Evidence for independent parallel channels in tachistoscopic perception

This paper reviews the implications of a number of experimental results for a test between two different types of models of perceptual processing: models that assume a limitation of perceptual capacity vs models that postulate independent, parallel perceptual channels. The results of recent “detection” experiments (e.g., Estes & Taylor, 1966) have been consistent with the limited-capacity model developed by Rumelhart (1970). The same results, however, are predicted by the “ICC” independent-parallel-channels model, an extension of work by Eriksen and Spencer (1969) developed in the present paper. This model emphasizes the interaction of two factors: decisional properties of the detection task, plus perceptual confusion phenomena known to occur under tachistoscopic conditions.Two experiments relevant to a test between the ICC and Rumelhart conceptions are reported. Experiment I involved a “time-sharing” paradigm that varied the demands of two detection tasks performed within a single trial. Experiment II involved the elimination of certain perceptual confusion phenomena. The results of Expts I and II appeared consistent with the ICC model but inconsistent with the Rumelhart model. After consideration of alternative limited-capacity models, it was concluded that: (1) a decision-confusion interaction is a necessary component of information-processing models, and that (2) the ICC independent-parallel-channels model is sufficient to account for the broad spectrum of experimental results reviewed.     

Factors contributing to the effectiveness of social and nonsocial reinforcers in the discrimination learning of children from two socioeconomic groups

Middle- and lower-class children who had been treated by E in a warm or aloof manner were given a discrimination learning task under one of six conditions forming a 3 × 2 design: three reinforcement types (Verbalintoned, Verbal-nonintoned, or Symbolic) and reinforcement for correct or incorrect responses. In accordance with Zigler's valence theory of social reinforcement, lower-class girls and middle-class children of both sexes tended to perform better when they had previously received warm treatment. No significant differences among the three types of reinforcers occurred in either SE group, thus failing to support the implications of several theories about the relative effectiveness of social and nonsocial reinforcers and tonality factors related to SES.     

Cognitive tuning and receptivity to novel information

An experiment was conducted to test the hypothesis that cognitive tuning would cause receivers to be more receptive to novel than to familiar information, compared to transmitters. The information receptivity of transmitters and receivers was contrasted against a control group. The influence of the source and audience, possible limits on the influence of the tuning set, was also explored. Finally, amount of variance controlled by cognitive tuning, personality variables and information utility were examined.While the results strongly support the prediction that transmitters prefer familiar information, receivers and control group subjects did not significantly differ in preferences for novel information. The anticipated expertise of source or audience had no influence on information receptivity. Among the three sets of variables used, the greatest amount of variance was explained by information utility, followed by cognitive tuning and personality measures, though all three variables controlled a significant amount of variance.     

Semantic and acoustic processing in free and cued recall by educable mentally retarded adolescents

The abilities of educable mentally retarded adolescents to encode and retrieve words with semantic and acoustic cues were investigated in a free and cued recall task. On each of three trial blocks, seven groups of subjects were presented 20 unrelated stimulus words. Groups received either semantic, acoustic, or no encoding cues along with the stimuli. Free recall was requested from all subjects, followed immediately by a second period of either free recall or cued recall with the semantic or acoustic cues. Semantic cues were most effective when presented both at encoding and retrieval. The subjects were unable to use acoustic information as effective retrieval aids. Results were discussed in terms of encoding dimension dominance and mediational deficiencies.     

Clustering by aphasics in free recall

Aphasic performance was compared to normal and left hemiplegic controls in the use of clustering to aid recall of a list of words in a multitrial free recall experiment. Use of clustering correlated with increased recall scores. Left hemiplegic performance was superior to aphasic and inferior to normal suggesting that the presence of brain damage decreased clustering but that this decrease was greater in the presence of aphasia. A second experiment examined the possibility of remediating aphasic clustering behavior by providing cues as a training device. Cues, which aided normals, did not benefit the majority of aphasics. Results are interpreted in terms of their relationship to cognitive functioning.     

Maintenance and generalization of trained metamnemonic awareness by educable retarded children

The majority of educable retarded children (young group, MA 6; old group, MA 8) required to estimate their memory span was found to be unrealistic estimators. Following training in span estimation the older subjects improved under both explicit and implicit feedback conditions, while younger children only benefited from explicit feedback. Three posttests of the effects of training revealed long-term (1-year) maintenance of training for older subjects but younger subjects showed post-test improvement only on an immediate test. While long-term maintenance was found for older subjects, generalization to similar span-estimation tests was not found. The utility of training metamnemonic knowledge which does not generalize was questioned and alternate training procedures were proposed.     

The efficacy of progressive relaxation in systematic desensitization and a proposal for an alternative competitive response--the relaxation response.

The theoretical basis of systematic desensitization is reciprocal inhibition in which an alternative, competitive response to anxiety is conditioned to arousal-producing, phobic stimuli. Abbreviated training in progressive relaxation is believed to serve as a competitive response to anxiety by decreasing autonomic nervous system activity. However, physiologic studies of progressive relaxation have not substantiated that its practice is associated with such decreased autonomic activity. Consequently, the use of progressive relaxation has been a confounding factor in the determination of the function of reciprocal inhibition in systematic desensitization. To confirm and refine the theoretical constructs of reciprocal inhibition, it is necessary to test the effects of a response which is competitive to the anxiety response. Such a response may be the relaxation response which is characterized by physiologic changes consistent with decreased autonomic nervous system activity. Derived from meditational practices, techniques which ehcit the relaxation response incorporate the element of focused attention which has been implicated as a critical factor in systematic desensitization. Thus, the use of the relaxation response should be a more appropriate method than progressive relaxation if the therapeutic usefulness of systematic desensitization is indeed due to reciprocal inhibition.     

Choice behavior of rats searching for food

The experiments reported here were designed to determine if several general principles drawn from appetitively motivated discrimination experiments in standard laboratory apparatus might also apply to food-searching behavior under more naturalistic conditions. Food-deprived rats searched for food in an open observation area. Choice behavior after finding food and after not finding food was analyzed. In all cases, not finding food in a possible food location was sufficient to direct subsequent search behavior away from that location for the remainder of the day's test. Finding food had variable effects on subsequent choice behavior, depending on the number of locations that actually contained food and the number of days food was in one location before being shifted to another. The results indicate that the rat's search strategy was influenced by food availability and distribution in ways that are predicted by discrimination learning experiments.     

Influence of aging on recovery from aphasia in polyglots

We analyzed patterns of recovery, according to the rules of Pitres [1895, Revue de Medecine (Paris), 15, 873–899] and Ribot (1881, Les Maladies de la Memoire, Paris: Libraire Germer Baillere et Cie, pp. 146–147), in polyglot aphasics divided into subgroups by age. The rule of Ribot did not apply predictably for any age group. Pitres' rule clearly applied, but only for the nonelderly groups. Aging and its concomitant deterioration of recent memory seem to influence patterns of recovery from aphasia in polyglots.