Driven to distraction: Age-related differences
Older adults are considered more susceptible to distraction while driving in traffic or undertaking other daily activities that require us to keep track of multiple objects at a time. Researchers have understood for some time that this age-related increase in distractibility is due to so-called “selective processing,” whereby our brains pay more attention to relevant information and suppress neural responses to irrelevant information. However, little research has explained the exact timing and mechanisms for this decline. A new study examines this issue by measuring differences in electrophysiological responses to a moving object task among younger and older adults. The authors write: “By means of EEG recordings, we were able to delineate the neural processing of target objects, moving distractor objects, and stationary distractor objects on a millisecond time scale.” They found that normal aging affects the efficiency and timing of early visual processing during multiple- object tracking, in particular with older adults showing a delay in selective processing at an early phase of visual attention.
“Normal Aging Delays and Compromises Early Multifocal Visual Attention during Object Tracking,” Viola S. Störmer (Max Planck Institute for Human Behavior), Shu-Chen Li, Hauke R. Heekeren, and Ulman Lindenberger, Journal of Cognitive Neuroscience, published online September 27, 2012.
Accentuating our speech
The melody and rhythm of how we talk – so-called “prosody” – shapes how a listener understands our message. Accenting a word, for example, denotes emphasis and importance. Researchers wanted to study how we neurally process such accents both when they assist with meaning and when they are superfluous or incongruent with the overall message. Using ERP (event-related potential) they measured brain responses to sentences that contained accented elements that were either congruous or incongruous relative to a preceding question. They found that superfluous accents activated a specific set of neural systems that are inactive when incongruent information remains unaccented. They did not find this effect when accents were missing for contextually relevant information. “These results challenge previous findings of greater processing for missing accents and suggest that the natural processing of prosody involves a set of distinct, temporally organized neural systems,” they write.
“Less Is Not More: Neural Responses to Missing and Superfluous Accents in Context,” Diana V. Dimitrova (University of Groningen), Laurie A. Stowe, Gisela Redeker, and John C. J. Hoeks, Journal of Cognitive Neuroscience, published online September 27, 2012.
Why handshakes matter: How our brains process body language in business settings
Body language can be a powerful determinant of first impressions in social interactions. A new study seeks to better understand how our brains process such body language in business settings. The researchers designed video presentations involving a host using whole body language to signal approach or avoidance; half of the interactions were preceded by a handshake. Subjects watching the videos underwent fMRI scanning, and following and the video viewing, they rated the hosts on “interest in doing business,” “competence,” and “trustworthiness.” In general, participants rated the approach condition more favorably than the avoidance one, and the handshake improved the favorable ratings for both conditions. The researchers also found that common brain regions in the social cognition network were involved in the evaluation of the approach and avoidance conditions. Specifically, the results showed that positive evaluation of the approach behavior and the positive impact of the handshake were linked to increased sensitivity to approach versus avoidance in the amygdala and superior temporal sulcus. And they found greater activity in the nucleus accumbens for the handshake than for the no-handshake condition. Read more about this story in an upcoming web feature on this site.
“The Power of a Handshake: Neural Correlates of Evaluative Judgments in Observed Social Interactions,” Sanda Dolcos (University of Illinios), Keen Sung, Jennifer J. Argo, Sophie Flor-Henry, and Florin Dolcos, Journal of Cognitive Neuroscience, published online September 27, 2012.