Feeling and Thinking about It Are Two Different Things: How to Capture Momentary Emotions of Extreme Sports in the Field

To learn about extreme sports and what motivates such activities, we need to understand the emotions embedded in the experience itself. However, how we go about assessing these emotions might provide us with very different answers. An experience is a fleeting and ever-changing phenomenon, rich in detail and filled with nuances. What we remember and, therefore, what we are able to report from our experience might, however, be strikingly different to what we experienced. Our memories are grained by time, impaired by arousal, and affected by context. Despite these limitations, the most common way to measure an experience is by self reporting. The current paper reviews some of the relevant theory on emotions and how this might impact different assessments. I also describe a new way of measuring momentary emotions in the field by use of video cameras and automatic coding of facially expressed emotions. Extreme sports may leave us with positive memories but may be anything but pleasant while in the midst of them. In the end, this paper may give some hints to why.

Does surprise enhance infant memory? Assessing the impact of the encoding context on subsequent object recognition

A discrepancy between what was predicted and what is observed has been linked to increased looking times, changes in brain electrical activity, and increased pupil dilation in infants. These processes associated with heightened attention and readiness to learn might enhance the encoding and memory consolidation of the surprising object, as suggested by both the infant and the adult literature. We therefore investigated whether the presence of surprise during the encoding context enhances subsequent encoding and recognition memory processes for the items that violated infants' expectations. Seventeen-month-olds viewed 20 familiar objects, half of which were labeled correctly, while the other half were mislabeled. Subsequently, infants were presented with a silent recognition memory test where the previously labeled objects appeared along with new images. Pupil dilation was measured, with more dilated pupils indicating (1) surprise during those labeling events where the item was mislabeled and (2) successful retrieval processes during the memory test. Infants responded with more pupil dilation to mislabeling compared to correct labeling. Importantly, despite the presence of a surprise response during mislabeling, infants only differentiated between the previously seen and unseen items at the memory test, offering no evidence that surprise had facilitated the encoding of the mislabeled items.

Should Posttraumatic Stress Be a Disorder or a Specifier? Towards Improved Nosology Within the DSM Categorical Classification System

PURPOSE OF REVIEW

Since 1980, posttraumatic stress (PTS) disorder has been controversial because of its origin as a social construct, its discriminating trauma definition, and the Procrustean array of symptoms/clusters chosen for inclusion/exclusion. This review summarizes the history of trauma-related nosology and proposed changes, within current categorical models (trauma definitions, symptoms/clusters, subtypes/specifiers, disorders) and new models.

RECENT FINDINGS

Considering that trauma is a risk factor for virtually all mental disorders (particularly depressive, anxiety, dissociative, personality), the multi-finality of trauma (some survivors are resilient, and some develop PTS and/or non-PTS symptoms), and the various symptoms that trauma survivors express (mood, cognitive, perceptual, somatic), it is difficult to classify PTS. Because the human mind best comprehends categories, reliable classification generally necessitates using a categorical nosology but PTS defies categories (internalizing and/or externalizing, fear-based and/or numbing symptoms), the authors conclude that PTS-like DSM-5's panic attacks specifier-is currently best conceptualized as a specifier for other mental disorders.

Trauma-related Structural Dissociation of the Personality

Many traumatized individuals alternate between re-experiencing their trauma and being detached from, or even relatively unaware of the trauma and its effects. At first sight one may be inclined to conceptualize detachment from trauma and re-experiencing of trauma as mental states. However, on closer scrutiny it becomes apparent that in both cases a range or cluster of states rather than a singular state is involved. For example, being detached from trauma does not itself exclude being joyful, ashamed, sexually aroused, or curious at times, and re-experiencing trauma can encompass states such as fleeing, freezing, and being in pain or being analgesic. In this paper we relate detachment from trauma and re-experiencing trauma to emotional operating systems (Panksepp, 1998) and functional systems (Fanselow & Lester, 1988), briefly addressed as action systems. Action systems control a range of functions, but some are more complex than others. Reexperiencing trauma will be associated with the inborn and evolutionary derived defensive system that is evoked by severe threat, in particular threat to the integrity of the body. As a complex system, it encompasses various subsystems, such as flight, freeze, and fight. Detachment from trauma, in our view, is associated with several action systems (Panksepp, 1998), i.e., the ones that control functions in daily life (e.g., exploration of the environment, energy control), and the ones that are dedicated to survival of the species (e.g., reproduction, attachment to and care for offspring). In this context we will maintain that severe threat may provoke a structural dissociation of the premorbid personality (Van der Hart, 2000). In its primary form this dissociation is between the defensive system on one hand, and the systems that involve managing daily life and survival of the species on the other hand. To summarize the essence of the theory of structural dissociation of the personality, we argue (1) that traumatic experiences, especially when they occur early in life and involve severe threat to the integrity of the body, may activate psychobiological action systems that have been developed by evolution, and (2) that due to extreme stress levels and classical as well as evaluative conditioning to traumatic memories these systems may remain unintegrated to varying degrees.

Emotional Intelligence and Task Performance

Theory and some empirical research suggest that there is a relationship between emotions and performance on cognitive tasks. The construct of emotional intelligence may provide a vehicle for exploring the connection between emotions and cognitive task performance. The present study tested the hypotheses that: a) individuals with higher emotional intelligence would perform better on cognitive tasks; and b) they would be better able to deal with the frustration or helplessness that may result from encountering very difficult tasks. Participants recruited from community and university settings participated in a study in which their emotional intelligence was assessed and they worked on three sets of anagrams. The first set of anagrams was moderately difficult, the second set was very difficult, and the third set was again moderately difficult. The first hypothesis was supported in that participants higher in emotional intelligence solved more problems on the first set of moderately difficult anagrams. The second hypothesis was supported in that the participants higher in emotional intelligence solved more problems after encountering a very difficult and frustrating set of problems, even when initial performance was held constant. The results suggest that study of the emotional intelligence construct holds promise for better understanding and perhaps in the future enhancing cognitive task performance.

Tracelink: A model of consolidation and amnesia

A connectionist model is presented, the TraceLink model, that implements an autonomous "off-line" consolidation process. The model consists of three subsystems: (1) a trace system (neocortex), (2) a link system (hippocampus and adjacent regions), and (3) a modulatory system (basal forebrain and other areas). The model is able to account for many of the characteristics of anterograde and retrograde amnesia, including Ribot gradients, transient global amnesia, patterns of shrinkage of retrograde amnesia, and correlations between anterograde and retrograde amnesia or the absence thereof (e.g., in isolated retrograde amnesia). In addition, it produces normal forgetting curves and can exhibit permastore. It also offers an explanation for the advantages of learning under high arousal for long-term retention.

Increasing set size breaks down sequential congruency: evidence for an associative locus of cognitive control

In recent years, a number of studies have revealed that cognitive control is strongly context-dependent (e.g., Crump et al., 2006). Inspired by this, computational models have been formulated based on the idea that cognitive control processes are based on associative learning (Blais et al., 2007; Verguts & Notebaert, 2008). Here, we test a natural consequence of this idea, namely, that sequential congruency effects (Gratton et al., 1992) should gradually decrease with an increasing number of task-relevant features (e.g., stimuli). The effect is empirically observed and simulated in a computational model. Implications of our findings are discussed.

Memory modulation in the classroom: selective enhancement of college examination performance by arousal induced after lecture

Laboratory studies examining moderate physiological or emotional arousal induced after learning indicate that it enhances memory consolidation. Yet, no studies have yet examined this effect in an applied context. As such, arousal was induced after a college lecture and its selective effects were examined on later exam performance. Participants were divided into two groups who either watched a neutral video clip (n=66) or an arousing video clip (n=70) after lecture in a psychology course. The final examination occurred two weeks after the experimental manipulation. Only performance on the group of final exam items that covered material from the manipulated lecture were significantly different between groups. Other metrics, such as the midterm examination and the total final examination score, did not differ between groups. The results indicate that post-lecture arousal selectively increased the later retrieval of lecture material, despite the availability of the material for study before and after the manipulation. The results reinforce the role of post-learning arousal on memory consolidation processes, expanding the literature to include a real-world learning context.

What does the amygdala contribute to social cognition?

The amygdala has received intense recent attention from neuroscientists investigating its function at the molecular, cellular, systems, cognitive, and clinical level. It clearly contributes to processing emotionally and socially relevant information, yet a unifying description and computational account have been lacking. The difficulty of tying together the various studies stems in part from the sheer diversity of approaches and species studied, in part from the amygdala's inherent heterogeneity in terms of its component nuclei, and in part because different investigators have simply been interested in different topics. Yet, a synthesis now seems close at hand in combining new results from social neuroscience with data from neuroeconomics and reward learning. The amygdala processes a psychological stimulus dimension related to saliency or relevance; mechanisms have been identified to link it to processing unpredictability; and insights from reward learning have situated it within a network of structures that include the prefrontal cortex and the ventral striatum in processing the current value of stimuli. These aspects help to clarify the amygdala's contributions to recognizing emotion from faces, to social behavior toward conspecifics, and to reward learning and instrumental behavior.

Preventing postsurgical dissatisfaction syndrome after rhinoplasty with propranolol: a pilot study

BACKGROUND

Rhinoplasty patients are commonly anxious about their result when the splint is removed. A small group of them, however, are overtly unhappy with their appearance despite objectively satisfactory early results, cannot be reassured about their favorable long-term prognosis, and remain dissatisfied despite objectively satisfactory end results. The authors have termed this symptom complex "postsurgical dissatisfaction syndrome." In these patients, it seems that persistence of the original negative image of their appearance at the time of splint removal fails to yield to an improved self-image as healing progresses.

METHODS

The authors theorized that the syndrome is analogous to the persistence of negative emotional memories seen in posttraumatic stress disorder. In trauma-exposed patients, the beta-adrenergic blocker propranolol, when given within a few hours of the traumatic event, may reduce the subsequent emotional strength of the traumatic memory. The authors hypothesized that giving propranolol to postrhinoplasty patients with the above early symptomatology would reduce the likelihood of postsurgical dissatisfaction syndrome.

RESULTS

A retrospective review of 1000 consecutive rhinoplasty patients identified 11 with early symptomatology. Of these 11 (not taking propranolol), nine (82 percent) developed postsurgical dissatisfaction syndrome. In addition, a prospective study was performed of nine additional patients with the same early symptomatology who were immediately treated with propranolol. In contrast, only three developed postsurgical dissatisfaction syndrome (p < 0.04). Results of a randomized, double-blind, placebo-controlled study of 50 additional postrhinoplasty patients suggests that propranolol's effect is not due to anxiolysis.

CONCLUSIONS

Propranolol given immediately after splint removal in anxious, unhappy cosmetic surgery patients may prevent postsurgical dissatisfaction syndrome. A double-blind study appears warranted.

Drug enhancement of memory consolidation: historical perspective and neurobiological implications

INTRODUCTION

Studies of drug enhancement of cognition began with Lashley's (Psychobiology 1:141-170, 1917) report that strychnine administered before daily training trials enhanced rats' maze learning. Many subsequent studies confirmed that finding and found that stimulant drugs also enhance the learning of a wide range of tasks.

DISCUSSION

A central problem in interpreting such findings is that of distinguishing the drug effects on brain processes underlying memory formation from many other possible effects of the drugs on the behavior used to assess learning. The subsequent finding that comparable learning enhancement can be obtained by posttraining drug administration provided compelling evidence that drugs can enhance memory by acting on memory consolidation processes. Such evidence stimulated the investigation of endogenous regulation of memory consolidation by arousal-released adrenal stress hormones.

CONCLUSION

Considerable evidence now indicates that such hormones regulate memory consolidation via activation of the basolateral amygdala and subsequent influences on many efferent brain regions involved in processing recent experiences. The implications of these findings for the development of cognitive enhancing drugs are discussed.

Stress hormones and post-traumatic stress disorder in civilian trauma victims: a longitudinal study. Part II: the adrenergic response

The aim of the study was to prospectively evaluate the association between the occurrence of post-traumatic stress disorder (PTSD) and the adrenergic response to the traumatic event, and additionally, to explore the link between PTSD and the initial norepinephrine:cortisol ratio. Plasma levels and urinary excretion of norepinephrine (NE) were measured in 155 survivors of traumatic events during their admission to a general hospital emergency room (ER) and at 10 d, 1 month and 5 months later. Symptoms of peri-traumatic dissociation, PTSD and depression were assessed in each follow-up session. The Clinician-Administered PTSD Scale (CAPS) conferred a diagnosis of PTSD at 5 months. Trauma survivors with (n=31) and without (n=124) PTSD had similar levels of plasma NE, urinary NE excretion, and NE:cortisol ratio in the ER. Plasma NE levels were lower in subjects with PTSD at 10 d, 1 month, and 5 months. There was a weak but significant positive correlation between plasma levels of NE in the ER and concurrent heart rate, and a negative correlation between NE in the ER and dissociation symptoms. Peripheral levels of NE, shortly after traumatic events, are poor risk indicators of subsequent PTSD among civilian trauma victims. Simplified biological models may not properly capture the complex aetiology of PTSD.

Emotional arousal enhances declarative memory in patients with Alzheimer's disease

OBJECTIVE

To verify whether the long-term retention of an emotionally arousing story is stronger than the retention of a neutral story, and the enhancing effects of emotional arousal on declarative memory in Alzheimer's disease (AD) patients.

METHOD

Twenty subjects (10 with AD and 10 controls matched for age and educational level) were studied. After the audiovisual presentation (neutral story), the subjects rated the narrative's emotionality. Later, they answered a multiple-choice questionnaire about the stories. Two weeks later, they watched the emotionally arousing story.

RESULTS

Subjects who watched the emotionally arousing story assigned a score of emotionality higher than the subjects in the neutral group (P = 0.023). In addition, the participants remembered more details of the arousing story, and had a higher score in the questionnaire (P < 0.001).

CONCLUSIONS

We demonstrated that an emotionally arousing content enhances long-term declarative memory in AD. Furthermore, present finding supports the use of this instrument for clinical and research purposes.

Memory enhancement by a semantically unrelated emotional arousal source induced after learning

It has been well established that moderate physiological or emotional arousal modulates memory. However, there is some controversy about whether the source of arousal must be semantically related to the information to be remembered. To test this idea, 35 healthy young adult participants learned a list of common nouns and afterward viewed a semantically unrelated, neutral or emotionally arousing videotape. The tape was shown after learning to prevent arousal effects on encoding or attention, instead influencing memory consolidation. Heart rate increase was significantly greater in the arousal group, and negative affect was significantly less reported in the non-arousal group after the video. The arousal group remembered significantly more words than the non-arousal group at both 30 min and 24 h delays, despite comparable group memory performance prior to the arousal manipulation. These results demonstrate that emotional arousal, even from an unrelated source, is capable of modulating memory consolidation. Potential reasons for contradictory findings in some previous studies, such as the timing of "delayed" memory tests, are discussed.

Traumatic memories are not necessarily accurate memories

Some therapists, as well as other commentators, have suggested that memories of horrific trauma are buried in the subconscious by some special process, such as repression, and are later reliably recovered. We find that the evidence provided to support this claim is flawed. Where, then, might these memory reports come from? We discuss several research paradigms that have shown that various manipulations can be used to implant false memories--including false memories for traumatic events. These false memories can be quite compelling for those who develop them and can include details that make them seem credible to others. The fact that a memory report describes a traumatic event does not ensure that the memory is authentic.

The development of persistent pain and psychological morbidity after motor vehicle collision: integrating the potential role of stress response systems into a biopsychosocial model

OBJECTIVES

Persistent pain and psychological sequelae are common after motor vehicle collision (MVC), but their etiology remains poorly understood. Such common sequelae include whiplash-associated disorders (WAD), fibromyalgia, and posttraumatic stress disorder (PTSD). Increasing evidence suggests that these disorders share overlapping epidemiologic and clinical features. A model is proposed in which central neurobiological systems, including physiologic systems and neuroanatomical structures involved in the stress response, are an important substrate for the development of all 3 disorders and interact with psychosocial and other factors to influence chronic symptom development.

METHODS

Epidemiologic and clinical characteristics regarding the development of these disorders after MVC are reviewed. Evidence suggesting a role for stress response systems in the development of these disorders is presented.

RESULTS

Contemporary evidence supports a model of chronic symptom development that incorporates the potential for interactions between past experience, acute stress responses to trauma, post-MVC behavior, and cognitive/psychosocial consequences to alter activity within brain regions which process pain and to result in persistent pain, as well as psychological sequelae, after MVC. Such a model incorporates factors identified in prior biopsychosocial theories and places them in the landscape of our rapidly developing understanding of stress systems and CNS pain-modulating pathways.

CONCLUSION

New models are needed to stimulate deeper examination of the interacting influences of initial tissue damage, acute pain, psychosocial contingencies, and central stress pathways during chronic symptom development after MVC. Deeper understanding could contribute to improved treatment approaches to reduce the immense personal and societal burdens of common trauma-related disorders.

Conceptually driven pharmacologic approaches to acute trauma

Secondary prevention of posttraumatic stress disorder (PTSD) entails intervening in the aftermath of a traumatic event to forestall the development of PTSD. There has been little psychopharmacologic research in this area. This is surprising, given that PTSD is the mental disorder with the most clearly identified cause and onset. In a translational model of PTSD's pathogenesis presented herein: A traumatic event (unconditioned stimulus) overstimulates endogenous stress hormones (unconditioned response); these mediate an overconsolidation of the event's memory trace; recall of the event in response to reminders (conditioned stimulus); releases further stress hormones (conditioned response); these cause further overconsolidation; and the overconsolidated memory generates PTSD symptoms. Noradrenergic hyperactivity in the basolateral amygdala is hypothesized to mediate this cycle. Preventing pre-synaptic norepinephrine release with alpha2-adrenergic agonists or opioids, or blocking post-synaptic norepinephrine receptors with beta-adrenergic antagonists such as propranolol, reduces hormonally enhanced memories and fear conditioning. Two controlled studies of trauma victims presenting to emergency rooms suggest that posttrauma propranolol reduces subsequent PTSD, as does one naturalistic clinical study of morphine treatment of burned children. Cortisol both enhances memory consolidation and reduces memory retrieval, leading to mixed predictions. Two controlled studies of intensive care unit patients found that cortisol reduced PTSD. One study did not find benzodiazepines effective in preventing PTSD. Selective serotonin reuptake inhibitors, antiepileptics, and alpha2-adrenergic agonists have yet to be tried.

Differential effects of adrenergic and corticosteroid hormonal systems on human short- and long-term declarative memory for emotionally arousing material

The effects of adrenergic and corticosteroid hormonal systems on emotional memory were measured in 64 young men. Placebo, propranolol (40 or 80 mg; beta blocker), or metyiapone (corticosteroid synthesis inhibitor) was administered before the viewing of a story composed of emotional and neutral segments. Short- and long-term declarative memory for the story was assessed. Propranolol 40 mg had no effects on declarative memory. Propranolol 80 mg impaired short- and long-term declarative memory for emotionally arousing material. Metyrapone did not impair short-term declarative memory but impaired long-term declarative memory for emotionally arousing and neutral material. Results demonstrate that adrenergic and corticosteroid hormonal systems differentially affect declarative memory for emotionally arousing and neutral material, and suggest that interactions between adrenal hormonal systems modulate emotionally arousing declarative memory in humans.

Pilot study of secondary prevention of posttraumatic stress disorder with propranolol

BACKGROUND

Preclinical considerations suggest that treatment with a beta-adrenergic blocker following an acute psychologically traumatic event may reduce subsequent posttraumatic stress disorder (PTSD) symptoms. This pilot study addressed this hypothesis.

METHODS

Patients were randomized to begin, within 6 hours of the event, a 10-day course of double-blind propranolol (n = 18) versus placebo (n = 23) 40 mg four times daily.

RESULTS

The mean (SD) 1-month Clinician-Administered PTSD Scale (CAPS) score of 11 propranolol completers was 27.6 (15.7), with one outlier 5.2 SDs above the others' mean, and of 20 placebo completers, 35.5 (21.5), t = 1.1, df = 29, p =.15. Two propranolol patients' scores fell above, and nine below, the placebo group's median, p =.03 (sign test). Zero of eight propranolol, but six of 14 placebo, patients were physiologic responders during script-driven imagery of the traumatic event when tested 3 months afterward, p =.04 (all p values one-tailed).

CONCLUSIONS

These pilot results suggest that acute, posttrauma propranolol may have a preventive effect on subsequent PTSD.

Memory, neurodynamics, and human relationships

In this article we discuss the implications of the functional organization and dynamics of the brain for understanding human relationships. In particular, we focus on the brain's multiple memory systems and the various roles they play in organizing the interactions of people as they come to know one another. The distinction between the relatively independent declarative, procedural, and emotional learning systems is especially significant in this regard, as the former mediates what we know about one another, the second mediates what we do with one another, and the third affects behavior by altering our emotional state. Knowledge of the functioning of these dissociable memory systems provides a novel perspective on relationships--both ordinary social relationships and those that develop in psychotherapy--and further illuminates psychotherapeutic transference and countertransference phenomena. We begin with a review of the neural basis of these processes, then turn our attention to the interpersonal level of analysis.

The effects of endomorphin-1 on conditioned defeat in Syrian hamsters (Mesocricetus auratus)

The present study examined the effect of endomorphin-1 (EM1), an endogenous opioid with a high affinity for the mu opiate receptor, on conditioned defeat. Conditioned defeat is a phenomenon in which hamsters that have been defeated subsequently fail to exhibit normal territorial aggression and instead display submissive/defensive behaviors even when paired with a non-aggressive intruder. In experiment 1, animals were placed in the home cage of a larger resident for 15 min and were defeated. After 24 h, animals received a 3-microl injection of EM1 (0.0, 0.3, 3.0, or 10 nmol) into the left lateral cerebral ventricle 5 min before a smaller non-aggressive intruder was placed in the home cage of the experimental animal. In experiment 2, animals were infused with EM1 immediately after the initial defeat and were paired with a non-aggressive intruder 24 h later as in experiment 1. EM1 reduced the duration of submissive/defensive behavior in experiment 1 (P<0.05) but not in experiment 2 (P>0.05). These data support the hypothesis that the highly selective mu receptor agonist endomorphin-1 modulates the expression of conditioned defeat, but provides no support for the hypothesis that endomorphin-1 modulates the consolidation of conditioned defeat.

Peripheral modulation of learning and memory: enkephalins as a model system

Extensive research on the effects of enkephalins on conditioning is reviewed and used as the basis for a model of peripheral modulation of learning and memory. An overall theme emphasized throughout our discussion is that these peptides can influence the strength with which a memory is acquired and stored by acting outside the blood-brain barrier. This assertion is supported by research on the behavioral effects of systemically administered enkephalins and opioid antagonists, the rapid hydrolysis of circulating enkephalins in vivo, and the limited ability of these peptides to penetrate the blood-brain barrier. A consideration of the extensive distribution of enkephalins throughout peripheral autonomic systems leads to the proposal that enkephalins may act to modulate learning and memory by altering peripheral autonomic function; autonomic afferents may then communicate with the memory trace in the CNS through a central modulatory pathway outlined herein. Evidence that some stressful experiences may lead to increases in circulating enkephalins also is discussed. The sites of action of these circulating enkephalins may involve peripheral autonomic sites, or additionally may involve the circumventricular organs. As a further regulatory mechanism, circulating enkephalin levels may be controlled by experience-dependent alterations of the activity of enzyme systems that participate in their breakdown. Finally, it is emphasized that the mechanisms of enkephalin action postulated herein may be applicable to the actions of other peripheral hormones, peptides, and neurotransmitters that participate in the modulation of learning and memory storage processes.

Dependency in the Treatment of Complex Posttraumatic Stress Disorder and Dissociative Disorders

Dependency is a major and ubiquitous issue in the treatment of chronically traumatized patients, such as those with complex posttraumatic stress disorder (PTSD), trauma-related borderline personality disorder, and dissociative disorders. Within this context, the concept of dependency is often paired with pejorative adjectives, and is dichotomized and negatively compared to a preferred state of independence. This paper explores prevailing sociocultural and theoretical beliefs regarding dependency in the psychotherapy of trauma survivors, provides a working definition of dependency, offers an analysis of its complex nature, and describes the theory of structural dissociation, which helps illuminate the often contradictory manifestations of dependency in chronically traumatized patients. A distinction is made between secure and insecure dependency. Finally, this paper outlines the collaborative therapeutic process required to manage insecure dependency productively within a phase-oriented treatment model. Countertransference responses that interfere with a patient's conflicts regarding dependency are also discussed.

Enhancement of declarative memory associated with emotional content in a Brazilian sample

Several studies have documented that emotional arousal may enhance long-term memory. This is an adaptation of a paradigm previously used in North American and European samples in investigations of the influence of emotion on long-term retention. A sample of 46 healthy adults of high and low educational levels watched a slide presentation of stories. A randomly assigned group watched a story with an arousing content and another group watched a neutral story. The stories were matched for structure and comprehensibility and the set and order of the 11 slides were the same in both conditions. Immediately after viewing the slide presentation, the participants were asked to rate the emotionality of the narrative. The arousing narrative was rated as being more emotional than the neutral narrative (t(44) = -3.6, P<0.001). Ten days later subjects were asked to remember the story and answer a multiple-choice questionnaire about it. The subjects who watched the arousing story had higher scores in the free recall measure (t(44) = -2.59, P<0. 01). There were no differences between groups in the multiple-choice test of recognition memory (t(44) = 0.26). These findings confirm that an emotional arousing content enhances long-term declarative memory and indicate the possibility of applying this instrument to clinical samples of various cultural backgrounds.

Social sharing of Gulf War experiences: association with trauma-related psychological symptoms

It commonly is believed that talking with family and friends (social sharing) about stressful or traumatic experiences can be therapeutic with regard to stress-related psychological symptoms. Two years after serving in the Gulf War, 58 National Guard Reservists completed the Mississippi Posttraumatic Stress Disorder Scale (PTSD), the Brief Symptom Inventory, and a measure of social sharing that asked how much they had talked to family and friends about their experiences in the Gulf during the 2-year period since returning from the war. Subjects had a broad range of Mississippi PTSD scores. Six subjects met Mississippi criteria for PTSD. Degree of talking to family and friends about Gulf War experiences did not account for a significant portion of the variance in the prediction of PTSD symptoms but did significantly contribute to prediction of scores for interpersonal sensitivity, depression, and psychoticism. Thus, degree of talking with family and friends was not found to be related to PTSD symptoms, although it may have influenced some symptoms of general psychopathology, such as depression, that are not specific to PTSD.

Chronic propranolol induces deficits in retention but not acquisition performance in the water maze in mice

Agents that alter adrenergic receptors, such as "beta-blockers," also alter memory storage. However, reports suggest that beta-adrenergic receptor antagonists, such as propranolol, have conflicting behavioral effects with acute vs chronic dosing. This study was designed to evaluate the effects of chronic propranolol on retention for a spatial learning task. Adult male ICR mice were given daily injections of propranolol (2, 4, 8, or 12 mg/kg ip) or 0. 9% NaCl for 15 days prior to, and during, trials in a Morris water maze. Mice received five massed acquisition (escape) trials in each of three daily sessions, followed by a single 60-s probe trial on the fourth day. The location of the submerged platform was constant for each animal over acquisition trials, but varied across animals; starting position varied across trials. A 5 (dose) x 3 (trial blocks) mixed factorial ANOVA for escape time yielded a significant trial blocks effect only (p <.001), showing performance improving over sessions. Time spent in the target quadrant on the probe trial was shorter under all doses of propranolol when compared to vehicle group (all p <.001), indicating poorer retention of prior platform location. This effect, however, was not dose-related. Swim speed was not significantly affected by propranolol. These data demonstrate that chronic dosing with propranolol can impair retention of spatial learning, which cannot be attributed to reduced arousal or motor function.

Decreased GABAA-receptor clustering results in enhanced anxiety and a bias for threat cues

Patients with panic disorders show a deficit of GABAA receptors in the hippocampus, parahippocampus and orbitofrontal cortex. Synaptic clustering of GABAA receptors in mice heterozygous for the gamma2 subunit was reduced, mainly in hippocampus and cerebral cortex. The gamma2 +/- mice showed enhanced behavioral inhibition toward natural aversive stimuli and heightened responsiveness in trace fear conditioning and ambiguous cue discrimination learning. Implicit and spatial memory as well as long-term potentiation in hippocampus were unchanged. Thus gamma2 +/- mice represent a model of anxiety characterized by harm avoidance behavior and an explicit memory bias for threat cues, resulting in heightened sensitivity to negative associations. This model implicates GABAA-receptor dysfunction in patients as a causal predisposition to anxiety disorders.

Pavlovian heart rate and jaw movement conditioning in the rabbit: effects of medial prefrontal lesions

An experiment was conducted in which jaw movements (JM) and heart rate (HR) were concomitantly assessed in rabbits during simple Pavlovian conditioning. A 2-s 1200-Hz tone was the conditioned stimulus (CS) and an intraoral 1-cc pulse of 0.5 M sucrose-water solution was the unconditioned stimulus (US). Sham and medial prefrontal (mPFC)-lesioned animals received paired CS/US training with a 70- to 75-dB CS and were compared with sham- and mPFC-lesioned animals that received explicitly unpaired CS/US presentations. The percentages of JM CRs were significantly greater in the paired than the unpaired groups, but mPFC lesions had no effect on this measure. Conditioned HR decelerations occurred only in the paired groups and then only during the first session of training. Moreover, these CS-evoked cardiac decelerations were somewhat attenuated by the mPFC lesion. CS-evoked HR accelerations, which were significantly greater in unpaired than in paired animals, occurred during the four subsequent sessions. These results suggest that a CS-evoked cardioinhibitory process, mediated by the mPFC, is engendered by Pavlovian appetitive conditioning, as has been previously demonstrated for aversive conditioning. However, during JM conditioning these inhibitory changes are quickly replaced by tachycardia, possibly related to increased nonspecific somatomotor activity, since the tachycardia was somewhat greater in the unpaired animals.

Frontal lobe contributions to theory of mind

"Theory of mind," the ability to make inferences about others" mental states, seems to be a modular cognitive capacity that underlies humans" ability to engage in complex social interaction. It develops in several distinct stages, which can be measured with social reasoning tests of increasing difficulty. Individuals with Asperger"s syndrome, a mild form of autism, perform well on simpler theory of mind tests but show deficits on more developmentally advanced theory of mind tests. We tested patients with bilateral damage to orbito-frontal cortex (n = 5) and unilateral damage in left dorsolateral prefrontal cortex (n = 5) on a series of theory of mind tasks varying in difficulty. Bilateral orbito-frontal lesion patients performed similarly to individuals with Asperger"s syndrome, performing well on simpler tests and showing deficits on tasks requiring more subtle social reasoning, such as the ability to recognize a faux pas. In contrast, no specific theory of mind deficits were evident in the unilateral dorsolateral frontal lesion patients. The dorsolateral lesion patients had difficulty only on versions of the tasks that placed demands on working memory.

5-Hz stimulation of CA3 pyramidal cell axons induces a beta-adrenergic modulated potentiation at synapses on CA1, but not CA3, pyramidal cells

In mouse hippocampal slices, long-term potentiation (LTP) at Schaffer collateral fiber synapses onto CA1 pyramidal cells could be induced by brief trains of 5-Hz synaptic stimulation (30 s) or by longer trains of 5-Hz stimulation (3 min) delivered during beta-adrenergic receptor activation. In contrast, 5-Hz stimulation, either alone or in the presence of the beta-adrenergic receptor agonist isoproterenol, failed to induce LTP at associational-commissural (assoc-com) fiber synapses onto CA3 pyramidal cells. Our results suggest that although CA3 pyramidal cells give rise to both the Schaffer collateral fiber synapses in CA1 and the assoc-com fiber synapses in CA3, the induction of LTP at these synapses may be regulated by different activity- and modulatory neurotransmitter-dependent processes.

The Neurobiological Basis of Anxiety and Fear: Circuits, Mechanisms, and Neurochemical Interactions (Part II)

This article is Part II of a review of the neuronal circuits, neural mechanisms, and neuromodulators that seem to be involved in anxiety and fear states. Part I focused on the specific brain structures, including the roles of the amygdala, locus coeruleus, hippocampus, and various cortical regions and the neural mechanisms of fear conditioning, extinction, and behavioral sensitization in mediating the signs and symptoms of anxiety and fear. Part II attempts to develop a better understanding of neurochemical mediation of traumatic remembrance and the neurobiological consequences of stress, particularly when experienced early in life. Finally, the data is synthesized to provide a basis for understanding the pathophysiology of anxiety disorders, such as Panic disorder and Posttraumatic Stress Disorder. NEUROSCIENTIST 4:122–132, 1998

The neuropsychology of REM sleep dreaming

Recent PET imaging and brain lesion studies in humans are integrated with new basic research findings at the cellular level in animals to explain how the formal cognitive features of dreaming may be the combined product of a shift in neuromodulatory balance of the brain and a related redistribution of regional blood flow. The human PET data indicate a preferential activation in REM of the pontine brain stem and of limbic and paralimbic cortical structures involved in mediating emotion and a corresponding deactivation of dorsolateral prefrontal cortical structures involved in the executive and mnemonic aspects of cognition. The pontine brainstem mechanisms controlling the neuromodulatory balance of the brain in rats and cats include noradrenergic and serotonergic influences which enhance waking and impede REM via anticholinergic mechanisms and cholinergic mechanisms which are essential to REM sleep and only come into full play when the serotonergic and noradrenergic systems are inhibited. In REM, the brain thus becomes activated but processes its internally generated data in a manner quite different from that of waking.

Opposite effects on two different measures of retention following unilateral inactivation of the amygdala

We previously reported finding differential effects of unilateral infusion of lidocaine into the right and left amygdalae prior to a retention test 24 h after one-trial inhibitory avoidance training. The present study was undertaken to determine whether the degree of training in an escape task influences the effects of unilateral inactivation of the amygdala with lidocaine prior to the retention test. Male Sprague-Dawley rats, implanted with bilateral cannulae aimed at the amygdaloid complex received 0 (no shock), 2, or 10 training trials in a footshock-motivated escape task (0.4 mA). Forty-eight h later, the rats received bilateral microinfusions into the amygdalae of either buffer, or lidocaine into one amygdala and buffer in the other, 5 min before they were tested for retention of the escape training using a continuous multiple trial inhibitory avoidance (CMIA) procedure (0.4 mA). Forty-eight h after CMIA training the animals were retested, this time without influence of drugs. As indicated by initial response latencies on the first retention test, unilateral inactivation of either the right or the left amygdala severely impaired retention performance for the escape training regardless of the number of prior escape training trials received. However, unilateral inactivation of either amygdala had no effect on acquisition of CMIA. Furthermore, unilateral inactivation of either amygdala during CMIA training did not affect retention tested 48 h later. These results suggest that the differential involvement of the right and left amygdalae may be limited to certain training conditions. Furthermore, these findings demonstrate opposite effects on 2 different measures of retention indicating that the method of testing retention affects the interpretation of the memory impairment induced by infusion of lidocaine into the amygdala.

Implicit and explicit memory in amnesia: some explanations and predictions by the TraceLink model

After a brief overview of some of the characteristics and neuroanatomy of amnesia, a new model of amnesia is described: the TraceLink model. One novel aspect of the model is that it makes specific and testable predictions regarding semantic dementia, a recently described disorder that is viewed here as being related to amnesia. The TraceLink model consists of: a trace system (roughly the neocortix), a link system (hippocampus and adjacent areas), and a modulatory system (certain basal forebrain nuclei). Different forms of learning in the TraceLink model are explained, followed by a discussion of implicit and explicit memory, prominence (ease of recall) and persistence (resistance to brain damage), consolidation, and Ribot gradients in retrograde amnesia. Patterns of recovery from retrograde amnesia are also discussed, and novel predictions are derived regarding implicit memory and various forms of amnesia.

Involvement of the amygdala in memory storage: interaction with other brain systems

There is extensive evidence that the amygdala is involved in affectively influenced memory. The central hypothesis guiding the research reviewed in this paper is that emotional arousal activates the amygdala and that such activation results in the modulation of memory storage occurring in other brain regions. Several lines of evidence support this view. First, the effects of stress-related hormones (epinephrine and glucocorticoids) are mediated by influences involving the amygdala. In rats, lesions of the amygdala and the stria terminalis block the effects of posttraining administration of epinephrine and glucocorticoids on memory. Furthermore, memory is enhanced by posttraining intraamygdala infusions of drugs that activate beta-adrenergic and glucocorticoid receptors. Additionally, infusion of beta-adrenergic blockers into the amygdala blocks the memory-modulating effects of epinephrine and glucocorticoids, as well as those of drugs affecting opiate and GABAergic systems. Second, an intact amygdala is not required for expression of retention. Inactivation of the amygdala prior to retention testing (by posttraining lesions or drug infusions) does not block retention performance. Third, findings of studies using human subjects are consistent with those of animal experiments. beta-Blockers and amygdala lesions attenuate the effects of emotional arousal on memory. Additionally, 3-week recall of emotional material is highly correlated with positronemission tomography activation (cerebral glucose metabolism) of the right amygdala during encoding. These findings provide strong evidence supporting the hypothesis that the amygdala is involved in modulating long-term memory storage.

Activity-dependent beta-adrenergic modulation of low frequency stimulation induced LTP in the hippocampal CA1 region

beta-Adrenergic receptor activation has a central role in the enhancement of memory formation that occurs during heightened states of emotional arousal. Although beta-adrenergic receptor activation may enhance memory formation by modulating long-term potentiation (LTP), a candidate synaptic mechanism involved in memory formation, the cellular basis of this modulation is not fully understood. Here, we report that, in the CA1 region of the hippocampus, beta-adrenergic receptor activation selectively enables the induction of LTP during long trains of 5 Hz synaptic stimulation. Protein phosphatase inhibitors mimic the effects of beta-adrenergic receptor activation on 5 Hz stimulation-induced LTP, suggesting that activation of noradrenergic systems during emotional arousal may enhance memory formation by inhibiting protein phosphatases that normally oppose the induction of LTP.

Age-related changes in hippocampal drug facilitation of memory processing in SAMP8 mice

SAMP8/TaJf(P8) mouse strain has an inherited age-related impairment of learning and memory, while age-matched subjects of the closely related SAMR1/TaJf(R1) show no impairment. After training on footshock avoidance, P8 and R1 received a drug injection into the hippocampus. Retention was tested 1 week later. The results indicate that bicuculline (GABA antagonist), SKF38393 (DA agonist), and ST587 (NE agonist) facilitated retention with little change in the dose-response curves for P8 mice 4, 8, and 12 months of age. L-glutamate, acting at the NMDA receptor, showed a modest decline in ability to improve retention with increasing age. Arecoline, a muscarinic agonist, had the strongest trend for an age-related decline in potency. The same drug treatments yielded dose-dependent facilitation of retention but no age-related changes in R1 mice. Reduced cholinergic activity in the hippocampus may be, in part, responsible for age-related decline in memory retention in P8 mice.

TraceLink: a model of amnesia and consolidation of memory

A model of amnesia is introduced, called TraceLink, that consists of three systems: 1) a trace system (neocortex), 2) a link system (hippocampus), and 3) a modulatory system (hippocampus/fornix/basal forebrain). It aims to explain salient aspects of the neuropsychology of amnesia, such as Ribot gradients in retrograde amnesia, patterns of dissociation between anterograde and retrograde amnesia, recovery from amnesia, and a newly discovered form of amnesia (semantic dementia) that results from certain temporal lobe lesions that do not affect the hippocampus. The model, furthermore, offers a new explanation for the global neuroanatomy of the hippocampus and neocortex based on the assumption that the brain aims to minimize connectivity volume. It also offers various strategies for the consolidation of memory, the effects of which are explored in computer simulations. The paper concludes with ten, largely untested; predictions derived from the TraceLink model.