Gallbladder distention and the effects of several drugs on heart rate,respiratory movements and cortical potentials in cats with hypothalamic lesions

The effects of chronic hypothalamic lesions and various drugs on the viscero-visceral reflexes of cats have been investigated, utilizing measurement of the bioelectrical activity of the cerebral cortex. After coagulation of the posterolateral hypothalamus the heart rate decreased by 40–60 beats per minute, but eventually it regained its initial value. The viscero-visceral reflexes from the gallbladder to the heart were preserved after the operative procedure. Chlorpromazine and atropine blocked both arousal and the cardiorespiratory response to stimulation of the gallbladder. Similar effects were produced by novocaine and pantocaine.     

Arousal and paired-associate learning

Walker and Tarte (1963) postulate that at short retention intervals high arousal paired-associates are reproduced more poorly than low arousal items. Walker and colleagues believe that this hypothesis is confirmed by their paired-associate learning studies. However, results of these paired-associate learning studies are position confounded artifacts. Better recall of low arousal items at short-term retention is caused by the coincidence of the recency effect and low arousal at the end of the trial. When these position effects are controlled there is no action decrement for the high arousal paired-associates. To test this assumption, the Kleinsmith and Kaplan study (1963) was replicated and two other variations were conducted. In these three studies with 76 subjects, which were tested at two minutes or 1 week, the action decrement occurs only when the two position effects coincide.     

Perceived numerosity of spatiotemporal events

Numerosity discrimination was examined when items were varied in space-time position rather than in space only. Observers were instructed to indicate which of two adjacent streamsof visual events contained more items. The precision of numerosity discrimination of dynamic events was not remarkably different from that of static patterns. Two basic numerosity biases previously found for static dot patterns—inhibitory overestimation and satellite underestimation—were demonstrated for items distributed randomly over a spatiotemporal interval. It was also demonstrated that two streams, equated in the number and luminous energy of items, are not judged equal in their visible number if items in one of these two streams have longer duration than items in the second stream. These findings can be accounted for by the occupancy model of perceived numerosity (Allik & Tuulmets, 1991a) if it is supposed that the impact that each element has on its neighborhood is spread along both spatial and temporal coordinates. Perceived numerosity decreases with both spatial and temporal proximity between the-visual-items. Space and time have interchangeable effects on perceived numerosity: the amount of numerosity bias caused by the spatial proximity of items can also be produced by the properly chosen temporal proximity of items     

Additivity of loudness across critical bands: A critical test

The use of magnitude estimation as well as axiomatic measurement theory has led to the suggestion that loudness adds across critical bands. In the present paper, we challenge this postulate by applying a more sensitive methodology, based on Falmagne’s (1976) random conjoint measurement procedure. A necessary condition for additivity of loudness was investigated in tone complexes consisting of 2-kHz and 5-kHz (resp. 3-kHz) components; the results showed systematic deviations from additivity. We argue that these deviations are due to asymmetric masking of the higher component by the lower one, and we propose a tentative quantitative model to account for the data. Such a model is in line with results from tone-on-tone masking, which show masking to be effective over a range of several critical bands.