Dissociable influences of auditory object vs. spatial attention on visual system oscillatory activity

Given that both auditory and visual systems have anatomically separate object identification ("what") and spatial ("where") pathways, it is of interest whether attention-driven cross-sensory modulations occur separately within these feature domains. Here, we investigated how auditory "what" vs. "where" attention tasks modulate activity in visual pathways using cortically constrained source estimates of magnetoencephalograpic (MEG) oscillatory activity. In the absence of visual stimuli or tasks, subjects were presented with a sequence of auditory-stimulus pairs and instructed to selectively attend to phonetic ("what") vs. spatial ("where") aspects of these sounds, or to listen passively. To investigate sustained modulatory effects, oscillatory power was estimated from time periods between sound-pair presentations. In comparison to attention to sound locations, phonetic auditory attention was associated with stronger alpha (7-13 Hz) power in several visual areas (primary visual cortex; lingual, fusiform, and inferior temporal gyri, lateral occipital cortex), as well as in higher-order visual/multisensory areas including lateral/medial parietal and retrosplenial cortices. Region-of-interest (ROI) analyses of dynamic changes, from which the sustained effects had been removed, suggested further power increases during Attend Phoneme vs. Location centered at the alpha range 400-600 ms after the onset of second sound of each stimulus pair. These results suggest distinct modulations of visual system oscillatory activity during auditory attention to sound object identity ("what") vs. sound location ("where"). The alpha modulations could be interpreted to reflect enhanced crossmodal inhibition of feature-specific visual pathways and adjacent audiovisual association areas during "what" vs. "where" auditory attention.     

Correspondence between spectral power and synchronization of the brain rhythms in the norm and cognitive pathology

The work is aimed at the study of correlations between the measures of spectral power and cortical interactions of EEG rhythms in healthy subjects and schizophrenic patients ("acute" and chronic cases). All brain rhythms in healthy subjects appeared to be symmetrical and synchronous both in phase and frequency. In "acute" schizophrenics, opposite to healthy subjects, the distribution of cortical activity is asymmetrical, and in the chronic cases, the spectral power of most cortical rhythms is decreased as compared to healthy subjects. In the "acute" patients, interhemispheric connections are absent in all rhythms but alpha. In the chronic patients, the number of cortical connections is slightly higher than in the acute patients; and they are located in the posterior areas in the gamma rhythm. These neurophysiological aberrations evidently underlie the multiple mental activity disorders in schizophrenic patients. Thus, the correspondence between the brain rhythms and their synchronization is a necessary condition for normal perception, emotions and cognition evidently influencing behavior and consciousness.     

QUANTITATIVE BEHAVIORAL STUDY OF BOTTLENOSE DOLPHINS IN SWIM-WITH-DOLPHIN PROGRAMS IN THE UNITED STATES

The behavior of dolphins in four Swim-With-Dolphin programs was compared by type of Swim encounter, defined by the presence ("Controlled") or absence ("Not-Controlled") of explicit trainer regulation of interactions between dolphins and human swimmers. Dolphin-swimmer interactions involving aggressive, submissive, or sexual behavior were designated as "high-risk" in the Swim context; sexual behavior was included as high-risk based on analyses that demonstrated co-occurrence of sexual and agonistic behaviors. High-risk activity comprised a substantial proportion of dolphin-swimmer social activity during Not-Controlled Swims. In contrast, high-risk activity rarely occurred during Controlled Swims, even though agonistic and sexual behaviors were normal components of the same dolphins' free-time social repertoire. These results indicated that direct trainer control of dolphin-swimmer interactions virtually eliminated high-risk activity from the Swim context, and thereby diminished the potential for dolphin distress, swimmer injury, and rejection of dolphins from Swim programs due to swimmer injury. This study illustrates effective use of quantitative behavioral sampling techniques for evaluation of captive management concerns and promotes broader use of these techniques for a better understanding of cetacean behavior.     

Type of behavior and superoxide dismutase activity in the brain of rats (a comparison of 2 Tryon strains)

Differences in the type of behaviour in capable ("maze-bright") and incapable ("maze-dull") Tryon rats have been demonstrated in the situation with pain-irritated partner by the method of "emotional resonance". Most "bright" rats belonged to the type not avoiding the signals of another pain-irritated rat, they revealed a persistent ecologically defensive reaction of preferring a small closed space. The type of anxiety behaviour prevailed in the group of "dull" rats. In the open field test "bright" rats were characterized by low locomotor activity and high level of defecation and "dull" rats by high activity and low defecation. Increased levels of superoxide dismutase activity and high content of thiobarbituric acid-reactive material were observed in brains of dull rats. The interrelations between behavioural and molecular levels of defensive response to stress is discussed.     

Low-amplitude trapezius activity in work and leisure and the relation to shoulder and neck pain.

The aim of this study is to obtain evidence supporting or negating the hypothesis that muscle pain is associated with sustained activation of low-threshold motor units. Long-term surface electromyographic (EMG) recordings of trapezius activity pattern were related to subjectively reported shoulder and neck pain in work and leisure. Recordings from 118 female subjects (73 recorded both during work and leisure) were analyzed. Computer operators, secretaries, and health care and retail workers were represented in the material. The recordings were calibrated by the root-mean-square-detected response at maximal voluntary contraction (%maximum EMG). The analysis was performed by quantifying duration and amplitude of surface EMG activity exceeding 2% maximum EMG ("EMG bursts"). Three response categories were defined by duration of the burst periods during work: low- (<50%), intermediate- (50-70%), and high-response (>70%) groups. Shoulder and neck pain was assessed by hourly visual analog score throughout work and leisure and by pain score for the last 6 mo. Shoulder and neck pain was higher at work than leisure for subjects with long-term pain in both the high- and the low-response groups. Persistent pain, defined by the 6-mo score, was more prevalent in the high- than the low- and intermediate-response groups (73 vs. 37%); relative risk was 2.0. Trapezius activity was reduced from work to leisure for the high- but not the low-response group. The activity pattern is consistent with low-threshold motor unit overexertion for the high- but not the low-response group. We speculate that different mechanisms of muscle pain causation, dependent and independent of motor activity pattern, coexist.     

Gamma-glutamyl-transpeptidase (GGTP) and NA+K(+)-ATPase activities in different subpopulations of cloned cerebral endothelial cells: responses to glial stimulation

Glial stimulation of Na+K(+)-ATPase and gamma-glutamyl-transpeptidase was taken as parameter for blood brain barrier function in cloned cerebral endothelial cells of different phenotypes. In type I cells ("cobblestone" phenotypus) gamma-glutamyl-transpeptidase activity increased 10-12 fold and Na+K(+)-ATPase activity was 2-fold increased after glial stimulation. In type II cells ("spindle-form" phenotype) gamma-glutamyl-transpeptidase was only 2-fold increased, whereas Na+K(+)-ATPase was even depressed. K(+)-(86Rb) uptake was twice as high in type I cells. These data indicate that type I cells are involved in blood brain barrier function.     

Relative contributions of "pressure pump" and "peristaltic pump" to gastric emptying

The relative contributions to gastric emptying from common cavity antroduodenal pressure difference ("pressure pump") vs. propagating high-pressure waves in the distal antrum ("peristaltic pump") were analyzed in humans by high-resolution manometry concurrently with time-resolved three-dimensional magnetic resonance imaging during intraduodenal nutrient infusion at 2 kcal/min. Gastric volume, space-time pressure, and contraction wave histories in the antropyloroduodenal region were measured in seven healthy subjects. The subjects fell into two distinct groups with an order of magnitude difference in levels of antral pressure activity. However, there was no significant difference in average rate of gastric emptying between the two groups. Antral pressure history was separated into "propagating high-pressure events" (HPE), "nonpropagating HPEs," and "quiescent periods." Quiescent periods dominated, and average pressure during quiescent periods remained unchanged with decreasing gastric volume, suggesting that common cavity pressure levels were maintained by increasing wall muscle tone with decreasing volume. When propagating HPEs moved to within 2-3 cm of the pylorus, pyloric resistance was found statistically to increase with decreasing distance between peristaltic waves and the pylorus. We conclude that transpyloric flow tends to be blocked when antral contraction waves are within a "zone of influence" proximal to the pylorus, suggesting physiological coordination between pyloric and antral contractile activity. We further conclude that gastric emptying of nutrient liquids is primarily through the "pressure pump" mechanism controlled by pyloric opening during periods of relative quiescence in antral contractile wave activity.     

The psychophysiological testing of temperament]

A comparison was carried out of the dynamics of the activation focus of the human cerebral cortex with the data of psychological testing by the ergic parameter of the "Questionnaire for estimation of temperament structure". It is shown that the right hemisphere in the subjects conditionally attributed to the sting type ("highergice") is much more involved involving verbal tasks than in "week" types. In subjects conditionally attributed to the "week" type, at fulfillment of verbal tasks inert predominance of the left hemisphere activation is noted.     

Human gamma oscillations during slow wave sleep

Neocortical local field potentials have shown that gamma oscillations occur spontaneously during slow-wave sleep (SWS). At the macroscopic EEG level in the human brain, no evidences were reported so far. In this study, by using simultaneous scalp and intracranial EEG recordings in 20 epileptic subjects, we examined gamma oscillations in cerebral cortex during SWS. We report that gamma oscillations in low (30-50 Hz) and high (60-120 Hz) frequency bands recurrently emerged in all investigated regions and their amplitudes coincided with specific phases of the cortical slow wave. In most of the cases, multiple oscillatory bursts in different frequency bands from 30 to 120 Hz were correlated with positive peaks of scalp slow waves ("IN-phase" pattern), confirming previous animal findings. In addition, we report another gamma pattern that appears preferentially during the negative phase of the slow wave ("ANTI-phase" pattern). This new pattern presented dominant peaks in the high gamma range and was preferentially expressed in the temporal cortex. Finally, we found that the spatial coherence between cortical sites exhibiting gamma activities was local and fell off quickly when computed between distant sites. Overall, these results provide the first human evidences that gamma oscillations can be observed in macroscopic EEG recordings during sleep. They support the concept that these high-frequency activities might be associated with phasic increases of neural activity during slow oscillations. Such patterned activity in the sleeping brain could play a role in off-line processing of cortical networks.     

Asymmetry and directionality in production of new cell types during clonal growth: the switching pattern of homothallic yeast.

Homothallic Saccharomyces yeasts efficiently interconvert between two cell types, the mating types a and alpha. These interconversions have been proposed to occur by genetic rearrangement ("cassette" insertion) at the locus controlling cell type (the mating type locus). The pattern of switching from one cell type to the other during growth of a clone of homothallic cells has been followed by direct microscopic observation, and the results have been summarized as "rules" of switching. First, when a cell divides, it produces either two cells with the same mating type as the original cell or two cells that have switched to the other mating type. This observation suggests that the mating type locus is changed early in the cell cycle, in late Gl or during S. Second, the ability to produce cells that have switched mating type is restricted to cells that have previously divided ("experienced cells"). Spores and buds ("inexperienced cells") rarely if ever give rise to cells with changed mating type. A homothallic yeast cell thus exhibits asymmetric segregation of the potential for mating type interconversion--at each cell division, the mother, but not the daughter, is capable of switching cell types in its next division. Homothallic cells also exhibit directionality in switching: experienced cells switch to the opposite cell type in more than 50% of cell divisions. These results show that the process of mating type interconversion is itself controlled during growth of a clone of homothallic cells. By analogy and extension of these results, we propose that multiple cell types can be produced in a specific pattern during development of a higher eucaryote in a model involving sequential cassette insertion.     

Predictive validity of the cognitive vs. somatic anxiety distinction

The purpose of this study was to test the predictive validity of an instrument, The Cognitive-Somatic Anxiety Questionnaire (CSAQ), which purports to measure separately cognitive and somatic anxiety. Twelve subjects with either predominantly cognitive or somatic anxiety received a treatment that matched their predominant anxiety mode ("matched"), and twelve received a treatment which addressed the secondary anxiety mode ("mismatched"). After five sessions, the "matched" subjects reported significantly fewer anxiety symptoms than the "mismatched" subjects. The results support the predictive validity of the CSAQ, and suggest that anxiety may not be a unidimensional phenomenon. The implications of these results for clinical practice are discussed.     

Work volume and strength training responses to resistive exercise improve with periodic heat extraction from the palm

Body core cooling via the palm of a hand increases work volume during resistive exercise. We asked: (a) "Is there a correlation between elevated core temperatures and fatigue onset during resistive exercise?" and (b) "Does palm cooling between sets of resistive exercise affect strength and work volume training responses?" Core temperature was manipulated by 30-45 minutes of fixed load and duration treadmill exercise in the heat with or without palm cooling. Work volume was then assessed by 4 sets of fixed load bench press exercises. Core temperatures were reduced and work volumes increased after palm cooling (Control: Tes = 39.0 ± 0.1° C, 36 ± 7 reps vs. Cooling: Tes = 38.4 ± 0.2° C, 42 ± 7 reps, mean ± SD, n = 8, p < 0.001). In separate experiments, the impact of palm cooling on work volume and strength training responses were assessed. The participants completed biweekly bench press or pull-up exercises for multiple successive weeks. Palm cooling was applied for 3 minutes between sets of exercise. Over 3 weeks of bench press training, palm cooling increased work volume by 40% (vs. 13% with no treatment; n = 8, p < 0.05). Over 6 weeks of pull-up training, palm cooling increased work volume by 144% in pull-up experienced subjects (vs. 5% over 2 weeks with no treatment; n = 7, p < 0.001) and by 80% in pull-up na?ve subjects (vs. 20% with no treatment; n = 11, p < 0.01). Strength (1 repetition maximum) increased 22% over 10 weeks of pyramid bench press training (4 weeks with no treatment followed by 6 weeks with palm cooling; n = 10, p < 0.001). These results verify previous observations about the effects of palm cooling on work volume, demonstrate a link between core temperature and fatigue onset during resistive exercise, and suggest a novel means for improving strength and work volume training responses.     

The EEG correlates of the erroneous identification of noise-masked visual stimuli]

Specific features of EEG coherence of a man-operator were revealed before the erroneous actions ("false alarm" and "signal omission") in the process of training to recognize masked visual stimuli. In persons with expressed alpha-rhythm at rest the "false alarms" were associated with the highest level of beta-frequency correlation in the frontal areas. Errors of the "signal omission" type were observed against the background of increased alpha-coherence in the frontal and occipital derivations. These features were more pronounced in the right brain hemisphere. The results suggest that the erroneous actions are predetermined by a specific state of the frontal brain regions, which participate in decision making, and are probably related with inadequate information transmission from the caudal regions to the frontal ones.     

Saccade latency during probability presentation of the visual targets in man

The latent periods of saccadic eye movements in response to peripheral visual stimuli were measured in 8 right-handed healthy subjects using Posner's paradigm "COST-BENEFIT". In 6 subjects, the saccade latency in response to visual target presented in expected location in valid condition was shorter than that in neutral condition ("benefit"). Increase in saccade latency in response to the visual target presented in unexpected location in valid condition versus neutral condition took place only in 4 subjects ("cost"). A decrease in left-directed saccade latency in response to expected target presented in the left hemifield and increase in saccade latency in response to unexpected left target in comparison with analogous right-directed saccades were observed in valid condition. This phenomenon can be explained by the dominance of the right hemisphere in the processes of spatial orientation and "disengage" of attention.     

Use and fibre type composition in limb muscles of cats

As a background for studies concerning the effects of training on the properties and fibre type composition of skeletal muscle, information is needed concerning the normal duration of muscle use per day. Data of this kind were collected from adult cats, using implanted electrodes for electromyographic recording from hindlimb muscles acting across the ankle joint: extensor digitorum longus (EDL), tibialis anterior (TA), peroneus longus (PL), lateral gastrocnemius (LG) and soleus (SOL). The accumulated duration of any recorded activity was expressed, for each electrode site, as a percentage of total sampling time ("duty time"). As measured intermittently across 24 h periods (4 min sampling per 30 min), these duty times were markedly and significantly different among the various muscles, averages varying from 1.9% for EDL up to 9.5% for posterior PL and 13.9% for SOL. The distribution of activity across the various muscles was markedly different between highly active periods (mid-day) and periods of rest (mid-night). The 24 h duty times were strongly and significantly correlated to duty times obtained for only mid-day activity but not to those for only mid-night activity. Following the end of the physiological measurements, the animals were sacrificed and the muscles were analyzed with regard to fibre type composition (histochemistry). There was a significant positive correlation between the 24 h duty time and the percentage of type I fibres ("slow"). In the Discussion, the present results from cats are briefly compared to previously published data for humans.     

Reduction of Seizure Occurrence from Exposure to Auditory Stimulation in Individuals with Neurological Handicaps: A Randomized Controlled Trial

Background

The purpose of this work was to determine in a clinical trial the efficacy of reducing or preventing seizures in patients with neurological handicaps through sustained cortical activation evoked by passive exposure to a specific auditory stimulus (particular music). The specific type of stimulation had been determined in previous studies to evoke anti-epileptiform/anti-seizure brain activity.

Methods

The study was conducted at the Thad E. Saleeby Center in Harstville, South Carolina, which is a permanent residence for individuals with heterogeneous neurological impairments, many with epilepsy. We investigated the ability to reduce or prevent seizures in subjects through cortical stimulation from sustained passive nightly exposure to a specific auditory stimulus (music) in a three-year randomized controlled study. In year 1, baseline seizure rates were established. In year 2, subjects were randomly assigned to treatment and control groups. Treatment group subjects were exposed during sleeping hours to specific music at regular intervals. Control subjects received no music exposure and were maintained on regular anti-seizure medication. In year 3, music treatment was terminated and seizure rates followed. We found a significant treatment effect (p = 0.024) during the treatment phase persisting through the follow-up phase (p = 0.002). Subjects exposed to treatment exhibited a significant 24% decrease in seizures during the treatment phase, and a 33% decrease persisting through the follow-up phase. Twenty-four percent of treatment subjects exhibited a complete absence of seizures during treatment.

Conclusion/Significance

Exposure to specific auditory stimuli (i.e. music) can significantly reduce seizures in subjects with a range of epilepsy and seizure types, in some cases achieving a complete cessation of seizures. These results are consistent with previous work showing reductions in epileptiform activity from particular music exposure and offers potential for achieving a non-invasive, non-pharmacologic treatment of epilepsy.

Trial Registration

Clinicaltrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01459692","term_id":"NCT01459692"}}NCT01459692     

Effect of vertical jumping on the medial gastrocnemius and soleus muscles of rats

Ten rats were trained to perform approximately 30 jumps/day, 5 days/wk for at least 8 wk, from a force platform that enabled the number and height of jumps to be quantified. There was considerable variation in height jumped during an activity session both within and between rats. The two highest-jumping rats attained a displacement of center of mass of approximately 30 cm, estimated to be approximately 67% of the maximum attainable. The two lowest-jumping rats jumped to approximately 30% of the estimated maximum. The activity was described as "habitual activity" rather than "training" because there were no significant increases in the height of jumping by any rat over the period of activity. The isometric properties of medial gastrocnemius (MG) and soleus muscles were studied in terminal experiments on anesthetised rats. Five significant effects on MG were evoked by this pattern of exercise ("habituation"): 1) a 15-18% increase in force at frequencies of stimulation between 60 and 150 Hz and a 15% increase in maximum tetanic tension to 14.9 N, 2) a 3% increase in the maximum rate of rise of tetanic force to 3.4% of maximum tetanic tension per millisecond, 3) an increase in fatigability expressed as a smaller fatigue index in active rats (33%) than in controls (58%), 4) a decrease of 4% in the percentage of type IIa muscle fibers, and 5) an increase of 6% in the percentage of type II fibers that could not be classified with certainty as IIa or IIb.(ABSTRACT TRUNCATED AT 250 WORDS)     

Possible correlations between the level of alcoholic motivation and the electrophysiological structure of sleep in the rat

Using modified Porsolt's method, the electrophysiological sleep pattern was studied in normal conditions and after a single intraperitoneal ethanol injection to noninbred male albino rats divided into 2 groups ("high activity" and "low activity" rats). Voluntary alcohol intake in these rats was measured during free choice between 10% ethanol and water for 20 days. "Low activity" rats were characterized by a statistically significant 3.4-fold higher level of ethanol consumption and 2.7-fold longer REM-sleep stage, as compared to "high activity" animals. In "low activity" animals ethanol (1 g/k, 10% solution, i. p.) inhibits and in "high activity" rats it increases REM-sleep stage, thus removing differences in the sleep pattern in the two groups of rats. The data obtained suggest a possible role of REM-sleep in the development of alcohol motivation.     

On the So-Called Alternative Vision or Direct Vision Phenomenon

In this work, we present the first results of the study of the so-called alternative or direct vision of sighted and weakly-sighted subjects and the related brain activity. The aim of the work was the verification of the facts of alternative (direct) vision and testing the possibility to measure the related physiological parameters (physiological correlates). In this paper, we present the results of the visual observation of subjects displaying the ability to see with the eyes closed and the electrophysiological analysis (EEG, evoked potentials) of the brain of these subjects. To detect the brain correlates of this phenomenon, we compared the spontaneous activity of the brain (EEG) during the viewing of pictures and the comparison of evoked potentials (EP) during the execution of the same type of tasks involving the classification of pictures with common visual perception and the so-called alternative vision. Seven students of a high school who were trained with the B.M. Bronnikov method took part in the study. All subjects exhibited the ability of alternative vision in various test conditions. EEG data support the reorganization of brain activity to a different functioning mode during the functional tests involving viewing objects with the eyes closed. Alterations of the -activity are the most demonstrative. Statistically significant differences in the EP between image classification with and without a mask were revealed. These differences are individual-specific and nonstationary in their pattern. The discussion emphasizes the preliminary character of the study and the complexity of the instrumental methods used. However, the results are positive both with respect to the existence of the phenomenon and the possibility to study its objective correlates. It is hypothesized that the skin vision and activation of brain reserves could be involved in this phenomenon.     

Concordance among self-regulated responses: Is self-regulatory ability a psychophysiological “trait”?

The purposes of this study were to examine whether or not self-regulation of physiological responses demonstrates day-to-day reliability, to determine the degree of individual subject consistency (or concordance) in the ability to self-regulate across several different physiological responses, and, finally, to explore the impact of biofeedback training on interresponse concordance. Twenty normal subjects participated in six bidirectional self-regulation sessions—the first and last sessions involving instructions only, and the remainder, biofeedback. Self-regulation scores consisted of the absolute difference between increase and decrease trial means. The average test-retest reliability coefficients (r _s) for the self-regulation scores, across the four biofeedback sessions, were a highly significant .50, .68, .30, and .47 for EEG, EMG, HR, and SCL, respectively. By contrast, the average concordance among the self-regulation scores for the four feedback sessions, estimated by Kendall's coefficient of concordance, was a marginally significant 39% of the possible variance of the rank sums. This corresponds to an average between-responser _s value only of .19. The concordance level from the initial no-feedback (i.e., instructions only) session was not significant. Multivariate concordance levels did increase during the first three feedback sessions, but declined at the fourth, and again was nonsignificant during the final no-feedback session. Among the individual self-regulation response pairings, only the EEG/EMG combination was consistently associated during the no-feedback sessions. The present results suggest that self-regulatory ability is neither a highly unitary “trait”-like phenomenon nor an entirely response-specific event, but may vary considerably as a function of subject factors, or the situational circumstances, under which it is measured.