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Biomedical subjects

W T Roth

Publications and source records attributed to W T Roth.

At least 127 records · Page 7Linked to original sources
PubMed1975

Marihuana effects on TAT form and content.

In a double-blind study, 72 normal male subjects were given either placebo or marihuana containing 20 mg. Delta-9-tetrahydrocannabinol. Stories written to cards selected from the Thematic Apperception Test did not differ on hostile or sexual content scales between drug and placebo conditions, but 6 out of 10 scales specifically constructed to detect marihuana effects were successful at differentiating the two conditions. Under marihuana the stories had a timeless, non-narrative quality, with greater discontinuity in thought sequence and more frequent inclusion of contradictory ideas. Novelty of content was somewhat increased by marihuana, while relation to the picture, imagery, repetition, and closure were not significantly affected.

Adolescent↗
PubMed1975

Reliability of the contingent negative variation and the auditory evoked potential.

Contingent negative variations (CNVs) composed of 32 trials had a median subject consistency of 0.68 in retests separated from 5 min to 7 days. Hand measurement of the CNV was highly reliable with a median reliability of 0.96. Subject consistencies for the amplitudes and latencies of N1 and P2 components of a auditory evoked potential (AEP) had a median of 0.59 when 265 trials were averaged. These consistencies for N1 and P3 components had a median of 0.45 when only 16 trials were averaged. Median measurement reliabilities for the AEP were 0.92 for amplitudes and 0.66 for latencies.

Adult↗
PubMed1975

The contingent negative variation during a memory retrieval task.

Evoked potentials were recorded from the human scalp during performance of a memory retrieval task modeled after a paradigm originated by Sternberg (1966). Subjects were required to decide whether a probe digit was contained in a series of one to four target digits presented a few seconds before. The amplitude of the contingent negative variation (CNV) preceding the probe digit and the speed of CNV resolution after the probe varied as a function of target set size. CNV amplitude was greatest when the set size was one. The smaller the set size, the more positive the evoked potential 300 msec after the probe, regardless of whether a motor response was required.

Adult↗
PubMed1973

Evoked potential correlates of signal recognition between and within modalities.

Electrical responses evoked by clicks, flashes, changes in noise level, and changes in light level were recorded from the scalps of human subjects set to detect one of the stimuli. An early negative component of the evoked responses reflects selection between sensory modalities, whereas the later positive component reflects a more complex intramodal discrimination.

Acoustic Stimulation↗
PubMed1972

Effects on humans of 9 -tetrahydrocannabinol administered by smoking.

Twelve chronic marijuana users received triangle up(9)-tetrahydrocannabinol by smoking. The magnitude of their pulse increment was highly correlated with their subjective experiences. Three of the 12 subjects subsequently received triangle up(9)-tetrahydrocannabinol labeled with carbon-14; the time course of its concentration in plasma was highly correlated with the pulse increment. Subjective symptoms, however, appeared later and dissipated more slowly.

Adult↗