Why We Sometimes Can’t See the Obvious
Union College Psychology Professor Christopher Chabris, PhD, and his colleagues study inattentional blindness—how people fail to see what’s directly in front of them when they are focused on something else. A high-profile police brutality case in which a murder suspect in Boston was beaten by police depended on whether a cop who ran right by the beating while chasing another murder lied when he denied having seen the beating. The case spurred the researchers to create an experiment to test their theories on inattentional blindness.
“We simulated the Boston incident by having subjects run after a confederate along a route near which three other confederates staged a fight,” Chabris explains in the abstract to the article about this research. “At night only 35 percent of subjects noticed the fight; during the day 56 percent noticed. We manipulated the attentional load on the subjects and found that increasing the load significantly decreased noticing.”
The researchers conclude that their results “provide evidence that inattentional blindness can occur during real-world situations, including the Boston case.”
Source: The article about the experiment was published in Perception (2011), vol. 2, pages 150–153. For more information, see NPR’s article about the study.
Negative Emotion May Enhance Memory
By Tony Fitzpatrick
Picture a gory slaughterhouse or a devastating scene of a natural disaster. Psychology researchers have found that viewing such emotion-laden images immediately after taking a test enhances people’s retention of the tested material.
The data gathered are the first to show that negative arousal following successful retrieval of information enhances later recall of that information.
The finding is counterintuitive. One would think that viewing a negative scene would tend to blot out anything learned before seeing the image. Instead, learning is enhanced by the negative emotion, says Bridgid Finn, PhD, a Washington University in St. Louis researcher in psychology.
The researchers tested 40 undergraduate students who studied 10 lists of 10 pairs of Swahili–English vocabulary items (lulu/pearl, ubini/forgery, etc.). Participants were given a cued-recall test after studying each set of 10 pairs and then given a final test on all 100 pairs.
On the initial test, following each correct answer, they were shown a picture of either a negative emotional image, such as a pointed gun; a neutral image, such as a chair; or a blank screen.
They then did a one-minute multiplication test, a sort of mental palate-cleansing to remove the effects of short-term memory, like a serving of sherbet in a multiple-course meal.
A final cued-recall test on all 100 Swahili–English items revealed that participants did best on items that had been followed by the negative pictures.
The researchers conducted another study of 61 students to rule out the possibility that arousing images simply made certain pairs of words seem more distinct and thus made them easier to remember. This experiment was very similar to the other with one major distinction: Instead of taking the initial tests, participants restudied the items.
“For negative emotion to enhance later retention of something, this experiment shows that you have to retrieve that information,” Finn says. “That is, you have to go get it. In the absence of retrieval, the negative pictures do not enhance later performance. That’s critical.”
The researchers’ experiments with positive images do not yield the same effect of enhanced retrieval or retention.
Source: Posted June 17, 2011. The research was published in the June 2011 issue of Psychological Science.Fitzpatrick’s article is excerpted here.
Changes in Brain Affect Moral Sensitivity as People Age
By William Harms
People’s moral responses to similar situations change as they age, according to a new study that combines brain scanning, eye-tracking, and behavioral measures to understand how the brain responds to morally laden scenarios.
Both preschool children and adults distinguish between damage done either intentionally or accidentally when assessing whether a perpetrator has done something wrong. Nonetheless, adults are much less likely than children to think someone should be punished for damaging an object, especially if the action was accidental.
The different responses correlate with the various stages of development, the researchers say. The study provides strong evidence that moral reasoning involves a complex integration between affective and cognitive processes that gradually changes with age.
The researchers studied 127 participants, aged 4 to 36, who watched short video clips while undergoing an fMRI scan. The team also measured changes in the dilation of the subjects’ pupils as they watched the clips.
The participants watched a total of 96 clips. Some portrayed intentional harm, such as someone being shoved; others showed accidental harm, such as someone being struck unintentionally by a golf player swinging a club. The clips also showed intentional damage to objects, such as a person kicking a bicycle tire, and accidental damage, such as a person unwittingly knocking a teapot off a shelf.
Eye-tracking in the scanner revealed that all of the participants, irrespective of age, paid more attention to people being harmed and to objects being damaged than they did to the perpetrators.
The study revealed that what changed with age was the extent of activation in different areas of the brain as participants saw the morally laden videos. For young children, the amygdala, which is associated with generating emotional re-sponses to social situations, was much more activated than in adults.
In contrast, adults’ responses were highest in the dorsolateral and ventromedial prefrontal cortex—areas of the brain that allow people to reflect on the values linked to outcomes and actions.
In addition to viewing the video clips, participants were asked to determine, for instance, how mean the perpetrators were, and how much punishment they should receive for causing damage or injury. The responses showed a clear connection between moral judgments and the activation the team had observed in the brain.
When recommending punishments, adults were more likely to make allowances for actions that were accidental, the researchers discovered. The response showed that they had a better-developed prefrontal cortex and stronger functional connectivity between this region and the amygdala than children. Adults were better equipped to make moral judgments.
Source: Posted May 27, 2011. The researchers’ article, “The Contribution of Emotion and Cognition to Moral Sensitivity: A Neurodevelopmental Study,” was published in the journal Cerebral Cortex. Harms’ article is excerpted here.