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This is the 4th podcast for Memory & Mind News, a companion program to the Memory News Digest, a monthly newsletter put out by Memory Key dot com, a website devoted to providing information about memory and learning to help you achieve permanent memory improvement.

In this podcast, I will be talking about the role of perception in memory, with particular reference to how we construct our reality. Then I’ll discuss some of the news items that didn’t make it into the digest. References and links can be found on the website.

A couple of studies I came across recently — one that I reported in this month’s news, and one that I didn’t — have stimulated me to talk about perception and encoding this month.

Why do I include research about perception in a website devoted to memory and learning?

Memory is about construction and re-construction; about consolidation and re-consolidation. We construct our memories, and every time we recall a memory, we reconstruct it again. And perception is the first stage in that process.

We cannot remember what we didn’t first encode — that is, what we didn’t put into memory. And what we remember is constructed from what we encoded. And — here we come to the nub of it — what we encode is based on what we perceive. And the reality we perceive is not, it is not, some ‘pure’, objective reality that all observers would agree upon.

There are many factors affecting what we perceive. Some of these are situational, depending on what’s being perceived and on the conditions in which it is being perceived. Others relate to the perceiver, to more constant personality variables, and to more variable emotional and state variables. How do you look at the world? That’s a personality variable. How are you feeling? That’s a state variable.

Attention, of course, is a crucial factor. Attention may be thought of as the torch you shine on the world. It may be halogen-bright; it may be pale and flickering. It may shine there, or there, or there.

There’s a much-quoted study — this is so cute. There’s a circle of people and they’re tossing a ball between them. At some point a person dressed in a gorilla costume walks through the circle, stopping a moment to beat his chest. Pretty astonishing, huh? And hard to miss.

Half the people who watched a video of that event, and were asked to count the passes made by one person in the circle, didn’t notice the gorilla!

Attention — an amazing thing.

One of the recent research reports that prompted this topic was in fact a follow-up to this study. The study found that people who were given a simple visual task while mildly intoxicated (and we’re walking about half the legal limit here) were more than twice as likely to have missed seeing the person in a gorilla suit than were people who were not under the influence of alcohol.
So there’s another factor that affects attention.

The phenomenon evidenced by these 2 studies is called "inattentional blindness", and occurs when important, but unexpected, objects appear in the visual field but are not detected when people are focused on another task.
One of the studies I reported on this month is also concerned with this phenomenon — the study showing talking on a cell phone while driving is as bad as, if not worse than, driving while legally intoxicated.

The researcher suggests that the reason talking on a cellphone is worse than talking to a passenger in the car is because of inattentional blindness, because the drivers enter a kind of "virtual reality" with the person they're chatting with.

The researcher says — and the words ring so true, if you think of yourself on a phone — "Neither you nor the other person is really dealing with the physical environment that you're in. Instead you're in this kind of cell phone-induced virtual reality, and you interact in that virtual environment rather than talk about the physical here and now of driving. Even though the driver who is using the cell phone is looking out the windshield, they're not necessarily seeing what's out there because their mind is directed elsewhere.

But, as with our blind spot — and there’s another wonderful example of constructed reality — people don’t realize how much they’re missing. The drivers in the study had no idea they weren't really seeing everything in front of them on the road. They thought they were driving perfectly safely, and figured that if anyone had a problem driving while using a cell phone, it would be "the other guy."

It always is “the other guy”. Think about all those occasions when you and another person disagree about something that happened. Perhaps — here’s a common one — about whether you told them something. Both of you absolutely certain about the truth of the matter. Just bear in mind, however true it seems to you, a different memory s just as true to the other guy. And however much you argue, even if you get them to agree that maybe you were right, you probably won’t alter their remembering of something different. What’s encoded, or what isn’t, is what goes into the memory.

Or perhaps you will alter their memory. That’s another frightening thing, to anyone who wants a firm reality to cling to — how easily we can be persuaded that something happened that didn’t — that we can be persuaded to remember something happening that didn’t.

Which is what that rather cute study on advertising that I reported on did — the one that found that getting people to work out an anagram of a brand name helped persuade them that they had encountered the brand in high school!

And speaking of our elusive hold on reality, here’s another report that didn’t make it into this month’s news. British researchers have found the neurological basis for poor witness statements and hallucinations. In over a fifth of cases, people wrongly remembered whether they actually witnessed an event or just imagined it. The brain areas that were activated while remembering whether an event really happened or was imagined in healthy subjects turn out to be the very same areas that are dysfunctional in people who experience hallucinations. The researchers suggest that hallucinations are caused by a difficulty in discriminating information present in the outside world from information that is imagined.

Well, so far the variables I’ve talked about — alcohol, multitasking — are state variables. Let’s have a little look at personality variables.

Recently a British academic came out to New Zealand and was interviewed on our national radio station. I’ve given the link to an audio of the interview, but I’m not sure how long it will be available.

This is another cute study. Professor Wiseman is interested in luck. What makes same people lucky and some people not? And, the really interesting question, can you turn an unlucky person into a lucky one?

Here’s a study he did. People were asked, imagine you’re in a bank and someone comes in, and they’re robbing the bank, and in the excitement you’re shot in the arm … are you lucky, or unlucky?

Think about it. Is that good luck, or bad?

Well, people who thought they were unlucky said it was bad luck — they said, how could this be lucky? They were shot!!

But people who thought they were lucky said it was good luck — they could have been killed; they could have been really badly hurt. Instead, it was only their arm. Not only that, but they would probably be able to sell their story to the papers!

The message here is pretty clear, so let’s move on to how lucky people actually see the world differently.

People were given a newspaper and asked to go through it and tell the researcher how many photos were in it.

There were 2 big ads in the paper. One of them told how many photos there were in the paper; the other told them if they told the researcher they had seen the ad, they would get 250 pounds.

Guess which type of people was more likely to spot the ads?

Yes. The lucky ones.

Here’s a little roundup of some perception news that didn’t make it into this month’s news.

Researchers have discovered how the brain creates a scent symphony from signals sent by the nose (in mice at least, and probably in us). It turns out that nerve cells in the brain's olfactory bulb -- the first stop for information from the nose -- do not perceive complex scent mixtures as single objects, such as the fragrance of a blooming rose. Instead, these nerve cells, or neurons, detect the host of chemical compounds that comprise a rose's perfume. Smarter sections of the brain's olfactory system then categorize and combine these compounds into a recognizable scent. In other words, the brain processes each scent component like a jigsaw puzzle piece, assembling the signals until it recognizes what it’s a picture of.

I mentioned the study showing we can track more than 3 objects only if they’re color coded. A new study reports that cortical mechanisms track color much faster than perception, responding well to color alternations that are too rapid to be perceptible.

A new study attempts to answer the question of why the human brain fundamentally limited when attempting to execute two tasks at the same time or in close succession?

Two different approaches have come up with slightly contradictory conclusions. One says the simultaneous execution of two tasks is limited solely by a passive structural bottleneck in which the tasks are executed on a first-come, first-served basis. The other argues that switching back and forth between task configurations must be actively controlled by a central executive system. The new study provides evidence that both are true at different points, and suggests a hierarchical model of cognitive architecture that provides a synthesis of both paradigms.

Okay, that’s it for perception. Here’s a roundup of other memory news that didn’t make it into this month’s news digest.

A new study provides more support for the health benefits of Tai Chi. This study looked specifically at Tai Chi that included Qigong – a practice that is traditionally included in Tai Chi training. The study found that healthy seniors (average age 80) who practiced a combination of Qigong and Tai Chi three times a week for six months experienced significant physical benefits after only two months. Participants demonstrated noticeable improvements in balance, lower body strength and stance width. Anecdotal evidence also pointed to improvements in sleep quality, concentration, memory, self-esteem and overall energy levels.

It seems estrogen plays a different role during stress in black and white girls, a difference that may help explain higher cardiovascular disease rates in blacks. The study found estrogen levels dropped during stress in healthy black girls but remained consistent in whites.

A new study reveals late-onset depression, which first emerges in people aged 60 and over, is linked to a decline in the brain's executive functions that leads to repetitive, negative thought patterns. This link wasn’t found in those suffering from early-onset depression. The link between executive decline and late onset depression was brought about by their joint association with rumination. That is, executive decline was only associated with late-onset depression to the degree that it led people to ruminate. When executive dysfunction did not lead to rumination, it did not predict late-onset depression. These results suggest that executive function deficits may contribute to late-onset of depressive symptoms by interfering with the ability to control ruminative thoughts.

It appears that people over 50 are better able to deal with life's bad bits, because advancing age heralds a growth in emotional stability, with increased control over negative emotions and greater accessibility of positive emotions. The shift is underpinned by a shift in control of emotional reactions from the amygdala, a brain structure implicated in automatic fear responses, to the medial prefrontal cortex, an area more involved in conscious thought. The shift seems to reflect a conscious intent to use cognitive-control processes to help them avoid experiencing negative information and focus instead on positive information.

So-called mirror neurons enable us to “read minds” – that is, help us predict the actions of others. New research suggests that we pick up this ability early: Infants start to predict the goals of others' actions at about the same time they learn to perform those general actions themselves. That is, at around 7 to 9 months.

A new study explains the success of avoidance learning – learning to avoid something because you have had an unpleasant experience with it — by providing evidence that the same brain region that is activated when we’re rewarded is activated when we successfully avoid an unpleasant outcome. In other words, avoiding something bad is rewarding.

Despite wide usage, we don’t really understand why medications such as Ritalin quell symptoms of attention deficit hyperactivity disorder (ADHD).

But a new study now reveals that ADHD drugs primarily target activation of the neurotransmitter catecholamine within the prefrontal cortex, a region of the brain that is associated with attention, decision-making and an individual's expression of personality.

Researchers have discovered in the placenta what may be the earliest marker for autism, possibly helping physicians diagnose the condition at birth, rather than the standard age of two or older. The pilot study will need to be replicated by a larger study.

Two new studies challenge the hypothesis that an inadequate supply of essential brain chemicals called neurotrophins is to blame for Down syndrome and other neurodegenerative diseases. Instead the problem may be caused by impairments in the signaling and transport of neurotrophins. And for Down syndrome, a condition in which several hundred genes are triplicated due to a trisomy of chromosome 21, one gene associated with Alzheimer's disease may be the chief culprit – the gene for amyloid precursor protein (APP).

The researchers found that deleting the extra (3^rd) copy of the APP gene made a dramatic difference in mice, even though all the remaining genes on the extra chromosome 16 segment were still present in triplicate.

In the second study, the researchers showed that by deleting one copy of the gene for a truncated form of a particular receptor for the neurotrophin BDNF restored normal BDNF signaling.

In preliminary results, researchers have shown that a drug which mimics the effects of the nerve-signaling chemical dopamine causes new neurons to develop in the part of the brain where cells are lost in Parkinson's disease, and led to long-lasting recovery of function in rats with similar symptoms. The findings may lead to new ways of treating Parkinsons and other neurodegenerative diseases.

And that’s it for this month’s podnews; I hope you enjoyed it.