Pleasantness Of Pictures Research Articles

Savor the moment: Willful increase in positive emotion and the persistence of this effect across time.

Savoring is an emotion regulation technique that aims to increase, sustain, and deepen positive emotion. It has been incorporated into several novel, "positive affect" interventions for anxiety, depression, and chronic pain, but has not been studied in a laboratory setting. As such, it is unknown whether savoring can modulate subjective and neural correlates of emotion-processing and whether savoring might exert a persistent effect on stimulus processing (i.e., modulating response at subsequent encounter). Here, 49 participants savored or viewed positive and neutral pictures, before seeing the same pictures again approximately 20min later without instructions to savor (or view) pictures. Subjective valence and arousal ratings and the picture-elicited late positive potential (LPP) were assessed during both tasks. Results showed that savoring increased participant ratings of picture pleasantness and arousal as well as a picture-elicited LPP. Moreover, pictures that had previously been savored continued to elicit higher ratings during the subsequent picture viewing task. A larger LPP was observed for previously savored positive and neutral pictures during an early portion of picture viewing; later on during picture viewing, this effect was limited to positive pictures only (i.e., it was not evident for neutral pictures). Results validate savoring as an effective and durable means of increasing positive emotion and are discussed in the context of a broader emotion regulation literature, which has primarily examined the downregulation of negative picture processing.

The Influence of Olfactory Contexts on the Sequential Rating of Odor Pleasantness.

When we sequentially evaluate the characteristics of sensory stimuli, our evaluation of a current stimulus is influenced by those preceding it. One such effect is called hedonic contrast, whereby stimuli are rated more negatively (negative contrast) or positively (positive contrast) if they are preceded by more or less pleasant stimuli. The present study investigated the characteristics of hedonic contrast for olfaction and compared these characteristics with those of a more oft-studied modality, vision. The results from two experiments indicated that both positive and negative contrasts occurred in the sequential rating of picture pleasantness, whereas only negative contrast occurred for olfactory ratings. Notably, overrating of hedonically negative odors following a positive olfactory context was observed even when participants had already rated these same negative odors beforehand; conversely, this did not occur for positive contrast for either sense. These findings indicate that negative odors are more strongly influenced than positive ones, and the rating of positive stimuli may be adjusted to the preceding rating independent of stimulus context. The findings of this study revealed the unique characteristics of hedonic contrast for the olfactory senses.

Age-related increases in false recognition: the role of perceptual and conceptual similarity.

Older adults (OAs) are more likely to falsely recognize novel events than young adults, and recent behavioral and neuroimaging evidence points to a reduced ability to distinguish overlapping information due to decline in hippocampal pattern separation. However, other data suggest a critical role for semantic similarity. Koutstaal et al. [(2003) false recognition of abstract vs. common objects in older and younger adults: testing the semantic categorization account, J. Exp. Psychol. Learn. 29, 499–510] reported that OAs were only vulnerable to false recognition of items with pre-existing semantic representations. We replicated Koutstaal et al.’s (2003) second experiment and examined the influence of independently rated perceptual and conceptual similarity between stimuli and lures. At study, young and OAs judged the pleasantness of pictures of abstract (unfamiliar) and concrete (familiar) items, followed by a surprise recognition test including studied items, similar lures, and novel unrelated items. Experiment 1 used dichotomous “old/new” responses at test, while in Experiment 2 participants were also asked to judge lures as “similar,” to increase explicit demands on pattern separation. In both experiments, OAs showed a greater increase in false recognition for concrete than abstract items relative to the young, replicating Koutstaal et al.’s (2003) findings. However, unlike in the earlier study, there was also an age-related increase in false recognition of abstract lures when multiple similar images had been studied. In line with pattern separation accounts of false recognition, OAs were more likely to misclassify concrete lures with high and moderate, but not low degrees of rated similarity to studied items. Results are consistent with the view that OAs are particularly susceptible to semantic interference in recognition memory, and with the possibility that this reflects age-related decline in pattern separation.

Enhanced Choice for Viewing Cocaine Pictures in Cocaine Addiction

Individuals with cocaine use disorder (CUD) chose cocaine over nondrug rewards. In two newly designed laboratory tasks with pictures, we document this modified choice outside of a cocaine administration paradigm. Choice for viewing cocaine, pleasant, unpleasant, or neutral pictures--under explicit contingencies (choice made between two fully visible side-by-side images) and under more implicit contingencies (selections made between pictures hidden under flipped-over cards)--was examined in 20 CUD and 20 matched healthy control subjects. Subjects also provided self-reported ratings of each picture's pleasantness and arousal. Under both contingencies, CUD subjects chose to view more cocaine pictures than control subjects, group differences that were not fully explained by the self-reported picture ratings. Furthermore, whereas CUD subjects' choice for viewing cocaine pictures exceeded choice for viewing unpleasant pictures (but did not exceed choice for viewing pleasant pictures, in contrast to their self-reported ratings), healthy control subjects avoided viewing cocaine pictures as frequently as, or even more than, unpleasant pictures. Finally, CUD subjects with the most cocaine viewing selections, even when directly compared with selections of the pleasant pictures, also reported the most frequent recent cocaine use. Enhanced drug-related choice in cocaine addiction can be demonstrated even for nonpharmacologic (pictorial) stimuli. This choice, which is modulated by alternative stimuli, partly transcends self-reports (possibly indicative of a disconnect in cocaine addiction between self-reports and objective behavior) to provide an objective marker of addiction severity. Neuroimaging studies are needed to establish the neural underpinnings of such enhanced cocaine-related choice.

Affective pictures processing, attention, and pain tolerance

Two experiments were conducted to determine whether attention mediates the effects of affective distractors on cold pressor pain, or whether the cognitive processes of priming and appraisal best account for the effects. In Experiment I, 65 male respondents were exposed to either pleasant, neutral or unpleasant pictures selected from the International Affective Pictures System (IAPS). The cold-pressor test was administered simultaneously. Consistent with predictions based on priming and appraisal hypotheses, results revealed a linear trend across conditions, such that pain tolerance scores were higher as a function of picture pleasantness. A second study was conducted to examine the role of pain cues in the effects of negative affect on cold pressor pain. Thirty-nine male respondents were exposed to unpleasant pictures that either did or did not include pain-related material. Respondents who viewed pictures without pain cues tolerated the cold water for a longer period of time than respondents who viewed pictures that contained pain-related information. Priming and appraisal processes that might underlie the observed differences, and the type of affective distractors that could be meaningful for enhancing pain tolerance, are discussed.

Do subliminal priming effects on emotion have clinical potential?

Subliminal primes are able to influence the affective evaluation of subsequent supra-liminal stimuli. For example, Murphy and Zajonc (Journal of Personality and Social Psychology 64, 723–739, 1993) found that Chinese characters are evaluated more positively after they have been preceded by subliminal smiling faces. However, to be ther-apeutically relevant, subliminal primes should be able to change strong emotions. The present experiment explored this issue. Spider-fearful and non-fearful undergraduates were exposed to subliminally presented (8ms) positive, negative, and neutral primes. Primes were immediately followed by a picture of a spider or snake (1500ms). Subjects then evaluated the affective quality of the picture, using visual analogue scales. No evidence was found to suggest that (un) pleasantness of pictures can be modulated by subliminal priming. In the non-fearful group, spiders were evaluated as more frightening after negative priming. Yet, such an effect was not evident for the fearful group. The findings indicate that subliminal priming only affects the evaluation of relatively neutral stimuli. Thus, subliminal techniques seem to have little or no therapeutic value.

Probe P3 and blinks: two measures of affective startle modulation.

Two concurrent measures of the evoked startle response, the elicited blink reflex and the event-related potential, were measured while individuals viewed pictures that varied in pleasure and arousal. Replicating previous findings, the blink response was modulated by picture pleasantness, with larger reflexes elicited in the context of viewing unpleasant versus pleasant pictures. However, the probe P3 was primarily modulated by picture arousal, with smaller P3 responses elicited when viewing affective (pleasant or unpleasant) than when viewing neutral pictures. Both modulatory effects were sustained for probes presented in a subsequent picture imagery period. These data suggest that two measurable responses to the same startle probe are differentially modified by emotional context, with blink magnitude varying with pleasure and probe P3 varying with stimulus arousal.