Intratrial proactive interference in pigeon short-term memory: Manipulation of stimulus dimension and dimensional similarity

Proactive interference was studied using an intratrial preparation in two delayed matching-to-sample experiments employing pigeons. On interference trials, an interfering sample and a target sample were presented successively and were followed by a test consisting of a choice between two stimuli, one associated with each sample. Control trials were identical to interference trials except that the interfering sample was not presented. On both types of trials, choice of the comparison corresponding to the target sample was defined as correct. Colored fields and line orientations were employed as sample stimuli in Experiment 1, and samples of food and no food and of number of pecks were employed in Experiment 2. Interference was found to be equally robust regardless of whether the interfering and target samples were each selected from any of the four dimensions (color, line orientation, food/no food, or number of pecks). Amount of interference was found to be independent of whether the interfering and target samples employed on a trial were selected from the same dimension or from different dimensions. Evidence was also obtained suggesting that line orientation comparison stimuli are more likely to elicit a response not based on memory than are color comparison stimuli.     

Effect of sample presentation time on long-delay matching in the pigeon

The effect of sample stimulus presentation time on long-delay matching in highly practiced pigeons was investigated. The birds were found capable of above chance matching performance at a delay of 60 sec provided the sample stimulus was presented for 4 sec or longer. Matching accuracy increased as a negatively accelerated function of sample stimulus presentation time and decreased as a negatively accelerated function of time since the termination of the sample. The rate of forgetting was found to be independent of sample stimulus presentation time. The data were inconsistent with a temporal discrimination interpretation of the effect of presentation time on delayed matching. The data were interpreted as supporting a simple trace strength and decay model of pigeon delayed matching.     

Prospective versus retrospective coding of samples of stimuli,responses, and reinforcers in delayed matching with pigeons

Pigeons' performance with samples of stimuli (red and green), number of responses (1 and 20), and reinforcers (food and no food) was assessed in a matching-to-sample preparation. Samples of red, 20 responses, and food were each associated with the red comparison stimulus; samples of green, 1 response, and no food were each associated with the green comparison stimulus. Interest focused on whether physically different samples associated with the same comparison stimulus each establish a unique memorial representation embodying the physical attributes of the sample (retrospective coding), or whether they activate a unitary memorial representation embodying an instruction for test responding (prospective coding). In the first experiment, accuracy of choice responding was independent of whether successive sample presentations within a trial involved the same physical sample or physically different but associatively identical samples. A second experiment revealed that, in contrast to other matching preparations, accuracy was not reduced when sample elements were compounded during presentation. It was concluded that physically different samples which are associated with the same comparison stimulus are coded prospectively in terms of an instruction for choice responding.     

Stimulus control of information processing in pigeon short-term memory

Six pigeons were trained initially on a delayed successive matching-to-sample task using red and green fields as sample and test stimuli. Following acquisition, each sample was followed either by a vertical line (“remember” cue), which indicated that sample memory would be tested, or by a horizontal line (“forget” cue), which indicated that sample memory would not be tested. During the experiments, sample memory on forget trials was tested occasionally. A series of five experiments revealed: (a) better retention on remember trials than on forget trials, (b) increased effectiveness of a forget cue when it followed closely sample offset, (c) more rapid forgetting over a retention interval ranging from 3 to 6 sec on forget trials than on remember trials, (d) a “cancellation” effect in which a remember cue which followed immediately the offset of a forget cue attenuated markedly the effectiveness of the forget cue, and (e) an “insulation” effect in which the effectiveness of a forget cue was reduced considerably when presented after a remember cue. It was concluded that pigeons actively process or rehearse the sample memory during the retention interval.     

Inducing ordinal and cardinal representations of the first five natural numbers

The prediction that the ordinal property of natural number symbols (using these symbols to represent the terms in an ordered progression) is more easily learned than the cardinal property of natural number symbols (using these symbols to represent the manyness of collections) was examined in this experiment. Preschoolers who evidenced no proficiency with either the ordinal or cardinal properties of natural number symbols were trained to acquire these properties via simple feedback. Both properties proved to be trainable. The most important findings were that the ordinal property was much easier to train than the cardinal property, ordinal training effects were more durable across a 1-week interval than cardinal training effects, and ordinal training appeared to transfer better than cardinal training.     

The effects of cue reliability on infants' manual search.

Nine-month-old babies were presented a manual search problem in which toys were hidden in one of two containers, and then the containers were transposed. Over a series of training trials either two, one, or no cues were perfectly correlated with the location of the toy. The infants' first searches became more accurate over training trials in conditions with consistent container and/or position cues. In the final training trial block search performance was best with two cues, intermediate with one cue, and least accurate in the no-cue condition. In a subsequent reversal procedure, in which the toy was placed in the previously unused hiding place, the number of correct first searches also differed according to the nature of cues available across hidings. The implications for learning the concept of object permanence are discussed.     

Asymmetric attributions for compliance: Reward vs punishment

It was proposed that people attribute an individual's behavior more to internal factors when that individual's actions are influenced by reward than when those actions are influenced by punishment. Previous research has failed to control for the power of reward versus punishment which, in effect, creates a confounding of behavioral base rates (consensus) with the reward-punishment manipulation. The current research created reward and punishment contingencies that were equal in their base rates for producing a compliant response. In Experiment 1, subjects (n = 63) who produced the base-rate data also made attributions regarding a compliant target person. The results supported the reward-punishment attributional asymmetry hypothesis in that the target person was held more responsible for his actions in the reward than in the punishment conditions. A second experiment (n = 72) provided some attributors with information regarding base rates for compliance and measured perceived base rates for compliance. Knowledge of the base rates for compliance eliminated the reward-punishment attributional asymmetry phenomenon. Subjects not provided with such knowledge erroneously assumed different base rates for reward and punishment and maintained the perception of reward-punishment attributional asymmetry. Using subjects' estimates of base rate for compliance as a covariate eliminated the attributional asymmetry effect. It is suggested that erroneous base-rate assumptions mediate the attributional asymmetry phenomenon.     

Spatial cognition: gathering strategies used by preschool children

How preschool children retrieve hidden objects was examined in two cross-sectional studies. The first was a simple task in which 1- and 3-year-olds saw two treats hidden in their living room. The newly walking infants generally sought the closer treat first, providing evidence for a least-distance spatial strategy. However, this strategy was affected by a tendency to approach the hiding place most recently baited. Three-year-old children used a least-distance strategy regardless of the order of hidings. In Experiment 2, 3- and 5-year-olds saw 12 puzzle pieces hidden in various containers equally spaced within a naturally furnished children's laboratory. Factors in addition to age were the distinctiveness of the containers and a requirement to return to the center of the array after each retrieval. Overall, children of both age groups were quite successful at this task, retrieving 11 of the pieces. However, 3-year-olds were less efficient, retrieving fewer pieces and requiring more searches. Detailed analyses of errors and patterns of choices indicated differential processes in achieving their performance. Three-year-old children showed the use of memories for events, discrimination of classes of hiding places, and efficient spatial biases. Five-year-old children were more likely to exhibit these processes concurrently.     

Attribution and reconstructive memory

Two experiments were conducted to test the effects of making an attribution on later memory for the event that gave rise to the attribution. Subjects in Experiment 1 observed a scenario in which an actor's behavior was associated with high or low variance (distinctiveness) across situations, and high or low congruence (consensus) to the actions of others. Subjects either made attributions for the actor's behavior immediately following the scenario or not. One week later, subjects were asked to recall consensus and distinctiveness for the actor's original behavior. Subjects who made attributions were significantly better at estimating the high-high and low-low combinations of consensus and distinctiveness than were their no-attribution counterparts. It was suggested that making an attribution may allow for a reconstructed memory for the original event, but not enhance direct access to the original event information. A second experiment tested this concept further by having subjects view an edited version of the scenario in which either the distinctiveness or the consensus information was deleted and having subjects make attributions or not. One week later, subjects were asked to indicate their certainty that consensus and distinctiveness information was a part of the original scenario and to estimate the levels of consensus and distinctiveness. Subjects who made attributions were more confident and accurate in estimating the level of consensus or distinctiveness that was given in the original scenario than were no-attribution subjects. However, attribution subjects were also more confident that consensus information or distinctiveness information was contained in the scenario (when it was not) than were the noattributio subjects. Results of the two experiments suggest that eliciting attributions can distort subsequent memory for the event on which the attributions were based.     

Three experiences affecting spatial discrimination learning by ambulatory children

Children 1 and 3 years of age were given a two-choice spatial discrimination task. They were placed in front of a barrier and encouraged to walk around it; one route around the barrier was blocked. Three experiments studied the effects of different types of experience with this spatial problem. The first examined trial and error experience, in which the child was allowed to walk the route he or she had chosen. Although most children readily learned to choose the open route, the pattern of choices indicated that 3-year-olds were more likely to achieve a learning criterion after an error than 1-year-olds. A second experiment looked at the effects of showing the children the layout of the problem prior to trial and error experience. The 3-year-olds were again more likely than the 1-year-olds to achieve criterion after an error; furthermore, they were likely to know the correct route on the first trial. The third experiment let the children watch their parents take the correct route. This procedure eliminated age differences in performance. The initial choices of the 1-year-olds indicated that they were likely to know the correct route, and if they did not, they were just as likely to learn from their mistakes as the 3-year-olds. The data were interpreted within a mathematical model of learning. Based upon these analyses, we propose two developmental trends. One involves a growth in sensitivity to the consequences of a choice of route. The other is a progression from social learning to more independent and ideational methods of spatial problem solving.     

The effects of cue distinctiveness on infants' manual search

Nine- and sixteen-month-old infants were repeatedly presented a manual search problem in which a toy was hidden in one of two containers, which were then moved into reach. The distinctiveness of the containers or their closeness during the movement was varied in different conditions. Overall, the older infants performed better than younger infants, performance improved across trials, and there were more correct searches when the containers or trajectories were distinctive. Analyses of visual orienting indicated that infants learned to restrict their looking to the hiding place. The ability to maintain attention to discriminative cues may be instrumental to progress in delayed-reaction and object permanence tasks.     

Increasing and decreasing intrinsic interest with contingent rewards: A test of cognitive evaluation theory

The study examined Deci's (Deci, E. L. Intrinsic motivation. New York: Plenum Press, 1975) hypotheses regarding the effects of contingent rewards on intrinsic task interest. Seventy-two male university students worked on a series of puzzles and were given either a high value reward ($1.50) or a low value reward ($.45). The money was given either contingent upon the simple execution of the task (task-contingent), contingent upon the ostensible attainment of a performance criterion level (criterion-contingent), or noncontingent and unexpected (control). Compared to the high payment control subjects, subjects who received the task-contingent high reward rated the task as less interesting, while subjects who received the criterion-contingent high reward rated it as more interesting. Also, subjects expressed less interest in the task after receiving the high task-contingent reward than the low task-contingent reward, but indicated greater interest after receiving the high criterion-contingent reward than the low criterion-contingent reward. It was concluded that substantial support was obtained for Deci's (1975) cognitive evaluation theory.     

On the measurement of storage and retrieval contributions to memory development

We report two free recall experiments and a cued recall experiment in which a new two-stage model was used to obtain numerical measurements of age changes in various aspects of storage and retrieval. The subjects in all three experiments were 7-year-olds (second graders) and 11-year-olds (sixth graders). The major findings in the free recall experiment were that getting a trace into storage posed less of a problem for elementary schoolers than learning how to get it out on test trials, that retrieval development is more rapid during the elementary school years than storage development, and that the superiority of older children's storage and retrieval abilities tends to become more pronounced as learning progresses. A similar pattern of results was obtained under different conditions in the cued recall experiment.     

Recipient mood states and helping behavior

Three studies investigated the effects of perceived recipient mood on helping behavior. Based upon Schwartz' (in Advances in experimental social psychology, Vol. 10, N.Y.: Academic Press, 1977) discussion of need-based helping, it was predicted that donors would perceive greater psychological need and would help more when the recipient's mood was negative than when it was neutral. These predictions were confirmed for females but not for males. The results also confirmed the hypothesis, derived from Schwartz (1977), that a negative recipient mood would elicit greater helping than a neutral recipient mood when this mood is perceived as changeable but not when it is perceived as unchangeable.     

Current issues in theory construction: A commentary on Waters and Sroufe

The view of competence proposed by Waters and Sroufe remains faithful to a kind of theorizing about human personality which emphasizes its unitary and universal properties. Developments in other areas of inquiry, however, are redirecting theoretical efforts toward a more pluralistic and contextualistic view of human nature and development. Implications for future theories of development are discussed.     

Three-state models of memory development: A review of advances in statistical methodology

A certain family of three-state Markov processes has been widely used in experiments on children's memory. Although the statistical machinery for these models is well developed in most respects, two shortcomings have been noted in recent literature reviews. First, the parameters of the models are not identifiable. Second, goodness-of-fit tests are laborious to execute and their sampling distributions are unknown. New procedures for dealing with these difficulties are reported.     

Reading disability: A problem in rule learning and word decoding

Traditional explanations of reading disability (e.g., perceptual, memory, and phonetic receding deficits) have encountered logical difficulties and substantial empirical disconfirmation. An alternative conceptualization of the nature of reading disability is proposed. Disabled readers are hypothesized to suffer a fundamental problem in acquiring word knowledge and word processing skills. Poor decoding skills prevent them from developing sophisticated reading comprehension skills. From this perspective, the cognitive deficits of disabled readers result from failure to acquire and generalize complex processing skills originally mastered through reading experience. Recent research of the author and of others relating to these issues is discussed.     

Nonimmediate language style and inconsistency between private and expressed evaluations

It was hypothesized that certain language style variations would reflect apprehension about affirming the validity of communication content. Wiener and Mehrabian (Language within language: Immediacy, a channel in verbal communication. New York: Appleton-Century-Crofts,1968) have identified a cluster of such variations called verbal nonimmediacy, which they describe as indicators of psychological distance between the communicator and his/her communication. Four experiments are reported. Experiments 1 and 2 showed that communication about positive manifestations of disliked traits and negative manifestations of liked traits was more nonimmediate than when positive manifestations of liked traits or negative manifestations of disliked traits were described. This was true both when one's own or another's personality traits were described. In Experiment 3, nonimmediacy was found to increase when communications involved clear fabrications about either one's liked or disliked traits. Experiment 4 showed that when self-regard was experimentally manipulated, low self-regard subjects showed more opinion conformity and nonimmediacy in their disclosures to a confederate than did high self-regard subjects.     

The role of Canadian school psychologists: Perceptions of a sample from the general public

A sample of 77 subjects responded to a questionnaire designed to collect information about their perceptions of the role of school psychologists. The results indicate that overall the respondents had a fairly accurate sense of what a school psychologist does, although they overestimated the importance of psychotherapy as one of the school psychologist's functions. It is recommended that school psychologists more clearly specify their function when dealing with members of the general public.     

The development of alertness

Two experiments explored variation in the alerting process across age and warning interval as well as the effects of alertness on subsequent processing. Experiment 1 obtained alertness functions for a group of 5-year-olds, 8-year-olds, and adults. Results revealed strong age differences in speed of alerting and in maintenance of alertness over a 1-sec interval. Five-year-olds alerted more slowly than older groups and sustained optimal alertness less well. Both groups of children showed more variability in alerting functions compared with adults. Experiment 2 examined the degree to which age differences in processing speed were attributable to differential speed and maintenance of alerting. Masking functions obtained across variations in the alerting interval revealed that when level of alertness was optimal in both 5-year-olds and adults, minimal age differences in processing speed were observed. During short, nonoptimal alerting intervals, speed of processing in adults was faster than in 5-year-old children. The pattern of results across studies suggested that alertness can fluctuate over time in young children, that level of alertness affects subsequent perceptual processing speed, and that developmental variation in speed and maintenance of alertness can partly explain observed age differences in processing speed. The potential role of alertness in more complex cognitive tasks is discussed.