Feeling happy when feeling down : the effectiveness of positive mental imagery in dysphoria

Background and objectives Mental imagery can evoke strong emotional responses, but imagery perspective can influence the response, with observer perspective reducing emotionality. This is important provided that positive imagery can be an effective mood repairing strategy in healthy individuals. However, (sub-clinical) depressed individuals tend to spontaneously adopt an observer perspective. We investigated whether positive imagery would result in a similar emotional response in dysphoric and non-dysphoric individuals when instructed and trained to use field perspective imagery. Additionally, we compared the emotional response in dysphoric individuals who received instructions to dysphoric individuals who received no instructions on processing mode during positive memory recall. Methods Dysphoric and non-dysphoric individuals completed a mood induction procedure imagining positive or neutral memories. They received instructions and practice in the use of field perspective imagery. An additional control group of dysphoric individuals recalled positive memories without receiving instructions on processing mode. Results Dysphoric and non-dysphoric individuals who received instructions on field perspective imagery reported similar use of field and observer perspective imagery, and a similar positive emotional response. Dysphoric individuals who did not receive specific instructions, as compared to those who did, reported greater use of observer perspective and lower levels of positive affect afterwards. Limitations A dysphoric sample limits generalization to clinically depressed individuals, although these individuals are at risk for developing depression. However, mental imagery used in relapse prevention is likely targeting sub-clinical populations. Conclusions Providing practice in field perspective imagery could potentially improve the effectiveness of positive memory recall as a mood repair strategy in (sub-clinically) depressed individuals, and may therefore have important therapeutic benefits.</p

Feeling happy enhances early spatial encoding of peripheral information automatically: electrophysiological time-course and neural sources.

Previous research has shown that positive mood may broaden attention, although it remains unclear whether this effect has a perceptual or a postperceptual locus. In this study, we addressed this question using high-density event-related potential methods. We randomly assigned participants to a positive or a neutral mood condition. Then they performed a demanding oddball task at fixation (primary task ensuring fixation) and a localization task of peripheral stimuli shown at three positions in the upper visual field (secondary task) concurrently. While positive mood did not influence behavioral performance for the primary task, it did facilitate stimulus localization on the secondary task. At the electrophysiological level, we found that the amplitude of the C1 component (reflecting an early retinotopic encoding of the stimulus in V1) was enhanced in the positive, as compared with the neutral, mood group. Importantly, this effect appeared to be largely automatic, because it occurred regardless of the task relevance of the peripheral stimulus and prior to top-down gain control effects seen at the level of the subsequent P1 component. This early effect was also observed irrespective of a change of the target-related P300 component (primary task) by positive mood. These results suggest that positive mood can automatically boost the spatial encoding of peripheral stimuli early on following stimulus onset. This effect can eventually underlie the broadening of spatial attention, which has been associated with this specific mood state

Modulatory effects of positive mood on cognition : lessons from attention and error monitoring.

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Positive emotion broadens attention focus through decreased position-specific spatial encoding in early visual cortex: evidence from ERPs

Recent evidence has suggested that not only stimulus-specific attributes or top-down expectations can modulate attention selection processes, but also the actual mood state of the participant. In this study, we tested the prediction that the induction of positive mood can dynamically influence attention allocation and, in turn, modulate early stimulus sensory processing in primary visual cortex (V1). High-density visual event-related potentials (ERPs) were recorded while participants performed a demanding task at fixation and were presented with peripheral irrelevant visual textures, whose position was systematically varied in the upper visual field (close, medium, or far relative to fixation). Either a neutral or a positive mood was reliably induced and maintained throughout the experimental session. The ERP results showed that the earliest retinotopic component following stimulus onset (C1) strongly varied in topography as a function of the position of the peripheral distractor, in agreement with a near-far spatial gradient. However, this effect was altered for participants in a positive relative to a neutral mood. On the contrary, positive mood did not modulate attention allocation for the central (task-relevant) stimuli, as reflected by the P300 component. We ran a control behavioral experiment confirming that positive emotion selectively impaired attention allocation to the peripheral distractors. These results suggest a mood-dependent tuning of position-specific encoding in V1 rapidly following stimulus onset. We discuss these results against the dominant broaden-and-build theory