Modeling semantic memory: Effects of presenting semantic information in different modalities

How is semantic information from different modalities integrated and stored? If related ideas are encountered in French and English, or in pictures and sentences, is the result a single representation in memory, or two modality-dependent ones? Subjects were presented with items in different modalities, then were asked whether or not subsequently presented items were identical with the former ones. Subjects frequently accepted translations and items semantically consistent with those presented earlier as identical, although not as often as they accepted items actually seen previously. The same pattern of results was found when the items were French and English sentences, and when they were pictures and sentences. The results can be explained by the hypothesis that subjects integrate information across modalities into a single underlying semantic representation. A computer model, embodying this hypothesis, made predictions in close agreement with the data.     

Figural emphasis and person perception

Based on Jones and Nisbett's (1972) proposition that actor-observer differences in causal attributions derive from differences in attentional focus, it was hypothesized that observers' focus of attention would influence their causal attributions for an actor's behavior. More specifically, it was predicted that the behavior of an actor who was the focus of attention by virtue of some salient physical attribute would be attributed by observers more to dispositional causes and less to situational causes than would the behavior of a less physically salient actor. The manipulations of physical salience were based upon Gestalt laws of figural emphasis in object perception. They included brightness (Study I), motion (Study II), pattern complexity (Study III), and contextual novelty (Studies IV and V). The results revealed that the salinece of the actors' environments (i.e., the other people present) rather than the salience of the actor him/herself had the most consistent influence on causal attributions. When environmental salience was high, behavior was attributed relatively more situationally than when it was low. Prior research findings are considered in light of the proposition that causal attributions for an actor's behavior vary only with the salience of his/her environment, and additional implications of this phenomenon are suggested. Some ambiguities in the application of Gestalt principles to the perception of people are discussed.     

The processing of fundamental frequency in a dichotic matching task

The temporal characteristics of auditory memory were investigated using a reaction time paradigm. The study attempted to determine whether or not there are functionally distinct left and right hemisphere components of auditory memory with different capacities for the retention of nonlinguistic information, such as fundamental frequency, over the course of several seconds. The results indicated that fundamental frequency information in auditory memory remains substantially unchanged over the course of 2 sec. No evidence was found for the existence of separate left and right hemisphere components of auditory memory with different temporal characteristics. The implications of this finding for the organization of auditory memory in the brain are discussed.     

Heart rate conditioning in the newborn infant

In an attempt to condition heart rate in newborns, 21 infants were assigned to Conditioning, Random Control, and Backward Conditioning Groups. During training trials, the Conditioning Group received an eight-second tone (CS), a six-second ISI, and a ten-second presentation of glucose via nipple (UCS) that overlapped the last two seconds of tone. The Random Control Group received tones at the same intertrial intervals as the Conditioning Group, but glucose varied randomly. The Backward Conditioning Group received glucose during the ten seconds immediately preceding tone onset. The response to both CS and UCS during base trials was HR acceleration. The response to tone habituated in all groups, but the acceleration to glucose was maintained throughout conditioning. Although no conditioned response to the tone developed over trials, a large HR deceleration appeared during extinction to the absence of the UCS in the Conditioning Group only. This deceleration was interpreted as an orienting response to the absence of an expected event.     

Children's binary prediction of partially learnable sequences followed by an all-correct procedure

Six groups of 20 subjects each were run individually in a binary prediction situation with each alternative occurring equally often. Two age groups were employed; subjects were either in second or sixth grades. For one-third of the subjects at each age level, the events occurred in runs of either two or six; another third observed events which occurred in runs of either five or six; the other subjects received a random sequence of events. All subjects then received an additional 50 trials in which every prediction was correct. The results indicated some sensitivity to run length characteristics. Fewer errors of all types were made in the prediction of 5–6 sequences. The verbal reports and all-correct trial protocols revealed that at least the sixth graders employed some simple run length structure rules, although many instances of runs other than those presented in training occurred, showing much processing error. The results were discussed in terms of a general limited-capacity model of information-processing.     

The identification of stuttering: Can you look and tell

This investigation focussed on how observers identify stutterers. It was found that stutterers are identified most correctly under visual circumstances as compared to auditory and combined auditory-visual conditions. Therefore, the reduction of stuttering should include removal of noticeable, interfering, and unnecessary nonverbal behaviors, particularly mouth and nostril movements.     

Choice times and Spence's discrimination learning theory

In two experiments, rats acquired brightness discriminations in a free-operant circular runway with two response alternatives. Both individual and group choice times revealed continuous changes that were not apparent in the discrete measure of choice. Two major assumptions of Spence's discrimination learning theory were confirmed: (a) learning is continuous, and (b) discriminative stimuli in simple discrimination tasks of both simultaneous and successive types are compounds with position elements as well as elements from the relevant visual dimension. The distinctive, consistent pattern of learning revealed by the choice-time measure suggests that position habits reflect a learning strategy in which the complex task is learned as a series of simpler ones.     

Socialization and career orientation among black and white college women

In a study of career orientation among black and white college women, support was found for hypotheses derived from postulates of Rotter's Social Learning Theory. Compared to whites, (1) blacks were less likely to expect the level of work involvement preferred; (2) blacks expected more employment; and (3) blacks were more likely to prefer less employment than they realistically expected. Antecedents of career expectation were categorized as internal, external, or neutral. As hypothesized, variables expressive of external control predicted level of career expectation among blacks, whereas variables expressive of internal control predicted high career expectations among whites.     

Fixed and optional stopping models for two-choice discrimination times

Several current models for choice- or discrimination-time experiments represent the stimulus as a sequence of independent and identically distributed observations. This paper develops and compares models based on two different stopping rules that a subject might use to terminate his sampling process and convert his perceptual evidence into an observable response. The fixed and optional stopping rules yield different predicted forms for the speed/accuracy tradeoff function and for the relation between mean and variance of response times. These predictions are developed in the general case and then specialized for certain conditions of symmetry, so that the expressions are easier to apply and to compare between models. A later section considers how changes in stopping criteria (either between or within experimental trials) affect predictions about mean response times for correct responses and errors, and then uses these ideas to relate the optional stopping rule for the Random Walk models to those of the Accumulator models. A final section considers specialized models for stimulus detection and intensity discrimination that assume Poisson-distributed sensory input, and relates these models to the present fixed stopping model.     

Evidence for a developmental shift in the basis for memory organization

Using a false recognition procedure, either with or without instructions to facilitate Synonym or Antonym encoding, 128 second- and sixth-grade boys and girls were tested. The results indicated that there were no grade or sex differences in generalization errors to synonyms or antonyms under neurtral learning instructions, but that facilitative instructions interacted with grade level. Under instructions to facilitate synonym encoding, second graders showed a marked increase in synonym errors. On the other hand, under instructions to facilitate antonym encoding, sixth graders showed an increase in antonym errors. In addition, association strength was directly related to the magnitude of the generalization errors in both grades. The results are discussed in terms of age-related shifts in the basis underlying the organization of verbal memories.