Read about the latest research published in Psychological Science:
A.-Sophie Dubarry, Anais Llorens, Agnès Trébuchon, Romain Carron, Catherine Liégeois-Chauvel, Christian-G. Bénar, and F.-Xavier Alario
There is still much debate as to whether cognitive processing occurs sequentially or in parallel for specific tasks. The authors examined the extent to which parallel processing occurs during picture naming by recording intercerebral activity from the cortex of patients with epilepsy while they performed a picture-naming task. The researchers looked for increases in activity in the high-gamma frequency band (thought to be indicative of cognitive processing). The researchers found a large degree of concurrent activity when analyzing average activation across trials; however, when they examined activity at the level of single trials they found low levels of concurrent activity in all areas except the sensory cortices. This suggests that parallel processing occurs in the cortices — but not elsewhere — during picture naming and it highlights potential problems with using averaged activity to test parallel-processing models.
Fei Wang, Kaiping Peng, Magdalena Chechlacz, Glyn W. Humphreys, and Jie Sui
Independence and interdependence are terms used to describe two different ways people think about themselves and the social world. Independence is associated with personal agency and uniqueness, whereas interdependence is associated with emphasis on interpersonal relations, collectivist values, and social harmony. To examine whether these two orientations are associated with differences in brain structure, participants underwent a structural brain scan and completed two measures of trait independence and interdependence that were used to create a composite score of independence-interdependence. The researchers found that stronger trait independence was associated with larger gray-matter volume in a number of brain regions, including the ventromedial prefrontal cortex (involved in processes including perceptual matching, self-relational thinking, and memory), the right dorsolateral prefrontal cortex (involved in creating a sense of self-agency), and the right rostrolateral prefrontal cortex (thought to be involved in the processing of self-generated information).
Thorsten Pachur, Rui Mata, and Ralph Hertwig
Studies of risky choice often focus on the characteristics of decision quality and risk aversion. Decision quality refers to people’s tendency to choose the option with the highest expected value, whereas risk aversion refers to people’s dislike for options with higher variability in outcome. In this study, the researchers examined cognitive and motivational factors underlying age-based differences in decision quality and risk aversion by having young adults (18-30 years old) and older adults (63-88 years old) complete gain, loss, and mixed-domain choice problems, measures of fluid and crystallized cognitive abilities, and measures of negative and positive affect. Older adults were found to have poorer decision quality than younger adults in the loss domain (a finding associated with older adults’ poorer cognitive abilities) and were found to have less risk aversion than younger adults in the gain and mixed domain (a finding associated with older adults’ lower levels of negative affect).
Heike Elchlepp, Maisy Best, Aureliu Lavric, and Stephen Monsell
Researchers who have studied what happens when participants switch between two different tasks have found that people take longer to respond and that they produce more errors on trials after a switch than on the second of two trials with the same task. Giving participants an advanced warning of the switch reduces these “switch costs” but does not eliminate them. Why might this be? Researchers recorded electroencephalogram (EEG) data as participants completed a task in which they had to categorize a letter as a vowel or a consonant or categorize the letter’s color as “warm” or “cold.” The researchers found that modulation of EEG amplitude related to color processing was delayed on trials in which participants switched from identifying letters to identifying colors compared with trials in which they repeated color identification. This occurred even when participants were given an opportunity to prepare for the task switch. The researchers hypothesize that perceptual encoding processes are prolonged during switch trials, leading to switch costs.