Theta waves

Convulsions occurred within two hours following occupational exposure to aldrin, dieldrin and endrin (Hoogendam et al. 1962, 1965). After removal from exposure, seizures subsided and complete recovery was achieved in 1-3 days. Abnormal electroencephalograms (EEGs) were usually observed in endrin-poisoned workers, and sometimes occurred without any clinical symptoms. Predominately bilateral synchronous theta waves, and synchronous spike and wave complexes were seen (Hoogendam et al. 

Yamamoto J. (1998). Effects of nicotine, pilocarpine, and tetrahydroaminoacridine on hippocampal theta waves in freely moving rabbits. EurJ Pharmacol. 359(2-3) 133-37. 

Eyes open, alertness, concentration on a task often in combination with low-amplitude theta waves... 

Chlorpromazine and clozapine at low doses lead to an increase in slow (delta, theta) waves and a decrease in alpha activity in the pharmaco-EEG of healthy subjects. Findings regarding beta activity are less uniform. Rohloff et ul. (1992) reported on an increase in slow frequency components and a decrease of alpha and beta activity after 4.0 mg of haloperidol. Low doses of amisulpride (up to 50 mg) were reported to display an alertness-enhancing effect (Rosenzweig et ul., 2002). 

Published pharmaco-EEG trials provide a heterogeneous picture some studies with J-amphetamine and methylphenidate reported a reduction in delta and theta waves other authors found either an increase in delta and theta activity or no effect at all on the quantified EEG. There is also no agreement in the case of changes in the alpha and beta bands after several stimulants. Some of the contradictory findings are most likely to be due to different experimental conditions, particularly the duration of EEG recordings (for details see Spiegel, 1996, p. 90). 

Figure 3.8 Effects of tf-amphetamine on the wake EEG Mean EEG spectral values for six healthy male subjects who took placebo. 5 mg and 10 mg of d-amphetamine on separate occasions in a balanced crossover trial are shown Whereas the EEG trace 2 h after placebo (upper third) shows a rapid decline in alpha waves and an increase in theta waves (see arrows pointing to the alpha decrease and the theta increaee), the corresponding changes occurred later after 5 mg (middle third) andlOmg (tower third) d-amphetamine The decay of alpha and increaee of theta activities occurred after 2 mm on placebo, but only after 7 min on 5 mg d-amphetanine and after 12 mn on 10 mg of d-amphetamine, thus reflecting a vigilance-stabilizing effect of tf-aiphetamine (Matejcek, 1979, with permission)...

Naturally, in terms of the Copenhagen paradigm, nothing at all comes from such a device. In this model the theta waves do not even exist. 

The two waves—one , from the common source S the other, 0 from the generator of theta waves S —overlap at the detection region. The expected intensity at the array of detectors DR, after n arrivals of particles, is given by the squared modulus of the superposition of two waves at each instant of time, summed for all n arrivals ... 

This result indicates that the existence theta wave is made evident by the presence of the interference pattern. In the usual Copenhagen interpretation, the waves theta do not exist and therefore the expected result would be simple the one produced by the single source... 

Since the direct and the coherent processes are not truly conclusive, it is necessary to look for another conceptually clear method that could, in principle, avoid the stated experimental difficulties. A conclusive experiment to decide on such important issue as the true nature of the quantum waves, regardless of whether they are real, must be conceptually very simple and, above all considerations, conclusive in principle. This process is known as incoherent interferometric detection of the theta waves. ... 

A different result is predicted by the Copenhagen school for this specific experiment. Since the theta waves do not exist, the expected intensity is given simply by... 

This experiment is, to a certain extent, the symmetric counterpart of the one we discussed earlier. In the first experiment, the theta waves were supposed to show their presence by blurring a clear interference pattern, while in this last experiment, the waves produce an interference pattern where no waves were expected. 

Figure 13. The theta wave, devoid of singularity, looses amplitude as it crosses the successive beamsplitters until nothing of it remains.

Normal ground pattern. Left central sharp theta waves (middle high) ... 

Headache, drowsiness, and dizziness are common with niridazole (2,4,5). More severe neuropsychiatric symptoms are more frequent in patients with liver disease, especially those with portosystemic shunts, in whom the drug bypasses the liver (6). Symptoms in these cases include insomnia, anxiety, depression, confusion, hallucinations, and convulsions the reactions may prove fatal. The electroencephalogram can show slowed alpha rhythms, beta waves, and theta waves, as well as sharp wave and spike forms with niridazole (7). A single case of acute cortical necrosis was recorded in the much older literature, but was probably coincidental (SED-8, 691) (8). Agitation can occur in patients with abnormal liver function. 

Epileptiform convulsions and abnormal electroencep-halographic patterns have been found in studies of insecticide manufacturing workers suffering from intoxication by isodrin. Fourteen patients with convulsions caused by the insecticide all showed specific anomalies in the electroencephalogram, consisting of bilateral synchronous theta wave activity and occasional bilateral synchronous spike and wave complexes believed to be associated with brain stem injury. 

In a placebo-controlled, randomized, double-blind, three-fold crossover clinical study, 12 healthy volunteers were evaluated for the effects of a single dose of kava extract equivalent to 120 mg kavalactones and 10 mg diazepam. Measurements were taken directly before, and two and six hours post ingestion. The washout period before crossover was seven days. After kava administration, a non-significant increase compared to placebo was noted in the quantitative EEG in the delta/theta intensity in the occipital and frontal areas, as well as a reduction of the alpha-wave relative intensity (P < 0.05). An increase in beta activity typically found with benzodiazepines was not observed with kava. The placebo group witnessed a decline in the relative intensity of the slow delta- and theta-waves and an increase in the alpha-waves (P < 0.001). Maximal effects of diazepam were usually observed two hours after application, as opposed to the kava extract where the effects had not decreased even after six hours. The critical flicker frequency in the psychophysiological tests was found to be lower under the influence of kava extract and diazepam compared to placebo (P < 0.05). In contrast, significant increases in performance in the Pauli Test after the administration of kava extract were noted which were not present with the placebo or diazepam (P < 0.05) (Gessner and Cnota, 1994). 

Recording electrical activity with electrodes surrounding the head made it possible to try to relate the mind to the brain. Slow electrical brain waves, called theta waves, were observed during states of low mental activity. At high degrees of arousal, fester beta waves were recorded. Alpha waves were recorded at medium levels of arousal. The greater the state of arousal, the greater the number of alpha and beta waves. 

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