Did I Do That? Distinguishing Real from Imagined Actions
Why is reality monitoring a challenge? To illustrate, let’s say you’re at the Louvre standing before the Mona Lisa. As you look at the painting, visual areas of your brain are busy representing the image with specific patterns of activity. So far, so good. But problems emerge if we rewind to a time before you saw the Mona Lisa at the Louvre. Let’s say you were about to head over to the museum and you imagined the special moment when you would gaze upon Da Vinci’s masterwork. When you imagined seeing the picture, you were activating the same visual areas of the brain in a similar pattern to when you would look at the masterpiece itself.*
When you finally return home from Paris and try to remember that magical moment at the Louvre, how will you be able to distinguish your memories of seeing the Mona Lisa from imagining her? Reality monitoring studies have asked this very question (minus the Mona Lisa). Their findings suggest that you’ll probably use additional details associated with the memory to ferret out the mnemonic wheat from the chaff. You might use memory of perceptual details, like how the lights reflected off the brushstrokes, or you might use details of what you thought or felt, like your surprise at the painting’s actual size. Studies find that people activate both visual areas (like the fusiform gyrus) and self-monitoring regions of the brain (like the medial prefrontal cortex) when they are deciding whether they saw or just imagined seeing a picture.
It’s important to know what you did and didn’t see, but another crucial and arguably more important facet of reality monitoring involves determining what you did and didn’tdo. How do you distinguish memories of things you’ve actually done from those you’ve planned to do or imagined doing? You have to do this every day and it isn’t a trivial task. Perhaps you’ve left the house and headed to work, only to wonder en route if you’d locked the door. Even if you thought you did, it can be hard to tell whether you remember actually doing it or just thinking about doing it. The distinction has consequences. Going home and checking could make you late for work, but leaving your door unlocked all day could mean losing your possessions. So how do we tell the possibilities apart?
Valerie Brandt, Jon Simons, and colleagues at the University of Cambridge looked into this question and published their findings last month in the journal Cognitive, Affective, and Behavioral Neuroscience. For the first part of the experiment (the study phase), they sat healthy adult participants down in front of two giant boxes – one red and one blue – that each contained 80 ordinary objects. The experimenter would draw each object out of one of the two boxes, place it in front of the participant, and tell him or her to either perform or to imagine performing a logical action with the object. For example, when the object was a book, participants were told to either open or imagine opening it.
After the study phase, the experiment moved to a scanner for fMRI. During these scans, participants were shown photographs of all 160 of the studied objects and, for each item, were asked to indicate either 1) whether they had performed or merely imagined performing an action on that object, or 2) which box the object had been drawn from.** When the scans were over, the participants saw the pictures of the objects again and were asked to rate how much specific detail they’d recalled about encountering each object and how hard it had been to bring that particular memory to mind.
The scientists compared fMRI measures of brain activation during the reality-monitoring task (Did I use or imagine using that object?) with activation during the location task (Which box did this object come from?). One of the areas they found to be more active during reality monitoring was the supplementary motor area, a region involved in planning and executing movements of the body. Just as visual areas are activated for reality monitoring of visual memories, motor areas are activated when people evaluate their action memories. In other words, when you ask yourself whether you locked the door or just imagined it, you may be using details of motor aspects of the memory (e.g., pronating your wrist to turn the key in the lock) to make your decision.
The study’s authors also found greater activation in the anterior medial prefrontal cortex when they compared reality monitoring for actions participants performed with those they only imagined performing. The medial prefrontal cortex encompasses a respectable swath of the brain with a variety of functions that appear to include making self-referential judgments, or evaluating how you feel or think about experiences, sensations, and the like. Other experiments have implicated a role for this or nearby areas in reality monitoring of visual memories. The study by Brandt and Simons also found that activation of this medial prefrontal region during reality-monitoring trials correlated with the number of internal details the participants said they’d recalled in those trials. In other words, the more details participants remembered about their thoughts and feelings during the past actions, the busier this area appeared to be. So when faced with uncertainty about a past action, the medial prefrontal cortex may be piping up about the internal details of the memory. I must have locked the door because I remember simultaneously wondering when my package would arrive from Amazon, or, because I was also feeling sad about leaving my dog alone at home.
As I read these results, I found myself thinking about the topic of my prior post on OCD. Pathological checking is a common and often disruptive symptom of the illness. Although it may seem like a failure of reality monitoring, severalbehavioralstudies have shown that people with OCD have normal reality monitoring for past actions. The difference is that people with checking symptoms of OCD have much lower confidence in the quality of their memories than others. It seems to be this distrust of their own memories, along with relentless anxiety, that drives them to double-check over and over again.
So the next time you find yourself wondering whether you actually locked the door, cut yourself some slack. Reality monitoring ain’t easy. All you can do is trust your brain not to lead you astray. Make a call and stick with it. You’re better off being wrong than being anxious about it – that is, unless you have really nice stuff.
“I think it’s very bad manners of people my age to turn around and say, well, the kids aren’t doing this and the kids aren’t doing that. Obviously I’m fascinated by teen culture, but I no longer live it and I don’t think it’s my place to be. So I don’t condemn today’s youth for whatever it is they are or are not doing, and I tend to remain thankful that teenagers, certainly people 18, 29, 20, 21—it’s a very powerful moment when you come out into the world and you realize the world isn’t great and, you know, you want to do something about it, if you’ve got any spirit of argument in you. I think that will always be the case, and I’m very hopeful that today’s teenagers will find solutions to the problems that they face, because they are also the problems that [old people] face, and if change doesn’t happen then you have stasis, entropy and decay.”—Jon Savage
Could hardly keep up on my ride today, especially since my friend was on a carbon fiber bike. I think I deserve a nice nap but the 70+ degree sunshine is making that choice very difficult. Maybe I’ll just go have more coffee. Ya
Barbara King has some interesting things to say when reviewing Michael Corballis book, The Recursive Mind. (here)
Here is her description the situation:
“Astonishing animals show up everywhere these days. Cooperative apes, grief-stricken elephants, empathetic cats and dogs crowd our bookshop shelves. It’s all the rage to plumb the cognitive and emotional depths of the animal world, rejecting sceptics’ sneers of “anthropomorphism” to insist that we’re finally coming to see animals for who they really are: not so different from us. Pushing against this tide of animal awe is a competing cultural trope, the relentless seeking of human superiority.”
She says that Corballis believes that humans uniquely have language, thought and civilization, which is due to having mental time travel and theory of mind, which in turn is due to having recursion. Well, here we go again with Chomsky’s uniquely human key, recursion.
Corballis is also a co-author with Suddendorf of a 1997 paper on mental time travel which makes a similar argument. “This article contains the argument that the human ability to travel mentally in time constitutes a discontinuity between ourselves and other animals. Mental time travel comprises the mental reconstruction of personal events from the past (episodic memory) and the mental construction of possible events in the future. It is not an isolated module, but depends on the sophistication of other cognitive capacities, including self-awareness, meta-representation, mental attribution, understanding the perception- knowledge relationship, and dissociation of imagined mental states from one’s present mental state. These capacities are also important aspects of so-called “theory of mind”, and they appear to mature in children at around age four. Furthermore, mental time travel is generative, involving the combination and recombination of familiar elements, and in this respect may have been a precursor to language. Current evidence, although indirect or based on anecdote rather than on systematic study, suggests that nonhuman animals, including the great apes, are confined to a “present” that is limited by their current drive states. In contrast, mental time travel by humans is relatively unconstrained, and allows a more rapid and flexible adaptation to complex, changing environments than is afforded by instincts or conventional learning. Past and future events loom large in much of human thinking, giving rise to cultural, religious, and scientific concepts about origins, destiny, and time itself.” So all the animal studies between 1997 and 2013 have not had any effect on Corballis.
But Corballis does seem to be aware of many relevant animal studies, even contributing to them, and so it is surprising that he would take this outlook. But for some, and Corballis may be one, it seems there is a real need to find a single, significant difference between humans and other animals. Why? I assume it is because they cannot imagine an alternative.
As I have said in previous posts. We are unique but all species are unique. We are not uniquely unique. We are unique in the same way other animals are. We have a little more of this and a little less of that, a different pattern to the mix. But we are basically very similar to other mammals. We are very unlikely to have some characteristic with no other animal having anything similar. The mammals are different from each other but metaphorically they are painted with the same palette. A few million year’s ago there was no difference at all between us and chimps, we were one species. Our paths diverged slightly and so we became a little different and then a little more. But we are still, some millions of years on, very similar to chimps anatomically, genetically, developmentally. But definitely we are not similar culturally.
But when we look at the chimp in the jungle and the astronaut traveling to the moon there is a world of difference. It is this difference that drives people to look for some important significant ability that separates us from the chimp. They look for a different physical characteristic or ability. But the big difference between us and the chimp is cultural not biological.
Cultural evolution was very distinct from biological evolution. It is exponential. Its growth feeds more growth. Suppose we start with some stones used as tools (chimps also use stones). But after a while we start fashioning their shape a bit. Sometime later we get a bit better at fashioning and develop a skill at knapping. Slowly, but at an increasing pace, we learn to make really great stone tools. The same would be true of language. We start as chimps do with communication of a limited kind: a few calls and cries that can be sequenced to a small extent and a number of gestures. We can build on this slowly, very slowly at first but with increasing speed. We end up with a primitive language. We start taking advantage of fires when they occur naturally, then we try to keep and manage them, then make them from scratch whenever we want a fire. Every step in the accumulation of culture is faster than the one before. The culture force becomes enormous and eventually we are changing our way of living constantly. Each innovator could have said, like Newton, “If I have seen farther it is by standing on the shoulders of giants”.
How much does it take for a species that is capable of cultural transmission (as chimp and humans both are) to become two species, one with very little culture and the other with a growing and finally exploding culture. It could be as little as a slightly different niche with slightly different problems and opportunities. Some of our joint ancestors stepped onto one path and some on to another. Of course there was biological evolution in humans but it appears to be mostly driven by cultural evolution rather than the other way around.
As an example of how this works look at the effect of population. Human population has been growing since the start of agriculture in an exponential fashion. As the growers of food can produce more than their family needs, they can have more children and so can others who are fed with the surplus. As long as there is land, we have more food – more people – more farms – more food in an ever increasing spiral. The amount of innovation depends on the population density (or, more likely, the number of people that an average person has contact with in some fashion). So cities are more innovating than the agricultural countryside and cities have been growing in number and size at an ever increasing rate. Soon more than half of all humans will live in large cities. The contact between people is also increasing with travel, writing, electronic communications and so on. So one exponential growth is the basis of another exponential growth and that is the basis of yet another. As far as cultural evolution is concerned it is not just growing at an exponential rate but the rate itself is growing.
The point I am making is that a small, almost immeasurable, difference in the amount of cultural change accumulated in a generation between the group that would become humans and the group that would become chimps, can over a few million years result in the sort of differences we see now. Humans could have come from the individuals with the slightly harder environment or something like that. There need be no biological difference at first. Later there will be some genetic change that is driven by cultural change, of course. For example, once some sort of pre-language culturally acquired vocal communication starts to be an important advantage then there is going to be a selective pressure for changes to the vocal apparatus, hearing and the brain to make that communication more fixed and efficient in the population. It has become a situation where the genetic change follows the cultural one.
We do not need to look for the source of our unusual life style and achievements in some special facility that we have and other animals do not. It is more likely that our history started with some small quirk of fate like which side of the Rift Valley was our home. Our biological changes are mostly caused by our cultural changes and need not actually be very large. There is no need to look for some very significant physical difference, like a brain that can uniquely do recursion, to explain our present situation.
Tell me about how light creates “wonder.” Wonder comes from all sorts of light. People tend to appreciate unusual light phenomena such as sunrises and sunsets, rays from behind clouds, exciting color contrasts, and rainbows. And while cultures vary, our shared sensory avenues for engaging with the world explain why we’re similarly affected by light. The Aboriginal people in Queensland, Australia, where I have worked for many years, may not have the same conversations that we do about the beauty of light and water, but they do sit and gaze at water bodies. And they generate ideas about what water and light mean.
What are some of these ideas? The notion of visibility and invisibility is central to Aboriginal thinking. There is the invisible and immaterial world that is held within the land where ancestral beings reside. From there, they generate life and emanate power upward into the visible material world. The notion that it’s the ray of light that rouses the spirit is all around their mythology. Even the words they use to describe the spiritual movement from the ancestor to a human being can be translated roughly into English as “becoming visible” or “becoming material.”
So light makes the Aboriginal ancestral beings visible? Yes, and it’s usually done through the interplay with water. Aboriginal Australia’s major ancestral being, the Rainbow Serpent is, in a sense, composed of water and its power is emitted by light or shine. Many other ancestral powers are contained in sacred water spots that are brought into the visible world through the shimmering water surface. A similar idea applies to rock and body art: The dots and patterns painted on the landscape or on the body represent the emanation of ancestral forces—their shimmer makes them manifest. In songs and stories too, “things that shine” are quite literally powerful and alive. The process of retelling the myths is meant to evoke the ancestors.
Are there specific rituals relating to how light interplays with water? The most common and important ritual in Aboriginal Australia is that of baptism (that has the same name as the Christian ritual in English but isn’t related to it) which involves the splashing of water from sacred places onto people from other clan groups. The ancestral beings of that place will now know them and grant them safe passage through the area. There is also the “passing through the Rainbow” ritual, where people are immersed in places where the Rainbow Serpent resides so the person gains sacred knowledge, and is thus considerably empowered.
How do the Aboriginals make use of light in their everyday lives? Even in a time when GPS devices are widely available, many Aboriginal Australians situate themselves in the land through an acute awareness of the characteristics of natural light in different times and places. Many of the parts of Australia where they tend to live are quite flat and covered with thin open forest, and there may be few landmarks or distinct features. Traditionally, clans have known every part of their estates intimately, but part of how they would read the environment would entail following the light of the sun and stars. There is an entire Aboriginal cosmology in which star patterns are described in their indigenous terms: instead of “Orion’s Belt” or “The Plough,” there are constellations known as “The Emu,” “The Snake,” and suchlike. The Milky Way appears in ancestral stories as a Sky River.
Many Aboriginal communities also depend heavily on fishing. People spend hours beside waterholes and estuaries scrutinizing light on water, where shifting patterns may indicate the flicker of fish or the presence of turtles—a favorite food. Or they may be keeping a lookout for the big and dangerous crocodiles, known as “salties,” that often find their way upstream during the wet season. So the need for light comes up over and over in daily life.
In addition to your research on Aboriginal culture, you also study Western individuals’ relationship to land and resources. What role does light play in establishing how we feel about, let’s say, the local park? There is good evidence that people who are affected by nature tend to be better environmentalists. Places shimmering with water and light are known to attract attention. If you can get more people to connect with places viscerally you will likely raise their levels of concern. Many environmental organizations capitalize on this: They enable closer connections between people and lakes and rivers, and encourage local communities to care about and protect them.
Is there a reason why people are riveted by light and water? In many cultures, but especially in the West, we tend to privilege our sense of sight above the other senses. Water’s capacity to reflect light is a particularly powerful sensory stimulus. So if you add together the fact that we prize visual experience, and that water and light in combination can produce large-scale, intricate, rapidly-moving patterns and effects with elements of both order and disorder, it seems reasonable to speculate that this is particularly stimulating and engaging to the brain, evoking something for which we can use the term wonder. There is, at least, a good research question here.
Is there a way to measure people’s emotional response to light and water? A fruitful line of research, I think, would be comparing ethnographic accounts of watching the play of light on water with neuroscientific research on how light affects the eye, the brain, and the body. I suspect that the shimmer of light on water echoes what is going on inside our heads. This constant neurological “fizz” or “shimmering” of thoughts might remind us of the mesmerizing effect of sitting beside a glittering body of water, watching the light sparkle on the surface. This remains rather speculative, but when I interview people in cultures such as ours about their experiences with water, they very often talk about its powerful mesmerizing or hypnotic effects. The nascent science of how light and water affect the mind makes me understand better why indigenous peoples, such as the Aboriginal Australians, would have practices that involve it.
“I can only note that the past is beautiful because one never realises an emotion at the time. It expands later, and thus we don’t have complete emotions about the present, only about the past.”—Virginia Woolf