Posts tagged time perception
Articles and news from the latest research reports.
Those with episodic amnesia are not ‘stuck in time,’ says philosopher Carl Craver
In 1981, a motorcycle accident left Toronto native Kent Cochrane with severe brain damage and dramatically impaired episodic memory. Following the accident, Cochrane could no longer remember events from his past. Nor could he predict specific events that might happen in the future.
When neuroscientist Endel Tulving, PhD, asked him to describe what he would do tomorrow, Cochrane could not answer and described his state of mind as “blank.”
Psychologists and neuroscientists came to know Cochrane, who passed away earlier this year, simply as “KC.” Many scientists have described KC as “stuck in time,” or trapped in a permanent present.
It has generally been assumed that people with episodic amnesia experience time much differently than those with more typical memory function.
However, a recent paper in Neuropsychologia co-authored by Carl F. Craver, PhD, professor of philosophy and of philosophy-neuroscience-psychology, both in Arts & Sciences at Washington University in St. Louis, disputes this type of claim.
“It’s our whole way of thinking about these people that we wanted to bring under pressure,” Craver said. “There are sets of claims that sound empirical, like ‘These people are stuck in time.’ But if you ask, ‘Have you actually tested what they know about time?’ the answer is no.”
Time and consciousness
A series of experiments convinced Craver and his co-authors that although KC could not remember specific past experiences, he did in fact have an understanding of time and an appreciation of its significance to his life.
Interviews with KC by Craver and his colleagues revealed that KC retained much of what psychologists refer to as “temporal consciousness.” KC could order significant events from his life on a timeline, and he seemed to have complete mastery of central temporal concepts.
For example, KC understood that events in the past have already happened, that they influence the future, and that once they happen, they cannot be changed.
He also knew that events in the future don’t remain in the future, but eventually become present. Even more interestingly, KC’s understanding of time influenced his decision-making.
If KC truly had no understanding of time, Craver argues, then he and others with his type of amnesia would act as if only the present mattered. Without understanding that present actions have future consequences or rewards, KC would have based his actions only upon immediate outcomes. However, this was not the case.
On a personality test, KC scored as low as possible on measures of hedonism, or the tendency to be a self-indulgent pleasure-seeker.
In systematic tests of his decision-making, carried out with WUSTL’s Len Green, PhD, professor of psychology, and Joel Myerson, PhD, research professor of psychology, and researchers at York University in Toronto, KC also showed that he was willing to trade a smaller, sooner reward for a larger, later reward.
In other words, KC’s inability to remember past events did not affect his ability to appreciate the value of future rewards.
‘Questions are now wide open’
KC’s case reveals how much is left to discover about memory and how it relates to human understanding of time.
“If you think about memory long enough it starts to sound magical,” Craver said. “How is it that we can replay these events from our lives? And what’s going on in our brains that allows us to re-experience these events from our past?”
Craver hopes that this article — the last to be published about KC during his lifetime — brings these types of questions to the forefront.
“These findings open up a whole new set of questions about people with amnesia,” Craver said. “Things that we previously thought were closed questions are now wide open.”
Depressed people have a more accurate perception of time
People with mild depression underestimate their talents. However, new research carried out researchers at the University of Limerick and the University of Hertfordshire shows that depressed people are more accurate when it comes to time estimation than their happier peers.
Depressed people often appear to distort the facts and view their lives more negatively than non-depressed people. Feelings of helplessness, hopelessness and worthlessness and of being out of control are some of the main symptoms of depression. For these people time seems to pass slowly and they will often use phrases such as “time seems to drag” to describe their experiences and their life. However, depressed people sometimes have a more accurate perception of reality than their happier friends and family who often look at life through rose-tinted glasses and hope for the best.
Dr Rachel Msetfi, senior lecturer in psychology, University of Limerick and one of the studies authors, said: “We found that depressed people tended to be more accurate when estimating time whereas non-depressed people tended to be less accurate. This finding, along with some of our other work, suggests that depression leads to more attention paid to time passing. Sometimes this might lead to a phenomenon known as ‘depressive realism’, though on other occasions time might seem to be moving more slowly than usual.”
In the study, volunteers, who were classified as mildly depressed or non-depressed, made estimates of the length of different time intervals of between two and sixty-five seconds. Overall, those volunteers who were mildly–depressed were more accurate in their time estimations.
Dr Msetfi noted that: “Time is a very important part of everyday experience, it flies when we are having fun or enjoying ourselves. One of the commonest experiences of depression is that people feel that time passes slowly and sometimes painfully. Our findings may help to shed a little light on how people with depression can be treated. People with depression are often encouraged to check themselves against reality, but maybe this timing skill can be harnessed to help in the treatment of mildly-depressed people. These findings may also link to successful mindfulness based treatments for depression which focus on encouraging present moment awareness.”
The paper, “Time perception and depressive realism: Judgement type, psychophysical functions and bias”, is published in PLOS ONE.
(Source: ul.ie)
Time perception altered by mindfulness meditation
New published research from psychologists at the universities of Kent and Witten/Herdecke has shown that mindfulness meditation has the ability to temporarily alter practitioners’ perceptions of time – a finding that has wider implications for the use of mindfulness both as an everyday practice, and in clinical treatments and interventions.
Led by Dr Robin Kramer from Kent’s School of Psychology, the research team hypothesised that, given mindfulness’ emphasis on moment-to-moment awareness, mindfulness meditation would slow down time and produce the feeling that short periods of time lasted longer.
To test this hypothesis, they used a temporal bisection task, which allows researchers to measure where each individual subjectively splits a period of time in half. Participants’ responses to this task were collected twice, once before and then again after a listening task. By separating people into two groups, participants listened for ten minutes to either an audiobook or a meditation exercise designed to focus their attention on the movement of breath in the body. The results showed that the control group (audiobook) didn’t change in their responses after the listening task compared with before. However, meditation led to a relative overestimation of durations i.e. time periods felt longer than they had before.
The reasons for this have been interpreted by Dr Kramer and team as the result of attentional changes, producing either improved attentional resources that allow increased attention to the processing of time, or a shift to internally-oriented attention that would have the same effect.
Dr Kramer said: ‘Our findings represent some of the first to demonstrate how mindfulness meditation can alter the perception of time. Given the increasing popularity of mindfulness in everyday practice, its relationship with time perception may provide an important step in our understanding of this pervasive, ancient practice in our modern world.’
Dr Kramer also explained that the benefits of mindfulness and mindfulness-based therapies in a variety of domains are now being identified. These include decreases in rumination, improvements in cognitive flexibility, working memory capacity and sustained attention, and reductions in reactivity, anxiety and depressive symptoms. Mindfulness-based treatments also appear to provide broad antidepressant and antianxiety effects, as well as decreases in general psychological distress. As such, these interventions have been applied with a variety of patients, including those suffering from fibromyalgia, psoriasis, cancer, binge eating and chronic pain.
Dr Dinkar Sharma, Senior Lecturer in Psychology at Kent, commented: ‘Demonstrating that mindfulness has an effect on time perception is important because it opens up the opportunity that mindfulness could be used to alter psychological disorders that are associated with a range of distortions in the perception of time - such as disorders of memory, emotion and addiction.’
Dr Ulrich Weger, of Witten/Herdecke’s Department of Psychology and Psychotherapy, concluded by stating that ‘the impact of a brief mindfulness exercise on elementary processes such as time perception is remarkable’.
Causation Warps Our Perception of Time
You push a button to call the elevator to your floor and you wait for what seems like forever, thinking it must be broken. When your friend pushes the button, the elevator appears within 10 seconds. “She must have the magic touch,” you say to yourself. This episode reflects what philosophers and psychological scientists call “temporal binding”: Events that occur close to one another in time and space are sometimes “bound” together and we perceive them as meaningful episodes.
New research published in Psychological Science, a journal of the Association for Psychological Science, suggests that binding may reveal important insights into how we experience time.
Research has shown that our perceptual system seems to pull causally-related events together – compared to two events that are thought to happen of their own accord, we perceive the first event as occurring later if we think it is the cause and we perceive the second event as occurring earlier if we think it is the outcome.
So how does this temporal binding occur?
Some researchers have hypothesized that our perceptual system binds events together if we perceive them to be the result of intentional action, and that temporal binding results from our ability to link our actions to their consequences. But psychological scientist Marc Buehner of Cardiff University, UK wondered whether temporal binding might be rooted in a more general capacity to understand causal relations.
“We already know that people are more likely to infer a causal relation if two things are close in time. It follows, via Bayesian calculus, that the reverse should also be true: If people know two things are causally related, they should expect them to be close in time,” Buehner says. “Time perception is inherently uncertain, so it makes sense for systematic biases in the form of temporal binding to kick in. If this is true, then it would suggest that temporal binding is a general phenomenon of which intentional action is just a special case.”
Though the seconds may tick by on the clock at a regular pace, our experience of the ‘fourth dimension’ is anything but uniform. When we’re waiting in line or sitting in a boring meeting, time seems to slow down to a trickle. And when we get caught up in something completely engrossing – a gripping thriller, for example – we may lose sense of time altogether.
But what about the idea that time flies when we’re having fun? New research from psychological science suggests that the familiar adage may really be true, with a caveat: time flies when we’re have goal-motivated fun.
Try this exercise: Put this book down and go look in a mirror. Now move your eyes back and forth, so that you’re looking at your left eye, then at your right eye, then at your left eye again. When your eyes shift from one position to the other, they take time to move and land on the other location. But here’s the kicker: you never see your eyes move. What is happening to the time gaps during which your eyes are moving? Why do you feel as though there is no break in time while you’re changing your eye position? (Remember that it’s easy to detect someone else’s eyes moving, so the answer cannot be that eye movements are too fast to see.)
All these illusions and distortions are consequences of the way your brain builds a representation of time. When we examine the problem closely, we find that “time” is not the unitary phenomenon we may have supposed it to be. This can be illustrated with some simple experiments: for example, when a stream of images is shown over and over in succession, an oddball image thrown into the series appears to last for a longer period, although presented for the same physical duration. In the neuroscientific literature, this effect was originally termed a subjective “expansion of time,” but that description begs an important question of time representation: when durations dilate or contract, does time in general slow down or speed up during that moment? If a friend, say, spoke to you during the oddball presentation, would her voice seem lower in pitch, like a slowed- down record?
If our perception works like a movie camera, then when one aspect of a scene slows down, everything should slow down. In the movies, if a police car launching off a ramp is filmed in slow motion, not only will it stay in the air longer but its siren will blare at a lower pitch and its lights will flash at a lower frequency. An alternative hypothesis suggests that different temporal judgments are generated by different neural mechanisms—and while they often agree, they are not required to. The police car may seem suspended longer, while the frequencies of its siren and its flashing lights remain unchanged.
Read more: Brain Time