An analysis of the word-superiority effect

It is easier to decide which of two letters was presented tachistoscopically if the critical letter was in a word rather than in a scrambled word. We showed that this word-superiority effect holds just as strongly for pronounceable nonwords as for words, even when the critical letters are constant over all trials. This finding rules out word meaning and familiarity as variables accounting for the effect. In addition, it was found that the superiority of pronounceable stimuli holds for two-letter stimuli as well as four, and it is therefore concluded that the effect is not due to a memory limitation. An explanation of the effect in terms of the use of additional acoustic information is ruled out by showing that the effect was not diminished when the two possible words sounded exactly alike. An experiment using correctly and incorrectly spelled chemical formulas suggested that spelling regularities, regardless of pronounceability per se, account for the superiority effect. Finally, when decisions about two critical letters must be made on each trial, the correlation between being correct on one and on the other is higher for pronounceable stimuli under some conditions.     

Individual differences in speed of phonemic analysis, visual analysis, and reading.

College student subjects (Ss) classified phrases as making sense or not according to sound in one condition, according to visual appearance in another, and in abasic task in which either strategy would yield right answers. Ss who were relatively fast in the visual condition were faster at the basic task than Ss who were relatively fast in the sound condition. Other results suggested that the former Ss used a visual strategy in the basic task while the latter used a phonemic strategy.     

Learned taste aversions in rats as a function of delay,speed, and duration of rotation

Rats fed a saccharin solution and then rotated on a turntable showed an aversion to the saccharin solution on later testing. In the first experiment, the rats learned to avoid saccharin with delays of as much as 9 hr between drinking the saccharin and the start of rotation. The second experiment showed that the critical determinant of aversiveness of rotation was number of rotations. The rats avoided saccharin as much after rotation at high speeds for short durations as after rotation at low speeds for long durations.     

Delayed matching in the pigeon: Effect on performance of sample-specific observing responses and differential delay behavior

Pigeons were trained on a delayed matching-to-sample task with a 0-sec delay and then transferred to a 1-sec delay (Experiment 1) or were trained with mixed 0-sec/1-sec delays and then transferred to longer mixed delays up to 28 sec (Experiment 2). Four groups were distinguished by the nature of the observing response required to each sample color (red and blue). For Group NN pecks were allowed to neither color. For Group PcPc pecks were required to both colors. For Group PcN pecks were required to red but were not allowed to blue. For Group PcPt pecks were required at the center key in the presence of red, but at a key located directly above the center key in the presence of blue. The results of both experiments indicated significant effects of both Pecking vs Not Pecking, and Sample-Specific vs Sample-Independent Responding. At the longer delays individual differences in sample-specific delay behavior were a better predictor of performance than the behavior required in the presence of the sample.     

Training child abusers in the use of positive reinforcement practices

A parent training program involving reading assignments, practice assignments, role-playing and contingent reinforcement was implemented for two parents identified as child abusers. Measures selected from the Patterson Coding System served as the dependent variables. Several constructive changes in parent-child interactions were observed, some of which were maintained for as long as five months post-training.     

Problem solving in semantically rich domains: An example from engineering thermodynamics

Recent research on human problem solving has largely focused on laboratory tasks that do not demand from the subject much prior, task-related information. This study seeks to extend the theory of human problem solving to semantically richer domains that are characteristic of professional problem solving. We discuss the behavior of a single subject solving problems in chemical engineering thermodynamics. We use as a protocol-encoding device a computer program called SAPA which also doubles as a theory of the subject's problem-solving behavior. The subject made extensive use of means-ends analysis, similar to that observed in semantically less rich domains, supplemented by recognition mechanisms for accessing information in semantic memory.     

Short-term proactive inhibition in the pigeon

Proactive inhibition in the pigeon was studied using a delayed-color-matching-to-sample task, with and without presentation of stimuli prior to the sample. Interference theory predicts that, relative to control performance, the disruptive effects of a prior stimulus should increase over a retention interval, while decay theory predicts that such disruptive effects should decrease over time. Results supported decay theory when performance was at a low level and interference theory when performance was at a high level. With performance at an intermediate level, parallel functions were obtained, an outcome supporting neither theory. It was concluded that the results supporting interference and decay theories were artifactually produced by floor and ceilling effects, respectively, and it was suggested that the results of earlier experiments using the present paradigm may well have been influenced by similar artifacts. Inserting a nondisruptive stimulus between a prior disruptive stimulus and the sample virtually eliminated the disruptive effects of the prior stimulus when tested immediately, but not when tested after 1 sec. The results of the present experiments and related findings can best be explained by either a modified decay theory (Grant, D. S. Proactive interference in pigeon short-term memory. Journal of Experimental Psychology: Animal Behavior Processes 1975, 104, 207–220) or a modified temporal discrimination theory.     

Visual masking,mental age,and retardation

Performance of retarded subjects under both forward and backward masking was less accurate than either an equivalent chronological age or equivalent mental age group of normals. It was suggested that the iconic memory impairment of retarded subjects in attributable in part to mental retardation and not simply to low mental age.     

Eliminating selective stimulus control: a comparison of two procedures for teaching mentally retarded children to respond to compound stimuli

Selective stimulus control occurs when behavior fails to come under control of all characteristics of a compound stimulus after discrimination training. Two different assessment procedures, one used in prior research and the other incorporating incorrect stimuli (S - 's) which differed minimally from the correct stimulus (S+), were used to detect stimulus control deficits characteristic of selective stimulus control. The efficacy of two training procedures in eliminating selective stimulus control observed with three trainable mentally retarded children was evaluated in Experiment 1. A training procedure using S - 's that were minimally different from the S+ was designed to reduce the probability that stimulus discriminations could be based on stimulus characteristics other than experimenter-specified characteristics defining the S+. This procedure proved more effective in preventing and eliminating selective stimulus control as measured by both assessment procedures than an alternate discrimination training procedure that failed to impact the more stringent measures of selective stimulus control. Experiment 2 indicated that these improvements in stimulus control were not a function of varying degrees of difficulty between stimulus sets or of a prior history of discrimination training with the less effective training procedure. The need for better assessment procedures to detect selective stimulus control and suggestions for further improvements in discrimination training procedures are discussed.     

Cardiac deceleration in newborns: habituation, dishabituation, and offset responses.

Twenty healthy, 1–4 day-old infants were selected from a sample of 135 neonates on the basis of alertness during testing. The infants were presented mild intensity colored light with gradual onset and offset while heart rate was monitored. Half the infants received six exposures to blue light followed by two exposures to blue-green light, whereas remaining subjects received colors in reverse order. Stimulus duration was 20 sec and variable periods between stimuli averaged 30 sec. Results of trend analysis of variance of the second-by-second cardiac data indicated that for infants older than the median age, the decelerative responses to both stimulus onset and offset were significant. Further, these subjects' onset decelerations significantly habituated within the six stimulus repetitions and significantly dishabituated with change in the stimulus color. Offset decelerations incremented over habituation trials and decremented with change in stimulus color. Responses of younger subjects were more variable which probably reflects their less complete recovery from the effects of maternal medication and the birth process.     

Comprehension,selective imitation,and the CIP hypothesis

The role of comprehension training in the selective imitation of indirect-direct object sentences was assessed for six preschool children. A modeling condition resulted in normal usage of indirect-direct object sentences for five of six subjects, but reversed usage was not obtained when modeling was reversed. Subsequent receptive comprehension training on normal and reversed forms of indirect-direct object sentences resulted in generalization to the productive mode. These results were related to an hypothesis about language acquisition in which selective imitation is a function of comprehension.     

Noticing and responding in a discrimination based on a distinguishing element

In learning a successive go/no-go discrimination between a positive display consisting of the elements A and B, and negative display consisting of A-alone, pigeons first trained to peck A shift to pecking the distinguishing B element. In order to learn whether or not the shift to B is facilitated by B's function as a signal of the reinforcer, apart from the direct reinforcement of B responses, six arrangements of the elements with respect to the food reinforcer were used. Discrete trials were terminated by a single peck or after 4 sec. The A and B elements were dots of different color. The most critical comparison was between two groups, both of which received no reinforcement for a response directed to B. In one case, B signaled the reinforcer: An A response was reinforced when B was present but not when A appeared alone. In the other, B signaled the absence of a reinforcer: An A response was nonreinforced when B was present, while the response to A-alone was reinforced. During training and in extinction many more reponses were made to B when it signaled the reinforcer than when it signaled its absence. It is concluded that in a discrimination between AB positive and A negative the shift from pecking A to pecking B is facilitated by B's role as a signal for the reinforcer even on trials in which the peck is not made to B. Results from certain other groups showed that, unless pecks shifted to B within the positive display, pecks to A continued on the negative, A-alone trials as well as on the positive AB trials.     

Response elimination in rats with schedules of omission training, including yoked and response-independent reinforcement comparisons

After rats were trained to lever press, response elimination began with factorial combinations of fixed vs variable and adjusting vs constant omission training schedules. A time interval scheduling reinforcement remained the same in a constant schedule, and its length was increased as response rate declined in the adjusting schedule. A variable time (VT) response-independent reinforcement schedule followed response elimination to test the durability of response cessation. Experiment I included groups whose reinforcement was yoked to that received by the omission schedule groups. Rate of response elimination was faster with an adjusting than a constant schedule, and slightly faster with a variable than a fixed schedule. There were no significant differences in rate of response elimination between omission schedule and yoked groups. Shorter delay of reinforcement tended to increase rate of response elimination. In the subsequent VT durability test all groups displayed near-zero response rates. In Experiment II adjusting fixed and variable omission schedules, including yoked groups, were compared with fixed time (FT) and VT reinforcement schedules. Response elimination was slower in the FT and VT groups, and they responded more in a subsequent VT durability test. It was concluded that differential reinforcement of other behavior fails to account for these omission training effects, and suggestions were made for an analysis based on the correlation between response and reinforcement rate.