1. First ever photo of Phineas Gage is discovered
2. Resting brain activity may be involved in motor learning
3. Can we deliberately forget specific parts of what we’ve read?
4. Our changing attitudes to time
5. How tools become part of the body
6. Detecting consciousness in a totally locked-in patient
7. Fear really does have a smell
Email the editor: [email protected]
Download past Digest issues as PDFs: www.researchdigest.org.uk
Visit the Digest blog: www.researchdigest.org.uk/blog
Download a free Digest poster: http://tinyurl.com/59c63v
Visit http://brightbytes.com/phineasgage/index.html to see the photo.
A pair of photograph collectors in Maryland, USA, have uncovered what they believe to be the first and only ever
photographic record of Phineas Gage - the railway worker who survived an iron tamping rod passing straight
through the front of his brain, following an explosives accident in 1848.
The story of Gage and the effects of his injury on his behaviour and personality have become one of the most
famous case studies in the history of psychology, inspiring plays, books and songs.
Jack and Beverly Wilgus have had the photograph - known as a daguerreotype after the Parisian photographic
pioneer Louis Jacques Mandé Daguerre - in their possession for over thirty years, but have only just confirmed its
identity.
The photograph shows Gage as a scarred, handsome, proud man, smartly dressed, with one eye closed, wielding the
tamping iron that made him famous. Jack and Beverly Wilgus originally thought the image was of a whaler, but
after posting the picture on Flick-r, they soon learned from expert whaling commenters that this was not the case (it
was not a harpoon that he was holding), and they followed up on an alternative suggestion that perhaps the image
was of Gage.
By carefully comparing the photograph with a life mask taken of Gage's head when he was alive, and the actual
tamping iron, both of which are at the Warren Anatomical Museum, the Wilgus's confirmed that the photo is
indeed of Gage. For example, an inscription on the real-life tamping iron is visible in the photograph, and scars
visible on Gage's life mask perfectly match up with the scars shown in the photograph.
The new photo is bound to intensify the debate over the effects of Gage's injuries on his personality and behaviour.
"One theory about Gage — that his personality might have changed because his appearance was made grotesque by
the accident (e.g., Kotowicz, 2007) — no longer seems credible to us," the Wilgus's said.
The article is not yet publicly available but is due for imminent publication at the Journal of the History of
Neurosciences. You can see the photo and read more about Gage here.
_________________________________
JACK WILGUS, & BEVERLY WILGUS (2009). Face to Face with Phineas Gage. Journal of the History of the
Neurosciences (In Press). http://www.tandf.co.uk/journals/titles/0964704X.asp
Photo is at: http://brightbytes.com/phineasgage/index.html
Most brain imaging experiments tend to follow a similar pattern - instruct the participant to perform some task, or
show them a picture, or play them a sound, and then see which areas of their brain light up. This approach has
propagated a misconception that the brain has to be prodded into action. But the reality is that the brain constantly
beavers away and guzzles just as much energy when we're resting doing nothing, as when we're engaged in an
externally focused task. In fact, there's a default network that actually ramps up its activity levels during rest
compared with when we're outwardly engaged. Such findings have prompted speculation about what all this resting
brain activity is for. Possibilities include preparing for the future and mind-wandering. A new study, however,
provides evidence that resting brain activity is involved in motor learning.
Neil Albert and colleagues scanned the brains of 24 participants twice: when they were resting before a joystick
task and then again resting afterwards. Crucially, half the participants performed the tracking task with a dodgy
joystick that became progressively disconnected from its cursor. These participants had to adapt continuously to the
changing de-synchronisation between joystick and cursor. The remaining control participants used a normal
joystick. All participants also performed an irrelevant four-minute visual task prior to the final resting brain scan.
This was to rule out any effects on the second resting scan that may have been caused by the participants still
thinking about that dodgy joystick.
The initial scan of the participants at rest revealed a number of resting state networks: suites of inter-connected
brain regions pulsing away in unison. In the brains of the participants who had to adapt to the dodgy joystick, but
not the control participants, the strength of one of these - a fronto-parietal network - was greater in the second
resting scan, as if it was still particularly busy consolidating the earlier motor learning. A second resting network,
incorporating the cauliflower-like cerebellum at the back of the brain, also grew in strength in the brains of the
participants who had to adapt to the dodgy joystick, whereas this network wasn't even present in the control
participants.
These findings suggest that it was specifically learning to control the dodgy joystick, not joystick use per se, that
led to increased activity in two resting state networks. "We have shown that motor learning, but not motor
performance, can modulate particular resting state networks," the researchers said. "Our results add a new
dimension to our understanding of the resting brain and potentially provide a powerful new technique to examine
the neuronal machinery of off-line processing," they concluded.
_________________________________
Albert, N., Robertson, E., & Miall, R. (2009). The Resting Human Brain and Motor Learning. Current Biology, 19
(12), 1023-1027 http://dx.doi.org/10.1016/j.cub.2009.04.028
Author weblink: http://list-albert.com/nba/nba.htm
The majority of research on memory is focused, as you might expect, on the remembering side of things - how much, how
accurate and so on. There is, however, a parallel, but less known, line of investigation into our ability to deliberately forget.
This is no mere academic curiosity. The ability to forget selectively that to which we've been exposed would be, if we had it,
an extremely useful ability - a kind of refuse collection service for the mind.
In one of the first studies of its kind, Peter Delaney and colleagues have now shown that people are indeed capable of reading a
series of sentences and then selectively forgetting just some of those sentences, whilst remembering the rest.
Dozens of undergrad students were first told to memorise an initial list of 16 sentences about the imaginary men, Tom and
Alex. Afterwards, half the students were unexpectedly told to forget the Tom sentences, so as to better remember the Alex
sentences. The remaining students acted as controls and didn't receive this additional instruction. Finally, all the students
attempted to memorise a second list of 14 random sentences about another man, Joe. A 90-second multiplication test acted as a
filler task before the students were tested on their ability to recall as many sentences as possible from the two lists.
The key finding was that the students were able to follow the forget instruction so long as the sentences about Tom and Alex
were of random meaning, with no discernible theme. In this case, students told to forget the Tom sentences subsequently
recalled just 28 per cent of them, in a two-minute free recall test, whereas the control students recalled 39 per cent. Moreover,
there was also a non-significant trend for the students who deliberately forgot the Tom sentences to remember more Alex
sentences (37 per cent) relative to the controls (32 per cent) - showing that their deliberate forgetting really had been selective
for the Tom sentences. Memories of the second test list (sentences about Joe) were unaffected by the forget instruction.
Another version of the experiment had the Tom and Alex sentences gradually forming discernible themes - Alex as a writer
who liked snow sports and Tom as a lawyer and family man, or vice versa. Curiously, in this version, the students were not
able to deliberately and selectively forget the Tom sentences. The researchers aren't sure why, but one possibility is that
remembering just one sentence in a theme involuntarily cues all the other sentences, thus hampering attempts to forget.
So how do we deliberately forget a portion of previously-seen material? One possibility is that the forget instruction prompts
people to cease mental rehearsal of to-be-forgotten items, in favour of extra rehearsal of the to-be-remembered items. Another
possibility is that items are selectively inhibited at the retrieval stage. "Future studies should use recognition tests to determine
whether forgotten items are available in memory but blocked from access, or if they are less well learned," the researchers said.
_________________________________
Delaney, P., Nghiem, K., & Waldum, E. (2009). The selective directed forgetting effect: Can people forget only part of a text?
The Quarterly Journal of Experimental Psychology, 62 (8), 1542-1550 http://dx.doi.org/10.1080/17470210902770049
Author weblink: http://www.uncg.edu/~p_delane/
Like a sand-castle crumbling away in the rising tide, the once-popular idea that there are innate gender differences in science
and maths aptitude is being undermined by a succession of new research findings.
Earlier this year, for example, Stephen Ceci and colleagues sifted through more than 400 relevant journal articles and
concluded that far from there being any evidence for a sex-linked difference in science aptitude, the principal factor affecting
the relative absence of women in science is their life choices, especially in relation to having children.
Now a new study, by Brian Nosek and colleagues, has looked at the number of people in different countries who hold implicit
gender-science stereotypes, and compared this with gender differences in international school science test scores. The
researchers' finding is that the two are mutually reinforcing - a culture's implicit belief that females are not associated with
science can actually harm girls' and women’s' science performance, they argue.
To recap, if something about being female really does predispose a person to be weaker at science, then across the world, girls
should under-perform, on average, relative to boys. However, whilst this is true in some countries, other countries actually
show the opposite pattern, with girls outperforming boys.
Inspired by such observations, Nosek's team wondered whether cultural beliefs about gender and science might negatively
affect girls' science performance. They used a version of the implicit association test, hosted on a website, to record implicit
beliefs about gender and science among more than half a million people from 34 countries. By allocating categories (e.g.
"male-related words" and "science-related words") to either the same or different response keys, the test shows how easily
people associate those categories in their mind. Around the world, 70 per cent of participants exhibited an implicit stereotype associating science with males more than females.
The researchers then looked at international science test scores recorded in 1999 and 2003 for children aged about 12 years.
They found a correlation with the implicit stereotype scores, so that in those countries where more people held stereotyped
beliefs about gender and science, girls tended to under-perform at science relative to boys.
Taken in the context of previous research showing that awareness of gender stereotypes can harm people's performance (e.g.
girls perform worse at maths after being reminded of the stereotype that females are inferior at maths), the researchers said
their correlational findings support the idea that a culture's implicit beliefs about science stereotypes can affect girls' science
performance in a mutually reinforcing fashion.
"National policy initiatives addressing both factors simultaneously stand the best chance to maximise national scientific
achievement," they said. "Education campaigns attempting to bolster women's participation and performance must overcome
the pervasive implicit stereotypes that are already embodied in individual minds."
_________________________________
Nosek, B., Smyth, F., Sriram, N., Lindner, N., Devos, T., Ayala, A., Bar-Anan, Y., Bergh, R., Cai, H., Gonsalkorale, K.,
Kesebir, S., Maliszewski, N., Neto, F., Olli, E., Park, J., Schnabel, K., Shiomura, K., Tulbure, B., Wiers, R., Somogyi, M.,
Akrami, N., Ekehammar, B., Vianello, M., Banaji, M., & Greenwald, A. (2009). National differences in gender-science
stereotypes predict national sex differences in science and math achievement. Proceedings of the National Academy of
Sciences, 106 (26), 10593-10597 http://dx.doi.org/10.1073/pnas.0809921106
Author weblink: http://projectimplicit.net/nosek/
When admiring a brilliant sportsman or woman, commentators often describe a wielded tennis racquet, cricket bat
or other sporting appendage, as having become like an extension of the athlete's own body, so fluid and deft is their
control of the lump of metal or wood. It's a metaphor we should be able to relate to, since all of us, champion
athlete or not, absorb tools into our inner representation of our own bodies - what cognitive psychologists call our
"body schema".
That's according to Lucilla Cardinali and colleagues who demonstrated this graphically in a new study in which
participants reached with their hand for a small block, both before and after using a 40-cm long grasping device
(similar to those used for picking up rubbish) to reach for the same block.
After several minutes using the grasping tool, the participants subsequent reaching movements with their hand were
slower to start and stop, making them longer-lasting overall, compared with before the tool use - as if their own arm
was now perceived as longer. Moreover, when the participants were subsequently blindfolded and asked to point to
where they'd just been touched by the researchers, on the tip of the middle finger and on the elbow, the places the
participants pointed to were further apart, compared with before tool use, again suggesting that they now perceived
their arm to be longer.
These effects lasted for at least 15 minutes after tool use, but the researchers haven't yet tested the duration of the
effects systematically.
Psychologists have known for some time that our representation of our bodies must be dynamic. You can't get to
where you want to go without knowing where you are to start with, so before moving the limbs, the brain and
spinal cord need to know the limbs' current location. What's more, the force needed to perform an action
appropriately depends on the length of the muscles, which is also affected by the position of the limbs. There are
also changes to the body brought about by growing, ageing and injury that must be accommodated for accurate
movement control. Given this adaptability it should perhaps come as no surprise that tools can be seamlessly and
rapidly incorporated into the body schema.
Lead author Lucilla Cardinali told the Digest that her lab are currently exploring whether expertise affects the way
tools are incorporated, such as when a tennis player wields a racquet.
_________________________________
Cardinali, L., Frassinetti, F., Brozzoli, C., Urquizar, C., Roy, A., & Farnè, A. (2009). Tool-use induces
morphological updating of the body schema. Current Biology, 19 (12) http://dx.doi.org/10.1016/j.cub.2009.05.009
Author weblink: http://tinyurl.com/kq55wh
Alert to your surroundings but helpless to respond. It's difficult to imagine a worse situation, but this is the
terrifying reality for a minority of brain damaged patients with total locked-in syndrome. Fortunately, researchers
are developing ways to reveal consciousness trapped inside a lifeless body. Such techniques will hopefully prevent
conscious, yet utterly paralysed, patients from being misdiagnosed as comatose.
In this new study, Caroline Schnakers used bed-side electroencephalography (EEG) to detect consciousness in a
21-year-old woman who fell into a coma-like state following a stroke. Twenty-five, 39 and 49 days after her brain
was damaged, the researchers uttered the woman's own name to her, together with a short list of irrelevant names,
all the while recording the surface electrical activity of her brain with EEG. The important twist was that they
sometimes instructed her to pay special attention to her own name, or to one of the unfamiliar names.
During the first two testing sessions, the woman's brain recordings betrayed no signs of awareness. On the third
session, however, when she was instructed to pay special attention to her own name, the woman's EEG signal
showed an exaggerated P300 response to her name, compared with when she was instructed to just listen passively.
The P300 is a spike of activity recorded from the parietal lobe, which is thought to be a marker of consciousness or
decision making. This suggests the woman had heard and heeded the task instruction - a sign that she was
conscious inside her paralysed body. Fourteen days later, she began to show behavioural signs of awareness, for
example by moving her finger in response to instructions.
The researchers said: "In conclusion, this active auditory event-related paradigm (requiring explicit comprehension
of auditory-verbal instructions) provides an interesting tool for detecting voluntary brain activity in patients that
behaviourally would be diagnosed as comatose". More research is now needed to validate this procedure, they
added.
The new case-study comes after research published in 2006 that used functional brain imaging to detect
consciousness in a patient in a persistent vegetative state. The EEG used in the current study has the advantage that
it can be administered bed-side.
_________________________________
Schnakers, C., Perrin, F., Schabus, M., Hustinx, R., Majerus, S., Moonen, G., Boly, M., Vanhaudenhuyse, A.,
Bruno, M., & Laureys, S. (2009). Detecting consciousness in a total locked-in syndrome: An active event-related
paradigm. Neurocase, 15 (4), 271-277 http://dx.doi.org/10.1080/13554790902724904
Author weblink: http://www.coma.ulg.ac.be/home/schnakers.html
People often talk with some drama about the smell of fear, and yet who among us could describe what the
odour is like? This vagueness seems to support the idea that fear as a smell is metaphorical - a way
raconteurs through the ages have conveyed the tendency for fear to spread rapidly and invisibly from one
person to the next. A new study, however, suggests there is, after all, a literal truth to the idea of fear
being communicated through our sense of smell.
Alexander Prehn-Kristensen and colleagues bottled the smell of fear by placing cotton pads under the
arms of students waiting to give an assessed oral presentation. For comparison the researchers also
collected fear-free sweat from the armpits of students performing cycling exercises.
Next the researchers scanned the brains of 28 students while the two sources of odour were delivered to
their noses using an adapted oxygen mask. Half the time, the students couldn't even perceive an odour.
They were also unable to distinguish between the two odour sources, rating them as equally pleasant.
Crucially, however, the participants' brain responses to the two odours did differ significantly.
The smell of sweat taken from students anxiously awaiting an oral exam led to proportionately greater
activation in the participants across a swathe of brain areas known to be involved in empathy, emotion,
representing other people's mental states and distinguishing the self from other. These included the insula,
the precuneus, the cingulate gyrus, the fusiform cortex and the dorsomedial prefrontal cortex.
This finding, of the smell of fear triggering an emotional brain response in the absence of any conscious
awareness, could help explain why we're sometimes moved by a whiff of fear in the air, without
registering any accompanying sensory experience. "It is concluded that the human brain automatically
guides physiological adjustments to chemosensory anxiety signals, without being dependent on conscious
mediation," the researchers said.
_________________________________
Prehn-Kristensen, A., Wiesner, C., Bergmann, T., Wolff, S., Jansen, O., Mehdorn, H., Ferstl, R., & Pause,
B. (2009). Induction of Empathy by the Smell of Anxiety. PLoS ONE, 4 (6)
http://dx.doi.org/10.1371/journal.pone.0005987
Author weblink: http://www.uni-kiel.de/index-e.shtml