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.     

Attention to components or compounds as a factor in discrimination transfer performance.

Prior to being tested with standard reversal or extradimensional (ED) shift procedures, two groups of mentally retarded subjects (MA: 4 to years) were pretrained using two different methods. The Component group received two problems which could be solved easily only by attending to the form components. The Compound group was trained on two problems requiring attention to compound color-form cues. It was assumed that the two solution modes would carry over to the third problem, which was for both groups a standard form discrimination with color variable and irrelevant within settings. The fourth problem was either an ED shift or a reversal. The Component group learned reversal faster than ED shift whereas the opposite was true for the Compound group. Subproblem analyses of ED shift performance showed dependent settings for the Component group and independent settings for the Compound group. Results are consistent with the view that compound and component solutions of discriminative problems are achieved by attention to the abstract dimensions of compounds or components and that attention to either of these dimensions can be trained at higher or lower developmental levels even though the salience of the compound dimension may be initially greater for lower level subjects.     

Cerebral asymmetry in infants.

This paper examines the intercorrelation matrix of the subtests of the Porch Index of Communication Ability using a variety of factor analytic and rotational procedures. In addition to a general factor reflecting overall language dysfunction, verbal, graphic, and gestural factors were also found which accounted for 83% of the total variance. These factors were related to Schuell's Howes', and Wepman's models of aphasia. The impact of factor analytic methodology on the conclusions drawn from the same data was also examined and suggestions for clinical use of this battery were discussed.     

Empirically derived groups in the assessment of recovery from aphasia.

This paper examines the pretreatment intercorrelation matrix of the subtests of the Porch Index of Communication Ability to derive factors reflecting components of language impairment. In addition to a general factor reflecting overall language dysfunction, five specific factors reflecting verbal competency (fluency), graphic-verbal expression, gestural-verbal expression, gestural-nonverbal comprehension, and graphic-geometric comprehension were found which accounted for 90.6% of the total variance. A cluster analysis of the five pretreatment factor scores yielded six groups which accounted for 79% of the variance for these factors. These groups were differentiated primarily in terms of impairment and showed a high rate of accuracy prediction for group membership (97.5%). These groups were extremely stable, as shown by the 75% accurate prediction rate derived from the post-treatment factor scores. The effectiveness of this model in generating homogeneous and highly discriminable groups based on objective measures of the patient's language functions indicates that classification of patients into empirical groups should be a major concern of any research design. Implications for assessing effectiveness of therapeutic intervention and the design of test battery were also discussed.     

Lateral-frontal slow potential shifts preceding language acts in deaf and hearing adults

Slow potential EEG shifts (SPSs) recorded over Broca's area and the paired contralateral site preceding cued language acts have been reported to identify the language-dominant hemisphere. A contingent negative variation paradigm SPS method was applied to the comparative study of 10 hearing adults and of 10 adult prelingually deaf persons whose first learned language was American Sign Language. Volunteers performed both language and non-language acts in both oral and manual expressive modes. The hearing group showed no lateralized SPS, failing to replicate previous reports. The deaf group showed a nonsignificant trend opposite in laterality to that of hearing groups in previous reports.     

Some aspects of language comprehension in anterior aphasia

The competency of language comprehension was evaluated in three groups: anterior aphasics, posterior aphasics, and normal control subjects. Test material was divided into two sentence groups (Fill in the Blank and True/False) emphasizing either (1) semantic, “real world,” identity words or (2) syntactic, relational words, and one paragraph interpretation task. Matching auditory and visual (written) presentations were given. The control subjects performed almost flawlessly but many errors were made by each aphasia group. Qualitative study revealed a marked difference in the comprehension problem of the two groups. The anterior aphasic group performed well on semantically weighted sentences but made errors on syntactically weighted material, regardless of mode of presentation. In contrast, the posterior aphasics made almost the same number of errors on both types of material, regardless of mode of presentation. These findings support the concept of defective language comprehension in anterior aphasia and further suggest that the defect centers on the syntactical structures which are also poorly handled in expressive output.     

Hemispheric asymmetries in human infants: Spectral analysis of flash and click evoked potentials

Evoked potentials of 16 human infants (mean age = 5.0 weeks, SD = 1.8 weeks) were recorded from the left and right, occipital and temporal areas. Spectral analysis showed a high amplitude, localized, coherent center of activity within the left temporal area for click stimuli, and a high amplitude, localized center of activity in the right occipital area for flash stimuli. It was proposed that the structured auditory information of the click and the unstructured visual information of the flash represented different degrees of familiarity to the subjects. With this hypothesis, left hemisphere involvement in stimulus processing would increase as the stimulus became more referrable to previous long- or short-term experience. Conversely, right hemisphere involvement would increase with unfamiliar stimuli which could not be readily associated with earlier data.     

Simultaneous and successive syntheses and intelligence

Recent studies on information processing have developed an alternative model of mental abilities which constitutes an integration of Russian clinical research and North American factor analytic research. This model proposes that information may be processed in a simultaneous synthesis or a successive synthesis. The present study examines variations in these syntheses in three intelligence groups in order to identify the types of information processing characteristic of different intelligence groups. A stratified sampling of verbal and nonverbal IQ was used to select 60 boys of age 9–10 in each of three verbal IQ ranges: 71–90, 91–110, and 111–130. A battery of tests used in previous research was administered to all subjects. Multivariate analyses of variance and discriminant analyses indicated that the IQ groups differed markedly on tests used to identify simultaneous synthesis, most notably Raven's Progressive Matrices, and differed slightly less on tests of successive synthesis. Factor analyses of the test intercorrelations for each group revealed more factorial invariance across the IQ groups than had been suggested by a previous exploratory study. It was concluded that strong individual differences exist in simultaneous and successive syntheses over the major portion of the standardized intelligence range, and no high degree of specialization of information processing was characteristic of an intelligence group.