Manipulating memory efficacy affects the behavioral and neural profiles of deterministic learning and decision-making

The dynamics of functional brain network segregation in feedback-driven learning

Prior evidence suggests that increasingly efficient task performance in human learning is associated with large scale brain network dynamics. However, the specific nature of this general relationship has remained unclear. Here, we characterize performance improvement during feedback-driven stimulus-response (S-R) learning by learning rate as well as S-R habit strength and test whether and how these two behavioral measures are associated with a functional brain state transition from a more integrated to a more segregated brain state across learning. Capitalizing on two separate fMRI studies using similar but not identical experimental designs, we demonstrate for both studies that a higher learning rate is associated with a more rapid brain network segregation. By contrast, S-R habit strength is not reliably related to changes in brain network segregation. Overall, our current study results highlight the utility of dynamic functional brain state analysis. From a broader perspective taking into account previous study results, our findings align with a framework that conceptualizes brain network segregation as a general feature of processing efficiency not only in feedback-driven learning as in the present study but also in other types of learning and in other task domains.

Unique patterns of hearing loss and cognition in older adults' neural responses to cues for speech recognition difficulty

Older adults with hearing loss experience significant difficulties understanding speech in noise, perhaps due in part to limited benefit from supporting executive functions that enable the use of environmental cues signaling changes in listening conditions. Here we examined the degree to which 41 older adults (60.56-86.25 years) exhibited cortical responses to informative listening difficulty cues that communicated the listening difficulty for each trial compared to neutral cues that were uninformative of listening difficulty. Word recognition was significantly higher for informative compared to uninformative cues in a + 10 dB signal-to-noise ratio (SNR) condition, and response latencies were significantly shorter for informative cues in the + 10 dB SNR and the more-challenging + 2 dB SNR conditions. Informative cues were associated with elevated blood oxygenation level-dependent contrast in visual and parietal cortex. A cue-SNR interaction effect was observed in the cingulo-opercular (CO) network, such that activity only differed between SNR conditions when an informative cue was presented. That is, participants used the informative cues to prepare for changes in listening difficulty from one trial to the next. This cue-SNR interaction effect was driven by older adults with more low-frequency hearing loss and was not observed for those with more high-frequency hearing loss, poorer set-shifting task performance, and lower frontal operculum gray matter volume. These results suggest that proactive strategies for engaging CO adaptive control may be important for older adults with high-frequency hearing loss to optimize speech recognition in changing and challenging listening conditions.

Altered brain activities associated with cue reactivity during forced break in subjects with Internet gaming disorder

BACKGROUND

Studies have proven that forced break can elicit strong psychological cravings for addictive behaviors. This phenomenon could create an excellent situation to study the neural underpinnings of addiction. The current study explores brain features during a cue-reactivity task in Internet gaming disorder (IGD) when participants were forced to stop their gaming behaviors.

METHODS

Forty-nine IGD subjects and forty-nine matched recreational Internet game users (RGU) were asked to complete a cue-reactivity task when their ongoing gaming behaviors were forced to break. We compared their brain responses to gaming cues and tried to find specific features associated with IGD.

RESULTS

Compared with RGU, the IGD subjects showed decreased activation in the anterior cingulate cortex (ACC), parahippocampal gyrus, and dorsolateral prefrontal cortex (DLPFC). Significant negative correlations were observed between self-reported gaming cravings and the baseline activation level (bate value) of the ACC, DLPFC, and parahippocampal gyrus.

CONCLUSIONS

IGD subjects were unable to suppress their gaming cravings after unexpectedly forced break. This result could also explain why RGU subjects are able to play online games without developing dependence.