Texting, Talking and Other Uses of the Cell Phone Behind the Wheel
(by Mary Madden, Senior Research Specialist and Amanda Lenhart, Senior Research Specialist, Pew Internet & American Life Project)

Overview of Study: Over the summer of 2009, the Pew Research Center's Internet & American Life Project conducted a survey of 800 teens ages 12-17 asking about their experiences with cell phone use in cars. All of the teens in our survey were asked about their experiences as passengers, and if they were age 16 or older and have a cell phone, they were also asked about their own actions behind the wheel including both talking and text messaging. Additionally, the Pew Internet Project and the University of Michigan conducted nine focus groups with teens ages 12-18 between June and October 2009 where the topic of driving and mobile phones was addressed. The following are the major findings from the survey and focus groups:

• 75% of all American teens ages 12-17 own a cell phone, and 66% use their phones to send or receive text messages.
  
• Older teens are more likely than younger teens to have cell phones and use text messaging; 82% of teens ages 16-17 have a cell phone and 76% of that cohort are cell phone texters.
  
• One in three (34%) texting teens ages 16-17 say they have texted while driving. That translates into 26% of all American teens ages 16-17.
  
• Half (52%) of cell-owning teens ages 16-17 say they have talked on a cell phone while driving. That translates into 43% of all American teens ages 16-17.
  
• 48% of all teens ages 12-17 say they have been in a car when the driver was texting.
  
• 40% say they have been in a car when the driver used a cell phone in a way that put themselves or others in danger.

[full report available here (.pdf)]

The first ever large-scale, longitudinal study of ketamine users has been published online today in the journal Addiction. With Ketamine (K, Special K) use increasing faster than any other drug in the UK (British Crime Survey, 2008) this research showing the consequences of repeated ketamine use provides valuable information for users and addiction professionals alike.

For the study, researchers from University College London followed 150 people over a year to see if changes in their ketamine use could predict changes in their psychological well-being, memory and concentration. Of these 150 people, 30 were taking large quantities of the drug nearly every day, 30 were taking it 'recreationally' (once or twice a month), 30 were former users, 30 used illicit drugs apart from ketamine and 30 did not use any illicit drugs.

The authors found that the heavy ketamine users were impaired on several measures, including verbal memory. Short term memory and visual memory in this group decreased over the year as ketamine use increased. These individuals also performed more poorly overall on verbal memory, displaying symptoms such as forgetfulness and experiencing difficulty recalling conversations and people's names.

The amount of increase in ketamine use over the course of one year was also a source of concern. Hair analysis showed that ketamine levels among recreational users doubled at follow-up compared to initial testing, a pattern seen with other addictive drugs. Ketamine levels in the frequent using group did not change across the year, but this group was already using up to ten grams per day at initial testing.

Interestingly, the recreational ketamine users and ex-ketamine users did not differ from non-drug-taking controls on memory, attention and measures of psychological well-being, suggesting that occasional ketamine use does not lead to prolonged harms to cognitive function and that any damage may be reversed when people quit using the drug. However, all groups of ketamine users showed evidence of unusual beliefs or mild 'delusions', with these being greatest in the frequent users and least in ex-users (i.e. it appeared dependent on the amount of the drug used). It is not clear to what extent this is a pre-existing difference in ketamine users, something that develops from using the drug or a mixture of both.

Says lead author Dr. Celia Morgan: "These findings have implications for the growing number of ketamine users in the UK as well as addiction professionals who may encounter increasing numbers of ketamine dependent users. These findings suggest these frequent ketamine users will be impaired, albeit transiently, in a variety of psychological domains."

Two new studies of pedestrian safety found that using a cell phone while hoofing it can endanger one's health. Older pedestrians, in particular, are impaired when crossing a busy (simulated) street while speaking on a mobile phone, the researchers found.

The studies, in which participants crossed a virtual street while talking on the phone or listening to music, found that the music-listeners were able to navigate traffic as well as the average unencumbered pedestrian. Users of hands-free cell phones, however, took longer to cross the same street under the same conditions and were more likely to get run over.

Older cell-phone users, especially those unsteady on their feet to begin with, were even more likely to become traffic casualties. "Many people assume that walking is so automatic that really nothing will get in the way," said University of Illinois psychology professor Art Kramer, who led the research with psychology professor Jason McCarley and postdoctoral researcher Mark Neider. "And walking is pretty automatic, but actually walking in environments that have lots of obstacles is perhaps not as automatic as one might think."

The first study, in the journal Accident Analysis and Prevention, found that college-age adults who were talking on a cell phone took 25 percent longer to cross the street than their peers who were not on the phone. They were also more likely to fail to cross the street in the 30 seconds allotted for the task, even though their peers were able to do so.

Each participant walked on a manual treadmill in a virtual environment, meaning that each encountered the exact same conditions – the same number and speed of cars, for example – as their peers. The second (and not yet published) study gave adults age 60 and above the same tasks, and included some participants who had a history of falling. The differences between those on and off the phone were even more striking in the older group, Kramer said. "Older adults on the phone got run over about 15 percent more often" than those not on the phone, he said, and those with a history of falling fared even worse. "So walking and talking on the phone while old, especially, appears to be dangerous," he said.

Most of the linguistic functions in humans are controlled by the left cerebral hemisphere. A study of captive chimpanzees at the Yerkes National Primate Research Center (Atlanta, Georgia), reported in the January 2010 issue of Elsevier's Cortex, suggests that this "hemispheric lateralization" for language may have its evolutionary roots in the gestural communication of our common ancestors. A large majority of the chimpanzees in the study showed a significant bias towards right-handed gestures when communicating, which may reflect a similar dominance of the left hemisphere for communication in chimpanzees as that seen for language functions in humans.

A team of researchers, supervised by Prof. William D. Hopkins of Agnes Scott College (Decatur, Georgia), studied hand-use in 70 captive chimpanzees over a period of 10 months, recording a variety of communicative gestures specific to chimpanzees. These included 'arm threat', 'extend arm' or 'hand-slap' gestures produced in different social contexts, such as attention-getting interactions, shared excitation, threat, aggression, greeting, reconciliation or invitations for grooming or for play. The gestures were directed at the human observers, as well as toward other chimpanzees.

"The degree of predominance of the right hand for gestures is one of the most pronounced we have ever found in chimpanzees in comparison to other non-communicative manual actions. We already found such manual biases in this species for pointing gestures exclusively directed to humans. These additional data clearly showed that right-handedness for gestures is not specifically associated to interactions with humans, but generalizes to intraspecific communication", notes Prof. Hopkins.

The French co-authors, Dr. Adrien Meguerditchian and Prof. Jacques Vauclair, from the Aix-Marseille University (Aix-en-Provence, France), also point out that "this finding provides additional support to the idea that speech evolved initially from a gestural communicative system in our ancestors. Moreover, gestural communication in apes shares some key features with human language, such as intentionality, referential properties and flexibility of learning and use".