Improving Memory through Real-Time Electrophysiological Monitoring: A Glimpse into the Future?

The year is 2115, and you are an undergraduate student hurrying across campus to make it on time to your next class. The class is Elementary Temporal Mechanics, your favorite, so you certainly don’t want to be late.

As you pass through the main quad, you glance at a young woman sitting in the grass and think for a moment she might be someone you know. Quickly, however, you realize her face is unfamiliar. But having already made eye contact, you say hello regardless.

Shortly afterwards, as you proceed on your way up the steps of Zuckerberg Hall, you receive a notification on your new iPhone 107 15GS Plus Jumbo Mini TM. The notification reads, “Female Face Not Fully Encoded into Memory. Probability of Recognition after 24 Hours 32%. Suggest Encoding Further.”

The notification is from Google Lid TM, the inconspicuous knit hat you wear nearly everywhere you go. You’re suddenly reminded of how comfortable the hat is, despite the fact that it contains 256 electrodes for continuous monitoring and recording of your ongoing brain activity.

As you take your seat in the lecture hall, you decide you’ll probably never see the woman again. So you’re not bothered by the fact that you didn’t fully commit her face to memory. With this thought in mind, you casually swipe your phone’s display to dismiss the notification and prepare for another rousing lecture on predestination paradoxes.

Does this futuristic scenario I’ve described sound a little far-fetched? Maybe.

However, researchers at the Vanderbilt Vision Research Center at Vanderbilt University recently made a discovery that could move us a tiny step closer to this imagined reality.

In a paper published earlier this year in the journal Psychological Science, researchers Keisuke Fukuda and Geoffrey Woodman demonstrate how real-time electrophysiological monitoring can help target and strengthen weak memories.

Participants in the experiment first studied pictures of real-world objects while brain activity was recorded via electroencephalography (EEG). Then they received a memory test comprised of studied pictures and new pictures, and tried to identify which pictures they recognized from earlier on. The researchers assessed how well each picture was learned during the initial study phase by taking each participant’s raw EEG data and converting it into Event-Related Potentials (ERP’s). Briefly, an ERP is the average electrical response of the brain to a specific sensory, cognitive, or motor “event.” In other words, it is a characteristic “brain wave” pattern triggered by something you see, hear, think, or do. ERP’s are important because they can serve as useful neural markers for underlying mental processes, such as memory encoding, memory retrieval, and various aspects of attention.

Across two experiments, Fukuda and Woodman confirmed previous findings suggesting that successful encoding of a picture into memory is associated with (at least) two distinct neural signatures – (1) a large sustained positive brain wave pattern over the frontal lobe of the brain, referred to as frontal positivity; and (2) suppressed alpha-band activity (i.e., electrical brain activity in the range of 8-12 Hz) over the occipital lobe of the brain, referred to as occipital alpha power suppression (See Figure 1).

Figure 1: Neural Signatures of Successful Encoding into Memory – Sustained Frontal Positivity over the Frontal Lobe for Subsequently Remembered vs. Forgotten Pictures (Left) and Suppressed Alpha-Band Activity over the Occipital Lobe for Subsequently Remembered vs. Forgotten Pictures (Right).

Frontal positivity and occipital alpha suppression

Note: All electrophysiological measures were recorded during encoding and prior to the memory test. Adapted from Figure 2 of Fukuda & Woodman (2015).

Indeed, when the researchers sorted trials according to the strength of the two neural patterns, they observed that recognition accuracy was positively related to frontal positivity and negatively related to occipital alpha power.

This means the best recognized pictures on the memory test were the ones that, during the original study phase, led to high frontal positivity (see the left panel of Figure 2) and low occipital alpha power (see the right panel of Figure 2).

Figure 2: Relationship Between Frontal Positivity and Recognition Accuracy (Left) and Occipital Alpha Power and Recognition Accuracy (Right).

predicting memory from erps

Note: Recognition accuracy, as measured by the area under the receiver-operating-characteristic (ROC) curve, was calculated separately for each quintile. Quintile 1 was comprised of the weakest 20% of brain signals, and Quintile 5 was comprised of the strongest 20% of brain signals. Adapted from Figure 3 of Fukuda & Woodman (2015).

Having established that each of these neural markers predicts subsequent memory for pictures, the authors proceeded in a second experiment to investigate what would happen if participants were given the opportunity to restudy some of the pictures that were poorly learned.

They reasoned that if low frontal positivity and high occipital alpha power together signal poor encoding into memory, then giving participants the opportunity to restudy pictures that elicited these neural patterns should lead to better memory.

And indeed this is precisely what they found.

Pictures that were restudied prior to the memory test were better recognized than pictures that were not restudied, and the effect of restudying was especially pronounced for pictures that elicited low frontal positivity and high occipital alpha power during the original study phase.

In fact, restudying poorly learned pictures led to a memory benefit that was 30% larger than the benefit for restudying initially well-learned pictures.

So to summarize and clarify things a bit here, the results of this study suggest it is possible to identify poorly encoded memories on the basis of neural activity alone and then specifically target and strengthen these memories immediately by encouraging people to engage in a bit of extra practice and rehearsal.

I don’t know about you, but I think that’s pretty cool.

So will this exciting finding pave the way for a future in which basic cognitive processes are monitored and improved in real time with help from wearable technologies?

Who knows? The idea of receiving an alert on your phone to attend more closely to a face you failed to commit to memory might forever remain in the realm of science fiction.

Nonetheless, it’s fun to speculate what the distant future might hold, especially considering the dearth of science fiction inspired by real psychological science as opposed to pseudo-scientific myth.

Article Reference:

Fukuda, K. & Woodman, G.F. (2015). Predicting and improving recognition memory using multiple electrophysiological signals in real time. Psychological Science, 26(7), 1026-1037. DOI: 10.1177/0956797615578122

 

Brian Kurilla is a psychological scientist with a Ph.D. in cognitive psychology. You can follow Brian on Twitter @briankurilla 

Leave a Reply

Your email address will not be published. Required fields are marked *