While each of 4 children between 10 and 15 years old with MAs from 3 to 4 years played with simple construction materials across a table from him, E recorded their eyeblinks on a cumulative recorder activated by a hidden switch. In operant and extinction sessions Ss received candy independently of blinking; in conditioning sessions candy was contingent upon blinking. Three Ss blinked faster in conditioning sessions.
An operant analysis of depth discrimination in premotor (70–85 day old) infants indicates that such infants, having had no opportunity to act in space, nonetheless can discriminate depth on the basis of cues other than the projected size of objects displaced in depth.
Paralog (C-V-C-V-C) distortions of real words were memorized in mixed lists no better than randomly generated paralogs. Reversed words apparently were unrecognized by most Ss. Error patterns permit inferences concerning memory encoding processes.
The present study was an attempt to clarify the data concerned with the adient properties of stimuli which have been associated with the termination of shock. Six different groups of rats were subjected to varying numbers of shock-tone pairings. The positively reinforcing effects of the tone were tested in an operant conditioning situation. The data showed that these properties are demonstrated within a narrow range of shock-tone pairings.
Sixteen Ss were asked to decide if pairs of words had the same meaning. It was found that asking S to repeat one of the words 1 or 15 sec. in advance equally facilitated his decision. The results indicate that forewarning and not semantic satiation reduces decision latency.
Rats were trained to press a lever for food reinforcement in one study and water reinforcement in a second. Rats which received marihuana extract each day before behavioral testing showed an impairment of responding on the first day of drug application, but developed behavioral tolerance to the drug by the sixth day of drug application. Rats which received equal doses of marihuana after each session, rather than before, over the same period, showed little or no evidence of behavioral tolerance when the drug was administered before testing. This result was interpreted to indicate that the development of behavioral tolerance to marihuana involves a learning process.
We manipulated thedepth andlateral displacement between the test and inducing fields of a classicalsimultaneous brightness contrast configuration. Depth separation varied with thebinocular disparity carried by the test fields, whereas directional displacement arose from decentration of the test fields. Neither depth nor lateral displacement influenced the magnitude of simultaneous brightness contrast although stereoscopic size and distance varied directly with disparity. The present results indicate that simultaneous brightness contrast is not affected by depth adjacency.
Pairs of mice will usually huddle closely together in response to lowered ambient temperature. We find that bilateral removal of the olfactory bulbs results in an attenuation in cold induced huddling behavior. This is not the consequence of the production of anosmia since peripherally induced anosmia does not result in a deficit in huddling behavior. The deficit in huddling behavior produced by bulbectomy is not paralleled by deficits in other forms of behavioral thermoregulation e.g., heat seeking in response to refrigeration, and cold induced overeating are not affected by bulbectomy.
Motion thresholds were determined for the fovea and peripheral retina with and without correction for peripheral refractive error. With correction, motion thresholds decreased and inidividual differences disappeared. These results imply that under normal observation conditions, peripheral sensitivity is limited mainly by dioptric rather than retinal variables.
University of Florida-The dolphin eye is specialized for vision in air and water.Rod and cone receptors eonverge on giant ganglion cells in the absence of a macula or area eentralis.A mechanism is proposed to correct for in-air myopia.Predicted acuity is 6 min of are.[D_edicated to the late W. N. Kellogg, who pioneered in this and many other areas .] 10 :50-11 :05 (19) The Optokinetic Response of the Bermudan Land Crab (Gecarcinus /ateralis).L. C. IRELAND, Woods Hole Oceanographic Institute, & L. T. GUZY, Alliance College-Two experiments were performed with crabs as Ss, both dealing with the increase in optokinetic responses elicited by revers al of an optokinetic drum.Binocular crabs showed increases of more than 300%.Only nasal to temyoral stimu!ation folluwE:Q by reversal served to elicit the increase in monocular crabs.Similar phenomena have been observed in marnmals, reptiles, and amphibians.11 :10-11 :20 (20) Response Plasticity in Neurons of Visual Cortex.PAUL G. SHINKMAN, University of North Carolina at ChapeI Hili-Temporal patterns of response to a photic stimulus were determined for single neu:ons in cat visual cortex.Reinforcing brain stimulation was made contingent upon a prespecifie~ change in a cell 's irring rate du ring aselected segment of the poststimulus interval.Response plasticity was observed in some cells but not in others; cells with modifiable response patterns appeared to have some common characteristics.11:20-11:35 (21) Effects of Sound on the Vestibular System.DONALD E. PARKER, Miami University-This paper reviews research on sound-induced physiological vestibular responses (nystagmus, postural orientation, disequilibrium, etc.) evoked by intense audiofrequency sound, interrupted audiofrequency sound, infrasound, and static pressure changes.Possible biomechanical mechanisms of acoustical vestibular stimulation, including middle-ear nonlinearities, are discussed.
The experiment reported below examined the role of the ingestion of food samples at the nest site on the feeding preferences of wild rat pups during weaning. The results indicated that although food preferences during the first few days of feeding on solid food were not affected by ingestion at the nest site, later preferences were. These data were interpreted as providing additional evidence of the insufficiency of the ingestion of food samples in the nest site to determine pups’ choice of diet for early ingestion and of the role of neophobia in maintaining adult-initiated food preferences.
Intact female rats acquired efficient DRL-20 performance more rapidly than normal males. Ovariectomy abolished this sex difference in acquisition by retarding the development of efficient performance. By contrast, castration had little effect on the performance of males.
A continuous chain of homogeneous responding was established in rats by training animals to hold a lever down for 10 sec or longer before releasing it for food reinforcement. When criterion releases were subsequently punished, completed holding chains were greatly suppressed, aborted chains increased markedly, while the rate of chain initiations remained unchanged.
Garcia & Koelling (1966) showed that if rats are poisoned after ingesting a flavored solution in the presence of audiovisual cues, they will subsequently avoid only the taste stimulus, whereas if they are shocked, they learn to avoid only the audiovisual cues. The present experiments replicated these findings with one major change in experimental conditions: both taste and nongustatory CSs were presented in the absence of approach and ingestive behaviors to minimize involvement of ingestion in the associative process. (The taste CS was presented by flushing the oral cavity with a saccharin solution under conditions in which the rat would not drink.) Despite these changes, Garcia and Koelling’s results were confirmed.
Groups of rats were trained with shock either contingent on freezing (punishment procedure) or contingent on not freezing (avoidance procedure). Although the different contingencies produced different levels of freezing behavior, these levels were attained immediately rather than over a number of trials. This result, together with the results of control rats, suggest that while freezing can be controlled by both punishment and avoidance procedures, in both cases the effects on freezing are due to elicitation rather than learning.
The basic experimental question in each of three experiments was whether exposure to acoustic stimulation in acquisition of an FR chain would increase -persistence in the subsequent extinction of that response. Other factors manipulated in the experiments were (a) the manner of introduction of the tone stimulus (gradual increase in intensity or terminal intensity from the outset), (b) locus of introduction of tone in the response chain (at beginning or end), and (c) the interaction of tone-in-acqui sition treatment with presence or absence of hippocampal lesions in the subjects. The findings were that introduction of the tone in acquisition increased resistance to extinction (a) more greatly under terminal than under gradual conditions, (b) both when it was introduced at the beginning and at the end of the response chain, and (c) in operated controls but not in rats with lesions of the hippocampus. Recently, a general principle of persistence has been proposed (Amsel, 1972) which holds that the maintenance of any ongoing behavior (R0) in the face of a stimulus (Sx) that evokes an orienting-dis ruptive response (Rx) increases resistance to extinction. According to this view, the mechanism responsible for this increased persistence is a more general form of the counterconditioning mechanism in the frustration theory of the partial reinforcement effect (PRE)—the counterconditioning of Sx. to R 0. The possibility is also raised in this statement that behavioral habituation is an active process involving counterconditioning, and that habituation to a disruptive stimulus may render the animal less susceptible to the effects of anticipatory frustration and so increase resistance to ex
Increasing ambient noise level causes male quail to (1) raise the intensity of individual separation crows, (2) increase the rate of crowing, and (3) increase bout length. Comparison between Japanese quail and human beings suggests that differences in response to noise are related to the type of signal system used by each species.
