Schaefer A, Fletcher K, Pottage CL, Alexander K, Brown C.
Neuroreport, 20, 319 - 324
The effects of negative emotional intensity on memory-related brain activity were tested by using human scalp event-related potentials (ERP). A neural index of memory function - the electrophysiological 'Old-New' effect - was obtained from participants undertaking a memory recognition test of previously studied ('old') and unstudied ('new') pictures of variable levels of negative emotional intensity. The magnitude of the old-new effect was compared across four different levels of linearly increasing stimulus emotional intensity. Results revealed an inverted-U-shaped effect of emotional intensity on the magnitude of ERP old-new differences starting at 300 ms after stimulus onset. These results suggest that moderate negative emotions can enhance memory brain function, whereas extreme levels of emotional intensity have the potential of inhibiting memory function. Results are discussed in terms of their implications for neurobiological and psychological models of emotion-memory interactions.
Showing posts with label memory. Show all posts
Showing posts with label memory. Show all posts
Friday, February 13, 2009
Saturday, October 11, 2008
ARTICLE UPDATE - Directed forgetting of emotional words.
Minnema MT, Knowlton BJ.
Emotion, 8, 643-652
Emotional material may induce processing limitations affecting memory performance. In the present study, the authors investigated how the emotional content of words influences the degree to which participants can be directed to forget them. In Experiment 1, the authors found that negative-valence words were recalled better when participants were told to forget them than when they were told to remember them. This effect was only obtained when a study-list of negative words was presented after the cue to remember or forget the first list. The effect was correlated with negative mood as assessed by the PANAS. Similar results were obtained in Experiment 2, in which the induction of negative arousal by a mild stressor abolished the directed forgetting of words when the following study list was comprised of negative words. These results support the idea that directed forgetting relies on cognitive control processes that may be disrupted by negative emotion.
Emotion, 8, 643-652
Emotional material may induce processing limitations affecting memory performance. In the present study, the authors investigated how the emotional content of words influences the degree to which participants can be directed to forget them. In Experiment 1, the authors found that negative-valence words were recalled better when participants were told to forget them than when they were told to remember them. This effect was only obtained when a study-list of negative words was presented after the cue to remember or forget the first list. The effect was correlated with negative mood as assessed by the PANAS. Similar results were obtained in Experiment 2, in which the induction of negative arousal by a mild stressor abolished the directed forgetting of words when the following study list was comprised of negative words. These results support the idea that directed forgetting relies on cognitive control processes that may be disrupted by negative emotion.
Friday, July 18, 2008
ARTICLE UPDATE - Discriminating between changes in bias and changes in accuracy for recognition memory of emotional stimuli.
Grider RC, Malmberg KJ.
Memory & Cognition, 36, 933-946
A debate has emerged as to whether recognition of emotional stimuli is more accurate or more biased than recognition of nonemotional stimuli. Teasing apart changes in accuracy versus changes in bias requires a measurement model. However, different models have been adopted by different researchers, and this has contributed to the current debate. In this article, different measurement models are discussed, and the signal detection model that is most appropriate for recognition is adopted to investigate the effects of valence and arousal on recognition memory performance, using receiver operating characteristic analyses. In addition, complementary two-alternative forced choice experiments were conducted in order to generalize the empirical findings and interpret them under a relatively relaxed set of measurement assumptions. Across all experiments, accuracy was greater for highly valenced stimuli and stimuli with high arousal value. In addition, a bias to endorse positively valenced stimuli was observed. These results are discussed within an adaptive memory framework that assumes that emotion plays an important role in the allocation of attentional resources.
Memory & Cognition, 36, 933-946
A debate has emerged as to whether recognition of emotional stimuli is more accurate or more biased than recognition of nonemotional stimuli. Teasing apart changes in accuracy versus changes in bias requires a measurement model. However, different models have been adopted by different researchers, and this has contributed to the current debate. In this article, different measurement models are discussed, and the signal detection model that is most appropriate for recognition is adopted to investigate the effects of valence and arousal on recognition memory performance, using receiver operating characteristic analyses. In addition, complementary two-alternative forced choice experiments were conducted in order to generalize the empirical findings and interpret them under a relatively relaxed set of measurement assumptions. Across all experiments, accuracy was greater for highly valenced stimuli and stimuli with high arousal value. In addition, a bias to endorse positively valenced stimuli was observed. These results are discussed within an adaptive memory framework that assumes that emotion plays an important role in the allocation of attentional resources.
Friday, May 09, 2008
ARTICLE UPDATE - In this paper we discuss the issue of the processes potentially underlying the emergence of emotional consciousness in the light of t
Kapucu A, Rotello CM, Ready RE, Seidl KN.
Journal of Experimental Psychology: Learning, Memory and Cognition, 34, 703-711
Older adults sometimes show a recall advantage for emotionally positive, rather than neutral or negative, stimuli (S. T. Charles, M. Mather, & L. L. Carstensen, 2003). In contrast, younger adults respond "old" and "remember" more often to negative materials in recognition tests. For younger adults, both effects are due to response bias changes rather than to enhanced memory accuracy (S. Dougal & C. M. Rotello, 2007). We presented older and younger adults with emotional and neutral stimuli in a remember-know paradigm. Signal-detection and model-based analyses showed that memory accuracy did not differ for the neutral, negative, and positive stimuli, and that "remember" responses did not reflect the use of recollection. However, both age groups showed large and significant response bias effects of emotion: Younger adults tended to say "old" and "remember" more often in response to negative words than to positive and neutral words, whereas older adults responded "old" and "remember" more often to both positive and negative words than to neutral stimuli.
Journal of Experimental Psychology: Learning, Memory and Cognition, 34, 703-711
Older adults sometimes show a recall advantage for emotionally positive, rather than neutral or negative, stimuli (S. T. Charles, M. Mather, & L. L. Carstensen, 2003). In contrast, younger adults respond "old" and "remember" more often to negative materials in recognition tests. For younger adults, both effects are due to response bias changes rather than to enhanced memory accuracy (S. Dougal & C. M. Rotello, 2007). We presented older and younger adults with emotional and neutral stimuli in a remember-know paradigm. Signal-detection and model-based analyses showed that memory accuracy did not differ for the neutral, negative, and positive stimuli, and that "remember" responses did not reflect the use of recollection. However, both age groups showed large and significant response bias effects of emotion: Younger adults tended to say "old" and "remember" more often in response to negative words than to positive and neutral words, whereas older adults responded "old" and "remember" more often to both positive and negative words than to neutral stimuli.
Friday, March 14, 2008
ARTICLE UPDATE - Immediate memory consequences of the effect of emotion on attention to pictures.
Talmi D, Anderson AK, Riggs L, Caplan JB, Moscovitch M.
Learning & Memory, 15, 172-182
Emotionally arousing stimuli are at once both highly attention grabbing and memorable. We examined whether emotional enhancement of memory (EEM) reflects an indirect effect of emotion on memory, mediated by enhanced attention to emotional items during encoding. We tested a critical prediction of the mediation hypothesis-that regions conjointly activated by emotion and attention would correlate with subsequent EEM. Participants were scanned with fMRI while they watched emotional or neutral pictures under instructions to attend to them a lot or a little, and were then given an immediate recognition test. A region in the left fusiform gyrus was activated by emotion, voluntary attention, and subsequent EEM. A functional network, different for each attention condition, connected this region and the amygdala, which was associated with emotion and EEM, but not with voluntary attention. These findings support an indirect cortical mediation account of immediate EEM that may complement a direct modulation model.
Learning & Memory, 15, 172-182
Emotionally arousing stimuli are at once both highly attention grabbing and memorable. We examined whether emotional enhancement of memory (EEM) reflects an indirect effect of emotion on memory, mediated by enhanced attention to emotional items during encoding. We tested a critical prediction of the mediation hypothesis-that regions conjointly activated by emotion and attention would correlate with subsequent EEM. Participants were scanned with fMRI while they watched emotional or neutral pictures under instructions to attend to them a lot or a little, and were then given an immediate recognition test. A region in the left fusiform gyrus was activated by emotion, voluntary attention, and subsequent EEM. A functional network, different for each attention condition, connected this region and the amygdala, which was associated with emotion and EEM, but not with voluntary attention. These findings support an indirect cortical mediation account of immediate EEM that may complement a direct modulation model.
Friday, March 07, 2008
ARTICLE UPDATE - Incidental encoding of emotional pictures: Affective bias studied through event related brain potentials.
Tapia M, Carretié L, Sierra B, Mercado F.
International Journal of Psychophysiology, in press
Emotional stimuli are better remembered than neutral stimuli. Most of the studies taking into account this emotional bias refer to explicit memory, use behavioral measures of the recall and predict better recall of negative stimuli. The few studies taking into account implicit memory and the valence emotional dimension are inconclusive on the effect of the stimulus' emotional valence. In the present study, 120 pictures (30 positive, 30 negative, 30 relaxing and 30 neutral) were shown to, and assessed by, 28 participants (study phase). Subsequently, event related brain potentials (ERPs) were recorded during the presentation of 120 new (shown for the first time) and 120 old (already shown in the study phase) pictures (test phase). No explicit instructions or clues related to recovery were given to participants, and a distractor task was employed, in order to maintain implicit the memory assessment. As expected from other studies' data, our results showed that old stimuli elicited an enhanced late positive component 450 ms after stimulus onset (repetition effect). Moreover, this effect was modulated by the stimuli's emotional valence, since the most positively valenced stimuli were associated with a decreased repetition effect with respect to the most negatively valenced stimuli. This effect was located at ventromedial prefrontal cortex. These results suggest the existence of a valence-mediated bias in implicit memory.
International Journal of Psychophysiology, in press
Emotional stimuli are better remembered than neutral stimuli. Most of the studies taking into account this emotional bias refer to explicit memory, use behavioral measures of the recall and predict better recall of negative stimuli. The few studies taking into account implicit memory and the valence emotional dimension are inconclusive on the effect of the stimulus' emotional valence. In the present study, 120 pictures (30 positive, 30 negative, 30 relaxing and 30 neutral) were shown to, and assessed by, 28 participants (study phase). Subsequently, event related brain potentials (ERPs) were recorded during the presentation of 120 new (shown for the first time) and 120 old (already shown in the study phase) pictures (test phase). No explicit instructions or clues related to recovery were given to participants, and a distractor task was employed, in order to maintain implicit the memory assessment. As expected from other studies' data, our results showed that old stimuli elicited an enhanced late positive component 450 ms after stimulus onset (repetition effect). Moreover, this effect was modulated by the stimuli's emotional valence, since the most positively valenced stimuli were associated with a decreased repetition effect with respect to the most negatively valenced stimuli. This effect was located at ventromedial prefrontal cortex. These results suggest the existence of a valence-mediated bias in implicit memory.
Thursday, February 21, 2008
ARTICLE UPDATE - The emotional memory effect: differential processing or item distinctiveness?
Schmidt SR, Saari B.
Memory & Cognition, 35, 1905-1916
A color-naming task was followed by incidental free recall to investigate how emotional words affect attention and memory. We compared taboo, nonthreatening negative-affect, and neutral words across three experiments. As compared with neutral words, taboo words led to longer color-naming times and better memory in both within- and between-subjects designs. Color naming of negative-emotion nontaboo words was slower than color naming of neutral words only during block presentation and at relatively short interstimulus intervals (ISIs). The nontaboo emotion words were remembered better than neutral words following blocked and random presentation and at both long and short ISIs, but only in mixed-list designs. Our results support multifactor theories of the effects of emotion on attention and memory. As compared with neutral words, threatening stimuli received increased attention, poststimulus elaboration, and benefit from item distinctiveness, whereas nonthreatening emotional stimuli benefited only from increased item distinctiveness.
Memory & Cognition, 35, 1905-1916
A color-naming task was followed by incidental free recall to investigate how emotional words affect attention and memory. We compared taboo, nonthreatening negative-affect, and neutral words across three experiments. As compared with neutral words, taboo words led to longer color-naming times and better memory in both within- and between-subjects designs. Color naming of negative-emotion nontaboo words was slower than color naming of neutral words only during block presentation and at relatively short interstimulus intervals (ISIs). The nontaboo emotion words were remembered better than neutral words following blocked and random presentation and at both long and short ISIs, but only in mixed-list designs. Our results support multifactor theories of the effects of emotion on attention and memory. As compared with neutral words, threatening stimuli received increased attention, poststimulus elaboration, and benefit from item distinctiveness, whereas nonthreatening emotional stimuli benefited only from increased item distinctiveness.
Friday, December 07, 2007
ARTICLE UPDATE - An investigation of the cognitive and experiential features of intrusive memories in depression.
Williams AD, Moulds ML.
Memory, 15, 912-920
Intrusive autobiographical memories of negative past events are a clinical feature common to post-traumatic stress disorder (PTSD) and depression. Recent investigations provide increasing evidence that shared cognitive processes are linked to the maintenance of intrusive memories in both conditions. Still absent from the existing literature, however, is a systematic examination of the basic content and defining characteristics of intrusive memories in depression. This study sought to: (i) outline the content and features of intrusive memories in depression, and (ii) investigate whether intrusion characteristics linked to the persistence of intrusive memories in PTSD are also characteristic of intrusive memories in depression. A sample of undergraduate students (n=250) were interviewed and assessed for the presence of an intrusive memory in the past week, and completed a battery of measures that indexed cognitive and affective responses to the memory. Consistent with prediction, intrusive memories contained high levels of sensory experience and were marked by a sense of "nowness". In accord with studies with PTSD samples, sensory features accounted for unique variance in the prediction of depression severity, over and above that accounted for by intrusion frequency. This pattern of findings was replicated in a dysphoric (BDI-II>/=12) sub-sample of participants. Our results underscore the value of drawing on theoretical conceptualisations and empirical findings from the post-traumatic stress literature to extend our understanding of intrusive memories in depression.
Memory, 15, 912-920
Intrusive autobiographical memories of negative past events are a clinical feature common to post-traumatic stress disorder (PTSD) and depression. Recent investigations provide increasing evidence that shared cognitive processes are linked to the maintenance of intrusive memories in both conditions. Still absent from the existing literature, however, is a systematic examination of the basic content and defining characteristics of intrusive memories in depression. This study sought to: (i) outline the content and features of intrusive memories in depression, and (ii) investigate whether intrusion characteristics linked to the persistence of intrusive memories in PTSD are also characteristic of intrusive memories in depression. A sample of undergraduate students (n=250) were interviewed and assessed for the presence of an intrusive memory in the past week, and completed a battery of measures that indexed cognitive and affective responses to the memory. Consistent with prediction, intrusive memories contained high levels of sensory experience and were marked by a sense of "nowness". In accord with studies with PTSD samples, sensory features accounted for unique variance in the prediction of depression severity, over and above that accounted for by intrusion frequency. This pattern of findings was replicated in a dysphoric (BDI-II>/=12) sub-sample of participants. Our results underscore the value of drawing on theoretical conceptualisations and empirical findings from the post-traumatic stress literature to extend our understanding of intrusive memories in depression.
Thursday, November 15, 2007
ARTICLE UPDATE - The role of medial temporal lobe in item recognition and source recollection of emotional stimuli.
Dougal S, Phelps EA, Davachi L.
Cognitive, Affective, Behavioural Neuroscience, 7, 233-242
Recent neuroimaging results suggest that distinct regions within the medial temporal lobe (MTL) may differentially support the episodic encoding of item and relational information for nonemotional stimuli . The present study was designed to assess whether these findings generalize to emotional stimuli. Behaviorally, we found that emotion reduced item recognition accuracy but did not reliably affect relational memory. fMRI analyses revealed that neutral and emotional words elicited distinct activation patterns within MTL regions predictive of subsequent memory. Consistent with previous findings for neutral words, hippocampal activation predicted later relational memory, whereas activation in the perirhinal cortex predicted successful item recognition. However, for emotional words, activation in the amygdala, hippocampus, and posterior parahippocampal cortex predicted item recognition only. These data suggest that MTL regions differentially support encoding of neutral and emotional stimuli.
Cognitive, Affective, Behavioural Neuroscience, 7, 233-242
Recent neuroimaging results suggest that distinct regions within the medial temporal lobe (MTL) may differentially support the episodic encoding of item and relational information for nonemotional stimuli . The present study was designed to assess whether these findings generalize to emotional stimuli. Behaviorally, we found that emotion reduced item recognition accuracy but did not reliably affect relational memory. fMRI analyses revealed that neutral and emotional words elicited distinct activation patterns within MTL regions predictive of subsequent memory. Consistent with previous findings for neutral words, hippocampal activation predicted later relational memory, whereas activation in the perirhinal cortex predicted successful item recognition. However, for emotional words, activation in the amygdala, hippocampus, and posterior parahippocampal cortex predicted item recognition only. These data suggest that MTL regions differentially support encoding of neutral and emotional stimuli.
ARTICLE UPDATE - Autonomic and prefrontal cortex responses to autobiographical recall of emotions.
Marci CD, Glick DM, Loh R, Dougherty DD.
Cognitive, Affective and Behavioural Neuroscience, 7, 243-250
The present study combined measures of regional cerebral blood flow (rCBF) using positron emission tomography (PET) with measures of the autonomic nervous system using skin conductance (SC), heart rate (HR), and the high frequency band of heart rate variability (HRV) in ten healthy participants who were exposed to autobiographical scripts of memories for three target emotions: anger, happiness, and sadness. According to the results, anger was the only emotion to show a significant increase in sympathetic activity, accompanied by a significant decrease in HRV when compared with a neutral script. Anger was also the only emotion to show significant changes in rCBF in the prefrontal cortex. By contrast, the results for the happy and sad conditions showed no significant increase in sympathetic activity and no changes in rCBF in the prefrontal cortex in comparison with the neutral script. The findings suggest that a relative increase in sympathetic activity with a reciprocal decrease in parasympathetic activity may be necessary to generate frontal activity in autobiographical recall of emotions.
Cognitive, Affective and Behavioural Neuroscience, 7, 243-250
The present study combined measures of regional cerebral blood flow (rCBF) using positron emission tomography (PET) with measures of the autonomic nervous system using skin conductance (SC), heart rate (HR), and the high frequency band of heart rate variability (HRV) in ten healthy participants who were exposed to autobiographical scripts of memories for three target emotions: anger, happiness, and sadness. According to the results, anger was the only emotion to show a significant increase in sympathetic activity, accompanied by a significant decrease in HRV when compared with a neutral script. Anger was also the only emotion to show significant changes in rCBF in the prefrontal cortex. By contrast, the results for the happy and sad conditions showed no significant increase in sympathetic activity and no changes in rCBF in the prefrontal cortex in comparison with the neutral script. The findings suggest that a relative increase in sympathetic activity with a reciprocal decrease in parasympathetic activity may be necessary to generate frontal activity in autobiographical recall of emotions.
Friday, November 02, 2007
ARTICLE UPDATE - How emotion strengthens the recollective experience: a time-dependent hippocampal process.
Sharot T, Verfaellie M, Yonelinas AP.
PLoS ONE, 2, e1068
Emotion significantly strengthens the subjective recollective experience even when objective accuracy of the memory is not improved. Here, we examine if this modulation is related to the effect of emotion on hippocampal-dependent memory consolidation. Two critical predictions follow from this hypothesis. First, since consolidation is assumed to take time, the enhancement in the recollective experience for emotional compared to neutral memories should become more apparent following a delay. Second, if the emotion advantage is critically dependent on the hippocampus, then the effects should be reduced in amnesic patients with hippocampal damage. To test these predictions we examined the recollective experience for emotional and neutral photos at two retention intervals (Experiment 1), and in amnesics and controls (Experiment 2). Emotional memories were associated with an enhancement in the recollective experience that was greatest after a delay, whereas familiarity was not influenced by emotion. In amnesics with hippocampal damage the emotion effect on recollective experience was reduced. Surprisingly, however, these patients still showed a general memory advantage for emotional compared to neutral items, but this effect was manifest primarily as a facilitation of familiarity. The results support the consolidation hypothesis of recollective experience, but suggest that the effects of emotion on episodic memory are not exclusively hippocampally mediated. Rather, emotion may enhance recognition by facilitating familiarity when recollection is impaired due to hippocampal damage.
PLoS ONE, 2, e1068
Emotion significantly strengthens the subjective recollective experience even when objective accuracy of the memory is not improved. Here, we examine if this modulation is related to the effect of emotion on hippocampal-dependent memory consolidation. Two critical predictions follow from this hypothesis. First, since consolidation is assumed to take time, the enhancement in the recollective experience for emotional compared to neutral memories should become more apparent following a delay. Second, if the emotion advantage is critically dependent on the hippocampus, then the effects should be reduced in amnesic patients with hippocampal damage. To test these predictions we examined the recollective experience for emotional and neutral photos at two retention intervals (Experiment 1), and in amnesics and controls (Experiment 2). Emotional memories were associated with an enhancement in the recollective experience that was greatest after a delay, whereas familiarity was not influenced by emotion. In amnesics with hippocampal damage the emotion effect on recollective experience was reduced. Surprisingly, however, these patients still showed a general memory advantage for emotional compared to neutral items, but this effect was manifest primarily as a facilitation of familiarity. The results support the consolidation hypothesis of recollective experience, but suggest that the effects of emotion on episodic memory are not exclusively hippocampally mediated. Rather, emotion may enhance recognition by facilitating familiarity when recollection is impaired due to hippocampal damage.
Wednesday, October 17, 2007
ARTICLE UDPATE - How Negative Emotion Enhances the Visual Specificity of a Memory
Elizabeth A. Kensinger, Rachel J. Garoff-Eaton and Daniel L. Schacter
Journal of Cognitive Neuroscience, 19, 1872-1887
Some studies have suggested that emotion primarily increases memory for "gist," and does not enhance memory for detail. There are, however, some instances in which negative objects (e.g., snake, grenade) are remembered with more visual detail than neutral objects (e.g., barometer, blender). In the present functional magnetic resonance imaging (fMRI) study, we examined the encoding processes that lead a person to remember the exact visual details of negative and neutral objects, and to remember which of two decisions were made about the objects (a size decision or an animacy decision). The enhancement in memory for a negative item's visual details appeared to result from enhanced visual processing: The right fusiform gyrus, a region known to be critical for processing exemplar-specific details, showed a greater extent and magnitude of activity during the successful encoding of negative objects. Activity in the right amygdala also corresponded with memory for visual detail, although it did not relate to memory for the task performed with the item. These data provide strong evidence that engagement of some amygdalar regions can correspond with enhanced memory for certain types of details, but does not ensure successful encoding of all contextual details.
Journal of Cognitive Neuroscience, 19, 1872-1887
Some studies have suggested that emotion primarily increases memory for "gist," and does not enhance memory for detail. There are, however, some instances in which negative objects (e.g., snake, grenade) are remembered with more visual detail than neutral objects (e.g., barometer, blender). In the present functional magnetic resonance imaging (fMRI) study, we examined the encoding processes that lead a person to remember the exact visual details of negative and neutral objects, and to remember which of two decisions were made about the objects (a size decision or an animacy decision). The enhancement in memory for a negative item's visual details appeared to result from enhanced visual processing: The right fusiform gyrus, a region known to be critical for processing exemplar-specific details, showed a greater extent and magnitude of activity during the successful encoding of negative objects. Activity in the right amygdala also corresponded with memory for visual detail, although it did not relate to memory for the task performed with the item. These data provide strong evidence that engagement of some amygdalar regions can correspond with enhanced memory for certain types of details, but does not ensure successful encoding of all contextual details.
Tuesday, October 16, 2007
ARTICLE UPDATE - The role of medial temporal lobe in item recognition and source recollection of emotional stimuli
Dougal, Sonya; Phelps, Elizabeth A.; Davachi, Lila
Cognitive, Affective, & Behavioral Neuroscience, 7, 233-242
Recent neuroimaging results suggest that distinct regions within the medial temporal lobe (MTL) may differentially support the episodic encoding of item and relational information for nonemotional stimuli (for a review, see Davachi, 2006). The present study was designed to assess whether these findings generalize to emotional stimuli. Behaviorally, we found that emotion reduced item recognition accuracy but did not reliably affect relational memory. fMRI analyses revealed that neutral and emotional words elicited distinct activation patterns within MTL regions predictive of subsequent memory. Consistent with previous findings for neutral words, hippocampal activation predicted later relational memory, whereas activation in the perirhinal cortex predicted successful item recognition. However, for emotional words, activation in the amygdala, hippocampus, and posterior parahippocampal cortex predicted item recognition only. These data suggest that MTL regions differentially support encoding of neutral and emotional stimuli.
Cognitive, Affective, & Behavioral Neuroscience, 7, 233-242
Recent neuroimaging results suggest that distinct regions within the medial temporal lobe (MTL) may differentially support the episodic encoding of item and relational information for nonemotional stimuli (for a review, see Davachi, 2006). The present study was designed to assess whether these findings generalize to emotional stimuli. Behaviorally, we found that emotion reduced item recognition accuracy but did not reliably affect relational memory. fMRI analyses revealed that neutral and emotional words elicited distinct activation patterns within MTL regions predictive of subsequent memory. Consistent with previous findings for neutral words, hippocampal activation predicted later relational memory, whereas activation in the perirhinal cortex predicted successful item recognition. However, for emotional words, activation in the amygdala, hippocampus, and posterior parahippocampal cortex predicted item recognition only. These data suggest that MTL regions differentially support encoding of neutral and emotional stimuli.
ARTICLE UPDATE - Autonomic and prefrontal cortex responses to autobiographical recall of emotions
Marci, Carl D.; Glick, Debra M.; Loh, Rebecca; Dougherty, Darin D.
Cognitive, Affective, & Behavioral Neuroscience, 7, 243-250
The present study combined measures of regional cerebral blood flow (rCBF) using positron emission tomography (PET) with measures of the autonomic nervous system using skin conductance (SC), heart rate (HR), and the high frequency band of heart rate variability (HRV) in ten healthy participants who were exposed to autobiographical scripts of memories for three target emotions: anger, happiness, and sadness. According to the results, anger was the only emotion to show a significant increase in sympathetic activity, accompanied by a significant decrease in HRV when compared with a neutral script. Anger was also the only emotion to show significant changes in rCBF in the prefrontal cortex. By contrast, the results for the happy and sad conditions showed no significant increase in sympathetic activity and no changes in rCBF in the prefrontal cortex in comparison with the neutral script. The findings suggest that a relative increase in sympathetic activity with a reciprocal decrease in parasympathetic activity may be necessary to generate frontal activity in autobiographical recall of emotions.
Cognitive, Affective, & Behavioral Neuroscience, 7, 243-250
The present study combined measures of regional cerebral blood flow (rCBF) using positron emission tomography (PET) with measures of the autonomic nervous system using skin conductance (SC), heart rate (HR), and the high frequency band of heart rate variability (HRV) in ten healthy participants who were exposed to autobiographical scripts of memories for three target emotions: anger, happiness, and sadness. According to the results, anger was the only emotion to show a significant increase in sympathetic activity, accompanied by a significant decrease in HRV when compared with a neutral script. Anger was also the only emotion to show significant changes in rCBF in the prefrontal cortex. By contrast, the results for the happy and sad conditions showed no significant increase in sympathetic activity and no changes in rCBF in the prefrontal cortex in comparison with the neutral script. The findings suggest that a relative increase in sympathetic activity with a reciprocal decrease in parasympathetic activity may be necessary to generate frontal activity in autobiographical recall of emotions.
Friday, October 05, 2007
ARTICLE UPDATE - The coupling of emotion and cognition in the eye: Introducing the pupil old/new effect.
Võ ML, Jacobs AM, Kuchinke L, Hofmann M, Conrad M, Schacht A, Hutzler F.
Psychophysiology, in press
The study presented here investigated the effects of emotional valence on the memory for words by assessing both memory performance and pupillary responses during a recognition memory task. Participants had to make speeded judgments on whether a word presented in the test phase of the experiment had already been presented ("old") or not ("new"). An emotion-induced recognition bias was observed: Words with emotional content not only produced a higher amount of hits, but also elicited more false alarms than neutral words. Further, we found a distinct pupil old/new effect characterized as an elevated pupillary response to hits as opposed to correct rejections. Interestingly, this pupil old/new effect was clearly diminished for emotional words. We therefore argue that the pupil old/new effect is not only able to mirror memory retrieval processes, but also reflects modulation by an emotion-induced recognition bias.
Psychophysiology, in press
The study presented here investigated the effects of emotional valence on the memory for words by assessing both memory performance and pupillary responses during a recognition memory task. Participants had to make speeded judgments on whether a word presented in the test phase of the experiment had already been presented ("old") or not ("new"). An emotion-induced recognition bias was observed: Words with emotional content not only produced a higher amount of hits, but also elicited more false alarms than neutral words. Further, we found a distinct pupil old/new effect characterized as an elevated pupillary response to hits as opposed to correct rejections. Interestingly, this pupil old/new effect was clearly diminished for emotional words. We therefore argue that the pupil old/new effect is not only able to mirror memory retrieval processes, but also reflects modulation by an emotion-induced recognition bias.
Friday, September 21, 2007
ARTICLE UPDATE - "Remembering" emotional words is based on response bias, not recollection.
Dougal S, Rotello CM.
Psychonomic Bulletin & Review, 14, 423-429
Recent studies have demonstrated that emotional stimuli result in a higher proportion of recognized items that are "remembered" (e.g., Kensinger & Corkin, 2003; Ochsner, 2000), leading to greater estimates of recollection by the dual-process model (Yonelinas, 1994). This result suggests that recognition judgments to emotional stimuli depend on a recollection process. We challenge this conclusion with receiver operating characteristic (ROC) curve data from two experiments. In both experiments, subjects studied neutral and emotional words. During the recognition test, subjects made old-new confidence ratings as well as remember-know judgments. Four models of remember-know judgments were fit to individual subjects' data: two versions of a one-dimensional signal-detection-based model (Donaldson, 1996; Wixted & Stretch, 2004), the dual-process model (Yonelinas, 1994), and the two-dimensional signal-detection-based model known as STREAK (Rotello, Macmillan, & Reeder, 2004). Consistent with the literature, we found that emotion increases subjective reports of "remembering:" However, our ROC analyses and modeling work reveal that the effect is due to response bias differences rather than sensitivity change or use of a high-threshold recollection process.
Psychonomic Bulletin & Review, 14, 423-429
Recent studies have demonstrated that emotional stimuli result in a higher proportion of recognized items that are "remembered" (e.g., Kensinger & Corkin, 2003; Ochsner, 2000), leading to greater estimates of recollection by the dual-process model (Yonelinas, 1994). This result suggests that recognition judgments to emotional stimuli depend on a recollection process. We challenge this conclusion with receiver operating characteristic (ROC) curve data from two experiments. In both experiments, subjects studied neutral and emotional words. During the recognition test, subjects made old-new confidence ratings as well as remember-know judgments. Four models of remember-know judgments were fit to individual subjects' data: two versions of a one-dimensional signal-detection-based model (Donaldson, 1996; Wixted & Stretch, 2004), the dual-process model (Yonelinas, 1994), and the two-dimensional signal-detection-based model known as STREAK (Rotello, Macmillan, & Reeder, 2004). Consistent with the literature, we found that emotion increases subjective reports of "remembering:" However, our ROC analyses and modeling work reveal that the effect is due to response bias differences rather than sensitivity change or use of a high-threshold recollection process.
Friday, August 31, 2007
ARTICLE UPDATE - Retrieval of emotional memories.
Buchanan TW.
Psychological Bulletin, 133, 761-779
Long-term memories are influenced by the emotion experienced during learning as well as by the emotion experienced during memory retrieval. The present article reviews the literature addressing the effects of emotion on retrieval, focusing on the cognitive and neurological mechanisms that have been revealed. The reviewed research suggests that the amygdala, in combination with the hippocampus and prefrontal cortex, plays an important role in the retrieval of memories for emotional events. The neural regions necessary for online emotional processing also influence emotional memory retrieval, perhaps through the reexperience of emotion during the retrieval process.
Psychological Bulletin, 133, 761-779
Long-term memories are influenced by the emotion experienced during learning as well as by the emotion experienced during memory retrieval. The present article reviews the literature addressing the effects of emotion on retrieval, focusing on the cognitive and neurological mechanisms that have been revealed. The reviewed research suggests that the amygdala, in combination with the hippocampus and prefrontal cortex, plays an important role in the retrieval of memories for emotional events. The neural regions necessary for online emotional processing also influence emotional memory retrieval, perhaps through the reexperience of emotion during the retrieval process.
Thursday, August 23, 2007
ARTICLE UPDATE - Does remembering emotional items impair recall of same-emotion items?
Sison JA, Mather M.
Psychonomic Bulletin & Review, 14, 282-287
In the part-set cuing effect, cuing a subset of previously studied items impairs recall of the remaining noncued items. This experiment reveals that cuing participants with previously-studied emotional pictures (e.g., fear-evoking pictures of people) can impair recall of pictures involving the same emotion but different content (e.g., fear-evoking pictures of animals). This indicates that new events can be organized in memory using emotion as a grouping function to create associations. However, whether new information is organized in memory along emotional or nonemotional lines appears to be a flexible process that depends on people's current focus. Mentioning in the instructions that the pictures were either amusement- or fear-related led to memory impairment for pictures with the same emotion as cued pictures, whereas mentioning that the pictures depicted either animals or people led to memory impairment for pictures with the same type of actor.
Psychonomic Bulletin & Review, 14, 282-287
In the part-set cuing effect, cuing a subset of previously studied items impairs recall of the remaining noncued items. This experiment reveals that cuing participants with previously-studied emotional pictures (e.g., fear-evoking pictures of people) can impair recall of pictures involving the same emotion but different content (e.g., fear-evoking pictures of animals). This indicates that new events can be organized in memory using emotion as a grouping function to create associations. However, whether new information is organized in memory along emotional or nonemotional lines appears to be a flexible process that depends on people's current focus. Mentioning in the instructions that the pictures were either amusement- or fear-related led to memory impairment for pictures with the same emotion as cued pictures, whereas mentioning that the pictures depicted either animals or people led to memory impairment for pictures with the same type of actor.
Monday, August 13, 2007
ARTICLE UPDATE - Pleasantness bias in flashbulb memories: positive and negative flashbulb memories of the fall of the Berlin Wall among East and West
Bohn A, Berntsen D.
Memory & Cognition, 35, 565-577
Flashbulb memories for the fall of the Berlin Wall were examined among 103 East and West Germans who considered the event as either highly positive or highly negative. The participants in the positive group rated their memories higher on measures of reliving and sensory imagery, whereas their memory for facts was less accurate than that of the participants in the negative group. The participants in the negative group had higher ratings on amount of consequences but had talked less about the event and considered it less central to their personal and national identity than did the participants in the positive group. In both groups, rehearsal and the centrality of the memory to the person's identity and life story correlated positively with memory qualities. The results suggest that positive and negative emotions have different effects on the processing and long-term retention of flashbulb memories.
Memory & Cognition, 35, 565-577
Flashbulb memories for the fall of the Berlin Wall were examined among 103 East and West Germans who considered the event as either highly positive or highly negative. The participants in the positive group rated their memories higher on measures of reliving and sensory imagery, whereas their memory for facts was less accurate than that of the participants in the negative group. The participants in the negative group had higher ratings on amount of consequences but had talked less about the event and considered it less central to their personal and national identity than did the participants in the positive group. In both groups, rehearsal and the centrality of the memory to the person's identity and life story correlated positively with memory qualities. The results suggest that positive and negative emotions have different effects on the processing and long-term retention of flashbulb memories.
Friday, July 27, 2007
ARTICLE UPDATE - Source monitoring is not always enhanced for valenced material.
Cook GI, Hicks JL, Marsh RL.
Memory & Cognition, 35, 222-230
Source monitoring for valenced materials has received very little attention from researchers interested in the residual effects that emotion can have on memory. The three previous studies that examined memory for valenced material found a source-monitoring enhancement effect. By contrast, we used two different combinations of sources and found a novel, consistent source-monitoring deficit for valenced words as compared with neutral ones. In addition, this memory deficit for contextual details did not consistently covary with item memory. We assert that it is possible to obtain an effect in which heightened attention toward valenced material reduces the binding of contextual details into memory.
Memory & Cognition, 35, 222-230
Source monitoring for valenced materials has received very little attention from researchers interested in the residual effects that emotion can have on memory. The three previous studies that examined memory for valenced material found a source-monitoring enhancement effect. By contrast, we used two different combinations of sources and found a novel, consistent source-monitoring deficit for valenced words as compared with neutral ones. In addition, this memory deficit for contextual details did not consistently covary with item memory. We assert that it is possible to obtain an effect in which heightened attention toward valenced material reduces the binding of contextual details into memory.
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