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PubMed2005

Feelings you can't imagine: towards a cognitive neuroscience of alexithymia.

Alexithymia, or 'no words for feelings', refers to an impairment of the ability to identify and communicate one's emotional state, in addition to diminished affect-related fantasy and imagery. A recent study by Mantani et al. reported reduced activation of the posterior cingulate cortex in people with alexithymia when they imagined a future happy event. This finding augments the emerging understanding of the neural basis of alexithymia, and potentially provides valuable insights into brain systems underlying normal emotion processing.

Affective Symptoms↗
PubMed1999

Imagined transformations of bodies: an fMRI investigation.

A number of spatial reasoning problems can be solved by performing an imagined transformation of one's egocentric perspective. A series of experiments were carried out to characterize this process behaviorally and in terms of its brain basis, using functional magnetic resonance imaging (tMRI). In a task contrast designed to isolate egocentric perspective transformations, participants were slower to make left-right judgments about a human figure from the figure's perspective than from their own. This transformation led to increased cortical activity around the left parietal-temporal-occipital junction, as well as in other areas including left frontal cortex. In a second task contrast comparing judgments about inverted figures to judgments about upright figures (always from the figure's perspective), participants were slower to make left-right judgments about inverted figures than upright ones. This transformation led to activation in posterior areas near those active in the first experiment, but weaker in the left hemisphere and stronger in the right, and also to substantial left frontal activation. Together, the data support the specialization of areas near the parietal-temporal-occipital junction for egocentric perspective transformations. These results are also suggestive of a dissociation between egocentric perspective transformations and object-based spatial transformations such as mental rotation.

Adult↗
PubMed2001

Brain activity evoked by inverted and imagined biological motion.

Previous imaging research has identified an area on the human posterior superior temporal sulcus (STS) activated upon viewing biological motion. The current experiments explore the relationship between neural activity within this region and perceptual experience. Biological motion perception is orientation dependent: inverting point-light animations make them more difficult to see. We measured activity levels within this region as observers viewed inverted point-light animations. We also measured neural activity while observers imagined biological motion and compared it to that measured while observers viewed the animations. In both experiments we found that the BOLD response was modulated with perceptual experience. Viewing inverted biological motion activated posterior STS more than scrambled motion, but less than upright biological motion. Mental imagery of biological motion was also sufficient to activate this region in most of our observers, but the level of activity was weaker than during actual viewing of the motion animations.

Female↗
PubMed1991

Vegetative response during imagined movement is proportional to mental effort.

Measurement of cardiac and respiratory activity during mental simulation of locomotion at increasing speed revealed a covariation of heart rate and pulmonary ventilation with the degree of imagined effort. The degree of vegetative activation of a subject mentally running at 12 km/h was comparable to that of a subject actually walking at 5 km/h. This effect cannot be explained by an increase in peripheral (e.g. muscular) metabolic demands. Indeed, oxygen uptake decreased during motor imagery. This finding is suggestive of a commonality of neural structures responsible for mental imagery of movement and those responsible for programming actual movement. In addition, it provides an quantifiable way of testing mental imagery in relation to movement by using easily accessible biological markers.

Adolescent↗
PubMed2001

Recognition of imagined hand movements with low resolution surface Laplacian and linear classifiers.

EEG-based Brain Computer Interfaces (BCIs) require on-line detection of mental states from spontaneous EEG signals. In this framework, it was suggested that EEG patterns can be better detected with EEG data transformed with Surface Laplacian computation (SL) than with the unprocessed raw potentials. However, accurate SL estimates require the use of many EEG electrodes, when local estimation methods are used. Since BCI devices have to use a limited number of electrodes for practical reasons, we investigated the performances of spline methods for SL estimates using a limited number of electrodes (low resolution SL). Recognition of mental activity was attempted on both raw and SL-transformed EEG data from five healthy people performing two mental tasks, namely imagined right and left hand movements. Linear classifiers were used including Signal Space Projection (SSP) and Fisher's linear discriminant. Results showed an acceptable average correlation between the waveforms obtained with the low resolution SL and these obtained with the SL computed from 26 electrodes (full resolution SL). More importantly, satisfactorily recognition scores for mental EEG-patterns were obtained with the low-resolution surface Laplacian transformation of the recorded potentials when compared with those obtained by using full resolution SL (82%). These results demonstrated also the utility of linear classifiers for the detection of mental patterns in the BCI field.

Biomedical Engineering↗
PubMed2000

Modelling a loss event: effect of imagined bereavement on the hypothalamic-pituitary-adrenal axis.

BACKGROUND: Loss events are the stressors most closely associated with the onset of depressive illnesses. The acute cortisol response to loss has been little studied although it could be an important mediator of the effects of environmental stress on psychological state. METHODS: The salivary cortisol response to an established negative mood induction procedure involving music and an imagined bereavement was measured in 30 healthy volunteers. RESULTS: Considerable but transient mood lowering in response to the negative mood induction was associated with a small increase in cortisol output over 30 min. CONCLUSIONS: This procedure has some potential as a tool to investigate individual differences in the neuroendocrine response to loss events, but this is limited. There remains a need for laboratory models of relevant psychosocial stressors in mood disorders research.

Adult↗
PubMed2002

Does imaginal exposure exacerbate PTSD symptoms?

Symptom exacerbation (i.e., treatment side effects) has often been neglected in the psychotherapy literature. Although prolonged exposure has gained empirical support for the treatment of chronic posttraumatic stress disorder (PTSD), some have expressed concem that imaginal exposure, a component of this therapy, may cause symptom exacerbation, leading to inferior outcome or dropout. In the present study, symptom exacerbation was examined in 76 women with chronic PTSD. To define a "reliable" exacerbation, we used a method incorporating the standard deviation and test-retest reliability of each outcome measure. Only a minority of participants exhibited reliable symptom exacerbation. Individuals who reported symptom exacerbation benefited comparably from treatment. Further, symptom exacerbation was unrelated to dropout. Thus, although a minority of individuals experienced a temporary symptom exacerbation, this exacerbation was unrelated to outcome.

Adult↗
PubMed2000

Psychophysiological responses to imagined infidelity: the specific innate modular view of jealousy reconsidered.

Three studies measured psychophysiological reactivity (heart rate, blood pressure, and electrodermal activity) while participants imagined a mate's infidelity. The specific innate modular theory of gender differences in jealousy hypothesizes that men are upset by sexual infidelity and women are upset by emotional infidelity, because of having faced different adaptive challenges (cuckoldry and loss of a mate's resources, respectively). This view was not supported. In men, sexual-infidelity imagery elicited greater reactivity than emotional-infidelity imagery. But, sexual imagery elicited greater reactivity even when infidelity was not involved, suggesting that the differential reactivity may not specifically index greater jealousy. In two studies with reasonable power, women did not respond more strongly to emotional infidelity. Moreover, women with committed sexual relationship experience showed reactivity patterns similar to those of men. Hypothetical infidelity self-reports were unrelated to reactivity.

Adult↗
PubMed1982

Interaction between perceived and imagined rotation.

In Experiment 1, subjects performed a mental-rotation task in which they were timed as they decided whether rotated letters were normal or backwards. Between presentations of the letters, they watched a rotating textured disk that induced an aftereffect of rotary movement on the letters. The function relating reaction times to orientation was influenced asymmetrically by the aftereffect, suggesting that perceived movement interacts with imagined movement. Experiment 2 showed that the aftereffect produced a negligible influence on perceived orientation, suggesting that the influence of the aftereffect on mental rotation was not caused by changes in the perceived orientations of the letters. Detailed analysis of the mental-rotation functions suggested that the aftereffect may sometimes have induced subjects to rotate letters through the larger rather than the smaller angle back to the upright where the aftereffect was in the appropriate direction.

Adolescent↗
PubMed1991

Imagined haptic exploration in judgments of object properties.

In Experiment 1, each subject rated a single, named object for its roughness, hardness, temperature, weight, size, or shape. In Experiment 2, each subject compared one pair of objects along the same dimensions. In both studies, a substantial proportion of subjects who judged the first four dimensions imagined a hand making exploratory movements appropriate for the designated information. The proportion of hand-exploration images decreased substantially when judging size or shape, or when judgments could be made readily through general semantic knowledge. The results suggest that the incorporation of haptic exploration into visual imagery provides access to information about haptically accessible object properties.

Adult↗
PubMed2000

Tool use and the effect of action on the imagination.

Three studies examined the claim that hand movements can facilitate imagery for object rotations but that this facilitation depends on people's model of the situation. In Experiment 1, physically turning a block without vision reduced mental rotation times compared with imagining the same rotation without bodily movement. In Experiment 2, pulling a string from a spool facilitated participants' mental rotation of an object sitting on the spool. In Experiment 3, depending on participants' model of the spool, the exact same pulling movement facilitated or interfered with the exact same imagery transformation. Results of Experiments 2 and 3 indicate that the geometric characteristics of an action do not specify the trajectory of an imagery transformation. Instead, they point to people's ability to model the tools that mediate between motor activity and its environmental consequences and to transfer tool knowledge to a new situation.

Adult↗
PubMed2005

Effects of transdermal nicotine during imaginal exposure to anxiety and smoking cues in college smokers.

In a 2 (patch) x 2 (smoking) x 2 (anxiety) mixed design, 52 undergraduate smokers randomly received a nicotine (21 mg) or placebo patch. After a 4-hr nicotine absorption/deprivation period, participants imagined several scenarios varying in cue content: (a) anxiety plus smoking, (b) anxiety, (c) smoking, and (d) neutral. Although smoking urge increased in both the nicotine and placebo conditions after the absorption/deprivation period, those who received the placebo reported significantly greater urge. During the cue reactivity trials, a significant Patch x Smoking x Anxiety interaction effect was observed for urge. However, participants who received nicotine still experienced moderate urges, indicating that nicotine did not attenuate cue-elicited urge. Transdermal nicotine did not diminish anxiety during the absorption/deprivation period or in response to the cues.

Administration, Cutaneous↗
PubMed1975

Involvement in everyday imaginative activities, attitudes toward hypnosis, and hypnotic suggestibility.

One hundred male and 83 female subjects were assessed on absorption (i.e., involvement in everyday imaginative activities), attitudes toward hypnosis, and hypnotic suggestibility. Significant positive correlations were obtained for both sexes between absorption and attitudes and between each of these variables and hypnotic suggestibility. Multiple regression analyses indicated that most of the predicted variance in hypnotic suggestibility scores was accounted for in both sexes by the absorption variable.

Activities of Daily Living↗
PubMed1990

Seeing versus imagining movement in depth.

Subjects judged the quality of rigid motion between pairs of three-dimensional drawings that differed by a rotation in depth. The figures were aligned with, and rotated around, either the vertical axis or an axis that was oblique with respect to the XYZ co-ordinate system. Rated quality of motion decreased with increasing angular disparity between the figures and with decreasing stimulus duration, regardless of whether the figures were vertical or oblique. The same subjects then participated in a mental rotation task using the same stimuli and angular disparities. An effect of principal axis emerged, such that subjects took longer to make decisions about obliquely aligned stimuli than about vertically aligned stimuli, especially if they received the oblique stimuli first. These data imply that perceived versus imagined movement through the same trajectory involves different processes. Whereas the apparent motion system performs its computations relatively automatically, the processes involved in mental rotation are more strategic in nature.

Adult↗
PubMed1995

Care, attention and imaginative identification in nursing practice.

This paper has relevance for both the major health care professions of medicine and nursing. Therefore the author tends to speak of health care practitioners rather than nurses or doctors. The author argues that health care practitioners need to be supported and facilitated in analysis of the concept of care both during their initial professional educational preparation and during their professional lives. Developing an adequate conceptual base for health care practice enables the practitioner to clarify issues of role, function and responsibilities. A conceptual analysis of caring in health care practice highlights the need for practitioners to develop skills of attention and imaginative identification. These skills enable the practitioner to provide constructive care for patients. Constructive care is care which is patient-based and patient-oriented, identification of patient need being the stimulus and the focus of practitioner response.

Attention↗
PubMed2004

Collective moral imagination: making decisions for persons with dementia.

Much debate concerning 'precedent autonomy'--that is, the authority of former, competent selves to govern the welfare of later. non-competent selves--has assumed a radical discontinuity between selves, and has overlooked the 'bridging' role of intimate proxy decision-makers. I consider a recent proposal by Lynn et al. (1999) that presents a provocative alternative, foregrounding an imagined dialogue between the formerly competent patient and her/his trusted others. I consider what standards must be met for such dialogues to have moral force, appealing to narrative and feminist ethics. I then critique the dualistic construction of selves implicit in much of the advance directive literature, noting the continuities of dependence, character, and body, as well as the social dimension of the construction of selves.

Decision Making↗
PubMedDate not supplied

Aging and scanning of imagined and perceived visual images.

The authors examined adult age differences in the proficiency of visually scanning across perceived and imagined displays. Participants were asked to indicate whether an arrow in the central region of a square grid ring pointed to a target square. The distance between arrow and target was varied, and all participants showed the expected increase in response times and error rates as scanning distance increased. The arrow and grid display either remained visible until the participant responded (perceptual condition) or disappeared after 50 ms (imagery condition). In both conditions, older participants required more time to scan and made more errors as distance increased than did younger participants. These findings conflict with previous studies showing that perceptual and imagery scanning are preserved with aging. Although methodological factors may have contributed to these differences, further research is needed to elucidate effects of aging on visual scanning.

Adolescent↗
PubMed2003

Visions of the dead: imagination and mourning.

Contemporary research recognizes the existence of an ongoing attachment between the mourner and the deceased. This research tends to focus on the subjective aspects of the attachment--the mourner's memory and emotions. A complementary perspective is offered by archetypal psychology, which considers the deceased to exist outside the mourner's subjectivity as an autonomous image. This approach is illustrated by an exemplary case: a woman named Verda who experienced the death of her twin sister,Vera.Their account suggests that Verda's mourning derives from her encounters with Vera's continuing imaginal presence.

Adaptation, Psychological↗