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Biomedical subjects

F Travis

Publications and source records attributed to F Travis.

At least 19 recordsLinked to original sources
PubMed2001

Autonomic and EEG patterns distinguish transcending from other experiences during Transcendental Meditation practice.

This study compared EEG and autonomic patterns during transcending to "other" experiences during Transcendental Meditation (TM) practice. To correlate specific meditation experiences with physiological measures, the experimenter rang a bell three times during the TM session. Subjects categorized their experiences around each bell ring. Transcending, in comparison to "other" experiences during TM practice, was marked by: (1) significantly lower breath rates; (2) higher respiratory sinus arrhythmia amplitudes; (3) higher EEG alpha amplitude; and (4) higher alpha coherence. In addition, skin conductance responses to the experimenter-initiated bell rings were larger during transcending. These findings suggest that monitoring patterns of physiological variables may index dynamically changing inner experiences during meditation practice. This could allow a more precise investigation into the nature of meditation experiences and a more accurate comparison of meditation states with other eyes-closed conditions.

Adolescent↗
PubMed2001

Physiological patterns during practice of the Transcendental Meditation technique compared with patterns while reading Sanskrit and a modern language.

This study tested the prediction that reading Vedic Sanskrit texts, without knowledge of their meaning, produces a distinct physiological state. We measured EEG, breath rate, heart rate, and skin conductance during: (1) 15-min Transcendental Meditation (TM) practice; (2) 15-min reading verses of the Bhagavad Gita in Sanskrit; and (3) 15-min reading the same verses translated in German, Spanish, or French. The two reading conditions were randomly counterbalanced, and subjects filled out experience forms between each block to reduce carryover effects. Skin conductance levels significantly decreased during both reading Sanskrit and TM practice, and increased slightly during reading a modern language. Alpha power and coherence were significantly higher when reading Sanskrit and during TM practice, compared to reading modern languages. Similar physiological patterns when reading Sanskrit and during practice of the TM technique suggests that the state gained during TM practice may be integrated with active mental processes by reading Sanskrit.

Adult↗
PubMed2000

Cortical plasticity, contingent negative variation, and transcendent experiences during practice of the Transcendental Meditation technique.

This study investigated effects of transcendent experiences on contingent negative variation (CNV) amplitude, CNV rebound, and distraction effects. Three groups of age-matched subjects with few (<1 per year), more frequent (10-20 per year), or daily self-reported transcendent experiences received 31 simple RT trials (flash (S(1))/tone (S(2))/button press) followed by 31 divided-attention trials - randomly intermixed trials with or without a three-letter memory task in the S(1)-S(2) interval). Late CNV amplitudes in the simple trials were smallest in the group with fewest, and largest in the group with most frequent transcendent experiences. Conversely, CNV distraction effects were largest in the group with fewest and smallest in the group with most frequent transcendent experiences (the second group's values were in the middle in each case). These data suggest cumulative effects of transcendent experiences on cortical preparatory response (heightened late CNV amplitude in simple trials) and executive functioning (diminished distraction effects in letter trials).

Adult↗
PubMed2000

Pure consciousness: distinct phenomenological and physiological correlates of "consciousness itself".

This paper explores subjective reports and physiological correlates of the experience of "consciousness itself"--self awareness isolated from the processes and objects of experience during Transcendental Meditation practice. Subjectively, this state is characterized by the absence of the very framework (time, space, and body sense) and content (qualities of inner and outer perception) that define waking experiences. Physiologically, this state is distinguished by the presence of apneustic breathing, autonomic orienting at the onset of breath changes, and increases in the frequency of peak EEG power. A model, called the junction point model, is presented that integrates pure consciousness with waking, dreaming, or sleeping. It could provide a structure to generate a coherent program of research to test the full range of consciousness and so enable us to understand what it means to be fully human.

Adult↗
PubMed1999

Autonomic and EEG patterns during eyes-closed rest and transcendental meditation (TM) practice: the basis for a neural model of TM practice.

In this single-blind within-subject study, autonomic and EEG variables were compared during 10-min, order-balanced eyes-closed rest and Transcendental Meditation (TM) sessions. TM sessions were distinguished by (1) lower breath rates, (2) lower skin conductance levels, (3) higher respiratory sinus arrhythmia levels, and (4) higher alpha anterior-posterior and frontal EEG coherence. Alpha power was not significantly different between conditions. These results were seen in the first minute and were maintained throughout the 10-min sessions. TM practice appears to (1) lead to a state fundamentally different than eyes-closed rest; (2) result in a cascade of events in the central and autonomic nervous systems, leading to a rapid change in state (within a minute) that was maintained throughout the TM session; and (3) be best distinguished from other conditions through autonomic and EEG alpha coherence patterns rather than alpha power. Two neural networks that may mediate these effects are suggested. The rapid shift in physiological functioning within the first minute might be mediated by a "neural switch" in prefrontal areas inhibiting activity in specific and nonspecific thalamocortical circuits. The resulting "restfully alert" state might be sustained by a basal ganglia-corticothalamic threshold regulation mechanism automatically maintaining lower levels of cortical excitability.

Adolescent↗
PubMed1999

Pure Consciousness: Distinct Phenomenological and Physiological Correlates of "Consciousness Itself"

This paper explores subjective reports and physiological correlates of the experience of "consciousness itself" - self awareness isolated from the processes and objects of experience during Transcendental Meditation practice. Subjectively, this state is characterized by the absence of the very framework (time, space, and body sense) and content (qualities of inner and outer perception) that define waking experiences. Physiologically, this state is distinguished by the presence of apneustic breathing, autonomic orienting at the onset of breath changes, and increases in the frequency of peak EEG power. A model, called the junction point model, is presented that integrates pure consciousness with waking, dreaming, or sleeping. It could provide a structure to generate a coherent program of research to test the full range of consciousness and so enable us to understand what it means to be fully human.

Journal Article↗
PubMed1998

Effects of distracting stimuli on CNV amplitude and reaction time.

The present study investigated the reliability of CNV distraction and rebound effects, and their relation with reaction time. Twenty-four subjects were presented three blocks of trials: (1) a control block--a fixed foreperiod reaction time task consisting of a flash-tone-key press sequence; (2) a divided-attention block--randomly intermixed trials with and without a short-term memory task (three visually-presented letters) in the S1-S2 interval (50% of each); and (3) a second control block. In trials with the short-term memory task, subjects recalled the letters after the key press to the tone. Compared to the control block, CNV amplitudes during trials with letters were significantly smaller and reaction times to S2 were significantly slower (distraction effect). In contrast, CNV amplitudes during trials with no-letters were significantly larger (CNV rebound), but the reaction times were again significantly slower. This dissociation of CNV rebound and reaction time could provide an objective neurophysiological tool to probe attention functions in both normal and clinical populations.

Adolescent↗
PubMed1998

Cortical and cognitive development in 4th, 8th and 12th grade students. The contribution of speed of processing and executive functioning to cognitive development.

This study investigated cortical/cognitive relations in 30 4th, 8th and 12th grade students. All students were administered the Figural Intersection Test, a measure of cognitive development, and performed, three times with different targets, an event-related potential (ERP) oddball/selective-attention task. Two independent factors emerged from the ERP task that predicted development--speed of processing (P300 latency to Block 1 targets) and maturation of executive functioning (a composite ERP variable calculated as the ratio of RT and P300 latency divided by the accuracy to Block 2 targets). These two variables loaded on orthogonal factors in a principal components analysis, and were the only variables included in a stepwise regression of physiological variables on cognitive development. Speed of processing is modulated by myelination and synaptogenesis, and executive functioning is modulated by maturation of the frontal system. These electrophysiological markers could index these cortical transformations underlying cognitive development.

Adolescent↗
PubMed1997

Autonomic patterns during respiratory suspensions: possible markers of Transcendental Consciousness.

In two experiments, we investigated physiological correlates of transcendental consciousness during Transcendental Meditation sessions. In the first, experimenter-initiated bells, based on observed physiological patterns, marked three phases during a Transcendental Meditation session in 16 individuals. Interrater reliability between participant and experimenter classification of experiences at each bell was quite good. During phases including transcendental consciousness experiences, skin conductance responses and heart rate deceleration occurred at the onset of respiratory suspensions or reductions in breath volume. In the second experiment, this autonomic pattern was compared with that during forced breath holding. Phasic autonomic activity was significantly higher at respiratory suspension onset than at breath holding onset. These easily measured markers could help focus research on the existence and characteristics of transcendental consciousness.

Adult↗
PubMed1996

Invincible Athletics program: aerobic exercise and performance without strain.

This study compared physiologic pattern during conventional aerobic exercise to those during Invincible Athletics--a program emphasizing balance and comfort during exercise to increase strength, endurance, and mind-body coordination gradually without the negative effects of the stress/recovery cycle. While heart rats were similar during both workouts, during Invincible Athletics: (1) perceived comfort tended to be higher and perceived exertion tended to be lower; (2) breath rates were significantly lower; (3) respiratory sinus arrhythmia and central-parietal alpha relative power were significantly higher; and (4) endurance was significantly longer. Respiratory sinus arrhythmia decreases with physiologic and mental stress. Heightened respiratory sinus arrhythmia and EEG alpha relative power along with subjective reports of greater comfort, less exertion, and observed increased endurance suggest that during Invincible Athletics athletes may be more easily adapting to the demands made upon them.

Adolescent↗
PubMed1994

A second linked-reference issue: possible biasing of power and coherence spectra.

The effect of a linked-ears reference on scalp-recorded potentials was investigated in six subjects during an eyes-closed counting task. EEG was recorded from the midline and surrounding electrodes with a linked-ears reference, and from Fz, Cz, and Pz with an active reference three cms anterior (close-bipolar). The linked-ears data were also converted to current source densities by applying the Laplacian. Coherence and power spectra were calculated for the three data sets. Linked-ears frontal relative power was significantly higher than current source density or close-bipolar power at 7-Hz--the frequency of peak parietal power. Also, the linked-ears coherence spectrum was significantly higher than current source density or close-bipolar coherence spectra, and tended to have a smaller range of values. These data replicate and extend earlier reports of distortion of coherence spectra by a common reference.

Adult↗
PubMed1992

Transpersonal experiences in childhood: an exploratory empirical study of selected adult groups.

A questionnaire was developed to assess adult recall for a range of transpersonal experiences throughout childhood and adolescence (mystical experience, out-of-body experience, lucid dreams, archetypal dreams, ESP), as well as nightmares and night terrors as indicators of more conflicted, negative states. In two exploratory studies this questionnaire was administered to subjects with high estimated levels of early transpersonal experiences and practising meditators, with respective undergraduate controls. A cognitive skills/precocity model of early transpersonal experience was contrasted with a vulnerability of self model by comparisons of these groups on questionnaire categories, imaginative absorption, neuroticism, and visual-spatial skills, with some support found for both models depending on experience type, age of estimated recall, and adult meditative practice.

Adult↗
PubMed1991

Acute deprivation of the terminal four hours of sleep does not increase delta (0-3-Hz) electroencephalograms: a replication.

This experiment evaluated further our previous finding that substitution of waking for the terminal 3-4 hr of sleep produces little or no increase in either visually scored or computer measures of delta sleep. Eleven young adults (mean age 24.5 yr) were studied on a baseline night, a night with sleep limited to an average of 188 min, and a recovery night. Visually scored sleep stages, eye movement activity and computer measures of 0-3 Hz were analyzed by nonrapid eye movement periods (NREMPs) and for all recorded sleep in each condition. In addition, we measured the heights, durations and areas under the curve manifested by the cyclic waxing and waning of 0-3-Hz integrated amplitude across sleep. Acute loss of 3.9 hr of sleep did not increase either visual or computer measures of delta electroencephalograms (EEG) on the recovery night, essentially confirming our previous findings. We hypothesize that augmentation of delta EEG above baseline levels after acute (one night's) sleep loss requires that disruption or loss of sleep from the first two NREMPs (or delta cycles). Rapid eye movement (REM) sleep durations on the recovery night were unaffected by the marked loss of REM sleep caused by partial deprivation. Although eye movements as well as stage REM were lost in the deprivation condition, eye movement density was significantly reduced rather than increased on the recovery night. This reduction is consistent with the hypothesis that REM activity varies inversely with sleep depth (or directly with central arousal level). The observations here, taken in association with previous results, suggest that a threshold for eye movement suppression by sleep deprivation in young adults lies in the range of 3-4 hr of prior sleep loss.

Adult↗
PubMed1989

The effects of the transcendental mediation technique and progressive muscle relaxation on EEG coherence, stress reactivity, and mental health in black adults.

Eighty-three black college students, staff and adults were pretested on EEG coherence, skin potential (SP) habituation to a series of loud tones, psychometric measures of mental health (Tennessee Self-Concept Empirical Scales and Spielberger State-Trait Anxiety Inventory) and IQ. They were then randomly assigned to one of the three treatment groups: the Transcendental Meditation technique (TM); Progressive Muscle Relaxation (PR); or cognitive-behavioral strategies (C). Approximately one year later, they were posttested. TM and PR increased significantly on an overall mental health factor (p less than .036) and anxiety (p less than .0006). TM showed a greater reduction in neuroticism than PR and C (p less than .032). TM also showed global increases in alpha and theta coherence among frontal and central leads during the TM period compared to eyes closed (p less than .016), whereas PR and C did not show EEG state changes. The coherence increases during TM were most marked in the right hemisphere (F4C4). TM showed faster SP habituation at posttest compared to pretest (p less than .047) whereas PR did not (data was missing for C). None of the groups showed longitudinal changes in EEG, perhaps due to lack of regularity of participation in the treatment programs.

Adolescent↗
PubMed1987

Psychosocial adjustment of 20 patients with Treacher Collins syndrome before and after reconstructive surgery.

Eight males and 12 females (mean age, 12.2 years) with Treacher Collins syndrome were studied longitudinally before and after craniofacial reconstruction. The patients and the parents of the 16 patients who were children were interviewed by a psychosocial team (child psychiatrist, psychologist and social worker) 6 months before and 1, 2, 3 and 4 years after surgery. The patients' facial appearance (Hay's Rating Scale), intellectual ability (Wechsler scales), self-esteem (Piers-Harris Self-Concept Scale for Children) and adaptive functioning (DSM III) were measured. The findings indicate that while their intellectual ability was unchanged, their appearance, self-esteem and adaptive functioning improved, peaking 1 year postoperatively and levelling off at the 2- and 4-year postoperative assessments. The improvement in the patients' facial appearance seems to have a direct, positive influence, creating psychosocial and social benefits for them.

Adaptation, Psychological↗
PubMed1986

Beauty and the eye of the beholder: social consequences and personal adjustments for facial patients.

Patients' pre- and postoperative self-reports were compared with reports of non-medical observers to investigate whether improved self-esteem is a direct result of increased social acceptance in maxillo- and craniofacial patients. Twenty-two children and adolescents undergoing reconstructive surgery for a variety of facial deformities were asked to rate their physical appearance on the Hay's Scale and fill out the Piers-Harris Self-Concept Scale. Their ratings were compared with scores given by a panel of lay volunteers on random presentation of pre- and postoperative photographs of the same patients. Patients rated their appearance as noticeably improved after surgery, their self-esteem rose significantly and they reported more social adeptness and acceptance at home and school. Raters observed only relatively subtle changes. Apparently, quality of life improved for the postsurgical facial patient because of increased self-esteem and confidence, which free him to overcome social barriers.

Adolescent↗
PubMed1986

Fact and fantasy: psychosocial consequences of facial surgery in 24 Down syndrome children.

Twenty-four children with Down syndrome were evaluated to investigate whether appearance, family functioning and intellectual functioning improved after facial reconstruction. Pre- and postoperatively, families were interviewed by a psychosocial team, the children's intellectual functioning was measured and parents were asked to rate their child's facial appearance on the Hay's Scale and to complete the FACES II, a questionnaire determining family functioning. Parents' ratings were compared with the scores of lay raters who viewed randomly presented pre- and postoperative photographs. Measurements of intelligence and family functioning revealed no postoperative improvement and lay raters considered postoperative appearance as slightly less attractive. However, parents rated their children's appearance as noticeably improved and reported happier personal, family and social lives. Thus, positive psychosocial consequences may largely be the result of parents' satisfaction with surgical results, providing them with hope for the future. Presurgical family assessment to clarify surgical limitations and parental expectations is essential.

Adolescent↗