Operant performance patterns of normal and nervous water-deprived dogs

Previous studies have shown that most food-deprived genetically nervous pointer dogs fail to learn a bar-pressing response for food reward and those which do learn are erratic in bar pressing compared to genetically normal pointer dogs which usually learn rapidly and perform well. Benzodiazepine drugs facilitate learning and performance of the responses in nervous dogs. The present study aimed at finding whether a stronger drive producing state, such as water deprivation, would facilitate learning and performance in even severely nervous dogs. Eight normal line and 7 nervous line dogs successfully learned to perform well a paddle-pressing response which activates a valve releasing water into a drinking pan. One disturbed dog of each line did not learn successfully. Behavior shaping was about as easy and as rapid in nervous line dogs as in normals. Nervous line dogs tended to be as consistent in responding. However, response rates of nervous line dogs averaged about two-thirds those of normal line dogs, the slowed rate of responses being taken up mostly in excessive, rather stereotyped, licking of the water pan. Response rates correlated well with degree of nervousness as measured on independent well standardized behavior tests. This behavior seems to add another dimension to the characterization of the nervousness of these “spooky” pointer dogs.     

Effect of person and environment on heart rates in two strains of pointer dogs

Several recent studies have shown that there is a general and marked canine cardiac response to humans and to petting from humans. Additional investigations have suggested that one of the major determinants of such responding is genetic. Some studies have indicated that such a response does not occur in nervous, short-haired pointer dogs. Evidence presented in this study indicates that a heart rate response to person and petting does occur in both the nervous as well as the normal pointer dog, but only when the animal is unrestrained. When placed in a restraining harness, only normal dogs showed a heart rate response to person and the characteristic bradycardia upon petting. Moreover, in this and two other separate experiments in which tones (CS’s) were given, it was observed in both normal and nervous strains that mean baseline heart rates were as much as 40 beats per minute lower in the restrained situation than in the unrestrained situation. These experiments measured retention of cardiac response to aversive conditional signals, since most dogs (9 of 12) had received both tones and shock in a bar jumping-shock avoidance experiment one year previously. However, heart rates varied inconsistently in both magnitude and direction of change upon CS showing little or no retention. These findings clarify ambiguity in previous reports and again show that the restraining conditions in an experiment can constitute a serious stress for the animal and be a major factor in the results.     

Does heart rate differentiate neurotic from normal people in a conditional reflex test?

This study is to compare heart reactivity between normals and anxiety neurotic patients. Five male and five female patients with anxiety neurosis and four male and five female normal persons were submitted to classic delayed conditional reflexes with different probabilities of reinforcement (shock), to a defensive instrumental conditional reflex, and to a neutral nonreinforced stimulus. The basal heart frequency was higher in neurotics and in women than in normals and men. The conditional stimulus (CS) associated with a shock generally produced a bradycardia in normal individuals and in neurotic men, but a tachycardia in neurotic women (effects most pronounced in cases with 100% shock probability). The instrumental CS caused a tachycardia in all of the groups, with highest values in neurotic women. The neutral stimulus produced bradycardia in all persons. The aftereffect of the light stimulus depended on whether a shock was administered and on the CS. The differences between neurotics and normals are explained as caused by the heightened excitatory level of the CNS of the neurotic group, produced by the unspecific activating effect of chronic anxiety, and differences of plastic processes in both groups, resulting in different effects of phasic anxiety on the heart. Complex inhibitory-excitatory interactions of the sympathetic and the vagal system underlying the heart rate changes may be assumed. Possible mechanisms leading to sex differences are discussed.     

Effect of person on nervous,stable and crossbred pointer dogs

Through selective mating and line breeding of pointer dogs we have developed and continued two strains which are fairly behaviorally distinct. We now have data accumulating from the crossing of these two lines. Although the offspring from the crosses are still young, it can be seen that some stable male parents have had nonenvironmental, i.e., genetic, effects. The offspring are in many respects like their nervous mothers, but in some behavior, notably social behavior, they can be mistaken for the stable strain of dog. Heart rates have mimicked those of the nervous mothers and seem in no way influenced by the stable ancestry in “Effect of Person” tests. There is a marked difference between stable and unstable dogs in the effect of “Person” on heart rate: the unstable dogs show practically no cardiac response to “Person” (petting), whereas the normal dogs show the usual marked bradycardia to petting.     

Crossbreeding and special handling of genetically nervous dogs

In studies of a healthy (A) and a nervous (E) genetic strain of pointer dogs, two techniques were utilized to determine environmental and hereditary influences. These were (1) reciprocal crossbreeding to females from each strain, and (2) split litters with special handling and human attention to one-half of each litter of nervous strain origin from birth through age six months. It is not possible to attribute the nervous behavior to an environmental mother effect since crossbred AE and EA offspring were highly similar on behavior tests of brief exploratory activity, rigid posturing to a loud noise and human avoidance behavior. Furthermore, special handling had almost no success in normalizing the responses of the nervous dogs in the behavior tests or in heart rate response to Effect-of-Person procedures. The results show that the biologic origin of the dogs is the most likely source of the nervousness; this has placed severe limits thus far on attempts to attenuate the condition.     

Sporadic transient atrioventricular block and slow heart rate in nervous pointer dogs

Two behaviorally distinct strains of pointer dogs, one bred for nervousness (pronounced freezing behavior, withdrawal behavior), the other bred for normal behavior, exhibit prominent differences in their heart rates and incidence of sporadic occurrences of atrioventricular heart block. Of 67 nervous-line dogs, 70 per cent showed second degree AV-block on at least one occasion, and their heart rates averaged 65 beats/min. Only 15 per cent of 52 normal-line dogs displayed AV-block (generally fewer instances per dog) and their heart rates averaged 110 beats/min. Fifth generation nervous-line puppies, two to six weeks old, exhibited occasional AV-block even at heart rates averaging 183 beats/min. The incidence and “severity” increased as the puppies aged. Dogs crossbred from second and third generation parents of the two main lines show intermediate incidences of AV-block and intermediate heart rates. The incidence of AV-block is predominant in females. This is interpreted as a sex-influenced, agedependent, polygenic mode of inheritance. Humoral factors probably account for the sex-influence, and psychological stress probably also plays a role. No sex difference is noted in heart rates.     

Mueller-Lyer illusion and size estimation performance in schizophrenics compared to normal controls

A size estimation (SE) paradigm and the Mueller-Lyer (ML) illusion were used to examine perceptual disturbances in schizophrenics. 35 reliably diagnosed (DSM III-R) schizophrenics were compared to 20 subjects with no history of psychiatric illness. Perceptual distortions found in previous studies of schizophrenics were only to a certain extent confirmed in the present results. More overestimators were found among the schizophrenics than among the normals on the SE task. The schizophrenics, first of all the chronic patients, also proved to be more prone to the Mueller-Lyer illusion. A reason why the very clear differences between schizophrenics and normals found in previous examinations were not confirmed in the present study, might be that a reliable diagnostic instrument was for the first time used in this kind of study.     

The rehabilitation of genetically nervous dogs

Aware that intensive efforts to rehabilitate half of split litters from a nervous strain of Pointers through daily human contact have been unsuccessful, the authors designed this study to determine if a radically different approach utilizing the natural interest for birds and hunting which most Pointers possess would be a bridge to normalcy so that dogs genetically prone to nervous behavior could be rehabilitated. Five nervous and three normal dogs approaching young adulthood were gradually desensitized to open areas, live quail, gun reports and humans—all of which usually produce catatonic freezing, hyper-startle and strong avoidance behavior in the nervous animals. Through a “naturalistic” approach in the framework of the Pointers’ non-laboratory ecological niche using graduated techniques, reciprocally competitive responses and social facilitation, which are described, all the nervous dogs that showed an original “interest” for the qua.l were trained as successful hunted dogs, not obviously different in final performance from their normal kennel mates. Although the nervous dogs overcame their freezing, hyper-startle and human aversion while hunting, generalization did not extend sufficiently to normalize standard behavior test scores obtained under laboratory conditions. These remained at their prerehabilitation level, raising the question of the adequacy of the behavioi tests conducted in a laboratory environment. This appears to be related to the limitations often seen in psychotherapeutic efforts.     

Immobility reactions: A modified classification

This theoretical paper sets the stage for subsequent experimental reports on mobility and immobility in the Arkansas Line of Nervous Pointer dogs as contrasted with kennel mates of the normal line. Exactly opposite to the normal animals, the nervous dogs show marked inhibition of heart rate and musculoskeletal responses to man, including reduced ambulation and durable immobility following inversion and brief manual restraint in an open sling. The sling immobility of the nervous dogs (which may not differ basically from their freezing in upright position) might be designated as “tonic immobility” (TI). We hypothesize that such immobility, common in laboratory and natural conditions in many species, should be divided into two classes: hypotonic (cataleptic) and hypertonic (catatonic). We provide examples of such behaviors, particularly in man and dog, and cursorily review TI studies of other species. Neurophysiologic and neurochemical studies which bear on possible immobility mechanisms are briefly noted. We suggest that inconsistencies in reported concommitants of TI might result from failure to discriminate between types of behavioral responses.     

Effects of stroking horses on both humans' and horses' heart rate responses1

Abstract: The present study examined both human and horse heart rates (HRs) when humans stroked horses for 90 seconds; the subjective arousal levels of the humans were measured by the Tohoku Activation Deactivation Adjective Check List before and after stroking horses. Six male subjects with a positive attitude toward companion animals and 6 male subjects with a negative attitude were selected by their scores on the Pet Attitude Scale, and these two groups, together with a third group, of 6 subjects who were male members of the Doshisha University horse-riding club, participated in this experiment. The HRs of the human subjects during the first 10 seconds immediately after the stroking began were significantly higher than those obtained after that period, but these higher levels gradually returned to baseline levels. This tendency appears more clearly in the negative attitude group. The HRs of the horses increased during the first 20 seconds immediately after the human subjects of the NA group started stroking them, but gradually reduced as the stroking continued. The results of subjective arousal levels suggest a decrease in tension by stroking horses. These results suggest that a certain affectional interaction may exist between humans and companion animals.     

Schizokinesis: Fragmentation of performance in two strains of pointer dogs

During the behavior shaping toward bar jumping to avoid shock at the termination of a tone, ten genetically nervous (“E”) and ten stable (“A”) dogs showed different performances in the acquisition of the adaptive motor response. When tested two months later and with concurrent monitoring of their electrocardiograms, these animals also showed differences in (1) baseline heart rate, (2) direction and degree of heart rate change to the conditioned tone stimulus (more often deceleration in the E dogs), and (3) response to the unconditioned shock stimulus. After having performed in an almost satisfactory manner for a few trials, thenervous animals often would suddenly freeze in rigid postures. These animals could frequently be made to emit the adaptive behavior by “breaking the frozen posture” through pushing, jumping, or pulling manipulation. Sometimes a forced righting reflex dramatically encouraged an integrated performance of varying duration. Thestable strain of dogs showed little or none of the rigidity and usually learned the smooth adaptive response. The stable A dogs showed retention of the cardiac Cr, but not of the motor Cr (which they re-formed after one or two reenforcements); the nervous E dogs also retained the cardiac Cr, but persisted in the maladaptive motor performance. The fragmented disorganized behavior in acquiring the adaptive motor act and thedifferential retention of the autonomic and motor responses are considered examples ofschizokinesis as conceptualized by Gantt. This schism is seen in clearer form in behavioral acquisition than in the usual frequency measure of the well-practiced act.     

Autonomic nervous control of heart rate orienting and alpha responses in dog

The object of this experiment is to study the autonomic nervous control of alpha responses elicited in classical conditioning. Twenty-two mongrel dogs were trained in classical discriminative conditioning. Typical two-phase tachycardic responses were observed in positive (CS+) trials while only the earliest, phase 1, response was observed in negative (CS-) trials. The phase 1 response, which was identical in CS+ and CS-trials, was compared in dogs before and after selective SA-nodal parasympathectomy (N=7) and beta-adrenergic blockade (N=11). The phase 1 tachycardic response was eliminated by selective SA-nodal parasympathectomy but not by beta-adrenergic blockade. We conclude that the phase 1 response observed in both CS+ and CS-trials with similar time sequence and magnitude is an alpha response. The heart rate orienting response results from a withdrawal of parasympathetic activity with little or no change in sympathetic tone.     

Correlations of normality and nervousness with cardiovascular functions in pointer dogs

Methylphenidate, 0.5 mg/kg, injected intravenously, was used in 10 normal (A line) and 10 genetically nervous (E line) dogs in a blind-design experiment to aid in prediction, from cardiovascular recordings alone, of behavioral normalityversus nervousness. The prediction was 75 per cent correct, based on heart rate (HR), form of the electrocardiogram (EKG), pattern of sinus arrhythmia, and pattern of HR response to methylphenidate. Nervous dogs were found to have slower baseline HR’s, delayed return of HR to baseline after methylphenidate, greater occurrence of baseline EKG abnormalities and much greater frequency of these after methylphenidate. Degree of nervousness was found to correlate rather highly (1)negatively with baseline HR level, (2)negatively with speed of BP response, and (3)positively with frequency of some of the EKG manifestations. These data, indicative of a relative inertness of physiological functions of nervous pointer dogs compared with normal pointers, are consistent with the behavioral and some of the biochemical findings previously reported.     

Fetal habituation performance: Gestational age and sex effects

Habituation is the decrement in response to repeated stimulation. Fetal habituation performance may reflect the functioning of the central nervous system (CNS) prenatally. However, basic characteristics of the prenatal habituation phenomena remain unclear, such as the relationship with gestational age (GA) and fetal sex. The current study investigated the relationship between habituation performance and both fetal sex and advancing gestational age, by comparing habituation performance at 31 and 35 weeks GA within a sample of 74 singleton pregnancies, all with normal neonatal outcomes. A vibroacoustic stimulus was used to habituate the fetus and motor responses were monitored via ultrasound. The criterion for habituation was defined as no response to five consecutive stimulus presentations. Prenatal habituation performance was found to demonstrate a developmental trend, with an increased proportion of fetuses habituating with advancing gestational age and requiring fewer stimulus presentations to satisfy the habituation criterion. Fetal sex also appears to have a moderating influence on gestational changes in habituation performance. Hence, the ongoing maturation of the fetal CNS does appear to be reflected in fetal habituation performance, indicating the need to consider the composition of fetal samples in terms of both gestational age and sex. Variability in interfetal performance was found to be high and clinical applications remain speculative.     

Comprehension and storage of four serially presented radio news stories by mild aphasic subjects

The present study investigated aphasic subjects' ability to comprehend and store serially presented discourse. Sixteen mild aphasic subjects, eight age-matched normals, and eight younger normals listened to four serially presented radio news stories and a single radio news story. Half of the aphasic subjects performed as well as age-matched normals in a single-news-story comprehension task. However, they demonstrated a drastic deterioration in performance when asked to listen to a series of four news stories. Age-matched normals, and aphasic subjects, to a lesser extent, showed an impairment in the comprehension and storage of the news story heard last in a series of four news stories. These results were discussed in terms of the comprehension and storage resources of working memory.     

Central and autonomic nervous system integration in emotion

Emotions involve physiological responses that are regulated by the brain. The present paper reviews the empirical literature on central nervous system (CNS) and autonomic nervous system (ANS) concomitants of emotional states, with a focus on studies that simultaneously assessed CNS and ANS activity. The reviewed data support two primary conclusions: (1) numerous cortical and subcortical regions show co-occurring activity with ANS responses in emotion, and (2) there may be reversed asymmetries on cortical and subcortical levels with respect to CNS/ANS interrelations. These observations are interpreted in terms of a model of neurovisceral integration in emotion, and directions for future research are presented.     

BDNF serum levels in subjects developing or not post-traumatic stress disorder after trauma exposure

Post-traumatic stress disorder (PTSD) is a syndrome resulting from exposure to a severe traumatic event that poses threatened death or injury and produces intense fear and helplessness. The neural structures implicated in PTSD development belong to the limbic system, an important region for emotional processing. Brain-derived neurotrophic factor (BDNF) is a neurotrophin that serves as survival factor for selected populations of central nervous system (CNS) neurons and plays a role in the limbic system by regulating synaptic plasticity, memory processes and behavior. Impaired BDNF production in the brain can lead to a variety of CNS dysfunctions including symptoms associated with PTSD. However, so far fewer studies have investigated this neurotrophin in patients with PTSD. Furthermore, given the multiple role of BDNF in various CNS disorders, it cannot be excluded that traumatic events per se may influence neurotrophin levels, without a direct association to the PTSD syndrome.     

Cardiovascular responses to avoidance conditioning in the dog: Effects of alpha adrenergic blockade

Laboratory dogs were trained to press a response panel to postpone shocks during daily one-hour avoidance conditioning periods. Each dog was also confined in the experimental environment for 5 hours prior to the avoidance periods. Blood pressure and heart rate were monitored continuously during these experiments from chronically indwelling arterial catheters. Extended training resulted in the emergence of a cardiovascular response pattern during the pre-avoidance interval characterized by gradual increases in blood pressure together with decreases in heart rate. Elevations in both blood pressure and heart rate were sustained during the avoidance periods. During sessions in which alpha adrenergic activity was suppressed by phenoxybenzamine, absolute levels of blond pressure were found to be lower than during control (non-drug) sessions, but a progressive rise in blood pressure continued to be observed during pre-avoidance. These results suggest that sustained cardiovascular responses during avoidance periods are associated with activation of the sympathetic nervous system, but that the gradual rise in blood pressure during pre-avoidance is due to other factors.     

Electrophysiological measurement during a time-out procedure in stuttering and normal speakers

Eight stuttering and eight normal speaking subjects were given a time-out (TO) procedure during reading. Simultaneous measures of heart rate and galvanic skin response were obtained in order to infer anxiety level during the TO period. Multivariate and univariate analysis of variance procedures indicated that stutterers, when compared to normals, initially relax during a TO period compared to base rate levels. Near the latter part of the TO period stutterers anticipate the onset of speech and become relatively more anxious. This anxiety level increases even more during the actual speech intervals. Normal speakers resent the intrusion of the TO interval and become more anxious during this period.