music, sport and education. Learning and Individual Differences, 22(1), 159-163. Elsevier Inc. doi:10.1016/j.lindif.2011.11.012

One of the few established cognitive differences between men and women lies in spatial ability. But in recent years, this ‘fact’ has been shaken by evidence that training can close the gap between the genders. In this new study, 545 students were given a standard 3D mental rotation task, while at the same time manipulating their confidence levels.

In the first experiment, 70 students were asked to rate their confidence in each answer. They could also choose not to answer. Confidence level was significantly correlated with performance both between and within genders.

On the face of it, these findings could be explained, of course, by the ability of people to be reliable predictors of their own performance. However, the researchers claim that regression analysis shows clearly that when the effect of confidence was taken into account, gender differences were eliminated. Moreover, gender significantly predicted confidence.

But of course this is still just indicative.

In the next experiment, however, the researchers tried to reduce the effect of confidence. One group of 87 students followed the same procedure as in the first experiment (“omission” group), except they were not asked to give confidence ratings. Another group of 87 students was not permitted to miss out any questions (“commission” group). The idea here was that confidence underlay the choice of whether or not to answer a question, so while the first group should perform similarly to those in the first experiment, the second group should be less affected by their confidence level.

This is indeed what was found: men significantly outperformed women in the first condition, but didn’t in the second condition. In other words, it appears that the mere possibility of not answering makes confidence an important factor.

In the third experiment, 148 students replicated the commission condition of the second experiment with the additional benefit of being allowed unlimited time. Half of the students were required to give confidence ratings.

The advantage of unlimited time improved performance overall. More importantly, the results confirmed those produced earlier: confidence ratings produced significant gender differences; there were no gender differences in the absence of such ratings.

In the final experiment, 153 students were required to complete an intentionally difficult line judgment task, which men and women both carried out at near chance levels. They were then randomly informed that their performance had been either above average (‘high confidence’) or below average (‘low confidence’). Having manipulated their confidence, the students were then given the standard mental rotation task (omission version).

As expected (remember this is the omission procedure, where subjects could miss out answers), significant gender differences were found. But there was also a significant difference between the high and low confidence groups. That is, telling people they had performed well (or badly) on the first task affected how well they did on the second. Importantly, women in the high confidence group performed as well as men in the low confidence group.

The evidence that adult brains could grow new neurons was a game-changer, and has spawned all manner of products to try and stimulate such neurogenesis, to help fight back against age-related cognitive decline and even dementia. An important study in the evidence for the role of experience and training in growing new neurons was Maguire’s celebrated study of London taxi drivers, back in 2000.

The small study, involving 16 male, right-handed taxi drivers with an average experience of 14.3 years (range 1.5 to 42 years), found that the taxi drivers had significantly more grey matter (neurons) in the posterior hippocampus than matched controls, while the controls showed relatively more grey matter in the anterior hippocampus. Overall, these balanced out, so that the volume of the hippocampus as a whole wasn’t different for the two groups. The volume in the right posterior hippocampus correlated with the amount of experience the driver had (the correlation remained after age was accounted for).

The posterior hippocampus is preferentially involved in spatial navigation. The fact that only the right posterior hippocampus showed an experience-linked increase suggests that the right and left posterior hippocampi are involved in spatial navigation in different ways. The decrease in anterior volume suggests that the need to store increasingly detailed spatial maps brings about a reorganization of the hippocampus.

But (although the experience-related correlation is certainly indicative) it could be that those who manage to become licensed taxi drivers in London are those who have some innate advantage, evidenced in a more developed posterior hippocampus. Only around half of those who go through the strenuous training program succeed in qualifying — London taxi drivers are unique in the world for being required to pass through a lengthy training period and pass stringent exams, demonstrating their knowledge of London’s 25,000 streets and their idiosyncratic layout, plus 20,000 landmarks.

In this new study, Maguire and her colleague made a more direct test of this question. 79 trainee taxi drivers and 31 controls took cognitive tests and had their brains scanned at two time points: at the beginning of training, and 3-4 years later. Of the 79 would-be taxi drivers, only 39 qualified, giving the researchers three groups to compare.

There were no differences in cognitive performance or brain scans between the three groups at time 1 (before training). At time 2 however, when the trainees had either passed the test or failed to acquire the Knowledge, those trainees that qualified had significantly more gray matter in the posterior hippocampus than they had had previously. There was no change in those who failed to qualify or in the controls.

Unsurprisingly, both qualified and non-qualified trainees were significantly better at judging the spatial relations between London landmarks than the control group. However, qualified trainees – but not the trainees who failed to qualify – were worse than the other groups at recalling a complex visual figure after 30 minutes (see here for an example of such a figure). Such a finding replicates previous findings of London taxi drivers. In other words, their improvement in spatial memory as it pertains to London seems to have come at a cost.

Interestingly, there was no detectable difference in the structure of the anterior hippocampus, suggesting that these changes develop later, in response to changes in the posterior hippocampus. However, the poorer performance on the complex figure test may be an early sign of changes in the anterior hippocampus that are not yet measurable in a MRI.

The ‘Knowledge’, as it is known, provides a lovely real-world example of expertise. Unlike most other examples of expertise development (e.g. music, chess), it is largely unaffected by childhood experience (there may be some London taxi drivers who began deliberately working on their knowledge of London streets in childhood, but it is surely not common!); it is developed through a training program over a limited time period common to all participants; and its participants are of average IQ and education (average school-leaving age was around 16.7 years for all groups; average verbal IQ was around or just below 100).

So what underlies this development of the posterior hippocampus? If the qualified and non-qualified trainees were comparable in education and IQ, what determined whether a trainee would ‘build up’ his hippocampus and pass the exams? The obvious answer is hard work / dedication, and this is borne out by the fact that, although the two groups were similar in the length of their training period, those who qualified spent significantly more time training every week (an average of 34.5 hours a week vs 16.7 hours). Those who qualified also attended far more tests (an average of 15.6 vs 2.6).

While neurogenesis is probably involved in this growth within the posterior hippocampus, it is also possible that growth reflects increases in the number of connections, or in the number of glia. Most probably (I think), all are involved.

There are two important points to take away from this study. One is its clear demonstration that training can produce measurable changes in a brain region. The other is the indication that this development may come at the expense of other regions (and functions).

I always like studies about embodied cognition — that is, about how what we do physically affects how we think. Here are a couple of new ones.

The first study involved two experiments. In the first, 86 American college students were asked questions about gears in relation to each other. For example, “If five gears are arranged in a line, and you move the first gear clockwise, what will the final gear do?” The participants were videotaped as they talked their way through the problem. But here’s the interesting thing: half the students wore Velcro gloves attached to a board, preventing them from moving their hands. The control half were similarly prevented from moving their feet — giving them the same experience of restriction without the limitation on hand movement.

Those who gestured commonly used perceptual-motor strategies (simulation of gear movements) in solving the puzzles. Those who were prevented from gesturing, as well as those who chose not to gesture, used abstract, mathematical strategies much more often.

The second experiment confirmed the results with 111 British adults.

The findings are consistent with the hypothesis that gestures highlight and structure perceptual-motor information, and thereby make such information more likely to be used in problem solving.

That can be helpful, but not always. Even when we are solving problems that have to do with motion and space, more abstract strategies may sometimes be more efficient, and thus an inability to use the body may force us to come up with better strategies.

The other study is quite different. In this study, college students searched for a single letter embedded within images of fractals and other complex geometrical patterns. Some did this while holding their hands close to the images; others kept their hands in their laps, far from the images. This may sound a little wacky, but previous research has shown that perception and attention are affected by how close our hands are to an object. Items near our hands tend to take priority.

In the first experiment, eight randomly chosen images were periodically repeated 16 times, while the other 128 images were only shown once. The target letter was a gray “T” or “L”; the images were colorful.

As expected, finding the target letter was faster the more times the image had been presented. Hand position didn’t affect learning.

In the second experiment, a new set of students were shown the same shown-once images, while 16 versions of the eight repeated images were created. These versions varied in their color components. In this circumstance, learning was slower when hands were held near the images. That is, people found it harder to recognize the commonalities among identical but differently colored patterns, suggesting they were too focused on the details to see the similarities.

These findings suggest that processing near the hands is biased toward item-specific detail. This is in keeping with earlier suggestions that the improvements in perception and attention near the hands are item-specific. It may indeed be that this increased perceptual focus is at the cost of higher-order function such as memory and learning. This would be consistent with the idea that there are two largely independent visual streams, one of which is mainly concerned with visuospatial operations, and the other of which is primarily for more cognitive operations (such as object identification).

All this may seem somewhat abstruse, but it is worryingly relevant in these days of hand-held technological devices.

The point of both these studies is not that one strategy (whether of hand movements or hand position) is wrong. What you need to take away is the realization that hand movements and hand position can affect the way you approach problems, and the things you perceive. Sometimes you want to take a more physical approach to a problem, or pick out the fine details of a scene or object — in these cases, moving your hands, or holding something in or near your hands, is a good idea. Other times you might want to take a more abstract/generalized approach — in these cases, you might want to step back and keep your body out of it.

Here’s an intriguing approach to the long-standing debate about gender differences in spatial thinking. The study involved 1,279 adults from two cultural groups in India. One of these groups was patrilineal, the other matrilineal. The volunteers were given a wooden puzzle to assemble as quickly as they could.

Within the patrilineal group, men were on average 36% faster than women. Within the matrilineal group, however, there was no difference between the genders.

I have previously reported on studies showing how small amounts of spatial training can close the gap in spatial abilities between the genders. It has been argued that in our culture, males are directed toward spatial activities (construction such as Lego; later, video games) more than females are.

In this case, the puzzle was very simple. However, general education was clearly one factor mediating this gender difference. In the patrilineal group, males had an average 3.67 more years of education, while in the matrilineal group, men and women had the same amount of education. When education was included in the statistical analysis, a good part of the difference between the groups was accounted for — but not all.

While we can only speculate about the remaining cause, it is interesting to note that, among the patrilineal group, the gender gap was decidedly smaller among those who lived in households not wholly owned by males (in the matrilineal group, men are not allowed to own property, so this comparison cannot be made).

It is also interesting to note that the men in the matrilineal group were faster than the men in the patrilineal group. This is not a function of education differences, because education in the matrilineal group was slightly less than that of males in the patrilineal group.

None of the participants had experience with puzzle solving, and both groups had similar backgrounds, being closely genetically related and living in villages geographically close. Participants came from eight villages: four patrilineal and four matrilineal.

[2519] Hoffman M, Gneezy U, List JA. Nurture affects gender differences in spatial abilities. Proceedings of the National Academy of Sciences [Internet]. 2011 ;108(36):14786 - 14788. Available from: http://www.pnas.org/content/108/36/14786.abstract

Following a study showing that playing Tetris after traumatic events could reduce memory flashbacks in healthy volunteers, two experiments have found playing Tetris after viewing traumatic images significantly reduced flashbacks while playing Pub Quiz Machine 2008 (a word-based quiz game) increased the frequency of flashbacks. In the experiments, volunteers were shown a film that included traumatic images of injury.

In the first experiment, after waiting for 30 minutes, 20 volunteers played Tetris for 10 minutes, 20 played Pub Quiz for 10 minutes and 20 did nothing. In the second experiment, this wait was extended to four hours, with 25 volunteers in each group.

In both experiments, those who played Tetris had significantly fewer flashbacks that the other two groups, and all groups were equally able to recall specific details of the film. Flashbacks were monitored for a week.

It is thought that with traumatic information, perceptual information is emphasized over conceptual information, meaning we are less likely to remember the experience of being in a high-speed road traffic collision as a coherent story, and more likely to remember it by the flash of headlights and noise of a crash. This perceptual information then pops up repeatedly in the victim's mind in the form of flashbacks to the trauma causing great emotional distress, as little conceptual meaning has been attached to them. If you experience other events that involve similar information, during the time window in which the traumatic memories are being processed, that information will interfere with that processing.

Thus, the spatial tasks of Tetris (which involves moving and rotating shapes) are thought to compete with the images of trauma, while answering general knowledge questions in the Pub Quiz game competes with remembering the contextual meaning of the trauma, so the visual memories are reinforced and the flashbacks are increased.

Because male superiority in mental rotation appears to be evident at a very young age, it has been suggested that testosterone may be a factor. To assess whether females exposed to higher levels of prenatal testosterone perform better on mental rotation tasks than females with lower levels of testosterone, researchers compared mental rotation task scores between twins from same-sex and opposite-sex pairs.

It was found that females with a male co-twin scored higher than did females with a female co-twin (there was no difference in scores between males from opposite-sex and same-sex pairs). Of course, this doesn’t prove that that the differences are produced in the womb; it may be that girls with a male twin engage in more male-typical activities. However, the association remained after allowing for computer game playing experience.

The study involved 804 twins, average age 22, of whom 351 females were from same-sex pairs and 120 from opposite-sex pairs. There was no significant difference between females from identical same-sex pairs compared to fraternal same-sex pairs.

* Please do note that ‘innate male superiority’ does NOT mean that all men are inevitably better than all women at this very specific task! My words simply reflect the evidence that the tendency of males to be better at mental rotation is found in infants as young as 3 months.

Following a monkey study that found training in spatial memory could raise females to the level of males, and human studies suggesting the video games might help reduce gender differences in spatial processing (see below for these), a new study shows that training in spatial skills can eliminate the gender difference in young children. Spatial ability, along with verbal skills, is one of the two most-cited cognitive differences between the sexes, for the reason that these two appear to be the most robust.

This latest study involved 116 first graders, half of whom were put in a training program that focused on expanding working memory, perceiving spatial information as a whole rather than concentrating on details, and thinking about spatial geometric pictures from different points of view. The other children took part in a substitute training program, as a control group. Initial gender differences in spatial ability disappeared for those who had been in the spatial training group after only eight weekly sessions.

Previously:

A study of 90 adult rhesus monkeys found young-adult males had better spatial memory than females, but peaked early. By old age, male and female monkeys had about the same performance. This finding is consistent with reports suggesting that men show greater age-related cognitive decline relative to women. A second study of 22 rhesus monkeys showed that in young adulthood, simple spatial-memory training did not help males but dramatically helped females, raising their performance to the level of young-adult males and wiping out the gender gap.

Another study showing that expert video gamers have improved mental rotation skills, visual and spatial memory, and multitasking skills has led researchers to conclude that training with video games may serve to reduce gender differences in visual and spatial processing, and some of the cognitive declines that come with aging.

Rodent studies have demonstrated the existence of specialized neurons involved in spatial memory. These ‘grid cells’ represent where an animal is located within its environment, firing in patterns that show up as geometrically regular, triangular grids when plotted on a map of a navigated surface. Now for the first time, evidence for these cells has been found in humans. Moreover, those with the clearest signs of grid cells performed best in a virtual reality spatial memory task, suggesting that the grid cells help us to remember the locations of objects. These cells, located particularly in the entorhinal cortex, are also critical for autobiographical memory, and are amongst the first to be affected by Alzheimer's disease, perhaps explaining why getting lost is one of the most common early symptoms.

[378] Doeller CF, Barry C, Burgess N. Evidence for grid cells in a human memory network. Nature [Internet]. 2010 ;463(7281):657 - 661. Available from: http://dx.doi.org/10.1038/nature08704

A rat study reveals that, for rats at least, an understanding of place and a sense of direction appears within two weeks of being born, seemingly independently of any experience of the world. The directional signal, which allows the animal to know which way it is facing, is already at adult levels as soon as it can be measured in newborn rats. Sense of place is also present early, but improves with age. Representations of distance appear a few days later. These processes depend on specialized cells in the hippocampus, which in humans plays a crucial role in long-term memory for events as well as spatial navigation. The findings fit in with the theory that a pre-wired spatial framework may provide a conceptual framework for experience.

Because Nicaraguan Sign Language is only about 35 years old, and still evolving rapidly, the language used by the younger generation is more complex than that used by the older generation. This enables researchers to compare the effects of language ability on other abilities. A recent study found that younger signers (in their 20s) performed better than older signers (in their 30s) on two spatial cognition tasks that involved finding a hidden object. The findings provide more support for the theory that language shapes how we think and perceive.

[1629] Pyers JE, Shusterman A, Senghas A, Spelke ES, Emmorey K. Evidence from an emerging sign language reveals that language supports spatial cognition. Proceedings of the National Academy of Sciences [Internet]. 2010 ;107(27):12116 - 12120. Available from: http://www.pnas.org/content/107/27/12116.abstract

Older news items (pre-2010) brought over from the old website

Video games may help visuospatial processing and multitasking

Another study has come out showing that expert video gamers have improved mental rotation skills, visual and spatial memory, and multitasking skills. The researchers conclude that training with video games may serve to reduce gender differences in visual and spatial processing, and some of the cognitive declines that come with aging.

[366] Dye MWG, Green SC, Bavelier D. Increasing Speed of Processing With Action Video Games. Current Directions in Psychological Science [Internet]. 2009 ;18(6):321 - 326. Available from: http://dx.doi.org/10.1111/j.1467-8721.2009.01660.x

http://www.eurekalert.org/pub_releases/2009-12/afps-rsa121709.php

The limited nature of the 'Mozart Effect'

The so-called ‘Mozart effect’ (which is far more limited than commonly reported in the popular press, and which argues that listening to Mozart can temporally improve spatial abilities, such as mental rotation) has been found in some studies but not in others. Now a study of 50 musicians and 50 non-musicians may explain the inconsistent results. The study found that only non-musicians had their spatial processing skills improved by listening to Mozart — partly because the musicians were better at the mental rotation task to start with. The effect may have to do with non-musicians processing music and spatial information in the right hemisphere, while musicians tend to use both hemispheres. The effect may also be restricted to right-handed non-musicians — all the participants were right-handed, and left-handed people are more likely to process information in both hemispheres. And finally, the effect may be further restricted to some types of spatial task — the present study used the same task as originally used. So, what we can say is that right-handed non-musicians may temporarily improve their mental rotation skills by listening to Mozart.

[301] Aheadi A, Dixon P, Glover S. A limiting feature of the Mozart effect: listening enhances mental rotation abilities in non-musicians but not musicians. Psychology of Music [Internet]. 2010 ;38(1):107 - 117. Available from: http://pom.sagepub.com/cgi/content/abstract/38/1/107

http://www.miller-mccune.com/news/mozart-effect-real-for-some-1394

Meditation technique can temporarily improve visuospatial abilities

And continuing on the subject of visual short-term memory, a study involving experienced practitioners of two styles of meditation: Deity Yoga (DY) and Open Presence (OP) has found that, although meditators performed similarly to nonmeditators on two types of visuospatial tasks (mental rotation and visual memory), when they did the tasks immediately after meditating for 20 minutes (while the nonmeditators rested or did something else), practitioners of the DY style of meditation showed a dramatic improvement compared to OP practitioners and controls. In other words, although the claim that regular meditation practice can increase your short-term memory capacity was not confirmed, it does appear that some forms of meditation can temporarily (and dramatically) improve it. Since the form of meditation that had this effect was one that emphasizes visual imagery, it does support the idea that you can improve your imagery and visual memory skills (even if you do need to ‘warm up’ before the improvement is evident).

[860] Kozhevnikov M, Louchakova O, Josipovic Z, Motes MA. The enhancement of visuospatial processing efficiency through Buddhist Deity meditation. Psychological Science: A Journal of the American Psychological Society / APS [Internet]. 2009 ;20(5):645 - 653. Available from: http://www.ncbi.nlm.nih.gov/pubmed/19476594

http://www.sciencedaily.com/releases/2009/04/090427131315.htm
http://www.eurekalert.org/pub_releases/2009-04/afps-ssb042709.php

Why it’s so hard to disrupt your routine

New research has added to our understanding of why we find it so hard to break a routine or overcome bad habits. The problem lies in the competition between the striatum and the hippocampus. The striatum is involved with habits and routines, for example, it records cues or landmarks that lead to a familiar destination. It’s the striatum that enables you to drive familiar routes without much conscious awareness. If you’re travelling an unfamiliar route however, you need the hippocampus, which is much ‘smarter’.  The mouse study found that when the striatum was disrupted, the mice had trouble navigating using landmarks, but they were actually better at spatial learning. When the hippocampus was disrupted, the converse was true. This may help us understand, and treat, certain mental illnesses in which patients have destructive, habit-like patterns of behavior or thought. Obsessive-compulsive disorder, Tourette syndrome, and drug addiction all involve abnormal function of the striatum. Cognitive-behavioral therapy may be thought of as trying to learn to use one of these systems to overcome and, ultimately, to re-train the other.

[931] Lee AS, Duman RS, Pittenger C. A double dissociation revealing bidirectional competition between striatum and hippocampus during learning. Proceedings of the National Academy of Sciences [Internet]. 2008 ;105(44):17163 - 17168. Available from: http://www.pnas.org/content/early/2008/10/24/0807749105.short

http://www.eurekalert.org/pub_releases/2008-10/yu-ce102008.php

More light shed on how episodic memories are formed

A rat study has revealed more about the workings of the hippocampus. Previous studies have identified “place cells” in the hippocampus – neurons which become more active in response to a particular spatial location. Activity in the hippocampus while rats searched for food in a maze where the starting and ending point was varied, has found that, while some cells signaled location alone, others were also sensitive to recent or impending events – i.e., activation depended upon where the rat had just been or where it intended to go. This finding helps us understand how episodic memories are formed – how, for example, a spatial location can trigger a reminder of an intended action at a particular time, but not others.

[1136] Ferbinteanu J, Shapiro ML. Prospective and retrospective memory coding in the hippocampus. Neuron [Internet]. 2003 ;40(6):1227 - 1239. Available from: http://www.ncbi.nlm.nih.gov/pubmed/14687555

http://www.eurekalert.org/pub_releases/2003-12/msh-ta121503.php

More learned about how spatial navigation works in humans

Researchers monitored signals from individual brain cells as patients played a computer game in which they drove around a virtual town in a taxi, searching for passengers who appeared in random locations and delivering them to their destinations. Previous research has found specific cells in the brains of rodents that respond to “place”, but until now we haven’t known whether humans have such specific cells. This study identifies place cells (primarily found in the hippocampus), as well as “view” cells (responsive to landmarks; found mainly in the parahippocampal region) and “goal” cells (responsive to goals, found throughout the frontal and temporal lobes). Some cells respond to combinations of place, view and goal — for example, cells that responded to viewing an object only when that object was a goal.

[1019] Ekstrom AD, Kahana MJ, Caplan JB, Fields TA, Isham EA, Newman EL, Fried I. Cellular networks underlying human spatial navigation. Nature [Internet]. 2003 ;425(6954):184 - 188. Available from: http://dx.doi.org/10.1038/nature01964

http://www.eurekalert.org/pub_releases/2003-09/uoc--vgu091003.php