Emotional Arousal and Valence Jointly Modulate the Auditory Response: A 40-Hz ASSR Study

Negative emotional cues improve free recall of positive and neutral words in unmedicated patients with major depressive disorder

Individuals with major depressive disorder (MDD) exhibit attentional biases toward negative, mood-congruent stimuli while filtering out positive and neutral stimuli, resulting in memory biases to negative content. While attentional and memory biases in MDD have been extensively studied, the underlying mechanisms of these biases remain unclear. The current study investigates a novel model proposing that exposure to negative emotional cues triggers a transient "attentional window" in individuals with MDD, leading to heightened and deeper cognitive processing of any subsequent information, irrespective of its content. Forty-two unmedicated patients with MDD and no comorbid disorder and 41 healthy controls, completed six blocks of the emotional memory task, in which they were asked to watch a short video (negative, neutral, or positive valence) followed by a memory test on a list of neutral or positive valance words. Results indicated that participants with MDD, but not healthy controls, had better recall performance after a negative video compared to after neutral or positive videos, and that this effect occurred for both neutral and positive word-lists. These findings provide evidence that participants with MDD engage in deeper information processing following exposure to negative emotional stimuli. Potential clinical implications are discussed.

Control your emotions: evidence for a shared mechanism of cognitive and emotional control

The current investigation examined the bidirectional effects of cognitive control and emotional control and the overlap between these two systems in regulating emotions. Based on recent neural and cognitive findings, we hypothesised that two control systems largely overlap as control recruited for one system (either emotional or cognitive) can be used by the other system. In two experiments, participants completed novel versions of either the Stroop task (Experiment 1) or the Flanker task (Experiment 2) in which the emotional and cognitive control systems were actively manipulated into either a high or low emotional-load condition (achieved by varying the proportions of negative-valence emotional cues) and a high and a low cognitive control condition (achieved through varying the proportion of conflict-laden trials). In both experiments, participants' performance was impaired when both emotional and cognitive control were low, but significantly and similarly improved when one of the two control mechanisms were activated - the emotional or the cognitive. In Experiment 2, performance was further improved when both systems were activated. Our results give further support for a more integrative notion of control in which the two systems (emotional and cognitive control) not only influence each other, but rather extensively overlap.

Trait anxiety modulates the detection sensitivity of negative affect in speech: an online pilot study

Acoustic perception of emotions in speech is relevant for humans to navigate the social environment optimally. While sensory perception is known to be influenced by ambient noise, and bodily internal states (e.g., emotional arousal and anxiety), their relationship to human auditory perception is relatively less understood. In a supervised, online pilot experiment sans the artificially controlled laboratory environment, we asked if the detection sensitivity of emotions conveyed by human speech-in-noise (acoustic signals) varies between individuals with relatively lower and higher levels of subclinical trait-anxiety, respectively. In a task, participants (n = 28) accurately discriminated the target emotion conveyed by the temporally unpredictable acoustic signals (signal to noise ratio = 10 dB), which were manipulated at four levels (Happy, Neutral, Fear, and Disgust). We calculated the empirical area under the curve (a measure of acoustic signal detection sensitivity) based on signal detection theory to answer our questions. A subset of individuals with High trait-anxiety relative to Low in the above sample showed significantly lower detection sensitivities to acoustic signals of negative emotions - Disgust and Fear and significantly lower detection sensitivities to acoustic signals when averaged across all emotions. The results from this pilot study with a small but statistically relevant sample size suggest that trait-anxiety levels influence the overall acoustic detection of speech-in-noise, especially those conveying threatening/negative affect. The findings are relevant for future research on acoustic perception anomalies underlying affective traits and disorders.

Steady-state auditory motion based potentials evoked by intermittent periodic virtual sound source and the effect of auditory noise on EEG enhancement

Hearing is one of the most important human perception forms, and humans can capture the movement of sound in complex environments. On the basis of this phenomenon, this study explored the possibility of eliciting a steady-state brain response in an intermittent periodic motion sound source. In this study, a novel discrete continuous and orderly change of sound source positions stimulation paradigm was designed based on virtual sound using head-related transfer functions (HRTFs). And then the auditory motion stimulation paradigms with different noise levels were designed by changing the signal-to-noise ratio (SNR). The characteristics of brain response and the effects of different noises on brain response were studied by analyzing electroencephalogram (EEG) signals evoked by the proposed stimulation. Experimental results showed that the proposed paradigm could elicit a novel steady-state auditory evoked potential (AEP), i.e., steady-state motion auditory evoked potential (SSMAEP). And moderate noise could enhance SSMAEP amplitude and corresponding brain connectivity. This study enriches the types of AEPs and provides insights into the mechanism of brain processing of motion sound sources and the impact of noise on brain processing.