Synchronization and coupling of phases in periodic processes of conditioning

Locomotor avoidance conditioning and locomotor food conditioning in male albino rats demonstrated that locking of temporary connections is accomplished by coupling of phases of different synchronized periodic neural processes. Phase coupling was verified by the formation of parallel periodic courses of reaction times and motor reaction times in the process of elaboration of conditional avoidance reflexes, and by the curve of the corresponding correlation coefficients, which were calculated from the reaction times and motor reaction times in food conditioning measured every day during the period of stabilization. The authors hold the view that a locking mechanism based on the synchronization of periodic processes in conditioning is most compatible with efficient formation of conditional reflexes and can promote adaptation. Furthermore, it is assumed that information storage, too, occurs periodically, according to the principle of rotary storage.     

Neuroendocrine and behavioral correlates of constitutional differences

Consistent and stable individual differences were observed in the renal responses of water-loaded dogs during the development of Pavlovian conditional motor defense reflexes by electrocutaneous reinforcement. Some dogs developed persistent and intense conditional antidiuretic responses (with a high urine osmolality) to the entire Pavlovian conditioning room complex, whereas other dogs failed to exhibit conditional antidiuresis. In contradistinction to the conditional motor defense reflexes, the conditional antidiuretic responses showed poor differentiation, thus demonstrating the phenomenon of schizokinesis discovered by Gantt. In addition to conditional water retention, the antidiuretic dogs also exhibited persistent hyperpnea, copious salivation and tachycardia. The physiologic responses of the antidiuretic dogs to the Pavlovian conditioning room resemble those described by Walter B. Cannon for a “fight or flight” response,i.e., physiologic reactions of animals engaged in intense muscular effort. The antidiuresis serves the function of conserving body water so that it may be available for evaporative cooling in order to maintain thermal homeostasis. Since our experimental dogs cannot engage in a consummatory “fight or flight” response, their physiologic reaction to a stressful psychologic environment can be considered maladaptive. Pharmacologic analysis suggested that the antidiuretic responses may involve cholinergic transmitters.     

Cortical steady-potential shifts in conditioning

Cortical steady-potential shifts obtained from nonpolarizing electrodes chronically implanted in freely moving cats and rats reveal cortical activation related to urgency of response to unconditional and conditional stimuli. Such shifts appear relatively independent of activation in the rhythmic electrocorticogram and are related to higher levels of activation. Shifting is found to be modulated by drive and level of learning, suggesting a correlation with the proposed reaction potential of Hull. Both approach and avoidance “urgency” are reflected in the onset slope and amplitude of SP shifts in a manner suggesting modulation of cortical activation by the effects of behavioral regulation of stimulus conditions.     

The“response” in behavior theory

The term“response” is a basic one in behavior theory, particularly reflex theory, but its definition is not clear. The origin of the term in the common vocabulary has affected its later extensions in the analysis of behavior. Some contemporary theorists accept the existence of two“types” of response, coordinating one with the Pavlovian conditioning procedure, the other with the operant conditioning procedure of the so-called“contingent” variety. Reservations are expressed here about such distinctions between response classes and conditioning paradigms, emphasizing the difficulties that arise from certain conventions and inadequacies in current definitions and conceptions of“response.” The critical nature of the problem for behavior theory is illustrated once again by the recent laboratory finding that a familiar and accepted conditional reflex, that of the“conditioned cardiac CR,” can be fractionated into“parts” and is therefore perhaps no longer to be treated as a single unitary“response.”     

Electrodermal pavlovian conditioning with prepared and unprepared stimuli

One-trial learning referred to by Guthrie has been suggested to occur in autonomic conditioning, if the conditional stimuli (CSs) are so-called prepared ones. To test this idea, half of 28 subjects were given spider or snake slides as “prepared” CSs, while the remainder were given neutral slides as “unprepared” CSs. A shock was employed as the unconditional stimulus (UCS), with a CS-UCS interval of 8 seconds. Electrodermal activity and probe reaction times were the dependent measures of conditioning, conceived in cognitive, information-processing terms as the learning of the CS/UCS contingency. Evidence for the usual CS/UCS contingency learning emerged in both indicators, and during both acquisition and extinction, but none for one-trial learning, perhaps because the UCS was insufficiently aversive.     

Ear differences in simple reaction time: The influence of attentional factors

Simple motor reaction times (right-handed) to tape-recorded consonant-vowel syllables were obtained from 12 subjects under two conditions of monotic stimulation: “expected” presentation (subject informed as to ear of presentation) and “random” presentation (ear of presentation varied randomly). Significantly faster left ear reaction times were obtained in the “expected” condition. The rank order of subjects' standard dichotic listening task scores correlated negatively with reaction time ear differences in the “expected” presentation condition. Results are discussed in terms of existing theories of response lateralization in simple reaction time tasks, and an expanded hypothesis is offered. Specifically, it is suggested that two or more distinct but potentially overlapping mechanisms may be responsible for observed asymmetries in monotic auditory perception. Both an attentional or lateralized motor response bias and an inherent lateralization of function may operate side by side, differentially activated by task demands, mode of stimulus presentation, and nature of stimuli.     

New insights on eye blindness and hand sight: Temporal constraints of visuo-motor networks

Pioneer experiments on saccadic suppression have shown that this effect is not followed by motor disorientation: Conscious perception of a target displacement can be dissociated from correct manual target reaching. It has subsequently been demonstrated that movement corrections with the same latency and spatial characteristics can be produced in conditions allowing perceptual awareness of perturbation of a target as in condition inducing saccadic suppression. In addition to the qualitative dissociation between motor performance and conscious awareness, quantitative temporal dissociations in action can be observed by manipulating different features of the visual target. When the target of an ongoing simple action is perturbed, a temporal advantage is found for responses to perturbations of location relative to colour and shape. Furthermore, there seems to be a temporal advantage for automatic motor corrections made in response to a target displacement as compared to other responses (other ongoing movement adjustments, movement interruption, conditional motor response such as pressing a key, verbal response, delayed matching-to-sample tasks). Thus, this paper reviews evidence for the fact that the temporal characteristics of any given response to a stimulus are dependent both on the sensory processes and on the type of response generated. Accordingly, identification responses (such as verbal report) to a visual stimulus are much slower than motor corrections of an ongoing movement in response to a target location change because of different processing times of the stimulus features (“What” compared to “Where”) and of the response itself (“What” compared to “How”). The existence of two continua (What/Where and What/How) is proposed between these two extreme stimulus- response combinations. This model may be a useful framework to better understand visuo-motor transformations and the network of connections between visual and motor areas.     

Cancelling discrete and stopping ongoing rhythmic movements: Do they involve the same process of motor inhibition?

Motor inhibition is considered to be an important process of executive control and to be implicated in numerous activities in order to cancel prepared actions and, supposedly, to suppress ongoing ones. Usually, it is evaluated using a “stop-signal task” in which participants have to inhibit prepared discrete movements. However, it is unknown whether other movement types involve the same inhibition process. We therefore investigated whether the inhibition process for discrete movements is involved in stopping ongoing rhythmic movements as well.Twenty healthy adults performed two counterbalanced tasks. The first task was used to estimate the stop-signal reaction time (SSRTd) needed to inhibit prepared discrete key-pressing movements. In the second task, participants drew graphic patterns on a tablet and had to stop the movement when a stop-signal occurred. We calculated the rhythmic stop signal-reaction time as the time needed to initiate stopping such ongoing rhythmic movement (SSRTr) and the same latency relative to the period of the rhythmic movement (relSSRTr). We measured these delays under different movement frequencies and motor coordination conditions and further investigated whether they varied as a function of several parameters of the rhythmic movements (speed, mean and variance of the relative phase, and movement phase at several time events).We found no correlation between inhibition measures in the two tasks. In contrast, generalized linear models showed a moderate yet significant influence of the motion parameters on the inhibition of ongoing rhythmic movements. We therefore conclude that the motor inhibition processes involved in cancelling prepared discrete movements and stopping ongoing rhythmic movements are dissimilar.     

The role of muscle tension in “repression”

Using an active partial avoidance conditioning paradigm, muscle tension was conditioned to a verbal conditional stimulus (CS), and recall of words semantically unrelated and related to the CS was tested under conditions of three levels of induced muscle tension with 20 subjects (Ss). Results showed the expected decrease in latency of response with moderate tension for all stimuli during the pretreatment period and for the unrelated words during the posttreatment period and a significant increase in latency of response for the related words during the posttreatment period. It is suggested that if the level of muscle tension associated with the conditional response (CR) is induced in Ss, then recall of CS-related material will be inhibited or “repressed.”     

Conditional mechanisms of decision making

Decision making is an important link in the central part of a reflex—the “mental element” according to Sechenov. The reflex nature of this mental process is revealed in experiments where a voluntary motor reaction is chosen unconsciously as a response to subliminal conditional visual stimuli. Thus, learning which is reflected by “advance” or prior decision making can be performed unconsciously through a conditional reflex. But, once elaborated, temporary connections are preserved only in shortterm memory. They are not transferred to long-term memory, as in the case of recognition of signals. Decision making, being the central mental part of the reflex, like any activity of the brain, is performed in time by a certain cortical structure. Analysis of P₃₀₀ amplitudes shows that decision making is related to local activation of the frontal parts of the cerebral hemispheres. We suggest that the local activation of these areas is induced by conditional excitation of the neuronal mechanisms of focused attention. It provides a “command” to perform a voluntary motor reaction adequate to the conditions at hand. A large part of latency of voluntary motor response of man is spent on decision making, especially in discrimination of signals and in choice of reactions.     

Cardiovascular generalization and differentiation: The relationship between heart rate and blood pressure

The present study was designed to study generalization and differentiation and to check the relation between heart rate and blood pressure in cardiovascular conditioning. Five naive mongrel dogs were presented with 10 sec 1000 cps tone regularly reinforced with 0.5-sec shock to a left foreleg. Four other 10-sec tones (600, 800, 1200, 1400 cps), never reinforced, were administered in a randomized and counterbalanced fashion using a differential reinforcing technique. The response measures were heart rate and three indices of blood pressure,i.e., systolic, diastolic, and pulse pressures.“Initial response” of heart rate showed rapid tachycardia to all tones, with no generalization and differentiation among five tones.“Terminal response” clearly indicated generalization gradients that tachycardia to 800 and 1200 cps tones were higher than those to 600 and 1400 cps tones, respectively. Some differences were noted among systolic, diastolic, and pulse pressures, with pulse pressure showing a trend of generalization and differentiation in the“initial response.” No statistical difference, however, was obtained in blood pressure scores. Beat-by-beat analyses of correlations between heart rate and diastolic blood pressure showed that the correlations successively decreased during the“terminal response.” Overall correlations between heart rate and three indices of blood pressure were obtained, with the highest correlation between heart rate and pulse pressure. Considering the above results in relation to the classical conditioning theory, it was tentatively concluded that“initial response” includes non-conditional factors, while“terminal response” reflects mainly a true conditional response, particularly, at a long CS-US interval. This interpretation leads to the hypothesis that conditional response with a short CS-US interval may attain better conditioning scores in terms of the summation effect between a non-conditional factor and a true conditional factor.     

Generalisation of fear and avoidance along a semantic continuum

Directly conditioned fear and avoidance readily generalises to dissimilar but conceptually related stimuli. Here, for the first time, we examined the conceptual/semantic generalisation of both fear and avoidance using real words (synonyms). Participants were first exposed to a differential fear conditioning procedure in which one word (e.g., “broth”; CS+) was followed with brief electric shock [unconditioned stimulus (US)] and another was not (e.g., “assist”; CS–). Next, an instrumental conditioning phase taught avoidance in the presence the CS+ but not the CS–. During generalisation testing, synonyms of the CS+ (e.g., “soup”; GCS+) and CS– (e.g., “help”; GCS–) were presented in the absence of shock. Conditioned fear and avoidance, measured via skin conductance responses, behavioural avoidance and US expectancy ratings, generalised to the semantically related, but not to the semantically unrelated, synonyms. Findings have implications for how natural language categories and concepts mediate the expansion of fear and avoidance repertoires in clinical contexts.     

Reaction times and error rates for “same”-“different” judgments of multidimensional stimull

Each S indicated whether two successively presented rows of letters were “same” or “different.” Reaction times of the “different” response seemed to indicate that S examined the stimulus letters in a serial, self-terminating manner. However, the reaction times of the “same” response were not consistent with this model. Consequently, it was proposed that S employs simultaneously two distinct processes for comparing stimuli. One process would generate the “different” responses; the other process would generate the “same” responses. Most false “same” responses occurred when the two rows of letters differed minimally. Thus, the false “same” responses appear to result from a failure to detect the difference between the two stimuli. However, when S made a false “same” response, he was aware that he had done so. Therefore, it was suggested that only one of the two comparison processes failed to detect the stimulus difference.     

Respiratory conditional reflex formation with CO2 and electric shock as unconditional stimuli

In 12 birds used in a CO₂ conditioning experiment there was no evidence of the formation of either a respiratory or a cardiac conditional reflex. Tone and light separately or together were used as conditional stimuli. CS-US intervals ranging from 0.5 to 10 seconds were used. CO₂ concentrations up to 7.4% were also employed. In the shock conditioning experiments six of seven birds showed a respiratory change to the conditional stimulus. In one pigeon perfect differentiation was obtained between the reinforced and nonreinforced tones. The marked difference in conditionability of sensory and chemical stimuli to the “respiratory center” is discussed in relation to the central nervous system connections of the respiratory control mechanism.     

The problem of switching in conditional behavior

This article reviews studies of various authors on the phenomenon of “switching,” which is observed in both classical and instrumental conditioning and consists in elicitation of different responses to the same conditional stimulus (CS) when it is applied in an environment different than the original one. The different responses include a decrease or an absence of the previously trained conditional response (CR), elicitation of an appetitive response instead a defensive one, or vice versa, as well as elicitation of two different instrumental CRs in the same trial. The studies suggest that, due to the repeated occurrence of CS in the same environment (E), also called “situation” or “context,” associations are formed between CS and E. Consequently, the CR is elicited to a compound CS+E rather than to CS alone. When the CS is applied alone in a different E than the original one, the previously formed associations are inactive and the CR cannot be elicited; this leads to switching. Studies also suggest that E plays a dominant role in conditioning compared with that of CS alone, which often appears to be only a trigger for eliciting the response. However, CS tested in a different E may still produce some components of the previously acquired CR, such as a general fear behavior to an originally defensive CS or an approach behavior to an originally alimentary CS. The environmental stimuli can be considered the “determining” stimuli that determine the kind of reaction to be elicited, or “tonic” stimuli that increase the tonus in the brain but do not elicit the CR. The “determining” or “tonic” stimuli do not seem to be a special class of stimuli. Instead, they are stimuli that initially can produce the CR (e.g., intertrial CRs), but by being not reinforced they become partly inhibited; nevertheless, due to associations with the reinforcement, they still can produce some excitement related to it, thus facilitating the CR.     

Lever attacking and pressing as a function of conditioning and extinguishing a lever-press avoidance response in rats

Six experimental rats were conditioned to press one of two available levers to avoid shock. The levers registered bites as well as presses. For four of these rats, shock was contingent on lever bites when a specified time period had elapsed after the previous shock. An extinction period, in which only periodic noncontingent shocks were presented, followed avoidance training. Six yoked-control rats received the same sequence of shocks as did the corresponding experimental rats in both the conditioning and extinction phases. All six experimental rats repeatedly bit the avoidance lever. Four bit it more than the nonavoidance lever during conditioning, and five bit it more during extinction. Five of the six experimental rats consistently bit the levers many more times during each session than did their respective control rats, suggesting that avoidance conditioning facilitated lever biting. Rates of lever biting and pressing by all of the experimental rats and by some of the control rats were highest immediately following shock throughout both phases. During later portions of the intervals following shock, characteristic effects of conditioning and extinction were observed. This finding suggests that extinction of avoidance behavior by unavoidable shock presentations can be demonstrated more readily when shock-elicited responding is extricated from the data.     

CONTINGENCY SPACES AND MEASURES IN CLASSICAL AND INSTRUMENTAL CONDITIONING1

The contingency between conditional and unconditional stimuli in classical conditioning paradigms, and between responses and consequences in instrumental conditioning paradigms, is analyzed. The results are represented in two- and three-dimensional spaces in which points correspond to procedures, or procedures and outcomes. Traditional statistical and psychological measures of association are applied to data in classical conditioning. Root mean square contingency, ø, is proposed as a measure of contingency characterizing classical conditioning effects at asymptote. In instrumental training procedures, traditional measures of association are inappropriate, since one degree of freedom—response probability—is yielded to the subject. Further analysis of instrumental contingencies yields a surprising result. The well established “Matching Law” in free-operant concurrent schedules subsumes the “Probability Matching” finding of mathematical learning theory, and both are equivalent to zero contingency between responses and consequences.     

A successive-conditionalization approach to disjunctive and syllogistic reasoning

With p and q each standing for a familiar event, a disjunctive statement, “either p or q”, seems quite different from its material conditional, “if not p then q”. The notions of sufficiency and necessity seem specific to conditional statements. It is surprising, however, to find that perceived sufficiency and necessity affect disjunctive reasoning in the way they affect conditional reasoning. With B and C each standing for a category name, a universal statement, “all B are C”, seems stronger than its logically equivalent conditional statement, “if B then C”. However, the effects of perceived sufficiency or necessity were found to be as pronounced in conditional reasoning as in syllogistic reasoning. Furthermore, two experiments also showed that (a) MP (modus ponens)-comparable disjunctive reasoning was as difficult as MT (modus tollens)-comparable disjunctive reasoning, and that (b) MT-comparable syllogisms were easier to solve than MT problems in conditional reasoning.