Differential acquisition of conditioned suppression in rats with increased and decreased luminance levels as CS + s

Using a conditioned suppression procedure, it was demonstrated that suppression of responding was substantially enhanced when the CS signaling the occurrence of shock was an increment in luminance level (bright CS), relative to an equivalent decrement in luminance level serving as a signal for shock (dim CS). The results of a pseudoconditioning control procedure illustrated that the differential effectiveness of the bright and dim CSs was dependent upon explicit CS-US pairings. The bright and dim stimuli were found to produce equivalent rates of conditioning when they were used to signal the availability of reinforcing stimuli in an appetitive discrimination procedure. The interpretation considered to be most consistent with the data is associative in nature; rats may be brought into the experimental setting prepared to associate bright light with danger and contraprepared to associate dim light with danger.     

The perception of alternated speech

When speech is rapidly alternated between the two ears, intelligibility declines as rates approach 3–5 switching cycles/sec and then paradoxically returns to a good level beyond that point. The present study examines previous explanations of the phenomenon by comparing intelligibility of alternated speech with that for presentation of an interrupted message to a single ear. Results favor one of two possible explanations, and a theoretical model to account for the effect is proposed.     

A psychological perspective interpretation of the attitude-behavior relationship

In two experiments subjects were shown seven items that described uses for photographs taken of them with an opposite-sex black. The uses formed a graded series ranging from a situation in which only other researchers would see the photos to one in which they would be employed in a nationwide campaign for integration. Subjects were either asked to sign releases so that the photographs could actually be taken and used in the ways specified (behavior) or to indicate their hypothetical agreement or disagreement with each release as part of a survey on attitudes (attitude). In both experiments, the attitude subjects agreed to more of the releases than did the behavior subjects. This difference has been termed an attitude-behavior discrepancy by some researchers. However, in both experiments, behavior subjects judged themselves as no less prejudiced than attitude subjects and scaled agreement with each photographic release as reflecting less prejudice than did attitude subjects. These data are consistent with the interpretation that subjects changed their psychological perspectives (Ostrom & Upshaw, 1968) in order to interpret their own behaviors as attitudinally consistent.     

Moral cognition and moral action: A theoretical perspective

Considerable theoretical work has been done in the area of moral reasoning. However, little conceptual thinking has been done about the relations between moral cognition and moral action. As a result, empirical research in this area has been unsystematic and difficult to interpret. A theoretical model, the Self Model, is proposed here, starting from the assumption that moral reasons are functionally related to action. First, a concept of cognitive motivation is presented as necessary for any cognitive account of morality. Two cognitive approaches to moral conduct, Piaget's and Haan's, are then discussed in their positive contributions and in their limitations. The Self Model is finally described through a set of empirically testable propositions. Its major theoretical characteristics are: it is cognitive, recognizing as the central function of human cognition the appraisal of truth; it acknowledges a basic duality of motivation, but stresses the normative pull of cognitive motivation; it is developmental; it uses the self as the central explanatory concept, establishing both the sense of personal responsibility and the dynamism of self-consistency.     

Aphasia type and aging

We analyzed the relationship between age and clinical type of aphasia in 167 right-handed men who had suffered cerebrovascular accidents. Patients with unequivocal diagnoses as Broca's, Wernicke's, anomic, conduction, and global aphasics were considered. The median age of the Broca's group (51 years old) was significantly lower than that of the total group (55.8 years old), while the median age of the Wernicke's group was significantly higher (63 years old). Moreover the incidence of Wernicke's aphasia increased steadily with age, while incidence of the other types of aphasia peaked in the sixth decade and then diminished with increasing age.     

Retrieval processes in recall

A reaction time (RT) paradigm was developed to study retrieval processes in paired associate (PA) recall. Prior to the experimental session, subjects learned lists of PAs (varying in length from three to 24 pairs); during the experimental session, subjects' RT to say the response word from the onset of a visually presented stimulus word was measured. The implications of several classes of retrieval models were discussed in the context of this paradigm. The shape of the RT-list length function, practice, and sequential effects were all of interest in distinguishing among models. Four experiments were reported which were designed to (1) establish the baseline effects in this paradigm, (2) determine which of these effects should be attributed to the retrieval stage of processing, and (3) investigate the effect of semantic memory in this task. Results suggest that simple serial scanning models are inadequate to handle the data from this task. Strength, direct-access, or parallel processing models, on the other hand, seem to capture the qualitative effects present in our experiments. When a strength model was formalized and fit to the data from Experiment I, it was found that a two-trace version gave good quantitative fits while a one-trace version did not, suggesting that both short- and long-term memory independently contribute in this task.     

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.     

Central capacity limits in consistent mapping,visual search tasks: Four channels or more?

The issue of limits in central processing capacity is of long-standing interest to psychologists. Some behaviors appear to draw on limited resources, others appear to have no resource limits. The existence of behaviors which do not compete for limited resources is suggested by the results from visual search experiments which keep constant the mapping of stimuli to responses. Behavior in such experiments is referred to as automatic detection. Results are reported which suggest, unlike the above, that resources are really quite limited in consistent mapping, visual search tasks. The results from this study (and other studies) are in agreement with a model of visual information processing behavior which assumes that the maximum number of cognitive comparison operations which can be executed simultaneously is restricted to somewhere in the neighborhood of four (the exact number depending on the subject). The model makes a strong prediction about the relation between the rate of stimulus presentation and accuracy, a prediction which is supported by the results. It is tentatively proposed that the steady-state, limited-channel model developed here may provide the beginnings of an integrated treatment of certain key results from subitizing and iconic memory experiments as well as visual search experiments.     

Stimulus-reinforcer and response-reinforcer relations in the control of conditioned appetitive headpoking (“goal tracking”) in rats

Experiment 1 studied the effect of several Pavlovian appetitive conditioning procedures on rats' headpoking into a food tray (goal tracking). The procedures included forward delay conditioning, CS-alone extinction, differential conditioning, and simultaneous compound conditioned inhibition training. In general, the headpoke behaved in all of these treatments much like a Pavlovian CR; however, one could also say that the headpoke behaved like an adventitiously reinforced operant for which the CS was an S^D. Experiment 2, therefore, used the differential-nondifferential technique (E. Gamzu & D. R. Williams, Science, 1971, 171, 923–925), and Experiment 3 used an omission technique (F. D. Sheffield, in W. F. Prokasy, Ed., Classical conditioning, New York: Appleton-Century-Crofts, 1965; D. R. Williams & H. Williams, Journal of the Experimental Analysis of Behavior, 1969, 12, 511–520), to try to separate the role of stimulus-reinforcer and response-reinforcer relations in controlling the headpoke. These techniques proved inadequate. The results of Experiment 2 could be given either operant or Pavlovian interpretations. Those of Experiment 3 showed that headpoking is dominated by response-reinforcer, rather than by stimulus-reinforcer, relations when the two compete but forced no conclusion about which dominates when the two act together as in acquisition. Implications for pigeon autoshaping are discussed.