Electrophysiological correlates of emotional responding in schizophrenia.

People with schizophrenia consistently report normal levels of pleasant emotion when exposed to evocative stimuli, suggesting intact consummatory pleasure. However, little is known about the neural correlates and time course of emotion in schizophrenia. This study used a well-validated affective picture viewing task that elicits a characteristic pattern of event-related potentials (ERPs) from early to later processing stages (i.e., P1, P2, P3, and late positive potentials [LPPs]). Thirty-eight stabilized outpatients with schizophrenia and 36 healthy controls viewed standardized pleasant, unpleasant, and neutral pictures while ERPs were recorded and subsequently rated their emotional responses to the stimuli. Patients and controls responded to the pictures similarly in terms of their valence ratings, as well as the initial ERP components (P1, P2, and P3). However, at the later LPP component (500–1,000 ms), patients displayed diminished electrophysiological discrimination between pleasant versus neutral stimuli. This pattern suggests that patients demonstrated normal self-reported emotional experience and intact initial sensory processing of and resource allocation to emotional stimuli. However, they showed a disruption in a later component associated with sustained attentional processing of emotional stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conflict and criterion setting in recognition memory.

Recognition memory requires both retrieval processes and control processes such as criterion setting. Decision criteria were manipulated by offering different payoffs for correct "old" versus "new" responses. Criterion setting influenced the following late-occurring (1,000+ ms), conflict-sensitive event-related brain potential (ERP) components: the stimulus-locked late posterior negativity (LPN) and the response-locked error-related negativity (ERN). The LPN-ERN were most negative to hits under conservative payoff conditions involving conflict between the correct old response and the payoff for new responses. This same conservative-hit condition was most frequently associated with response reversals when fast initial judgments were followed by slower judgments. Postresponse ERP activity may index conflict-sensitive processes underlying postretrieval cognitive control mechanisms involved with assessing responses to current items and updating response criteria on later trials. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The influence of emotional valence on age differences in early processing and memory.

This study examined older and younger adults' attentional biases and subsequent incidental recognition memory for distracting positive, negative, and neutral words. Younger adults were more distracted by negative stimuli than by positive or neutral stimuli, and they correctly recognized more negative than positive words. Older adults, however, attended equally to all stimuli yet showed reliable recognition only for positive words. Thus, although an attentional bias toward negative words carried over into recognition performance for younger adults, older adults' bias appeared to be limited to remembering positive information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Beyond good and evil: The time-course of neural activity elicited by specific picture content.

The present study examined electrocortical evidence for a negativity bias, focusing on the impact of specific picture content on a range of event-related potentials (ERPs). To this end, ERPs were recorded while 67 participants viewed a variety of pictures from the International Affective Picture System. Examination of broad categories (i.e., pleasant, neutral, unpleasant) found no evidence for a negativity bias in two early components, the N1 and the Early Posterior Negativity (EPN), but revealed that unpleasant images did elicit a larger late positive potential (LPP) than pleasant pictures. However, images of erotica and mutilation elicited comparable LPP responses, as did affiliative and threatening images. Exciting (i.e., sports) images and disgusting images elicited smaller LPPs than other emotional images, similar to neutral images containing people—which were associated with the largest LPPs among neutral pictures. When these three anomalous categories (exciting, disgusting, and scenes with people) were excluded, unpleasant images no longer elicited a larger LPP than pleasant images. Thus, including exciting images in pleasant ERP averages disproportionately reduces the LPP. The present findings are discussed in light of the motivational significance of specific picture subtypes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of emotional content on reality-monitoring performance in young and older adults.

Reality monitoring refers to a person's ability to distinguish between perceived and imagined events. Prior research has demonstrated that young adults show a reality-monitoring advantage for negative arousing information as compared with neutral information. The present research examined whether this reality-monitoring benefit extends to positive information in young adults and whether older adults show a reality-monitoring advantage for emotional information of either valence. Two studies revealed no evidence for a reality-monitoring advantage for positive information; in both age groups, the reality-monitoring advantage existed only for negative information. Older adults were, however, more likely to remember that a positive item had been included on a study list than they were to remember that a nonemotional item had been studied. Young adults did not show this mnemonic enhancement for positive information. These results indicate that although older adults may show some mnemonic benefits for positive information (i.e., an enhanced ability to remember that a positive item was studied), they do not always show enhanced memory for source-specifying details of a positive item's presentation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interdependent self-construal moderates the age-related negativity reduction effect in memory and visual attention.

There is some debate concerning whether people selectively attend to and remember less negative relative to positive or neutral information with age. We argue that such an age-related negativity reduction effect may be attenuated among individuals who are more interdependent, as they are likely to perceive negative information as equally useful and important as positive information. In 2 studies, we tested this hypothesis by examining memory for (Study 1) and visual attention to (Study 2) emotional (positive vs. negative) stimuli among younger, middle-aged, and older Chinese participants. Findings revealed that the age-related negativity reduction effect was found to a lesser extent among older Chinese individuals who were more interdependent than among those who were less interdependent. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging and emotional memory: The co-occurrence of neurophysiological and behavioral positivity effects.

The positivity effect is a trend for adults to increasingly process positive and/or decreasingly process negative information compared with other information with advancing age. The positivity effect has been observed with behavioral measures, such as in attention and memory tests, and with measures of neurophysiological activity, such as in amygdala activation and the late positive potential (LPP). In this study, it was investigated whether these behavioral and neurophysiological positivity effects co-occur. The electroencephalogram of younger (19–26 years) and older (65–82 years) adults was recorded while they encoded unpleasant, neutral, and pleasant pictures for retrieval in free and cued recall tests. Positivity effects occurred in the late LPP amplitude (700–1,000 ms) and in the free recall test, with negativity biases in younger adults and no biases in older adults. The occurrence of a valence bias in the LPP was substantially but nonsignificantly correlated with the occurrence of a similar valence bias in memory in the older adults. In conclusion, neurophysiological and behavioral positivity effects appear to co-occur, a finding that awaits expansion using different neurophysiological and behavioral measures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of aging on the neural correlates of successful item and source memory encoding.

To investigate the neural basis of age-related source memory (SM) deficits, young and older adults were scanned with fMRI while encoding faces, scenes, and face-scene pairs. Successful encoding activity was identified by comparing encoding activity for subsequently remembered versus forgotten items or pairs. Age deficits in successful encoding activity in hippocampal and prefrontal regions were more pronounced for SM (pairs) as compared with item memory (faces and scenes). Age-related reductions were also found in regions specialized in processing faces (fusiform face area) and scenes (parahippocampal place area), but these reductions were similar for item and SM. Functional connectivity between the hippocampus and the rest of the brain was also affected by aging; whereas connections with posterior cortices were weaker in older adults, connections with anterior cortices, including prefrontal regions, were stronger in older adults. Taken together, the results provide a link between SM deficits in older adults and reduced recruitment of hippocampal and prefrontal regions during encoding. The functional connectivity findings are consistent with a posterior-anterior shift with aging previously reported in several cognitive domains and linked to functional compensation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lorazepam and scopolamine: A single-dose comparison of effects on human memory and attentional processes.

This placebo-controlled, double-blind, double-dummy, independent groups study directly compared effects of the benzodiazepine, lorazepam (2.0 mg/70 kg orally administered), and the anticholinergic scopolamine (0.6 mg/70 kg subcutaneously administered) on memory and attentional measures hypothesized to differentiate the drugs. At the studied doses, lorazepam and scopolamine produced similar decrements in psychomotor performance, free recall, and overall sensitivity in distinguishing between studied and nonstudied items on a recognition memory test. However, the drugs differed with respect to effects on working memory, response bias, metacognition, subjective awareness, and selective attention. In addition to providing information about the cognitive psychopharmacological profiles of drugs with distinct neurochemical and pharmacological mechanisms of action, this study also informs the understanding of memory and attentional processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of emotional valence and arousal upon memory trade-offs with aging.

Attention can be attracted faster by emotional relative to neutral information, and memory also can be strengthened for that emotional information. However, within visual scenes, often there is an advantage in memory for central emotional portions at the expense of memory for peripheral background information, called an emotion-induced memory trade-off. The authors examined how aging impacts the trade-off by manipulating valence (positive, negative) and arousal (low, high) of a central emotional item within a neutral background scene and testing memory for item and background components separately. They also assessed memory after 2 study–test delay intervals, to investigate age differences in the trade-off over time. Results revealed similar patterns of performance between groups after a short study–test delay, with both age groups showing robust memory trade-offs. After a longer delay, young and older adults showed enhanced memory for emotional items but at a cost to memory for background information only for young adults in negative arousing scenes. These results emphasize that attention and consolidation stage processes interact to shape how emotional memory is constructed in young and older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

When side matters: Hemispheric processing and the visual specificity of emotional memories.

Previous studies have shown that the right hemisphere processes the visual details of objects and the emotionality of information. These two roles of the right hemisphere have not been examined concurrently. In the present study, the authors examined whether right hemisphere processing would lead to particularly good memory for the visual details of emotional stimuli. Participants viewed positive, negative, and neutral objects, displayed to the left or right of a fixation cross. Later, participants performed a recognition task in which they evaluated whether items were "same" (same visual details), "similar" (same verbal label, different visual details), or "new" (unrelated) in comparison with the studied objects. Participants remembered the visual details of negative items well, and this advantage in memory specificity was particularly pronounced when the items had been presented directly to the right hemisphere (i.e., to the left of the fixation cross). These results suggest that there is an episodic memory benefit conveyed when negative items are presented directly to the right hemisphere, likely because of the specialization of the right hemisphere for processing both visual detail and negatively valenced emotional information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temporal processing of emotional stimuli: The capture and release of attention by angry faces.

Neuroimaging data suggest that emotional information, especially threatening faces, automatically captures attention and receives rapid processing. While this is consistent with the majority of behavioral data, behavioral studies of the attentional blink (AB) additionally reveal that aversive emotional first target (T1) stimuli are associated with prolonged attentional engagement or “dwell” time. One explanation for this difference is that few AB studies have utilized manipulations of facial emotion as the T1. To address this, schematic faces varying in expression (neutral, angry, happy) served as the T1 in the current research. Results revealed that the blink associated with an angry T1 face was, primarily, of greater magnitude than that associated with either a neutral or happy T1 face, and also that initial recovery from this processing bias was faster following angry, compared with happy, T1 faces. The current data therefore provide important information regarding the time-course of attentional capture by angry faces: Angry faces are associated with both the rapid capture and rapid release of attention. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Working memory capacity and the self-regulation of emotional expression and experience.

This research examined the relationship between individual differences in working memory capacity and the self-regulation of emotional expression and emotional experience. Four studies revealed that people higher in working memory capacity suppressed expressions of negative emotion (Study 1) and positive emotion (Study 2) better than did people lower in working memory capacity. Furthermore, compared to people lower in working memory capacity, people higher in capacity more capably appraised emotional stimuli in an unemotional manner and thereby experienced (Studies 3 and 4) and expressed (Study 4) less emotion in response to those stimuli. These findings indicate that cognitive ability contributes to the control of emotional responding. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The beneficial effects of additional task load, positive affect, and instruction on the attentional blink.

The attentional blink reflects the impaired ability to identify the 2nd of 2 targets presented in close succession--a phenomenon that is generally thought to reflect a fundamental cognitive limitation. However, the fundamental nature of this impairment has recently been called into question by the counterintuitive finding that task-irrelevant mental activity improves attentional blink performance (C. N. L. Olivers & S. Nieuwenhuis, 2005). The present study found a reduced attentional blink when participants concurrently performed an additional memory task, viewed pictures of positive affective content, or were instructed to focus less on the task. These findings support the hypothesis that the attentional blink is due to an overinvestment of attentional resources in stimulus processing, a suboptimal processing mode that can be counteracted by manipulations promoting divided attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Elevated false recollection of emotional pictures in young and older adults.

Current theories predict opposing effects of emotionally arousing information on false memory. If emotion enhances true recollection, then false recollection might be lower for emotional than for neutral pictures. However, if emotion enhances conceptual relatedness, then false recollection might increase for nonstudied but emotionally related pictures. We contrasted these 2 factors in young and older adults, using the International Affective Pictures Systems set (Lang, Bradley, & Cuthbert, 2005). Although both age groups used recollection in our task, false recollection was greatest for emotional pictures, supporting a conceptual relatedness account. Finally, even after accuracy differences were controlled, age was related to high-confidence false recollection of emotional pictures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attachment and emotional memory: Investigating the source and extent of avoidant memory impairments.

Attachment avoidance has been associated with impairments in memory for material with emotional, attachment-related themes (e.g., loss). In the present study the author investigated the source and extent of these memory deficits by examining working memory capacity for attachment-related and nonattachment-related material. Avoidance was associated with deficits in working memory for positive and negative attachment-related stimuli. However, avoidance was unrelated to working memory capacity for nonattachment-related stimuli, both emotional and nonemotional. These findings are consistent with the proposal that avoidant individuals defensively limit the processing of potentially distressing information. Attachment anxiety was unrelated to working memory capacity across word type. Implications of the findings for defensive strategies and emotional memory are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preferences for emotional information in older and younger adults: A meta-analysis of memory and attention tasks.

The authors conducted a meta-analysis to determine the magnitude of older and younger adults' preferences for emotional stimuli in studies of attention and memory. Analyses involved 1,085 older adults from 37 independent samples and 3,150 younger adults from 86 independent samples. Both age groups exhibited small to medium emotion salience effects (i.e., preference for emotionally valenced stimuli over neutral stimuli) as well as positivity preferences (i.e., preference for positively valenced stimuli over neutral stimuli) and negativity preferences (i.e., preference for negatively valenced stimuli to neutral stimuli). There were few age differences overall. Type of measurement appeared to influence the magnitude of effects; recognition studies indicated significant age effects, where older adults showed smaller effects for emotion salience and negativity preferences than younger adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Long-lasting attentional influence of negative and taboo words in an auditory variant of the emotional Stroop task.

Using an auditory adaptation of the emotional and taboo Stroop tasks, the authors compared the effects of negative and taboo spoken words in mixed and blocked designs. Both types of words elicited carryover effects with mixed presentations and interference with blocked presentations, suggesting similar long-lasting attentional effects. Both were also relatively resilient to the long-lasting influence of the preceding emotional word. Hence, contrary to what has been assumed (Schmidt & Saari, 2007), negative and taboo words do not seem to differ in terms of the temporal dynamics of the interdimensional shifting, at least in the auditory modality. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The persistence of attention to emotion: Brain potentials during and after picture presentation.

Emotional stimuli have been shown to elicit increased perceptual processing and attentional allocation. The late positive potential (LPP) is a sustained P300-like component of the event-related potential that is enhanced after the presentation of pleasant and unpleasant pictures as compared with neutral pictures. In this study, the LPP was measured using dense array electroencephalograph both before and after pleasant, neutral, and unpleasant images to examine the time course of attentional allocation toward emotional stimuli. Results from 17 participants confirmed that the LPP was larger after emotional than neutral images and that this effect persisted for 800 ms after pleasant picture offset and at least 1,000 ms after unpleasant picture offset. The persistence of increased attention after unpleasant compared to pleasant stimuli is consistent with the existence of a negativity bias. Overall, these results indicate that attentional capture of emotion continues well beyond picture presentation and that this can be measured with the LPP. Implications and directions for future research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)