Nonverbal Organisms Research Articles

Exclusion performance in visual simple discrimination in dogs (Canis familiaris).

based on exclusion have been investigated in different species because of its emergent nature, leading to evidence of rudimentary symbolic behavior in non-verbal organisms. Simple discrimination procedures provide a simple method to investigate exclusion performance, in which each trial consists of the simultaneous presentation of two stimuli, one with a positive function (S+) and one with a negative function (S-). In exclusion probe trials, an undefined stimulus (UnS) is presented with a familiar S - , and choices based on exclusion may lead to choosing the UnS, excluding the previously known S - . Novelty control trials (S + /UnS) are also conducted to assess the possible preference for the UnS. In this case, if performance is not controlled by novelty, then the subjects must choose the S + and not the UnS. The present study investigated exclusion performance in visual simple simultaneous discrimination tasks in eight dogs. The results indicated that seven of eight dogs showed evidence of exclusion performance (p < .05). These findings corroborate the literature that shows that dogs are capable of responding by exclusion, suggesting that potentially symbolic behavior may rely on basic behavioral learning and conditioning principles.

1 &lt; 2 and 2 &lt; 3: Non-Linguistic Appreciations of Numerical Order

Ordinal understanding is involved in understanding social hierarchies, series of actions, and everyday events. Moreover, an appreciation of numerical order is critical to understanding number at a highly abstract, conceptual level. In this paper, we review findings concerning the development and expression of ordinal numerical knowledge in preverbal human infants in light of literature about the same cognitive abilities in non-human animals. We attempt to reconcile seemingly contradictory evidence, provide new directions for prospective research, and evaluate the shared basis of ordinal knowledge among non-verbal organisms. Our review of the research leads us to conclude that both infants and non-human animals are adapted to respond to monotonic progressions in numerical order, consonant with mathematical definitions of numerical order. Further, we suggest that patterns in the way that infants and non-human animals process numerical order can be accounted for by changes across development, the conditions under which representations are generated, or both.

Models of trace decay, eligibility for reinforcement, and delay of reinforcement gradients, from exponential to hyperboloid

Behavior such as depression of a lever or perception of a stimulus may be strengthened by consequent behaviorally significant events (BSEs), such as reinforcers. This is the Law of Effect. As time passes since its emission, the ability for the behavior to be reinforced decreases. This is trace decay. It is upon decayed traces that subsequent BSEs operate. If the trace comes from a response, it constitutes primary reinforcement; if from perception of an extended stimulus, it is classical conditioning. This paper develops simple models of these processes. It premises exponentially decaying traces related to the richness of the environment, and conditioned reinforcement as the average of such traces over the extended stimulus, yielding an almost-hyperbolic function of duration. The models account for some data, and reinforce the theories of other analysts by providing a sufficient account of the provenance of these effects. It leads to a linear relation between sooner and later isopreference delays whose slope depends on sensitivity to reinforcement, and intercept on that and the steepness of the delay gradient. Unlike human prospective judgments, all control is vested in either primary or secondary reinforcement processes; therefore the use of the term discounting, appropriate for humans, may be less descriptive of the behavior of nonverbal organisms.

Behavioural evidence for mental time travel in nonhuman animals

If episodic memory is an adaptation, it must have evolved to benefit present or future survival and reproduction, rather than to provide an accurate record of the past per se. Recent research has documented various links between the ability to construct episodes of the past and imagine potential future episodes, and it has been argued that the former may be a design feature of the latter. Thus, claims about the existence of episodic memory in non-verbal organisms may be evaluated by examining behavioural evidence for foresight. Here we review recent data on foresight in animals and conclude that the evidence to suggest episodic memory so far is equivocal. We suggest specific experimental criteria that could provide stronger evidence. We maintain that there must be uniquely human traits for which there are no animal models and it remains possible that mental time travel depends on several such traits. Identification of what precisely is unique about the human capacity and what is not, can inform us about the nature and evolution of the human capacities.

On the lack of evidence that non-human animals possess anything remotely resembling a 'theory of mind'.

After decades of effort by some of our brightest human and non-human minds, there is still little consensus on whether or not non-human animals understand anything about the unobservable mental states of other animals or even what it would mean for a non-verbal animal to understand the concept of a 'mental state'. In the present paper, we confront four related and contentious questions head-on: (i) What exactly would it mean for a non-verbal organism to have an 'understanding' or a 'representation' of another animal's mental state? (ii) What should (and should not) count as compelling empirical evidence that a non-verbal cognitive agent has a system for understanding or forming representations about mental states in a functionally adaptive manner? (iii) Why have the kind of experimental protocols that are currently in vogue failed to produce compelling evidence that non-human animals possess anything even remotely resembling a theory of mind? (iv) What kind of experiments could, at least in principle, provide compelling evidence for such a system in a non-verbal organism?

Abstract representations of numbers in the animal and human brain

There is evidence to suggest that animals, young infants and adult humans possess a biologically determined, domain-specific representation of number and of elementary arithmetic operations. Behavioral studies in infants and animals reveal number perception, discrimination and elementary calculation abilities in non-verbal organisms. Lesion and brain-imaging studies in humans indicate that a specific neural substrate, located in the left and right intraparietal area, is associated with knowledge of numbers and their relations (`number sense'). The number domain is a prime example where strong evidence points to an evolutionary endowment of abstract domain-specific knowledge in the brain because there are parallels between number processing in animals and humans. The numerical distance effect, which refers to the finding that the ability to discriminate between two numbers improves as the numerical distance between them increases, has been demonstrated in humans and animals, as has the number size effect, which refers to the finding that for equal numerical distance, discrimination of two numbers worsens as their numerical size increases.

Studies in the History of Psychology: CVI. An Appreciation of Fred S. Keller, 1899–1996

To casual acquaintances, Fred S. Keller may have been known chiefly for his excessive humility, his deadpan wit, his winning way with words, and his propensity for noting and reinforcing the best of the behavior of everyone with whom he came into contact. But to those familiar with the history of the experimental analysis of behavior he was also known as an innovative figure who introduced the use of nonverbal organisms as the laboratory material for the first course in psychology, as coauthor with W. N. Schoenfeld of the classic textbook in the analysis of behavior, as an academic progenitor of something like half of the first generation of behavior analysts, as the founder of scientific psychology in Brazil, and as the principal author of a teaching procedure known as the Personalized System of Instruction.

Chunking by a pigeon in a serial learning task

A basic principle of human memory is that lists that can be organized into memorable 'chunks' are easier to remember. Memory span is limited to a roughly constant number of chunks and is to a large extent independent of the amount of informaton contained in each chunk. Depending on the ingenuity of the code used to integrate discrete items into chunks, one can substantially increase the number of items that can be recalled correctly. Newly developed paradigms for studying memory in non-verbal organisms allow comparison of the abilities of human and non-human subjects to memorize lists. Here I present two types of evidence that pigeons 'chunk' 5-element lists whose components (colours and achromatic geometric forms) are clustered into distinct groups. Those lists were learned twice as rapidly as a homogeneous list of colours or heterogeneous lists in which the elements are not clustered. The pigeons were also tested for knowledge of the order of two elements drawn from the 5-element lists. They responded in the correct order only to those subsets that contained a chunk boundary. Thus chunking can be studied profitably in animal subjects; the cognitive processes that allow an organism to form chunks do no presuppose linguistic competence.

Establishing Equivalent Intraverbal Relations

This study applied the stimulus equivalence model to learning intraverbals, and found that for adult subjects the model is sufficient for predicting the occurrence of other intra· verbal relations, novel for the subjects. The relation between studies of verbal relations and those studies that show that nonverbal organisms have difficulties learning equivalent classes, suggest that analysis of verbal relations ought to include infants and other non· verbal organisms as subjects in order to reveal the necessary and sufficient conditions for learning verbal equivalence classes

A nonverbal organism's knowledge of ordinal position in a serial learning task.

A nonverbal organism's knowledge of ordinal position in a serial learning task.

Positive transfer from sequence production to sequence discrimination in a nonverbal organism.

Positive transfer from sequence production to sequence discrimination in a nonverbal organism.

A nonverbal organism's knowledge of ordinal position in a serial learning task.

A nonverbal organism's knowledge of ordinal position in a serial learning task.

Positive transfer from sequence production to sequence discrimination in a nonverbal organism.

Positive transfer from sequence production to sequence discrimination in a nonverbal organism.

Reaction times of younger and older men and temporal contingencies of reinforcement.

Influences of extended training and temporal contingencies on reaction time were studied in relation to developmental differences. Older and younger men were trained on a chained schedule in which completion of a variable interval produced a terminal link in which reaction time was measured. The reaction-time procedure involved a conditional discrimination with matching to sample in one component and oddity matching in the other. During baseline training, no time limit was placed on the response to the discrimination choice stimuli. Subsequently, increasingly severe time limits were imposed over a series of sessions. Older and younger men showed increased speeds (decreased reaction times) when temporal contingencies were imposed, and these changes were maintained during post-training baseline sessions when there was unlimited time in which to respond. The younger men generally responded faster than the older ones, and age differences were not appreciably reduced during the course of the experiment. The results indicated the feasibility of studying reaction time in human subjects using operant procedures analogous to those developed for the study of nonverbal organisms.

On metaknowledge in the pigeon: An organism’s knowledge about its own behavior

In two experiments, pigeons pecked side keys in a discrete-trials setting in which shorter and longer runs of successive pecks on the left key before a switch to the right key occasionally produced, after a brief retention interval, a short-term memory probe for the most recent run length. In Experiment 1, a probe involved red and green side keys. A peck to a green (red) key was reinforced if the previous run length was shorter (longer). The dependent variable was the probability of a peck to the correct color. In Experiment 2, a probe involved an autoshaping procedure in which a response-noncontingent reinforcer was delivered after a 5-sec presentation of a green (red) center key if the previous run had been a shorter (longer) one. A reinforcer was not delivered when a red key followed a shorter pattern or a green key followed a longer pattern. The production of runs conformed to many previous molecular data on the way the local temporal patterning of behavior adapts to, that is, displays knowledge of, a reinforcement contingency. The probe results showed that a pigeon can report which of two run lengths it recently has emitted. Thus, a pigeon can, in a sense, describe its own adaptive behavior. Since the adaptive behavioral patterning on the center key may be said to represent knowledge, and since the probe behavior is a self-characterization or self-report by the organism about this knowledge, the probe behavior may be said to represent knowledge about knowledge, or metaknowledge. The data extend previous work on metaknowledge in the pigeon to a third type of adaptive temporal pattern of behavior, that is, run length (instead of response duration and interresponse time), and provide a second type of probe procedure, that is, autoshaping, by means of which a nonverbal organism can be asked what it knows about what it is doing to adapt to an environmental contingency.

The local organization of behavior: discrimination of and memory for simple behavioral patterns.

A procedure was developed to enable nonverbal organisms to report what they remember of the temporal organization of their recent behavior. A baseline behavior with known temporal structure was established by a concurrent variable-interval variable-interval schedule for two temporal patterns of behavior (two different classes of reinforced inter-response times). The five pigeon subjects emitted these two temporal patterns on a center key and were occasionally given a short-term memory probe for their most-recently-emitted pattern. The probes consisted of symbolic delayed matching-to-sample tests, in which a response on a green side key was reinforced if the most recent pattern belonged to the shorter reinforced class, and a response to a red side key was reinforced if the most recent pattern belonged to the longer reinforced class. All subjects could report with over ninety percent accuracy what their most recently emitted behavioral pattern was when a retention interval separating the pattern from the memory probe was only .1 seconds. The retention interval was then manipulated, and it was found that recall for a pattern was frequently above chance after a delay of as much as eight seconds. Thus, pigeons can remember their most recent interresponse time not only right after it is emitted, but for several seconds thereafter. In other conditions, the patterns themselves were manipulated. It was found that as the patterns became more similar, discrimination became poorer. These results agree with the view that reinforcement tends to organize and integrate the local structure of behavior to the extent to which that structure is remembered.

EFFECT OF OVERTRAINING ON REVERSAL AND NONREVERSAL SHIFTS IN NURSERY SCHOOL CHILDREN.

A previous investigation (5) has shown that nursery school children, like nonverbal organisms, learn a nonreversal shift faster than a reversal shift. This experiment was designed to find out if overtraining which is known to facilitate a reversal shift in infrahuman subjects (8) would have a similar effect on young children. The results indicate that overtraining had a facilitating effect on reversal shift and no significant effect on a nonreversal shift. This was interpreted as support for a mediational explanation of the effect of overtraining. However, it may be that the mediators are of a perceptual type previously used to explain similar effects in infrahuman subjects (2, 6) rather than mediation by implicit verbal labeling (4, 5).