The uniqueness and significance of simple structure demonstrated by contrasting organic “natural structure” and “random structure” data

The study compares the extent to which naturally structured data and artificial, relatively random data (both with the same basic parameters) produce simple structure factors which are uniquely determined. Two examples of unstructured matrices were compared with the ball problem matrix. The results show that an oblique position of maximum hyperplane count in the structured data differs from that in the unstructured by reaching a significantly more unique position in terms of the exactitude with which it is re-discoverable when starting from different positions, and by reaching (at the maximum) a significantly higher hyperplane count.     

PSYCHOPHYSIOLOGICAL REACTIONS TO TWO DIFFERENT PLACEBO TREATMENTS

Reactions to a placebo introduced either as a depressant or as a stimulant drug were examined in 16 healthy female subjects. Comparisons between pre- and post-placebo measurements showed that the two treatments produced marked effects in opposite directions: (1) the 'depressant' placebo produced a statistically significant decrease in pulse rate, blood pressure, objective and subjective reaction speed, as well as significant effects on subjective mood in the expected directions, and (2) the 'stimulant' placebo produced opposite and significant changes in all variables. The subjective reactions were, on the whole, more pronounced than the effects on performance and physiological functions.     

Effects of pentobarbital on fixed-ratio reinforcement,

Certain doses of pentobarbital consistently increased the rate of pecking engendered by a fixed-ratio schedule of 30 responses in a group of 13 pigeons, and still higher doses produced decrements in rate of responding. For individual subjects, the dose-effect functions were qualitatively similar, but differed with respect to the doses producing the maximum increase and subsequent decrease in rate. In general, the maximum occurred at lower doses and the decrement was greater at the highest dose in the birds with the highest control rates. It was also possible to distinguish between the effects of pentobarbital and several other drugs on the behavior maintained by FR 30. The results indicate that changes in rate of responding on FR 30 after drug administration are dose-dependent, drug-specific effects.     

The effects of unavoidable shocks on a multiple schedule having an avoidance component

Two dogs were maintained on a multiple schedule having both a food reinforced and an avoidance component (Mult VI 1′ S^Δ Avoid_{SS20 RS20} S^Δ). The effects of superimposing an Estes-Skinner procedure for delivering unavoidable shocks on all components of the multiple schedule were observed. The buzzer-shock pairing of the Estes-Skinner procedure produced an increased rate of responding on the avoidance component of the schedule and also on the S^Δ components. No persistent change in rate was observed on the food component during the pre-shock stimulus. Control performances on all components could be regained by either extinguishing or eliminating the buzzer-shock pairing. Extinction of the avoidance responding had little effect on the increased rates of responding produced by the Estes-Skinner procedure on the S^Δ and avoidance extinction components and did not lead to a conditioned suppression of the food reinforced responding. Rate of responding during the pre-shock stimulus was observed to be relatively independent of changes in the maintaining schedules. Responding during the pre-shock stimulus could be conditioned and maintained after an extensive history of avoidance extinction.     

Generalization of auditory intensity as a function of small amounts of discrimination training

Rats were trained on a two-valued auditory-intensity discrimination for 5, 2, 1 or 0 days. Then, the bar-press response rate was sampled in the presence of seven added discrimination stimuli (generalization) for seven days. Daily training sessions were 4 hr in length throughout the experiment. Only the five-day group exhibited a marked superiority on the multi-valued discrimination when contrasted with the group having had no prior simple discrimination training.