Event Segmentation Enhances Older Adults' Reactive Cognitive Control Bias.

The present study examined the effect of event segmentation on cognitive control mode use in a sample of older adults (N = 30; Mage = 73, SDage = 4.75) using a modified AX-Continuous Performance Test (AX-CPT). This task included a perceptual event boundary between each cue and its forthcoming probe by means of a spatial shift across the left and right side of the display. Past research showed that young adults' existing proactive control bias could be enhanced in an event segmented AX-CPT relative to their performance on a standard AX-CPT. For older adults who adopt reactive control by default, the event boundary was expected to impede cue-reactivation during probe presentation, and thus further enhance their existing reactive control bias. To examine this, older adults were tested with a standard and an event segmented AX-CPT in two blocks, with error rates revealing a shift toward greater reactive control use in the event segmented relative to the standard AX-CPT. Findings supported our hypothesis that placing a spatial event boundary between each cue and forthcoming probe would further enhance older adults' reactive control bias. This study contributes to the sparse but growing literature on the effects of task-specific manipulations on cognitive control use. The results are discussed in light of the dual mechanisms of control framework and the event horizon model.

Music training modulates theta brain oscillations associated with response suppression.

There is growing interest in developing training programs to mitigate cognitive decline associated with normal aging. Here, we assessed the effect of 3-month music and visual art training programs on the oscillatory brain activity of older adults using a partially randomized intervention design. High-density electroencephalography (EEG) was measured during the pre- and post-training sessions while participants completed a visual GoNoGo task. Time-frequency representations were calculated in regions of interest encompassing the visual, parietal, and prefrontal cortices. Before training, NoGo trials generated greater theta power than Go trials from 300 to 500 ms post-stimulus in mid-central and frontal brain areas. Theta power indexing response suppression was significantly reduced after music training. There was no significant difference between pre- and post-test for the visual art or the control group. The effect of music training on theta power indexing response suppression was associated with reduced functional connectivity between prefrontal, visual, and auditory regions. These results suggest that theta power indexes executive control mechanisms in older adults. Music training affects theta power and functional connectivity associated with response suppression. These findings contribute to a better understanding of inhibitory control ability in older adults and the neuroplastic effects of music interventions.

The effect of oral contraceptive use on cortisol reactivity to the Trier Social Stress Test: A meta-analysis.

BACKGROUND: Some research suggests that oral contraceptive pills (OCPs) blunt the cortisol stress response, thus OCP users are often excluded from stress research. The current study examined changes in salivary cortisol among females taking OCPs and naturally cycling (NC) females after exposure to the Trier Social Stress Test (TSST). METHODS: The literature search included the terms "oral contraceptives" OR "oral contraception" OR "birth control" OR "birth control pill" AND "Trier Social Stress Test" OR "TSST" AND "cortisol" OR "salivary cortisol." A total of 14 studies with 36 independent samples were included in the meta-analysis. Participant information, including pre- and post- TSST measures of salivary cortisol, and subgroup (i.e., OCP or menstrual cycle phase), were extracted. Additional study characteristics including age, length of stressor, type of OCP, time of day the cortisol samples were collected, and type of cortisol assay used were also considered. RESULTS: Findings from the current meta-analysis indicated that changes in salivary cortisol in NC participants following the TSST, D = 4.31, SE = 0.53, 95% CI = 3.27, 5.35, were greater than the changes observed in participants on OCPs D = 1.50, SE = 0.30, 95% CI = 0.91, 2.09. Study effects were heterogeneous, Fisher's Z = 10.87, Q = 620.57, p = < 0.001. Between-phase analyses were also conducted. CONCLUSIONS: Results demonstrate that OCPs blunt cortisol reactivity relative to NC females. There was significant heterogeneity, except between OCP and follicular phase groups. Implications for research design and methodology are discussed.