Mediating factors in chick social pecking: II. effects of exposure to movement

Unfamiliarity with movement may lead isolated chicks to respond aggressively when tested with live, moving conspecifics. This hypothesis was tested by comparing the number and locus of pecks by isolated chicks to a stationary or moving model of a chick, and to a live chick. In a second test of the hypothesis chicks that viewed a moving object during isolation and chicks isolated without movement were tested with a live con-specific and their number and locus of pecks were compared. Neither experiment supported the hypothesis. Movement alone failed to excite aggressive pecks and prior experience with movement failed to suppress aggressive pecks. In the first experiment imlated chicks treated the live testmate more aggressively than the moving or stationary model. In the second experiment aggressive pecking of chicks was unaffected by prior experience with movement, These fmdmgs do not support the hypothesis that movement excites aggression in isolated chicks. Nonetheless the results focus attention on the generally neglected problem of emotional and motivational states produced by isolation.     

Defensiveness, intimacy, and heterosexual attraction

A previous study by Dion and Dion (1975) revealed that highly defensive individuals were less likely to report having experienced romantic love than less defensive persons. The hypothesis that this finding might reflect differential reactions to interpersonal intimacy was directly examined in the present study using a self-disclosure paradigm. To assess subjects' defensiveness, undergraduate women first completed the Marlowe-Crowne Social Desirability Scale. In a second session, subjects were exposed to high and low disclosing targets of the same and opposite sex and chose discussion topics for each target. On intimacy of self-disclosure, a “reciprocity effect” occurred: subjects chose more intimate topics for high vs low-disclosing targets. However, highly defensive women gave a less favorable self-presentation to male vs female targets. They also expressed less liking for high compared to low intimate targets and males vs females than less defensive subjects. The implications of these results for heterosexual attraction were discussed.     

Phonological encoding and ideographic reading by the disconnected right hemisphere: Two case studies

The mute disconnected right hemispheres (RHs) of two commissurotomy patients are able to understand spoken words and read printed words by matching them with pictures of the objects named. In this paper we report the results of five experiments. The RH of one patient could “evoke the sound image” of a word to the extent of matching two pictures with homonymous names (experiment 1) or with rhyming names (experiment 2) without being able to name either one. This transformation of picture to covert sound does not depend on orthographic similarity of word ends as a clue to homonymy or rhyme, nor does it improve with short-term learning. Yet neither RH can translate print into sound by matching a spelled word with a picture that has a rhyming name (experiment 3) or by matching two orthographically dissimilar rhymes, be they meaningful (experiment 4) or nonsense words (experiment 5). We suggest that these RHs read “ideographically,” recognizing words directly as visual gestalts without intermediate phonetic recoding or grapheme-to-phoneme translation.     

Field articulation and working memory

This experiment assessed the proposal that performance differences associated with field independence/field articulation reflect differential efficiency in the use of a limited capacity information-processing system termed working memory. Extreme scores on a group-administered version of the embedded figures test were used to identify subjects “high” and “low” in degree of field articulation. The task required that a subject retain a series of digits for subsequent report while performing a semantic modification of a target phrase. Concurrent information load on working memory was varied in two ways: by increasing memory load from 3 to 6 digits, and by increasing the complexity of the semantic processing required. In low information load conditions no differences were found between high FA and low FA groups. In high information load conditions low FA subjects made more errors in digit recall and took longer to perform the difficult semantic modification.     

Reinforcement magnitude effects in first- and second-order conditioning of directed action

Three experiments investigated the effects of reinforcement magnitude on conditioned key pecking in pigeons. Experiment 1, which included between-groups and within-subject designs, yielded significant effects of unconditioned stimulus (US) magnitude on the within-conditioned stimulus (CS) distribution of key pecks and on choice behavior, but no effect on the overall rate of key pecking. Experiment 2 employed a larger US-magnitude difference in a within-subject design. This manipulation resulted in differential rates of key pecking as well as a significant choice effect and differential within-CS key-peck distributions. A second-order conditioning procedure was used in Experiment 3, in which diffuse, visual stimuli (S1's) served as Pavlovian reinforcers for two key-light S2's. The S1 previously paired with a large US was more effective in conditioning second-order key-peck behavior to an S2 than was the S1 paired with a small US. The results of these experiments demonstrate that the associative effects of US magnitude can be expressed in the strength of CS-directed motor responding. The distinctive within-CS key-peck distributions in first-order conditioning suggests an interaction between CS- and US-directed responses.     

Early learning as ontogenetic adaptation for ingestion by rats

Ontogenetic adaptation is an “ecological” concept in which mammalian maturation is seen as a coordinated sequence of specializations (stages) that enables the infant to survive within a sequence of distinct niches created by the parent(s) and the rest of the environment. Natural selection is presumed to operate at each point in development. The development of ingestive behavior in the rat pup as a series of ontogenetic adaptations enabling the infant while in the nursing niche to obtain and utilize mother's milk and progress gradually into the feeding niche in which a variety of solid foods must either be obtained or avoided is discussed. Data to show that learning is an integral part of these ontogenetic adaptations for ingestion are reviewed and interpreted. Preweanling rats that are capable of learning and remembering toxiphobic food aversions do not display an aversion to a flavor conditioned stimulus (CS) paired with illness if the CS is presented during suckling. In contrast, 20-day-old pups (weanlings) trained identically do show conditioned taste aversions under these conditions. A perspective of ontogenetic adaptations to this phenomenon of “blockade of toxiphobia by suckling” and its dissolution at weaning is applied. The generality of the blockade phenomenon and its mechanisms are explored, and it is shown that feeding experience regulates the stage-appropriate learning strategies used by the pups.     

Locus of control and the perception of freedom in an agent of reinforcement

Internals and externals observed a staged videotape presentation that portrayed a “teacher” and a “learner” engaging in a 20-item anagrams task. For externals, any variability (10, 50, and 90% schedule) in the reinforcing behavior of the “teacher” (agent of reinforcement) resulted in significantly greater perceived freedom than when no variability (0 and 100% schedule) occurred in behavior. For internals, perceived freedom was a negative linear function of the amount of reinforcement administered. Internals indicated that they could influence the behavior of the “teacher” in all reinforcement conditions, whereas externals indicated that they could influence only the “teachers” in the variable reinforcement conditions. It was concluded that greater freedom is attributed to a person whose behavior is perceived as congruent with the person's inner disposition.     

Language skills in developmentally disabled children

Language measures of receptive and expressive vocabulary, story telling, and immediate verbal memory, as well as two perceptual tests, were administered to a group of developmentally disabled children, and three groups of normal children, one matched for chronological age, one for mean length of utterance, and one for performance on one of the perceptual tests. When diagnostic subgroups of “autism,” “childhood schizophrenia,” and “other severe disturbance” were formed using standard diagnostic tools, no language differences were found between diagnostic subgroups. When compared with the normal control groups, many of the language skills of the entire group of disabled children, and of the autistic children alone, were rather evenly delayed, showing only a relative sparing of the naming function, and a relative deficit on immediate verbal memory. Furthermore, a high correlation was found in a small subsample between the difficulty levels of morphemes in the disabled children and those reported for young normal children. Experienced special-education and early-childhood teachers could not discriminate the stories of the disabled children from those of young normal children. Analysis of the disabled children's error strategies, however, revealed features of their language not found in normal children's language: (1) extreme perseveration in test answers and stories, (2) attention to minor features of test stimuli, and (3) failure to adopt alternate, flexible communicative strategies. We conclude that the language acquisition of the developmentally disabled children is delayed but not deviant in its semantic and syntactic competence, and that current diagnostic practice does not differentiate linguistically distinct subgroups. We further argue that where developmentally disabled children do exhibit aberrant features of language, such deviance parallels similar features in other cognitive skills, and is not unique to language.     

The personality assessment system: A radical hypothesis

Two stories are presented. The first story is about a clinical practitioner developing an assessment method beginning with a connection of test “signs” with behavior, and proceeding to a system that could mystify observers. The second story is about the application of scientific methods to explain how the system could work. Together the stories are an example of practice informing science, and science informing practice. The basic hypothesis used is that much of what we call personality is “caused” by differential aptitudes as modified by long-term learning. It is also assumed that people would prefer to use those aptitudes they feel are their better ones and avoid those in which they feel weaker.     

The role of the response-reinforcer contingency in negative automaintenance

When a response key is briefly illuminated before a grain reinforcer is presented, key pecking is reliably developed and maintained in pigeons, even if pecking prevents reinforcement (negative automaintenance). This experiment demonstrated that pigeons are sensitive to a negative response-reinforcer contingency, even though it does not eliminate responding. Within individual pigeons, two kinds of trials were compared: red key trials, in which reinforcement was negatively contingent on responding, and white key trials, in which reinforcement was unrelated to responding. Reinforcement frequency in non-contingent trials was yoked to the obtained reinforcement frequency in negatively contingent trials. All eight pigeons pecked substantially more on the non-contingent key than on the negative key, and preferred the non-contingent key to the negative key on occasional “choice” trials where both were presented together. When the stimuli correlated with the two conditions were reversed, the pigeons' behavior also shifted. These response differences are taken as evidence that pigeons are sensitive to the negative response-reinforcer contingency.     

Through the looking glass: Sex differences in memory for self-facial poses

This study investigated recognition memory of photographs of the subject's own face. Male and female subjects were photographed as they projected sociable faces, trustworthy faces, and intelligent faces. After deciding which face of 10 best represented each characteristic, and judging which photograph best represented their “real self,” a recognition memory test of poses was given. Half of each sex were tested under intentional learning conditions and the remainder were tested under incidental learning conditions. Females demonstrated superior recognition memory of their own facial projections and, in particular, recalled photographs of their “real self” and “most sociable” self most easily. No differences were found between the two learning conditions. Subjects' recognition performance was not related to their confidence of judgments. The results were discussed in terms of sex differences and the role of self in memory.     

The dissociation of attention deficit disorder from reading disability: A reply to Share and Schwartz

In a study recently reported in this journal (R. H. Felton, F. B. Wood, I. B. Brown, S. K. Campbell, & M. R. Harter, 1987, Brain and Language, 31, 171–184), a 2 × 2 factorial design assessed the separable impact of presence vs. absence of reading disability (RD) and attention deficit disorder (ADD) on 11 different measures of verbal processing ability, with picture vocabulary and age as covariates in the analysis. Share and Schwartz have objected to this analysis on the grounds that only the allegedly “pure” groups in the design (RD without ADD, and ADD without RD) should be compared. They then use the data in the article to compare those two groups directly, concluding that because only two of the measures were significant in a small sample t test, the hypothesis of differential cognitive impacts of ADD and RD is not supported. They further cite Chapman and Chapman (1973) to suggest that because the 11 dependent measures were not matched for discriminating power the analyses are meaningless. In this commentary we submit that the Share and Schwartz argument (1) shows serious misunderstanding of elementary statistical principles; (2) commits what we call the “Fallacy of the Pure Case”; and (3) misunderstands the Chapman and Chapman argument. Noting that our design was not intended to answer the question that bothers Share and Schwartz (that of a distinctive cognitive deficit associated with “pure” ADD) we conclude with some suggestions about the types of designs and data that would more directly speak to their question.     

Stimulus properties of conspecific behavior

Two experiments identified the conditions in which the behavior of one bird acquired discriminative control of the behavior of a second bird. The schedule-controlled behaviors of the “stimulus” bird were differentially correlated with the components of a multiple schedule according to which the pecking of an “experimental” bird produced food. In Experiment 1, three pairs of pigeons acquired a successive discrimination and two reversals with the conspecific stimuli. Experiment 2 included a control condition in which no systematic relationship existed between the conspecific stimuli and the component schedules. While differential responding during the components of the multiple schedule was again found when the conspecific stimuli were available, differential responding did not occur in the control condition. Test conditions included in the experiments indicated that (a) the differential responding was not dependent on the discriminative properties of reinforcement, (b) the pecking of the stimulus and experimental birds was temporally interrelated, (c) the visual conspecific stimuli were critical to the maintenance of the discrimination, and (d) the observed stimulus control immediately generalized to an unfamiliar conspecific.     

Levels of experienced dimensionality in children and adults

This work presents a new conceptualization of the contrast between holistic and differentiated perception of multidimensional stimuli. Specifically, two hypotheses about the experiential status of dimensions within holistic perception are proposed and tested as explanations of young children's general perceptual mode and adults' integral mode. The major result is that three levels of dimensional status are realized: (1) the hypothesis of nonprimary axes characterizes adult “integral” perception of saturation and brightness relations, (2) the hypothesis of primary but not mandatory axes characterizes kindergarteners' “integral” perception of size and shade relations, and (3) the notion of mandatory axes characterizes adults' separable perception of size and shade relations. These results indicate a new interpretation of the integrality-separability distinction and the derivative developmental hypothesis. It is specifically hypothesized that the developmental history of most dimensional combinations includes these three levels.     

Stimulus control in a simple instrumental task: The role of internal and external stimuli

Two experiments using rats in a straight alley runway task tested the hypothesis that standard stimuli such as tones and lights (“external” stimuli) and schedule-generated aftereffect stimuli (“internal” stimuli) operate similarly and are similarly subject to the compounding rules specified by R. A. Rescorla and A. R. Wagner (In A. Black & W. Prokasy (Eds.), Classical conditioning II: Current theory and research. New York: Appleton-Century-Crofts, 1972). The experimental task was an instrumental analog of the classic blocking experiment (L. J. Kamin, In M. R. Jones (Ed.). In Experiment 1, blocking of an external discriminative stimulus by a different asymptotic discrimination was accomplished. In Experiment 2, blocking of an internal stimulus discrimination by an asymptotic external stimulus discrimination was obtained. The present results support the view that internal and external stimuli are indeed similar and function in the same manner with regard to blocking of stimulus control.     

Trigeminal nerve and eating in the pigeon (Columba livia): neurosensory control of the consummatory responses.

Electrophysiological, neurobehavioral, and cinematographic techniques were used to study the role of the trigeminal nerve in the neurosensory control of eating. Analaysis of single-unit data recorded in the pigeon's trigeminal ganglion indicates that the trigeminal nerve provides somatosensory inputs from the oral region that signal the location and movement of food and monitor the extent of mouth opening. Trigeminal deafferentation, although it does not affect pecking or swallowing, severly impairs the efficiency of eating. Cinematographic analysis shows that the impairment is due to disruption of the neurosensory control of mandibulation-the process by which grain is grasped at the beak tip and moved to the back of the mouth.     

Motor constancy and the upsizing of handwriting

Although handwriting can vary in size, it remains remarkably similar in form, demonstrating motor constancy (equivalence). A consideration of changes in writing size may indicate: (1) how rescaling is accomplished, and (2) those invariant features that remain constrained under size variation. In the experiment reported here nine participants wrote the word “minimum” (without dotting “i’s”) in cursive text, under three size conditions on a SmartBoard. The standard deviation of stroke slope did not change its relationship to mean stroke slope, but stroke durations and lengths did vary. Kinematic analysis indicated that the number of submovements, their efficiency, and their kinematic structure varied across the three writing size conditions. The results suggested that motor constancy does not merely reflect a simple change in a single parameter of scale.     

Analyzing the random control procedure: Effects of paired and unpaired CSs and USs on autoshaping the chick's key peck with heat reinforcement

A series of five experiments using a total of 264 subjects investigated the effects of paired and unpaired key light (CS) and heat (US) stimuli on autoshaping the chick's key peck. Experiment 1 established that paired presentations of CS and US promoted a more rapid rise in key pecking than did randomly presented CSs and USs and that the specific sequence of stimuli under the random control procedure affected key pecking performance. Experiment 2 used a trace conditioning procedure to determine the role of the CS-US interval on autoshaping and to define empirically unpaired CSs and USs. Key pecking declined as the trace delay interval was increased from 0 to 25 sec; at 25 sec, no conditioning of key pecking occurred. Experiments 3–5 assessed the effects on autoshaped key pecking of (a) number of daily CS-US pairings, (b) added unpaired CS presentations, and (c) added unpaired US presentations, since paired and random control schedules differed in all of these respects. Reduction in the number of CS-US pairings slowed the acquisition of key pecking as did the concurrent addition of nonreinforced CSs and unsignaled USs. These results support theories of association formation that stress the effects of both paired and unpaired CSs and USs.     

An investigation of the relationships between problem solving strategies, representation and memory

There has been considerable debate in recent years about the status of “imagery” in problem solving. The present experiment attempts to show that while subjects may employ representational strategies when they first encounter a class of problems, they abandon such strategies as they gain experience with the problems. It does this by asking subjects to answer unexpected questions which are based upon the information which they have just used to solve a problem. The hypothesis, which is supported by the results, is that increasing experience with problems will be paralleled by a decreasing ability to answer unexpected questions. The experiment also shows that such effects are not attributable to a build-up in proactive interference.     

Relative contributions of kind- and domain-level concepts to expectations concerning unfamiliar exemplars: Developmental change and domain differences

Two inferential routes allow children to produce expectations about new instances of ontological categories like “animal” and “artefact.” One is to generalise information from a “look-up table” of familiar kind-concepts. The other one is to use independent expectations at the level of ontological domains. Our experiment pits these two sources of information against each other, using a sentence-judgement task associating properties with images of familiar and unfamiliar artefacts and animals. “Strange” properties are compatible with the ontological concept, but not encountered in any familiar kind. A look-up strategy would lead children to reject them and an independent expectation strategy to accept them. In both domains, we find a difference in reaction to strange properties associated with familiar vs. unfamiliar items, which shows that even young children do use independent domain-level information. We also found a U-shaped curve in propensity to use such abstract information. In addition, animal categories are the object of much more definite domain-level expectations, which supports the notion that the animal domain is more causally integrated than the artefact domain.