Saving information to computer frees your mind to learn new material

Forgetting information that we save to
computer could have its advantages

A few years ago, researchers demonstrated that people had poorer memory for information that they were told had been saved to a computer. Technophobes jumped on the finding. "Imagine that in the future people become so used to external access for any form of reference that they have not internalized any facts at all," wrote Susan Greenfield.

Of course there are many flaws to this logic, not least that the old fashioned act of writing information down can also lead to increased forgetting. A new study has focused on another important point: forgetting information that we know is externally available could be advantageous - allowing us to free up cognitive resources to better learn new information.

Benjamin Storm and Sean Stone tested this possibility across three studies involving dozens of undergrads. The format was similar throughout. The students started by studying a list of ten words in one computer file, which they would be tested on later. Then they moved onto a second file with a new list of words to study. There was a 20-second delay then they were tested on this second list.

The critical finding is that the students performed better at remembering this second list if they were earlier given the chance to save the first list to computer. It's as if knowing the first list was stored on computer prompted them to deliberately forget it, so that they could focus all their mental resources on the second list.

Further details back up this interpretation. When the computer saving process was made unreliable - files kept getting lost - the saving process no longer boosted the students' performance on the second list. Also, when the first list was made up of just two words, meaning it placed little strain on memory, the act of saving it to computer no longer made a difference to memory for the second list.

Why else might saving information to computer help benefit new learning? Another intriguing suggestion made by the researchers is that the act of saving could provide the basis for an "event boundary" in memory, helping avoid confusion between the first and second lists. They further speculate that saving to computer likely doesn't just aid the learning of further information, but could also free up mental resources that underlie thinking and problem solving.

The researchers conclude with a Sherlock Holmes quote that captures the concept of adaptive forgetting: "... a man should keep his little brain-attic stocked with all the furniture that he is likely to use, and the rest he can put away in the lumber-room of his library, where he can get it if he wants it."

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Storm, B., & Stone, S. (2014). Saving-Enhanced Memory: The Benefits of Saving on the Learning and Remembering of New Information Psychological Science, 26 (2), 182-188 DOI: 10.1177/0956797614559285

Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest. 

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How to improve collaboration in virtual teams? Members' avatar style could be key

When a team rarely gets to be in a room together, it misses out on many of the in-person subtle cues that help members make sense of their relationships. The signals that are available become more important: subtext in email messages, tone of voice on a conference call, or seemingly minor visual features. That’s why researchers have become interested in the humble avatar – the image that’s used to represent each person in a virtual interaction.

Sarah van der Land and her colleagues asked 80 three-student teams to solve a crime mystery. Although clues available to all team members pointed to one culprit, the true answer required collaboration to exchange information that was only available to individual participants. To do this, each virtual team had 40 minutes discussion time, using an online chat system where contributions were labelled with the person’s name and an avatar.

In one condition, all team members shared the same avatar (a cartoon bear icon), whereas in another condition, each team member had their own unique avatar (their photo). In a third, critical condition, each team member’s avatar consisted of what they thought was their own photo morphed with elements of their team-mates’ photos - in other words, each person’s avatar was universal but also personalised.

Teams performed better when their avatars
reflected a mix of each member and
their team-mates. Image: Van der Land et al.

After the task, groups in this morphed condition reported feeling more social attraction towards their team-mates, and this was the reason that these groups performed better, reaching the correct solution 70 per cent of the time, compared to a success rate of, at best, 50 per cent in the other conditions.

Van der Land argues that this is because generic and unique/realistic avatars both have a downside. Individualised pictures do little to create a sense of shared group membership, and although common avatars do, their lack of resemblance to us can underline our distance from a real workspace, making us feel more anonymous, likelier to emotionally disengage, and readier to shirk duties. The morphed avatar, meanwhile, gives us both group membership and a sense of presence.

We should be aware the study used an exaggerated format to prove its point. Participants believed each person’s morphed avatar reflected a mix of that person’s face with the faces of the other two team members. In truth, each team member saw the same avatar against their own name and that of their colleagues: one made up of 60 per cent their own face and 40 per cent the face of a student who didn’t actually take part in the study.

Simply put, this set-up gave participants the impression their team-mates were uncannily similar to them (to an extent that would call for an identical twin in the team), which likely played up the levels of social attraction. I would be interested to see the effect of accurate avatar blends in real teams, as well as other ways of exploring this mixed avatar approach, such as whether pairing personalised faces with standardised uniforms also generates these effects.

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van der Land, S., Schouten, A., Feldberg, F., Huysman, M., & van den Hooff, B. (2015). Does Avatar Appearance Matter? How Team Visual Similarity and Member-Avatar Similarity Influence Virtual Team Performance Human Communication Research, 41 (1), 128-153 DOI: 10.1111/hcre.12044

Post written by Alex Fradera (@alexfradera) for the BPS Research Digest.

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The trouble with tDCS? Electrical brain stimulation may not work after all

By guest blogger Neuroskeptic

A widely-used brain stimulation technique may be less effective than previously believed.

Transcranial Direct Current Stimulation (tDCS) is an increasingly popular neuroscience tool. tDCS involves attaching electrodes to the scalp, through which a weak electrical current flows. The idea is that this current modulates the activity of the brain tissue underneath the electrode - safely and painlessly.

Outside of the neuroscience lab, tDCS is also used by hobbyists looking to boost their own brain power and a number of consumer stimulation devices are now being sold. The technique regularly makes the news, under headlines such as “Zapping your brain could help you lose weight”.

However, according to Australian neuroscientists Jared Horvath, Jason Forte and Olivia Carter, a single session of tDCS may have no detectable effect on cognitive function in most people. In a new paper published in the journal Brain Stimulation, Horvath and colleagues reviewed the published evidence on tDCS. They performed a meta-analysis of the data on how tDCS influences cognitive functions such as memory, language, and mental arithmetic.

For example, in experiments investigating language function, neuroscientists generally place the active tDCS electrode over the left frontal lobe of the volunteers. This ensures that the electrode is near to Broca’s area, a part of the brain known to be involved in language production. Then, the current is switched on and the volunteer is asked to do a linguistic task such as verbal fluency, in which the goal is to think of as many words beginning with a certain letter (say “p”) as possible within one minute. The performance of the volunteers given tDCS is compared to the performance of people given “sham” tDCS, in which the electrodes are attached but no current is applied.

Horvath et al. found that overall, there was no statistically significant difference between active and sham tDCS on any of the cognitive tasks that they examined. They say that:

Of the 59 analyses undertaken, tDCS was not found to generate a significant effect on any. Taken together, the evidence does not support the assertion that a single-session of tDCS has a reliable effect on cognitive tasks in healthy adult populations.

That seems pretty clear-cut. However, Horvath et al. acknowledge that their analysis did not include any of the studies that have been conducted on individuals with brain diseases or on the elderly, and they note that tDCS might be more effective in such cases.

What’s more, Horvath et al.’s meta-analysis didn’t utilize all of the studies on healthy people. The authors decided to only include results that had at least one published independent replication attempt. In other words, they only included studies that had measured the effects of tDCS on a given cognitive task, if more than one different research group had published papers using that technique. Even if one team of scientists had published several studies all showing that tDCS does influence some aspect of cognition, those results weren’t included unless at least one other team of researchers had published tDCS results using that same task. One hundred and seventy-six articles were excluded as a result.

Horvath et al. explain their decision not to consider those studies by saying that:

We chose to exclude measures that have only been replicated by a single research group to ensure all data included in and conclusions generated by this review accurately reflect the effects of tDCS itself, rather than any unique device, protocol, or condition utilized in a single lab.

However, this is a slightly unusual restriction to use on a meta-analysis. It might be interesting to see whether including these additional studies would have changed the results.

This is the second time Horvath, Forte and Carter have published a sceptical meta-analysis of tDCS. In November last year they reviewed studies on the neurophysiological effects of tDCS and concluded that tDCS has virtually no measurable effects on brain function. So Horvath et al. seem to have comprehensively shown that tDCS essentially has no impact in healthy people, either on a biological or on a cognitive level.

However, I spoke to Dr Nick Davis, Lecturer in Psychology at Swansea University who has published several papers about tDCS. Davis says that:

This is a really useful review, as it helps us to think about the way we talk about the effects of tDCS.

However I believe that the way the analysis was conducted may have obscured some of the very real effects of tDCS. The authors have made a judgement about which studies can be pooled together and which studies cannot be pooled. One always has to make these kinds of decisions and I am not sure I would have made the same decisions given the same choices.

tDCS is still a developing technology. I think that with more principled methods of targeting the current flow to the desired brain area, we will see tDCS become one of the standard tools of cognitive neuroscience, just as EEG and fMRI have become.

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Horvath, J., Forte, J., & Carter, O. (2015). Quantitative Review Finds No Evidence of Cognitive Effects in Healthy Populations from Single-Session Transcranial Direct Current Stimulation (tDCS) Brain Stimulation DOI: 10.1016/j.brs.2015.01.400

Post written for the BPS Research Digest by Neuroskeptic, a British neuroscientist who blogs for Discover Magazine.

--further reading--
It's shocking - How the press are hyping the benefits of electrical brain stimulation
Read this before zapping your brain
Bloggers behind the blogs: Neuroskeptic

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