Frequency and coding responses in verbal discrimination learning

Ss were given a verbal discrimination task where correct and incorrect stimuli appeared in one, two. or four different pairs in a within-Ss design. For a group tested with the usual anticipation procedure, correct repetitions helped and incorrect repetitions hurt performance. The pattern of results suggested that frequency is a salient cue in verbal discrimination learning but that coding or paired-associate processing may occur at the same time. Data from a second group of Ss for which frequency was a less salient cue gave more direct evidence for coding.     

Imagery and sentence mediators in verbal discrimination learning

The effect of instructions to use imagery and sentence strategies in verbal discrimination learning (VDL) was investigated in two experiments. In Experiment I, both imaging to and constructing a sentence for the correct item of each pair facilitated VDL relative to an uninstructed control condition. Incorporating both words of the pair into a compound image or compound sentence had no effect, a result that was replicated in Experiment It. Of the two compound instructions, only compound sentences consistently facilitated associative recall of the VDL pairs, suggesting that compound imagery instructions were not always adhered to by the Ss.     

The rights and wrongs of consequentialism

I argue that the strongest form of consequentialism is one which rejects the claim that we are morally obliged to bring about the best available consequences, but which continues to assert that what there is most reason to do is bring about the best available consequences. Such an approach promises to avoid common objections to consequentialism, such as demandingness objections. Nevertheless, the onus is on the defender of this approach either to offer her own account of what moral obligations we do face, or to explain why offering such a theory is ill-advised. I consider, and reject, one attempt at the second sort of strategy, put forward by Alastair Norcross, who defends a ‘scalar’ consequentialism which eschews the moral concepts of right, wrong and obligation, and limits itself to claims about what is better and worse. I go on to raise some considerations which suggest that no systematic consequentialist theory of our moral obligations will be plausible, and propose instead that consequentialism should have a more informal and indirect role in shaping what we take our moral obligations to be.     

The imagery effect and phenomenal background frequency in verbal discrimination learning

A series of four experiments was conducted to assess the role of phenomenal background frequency in verbal discrimination learning and its possible involvement in the imagery effect. The initial two experiments produced a reliable imagery effect for mixed and unmixed lists with respect to concreteness of pair members, regardless of phenomenal frequency manipulations, with words high in objective background frequency. No effects were found for phenomenal background frequency. Experiment 3 involved phenomenal frequency ratings for 200 abstract and 200 concrete words. Experiment 4 evaluated the role of phenomenal background frequency for a mixed list using words low in objective frequency. A reliable imagery effect was again found with no effects for phenomenal frequency. An alternative hypothesis involving differential accrual of situational frequency to abstract and concrete items during verbal discrimination learning to explain the imagery effect was also tested by Experiment 4 but was not supported by the data.     

Cue selection in verbal discrimination learning of retarded subjects.

A series of experiments was conducted to examine cue function in trigram verbal discrimination learning by retarded subjects. The issue was to determine the factors that control attention in this type of learning situation. The two variables of chief interest were trigram meaningfulness and reinforcement history. The major general conclusion was that retarded subjects employ complex cue selection strategies in solving a verbal discrimination involving compound verbal stimuli. Major findings were as follows: (a) Retarded subjects exhibit a response bias in favor of words over nonsense trigrams; (b) relatively little active cue selection based on meaningfulness was observed; (c) a compound stimulus discrimination was more difficult to learn than a discrimination involving single verbal stimuli; (d) compound and single stimuli may be processed differently in original discrimination learning; (e) cue position probably controls attention in compound discrimination learning; and (f) a frequency theory of verbal discrimination learning is supported by these data.     

Differences in factor content of rights and wrongs scores

The right-response scores and wrong-response scores of speeded aptitude tests were factor analyzed to determine whether they differ in factorial content. The information thus obtained was used to derive scoring formulas that yield purer measures of a factor than do scoring formulas derived in other ways.This paper is a revision of a dissertation submitted in partial fulfillment of the requirements for the Doctor of Philosophy degree at the University of Southern California, 1948, and a paper read to the American Psychological Association in September, 1949. The writer is greatly indebted to Dr. J. P. Guilford for providing the intercorrelation and distribution data from the files of the School of Aviation Medicine and for general guidance throughout the study. He also wishes to express his appreciation to T/Sgt. Frank C. Ivens and Sgt. James R. MacDonald for computational assistance in the extraction and rotation of the centroid factors, which were performed while the writer was a civilian employee of the Air Training Command, Human Resources Research Center. The opinions expressed are those of the writer and do not necessarily reflect the official views of the USAF.     

Center median "alerting" and verbal learning dysfunction

Previous data have shown that stereotaxic center median lesions alone or lesions in the amygdala, unilateral left and right and bilateral, do not impair verbal paired-word associates learning. However, “interactional” combined lesions in the amygdala and center median nucleus on the left side result in a significant decrease in test scores. Analysis of the types of errors made postoperatively by the six patients with this lesion combination indicates the persistence over trials of misnaming errors vs errors of omission. These findings are compatible with hypotheses of an alerting function performed by medial thalamic structures which, for effective learning, cosponsor attention to stimulus cues. Defective alerting is held to result in faulty labeling and subsequent mismatching (see Ojemann, 1975, Brain and Language, 2, 101–120, and Fedio &; Van Buren, 1975, Brain and Language, 2, 78–100).     

Phenomenal background frequency and the concreteness/imagery effect in verbal discrimination learning

College students gave frequency ratings for concrete and abstract words which were equated on normative frequency. The results replicated the finding of Galbraith and Underwood (1973) that abstract words are perceived to be higher in frequency than concrete words. Different subjects then learned verbal discrimination lists consisting of both abstract and concrete pairs. While the usual concreteness effect was obtained when abstract and concrete items differed widely on phenomenal frequency, it disappeared when these items were equated on perceived frequency. The finding that appropriate frequency manipulations can eliminate the concreteness/imagery effect, coupled with similar findings for other stimulus characteristics, lends strong support to the frequency theory of discrimination learning.     

Simultaneous paired associate and verbal discrimination learning as a simulation of the double-function list

In the critical condition, the subject was required to learn associations between words in the pairs and to learn to identify simultaneously the word in each pair that had been underlined on study trials. Over trials, both types of responding were required for each pair. Control conditions were used to assess the influence of these procedures. Paired associate learning was only modestly impaired, but the verbal discrimination learning (identifying the underlined word) appeared comparable to that for a double-function verbal discrimination list. The correlational evidence indicated that insofar as the present procedures simulated a double-function list, the association between the words in a pair is not involved in a causal way for the small amount of learning that occurs across trials in a double-function list.     

Individual differences in the functional neuroanatomy of verbal discrimination learning revealed by positron emission tomography

Why do some people have better memory abilities than others? This issue has been of long-standing interest to scientists and lay people. However, using purely behavioral methods, psychologists have made little progress in illuminating it. Now that functional brain imaging techniques have become available to study mind/brain relations, there is a new promise of understanding individual differences in learning and memory in terms of corresponding differences in brain activity. In this paper, we will present a positron emission tomography (PET) study designed to examine individual differences in learning and memory abilities. The basic assumption is that different patterns of brain activity serve as strong predictors of memory performance. Two specific questions were addressed in this study: (i) Can PET illuminate the relations between memory processes and their neuroanatomical correlates among individual learners and rememberers? and (ii) if so, how are these relations affected by the stage of practice on a given memory task? Our PET study examined individual differences in the neuroanatomical correlates of multi-trial verbal discrimination learning in 16 young healthy subjects. The results identified patterns of brain regions in which blood flow correlated with subjects' retrieval performance. However, these regions did not correlate with performance during all learning trials. Instead, a gradual shift was observed from one pattern of brain regions to another over the course of learning. These results suggest that individual differences in memory performance are related to differences in neural activity within specific brain circuits.