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.     

Recognition memory of retrieved sequences of words

The subject was asked to retrieve words belonging to a given category, natural or artificially created. After n words were retrieved, a recognition task was given either immediately after or after a delay (4 hours, 7, 14, or 28 days). Several probe words were presented and the subject had to decide whether each had been retrieved or not. The length of retrieval sequence, n, was systematically varied. Results of three experiments showed that, in general, mean decision time was almost independent of n. Namely, recognition regarding self-generated lists of words seems to be due to a different information processing than recognition regarding lists of words presented by the experimenter to memorize. Implications of the findings for retrieval from long term memory were discussed.     

Effects of question type and experimenter position on bilateral differences in electrodermal activity and conjugate lateral eye movements

28 dextral males participated in a within-subjects experiment which tasted for the effects of question type (verbal versus spatial) and experimenter-position (in front of or behind the subject) on direction of conjugate lateral eye movements (LEMs) and bilateral differences in skin conductance responses (SCRs). Question dependent asymmetries were observed for LEM direction but not for SCR magnitude. Experimenter-position had no significant effect. The results for LEM direction are consistent with the hypothesis linking eye movements to the left or right with activation of the cerebral hemisphere contralateral to the direction of gaze. The results for SCR magnitude, given certain assumptions, can be reconciled with a hemispheric model of contralateral excitatory control of that system.     

Infant pattern vision: A new approach based on the contrast sensitivity function

Current approaches to the study of infant pattern vision have yielded interesting findings but have not yielded a set of data or principles from which general predictions can be drawn. We propose an alternative approach based on measurements of the contrast sensitivity function (CSF). This approach has been successfully applied to the study of adult vision. In principle, the approach allows one to predict the detectability of a wide variety of two-dimensional patterns if one knows the observer's CSF. Two experiments were conducted. In Experiment 1, CSFs of 1-, 2-, and 3-month infants were measured using a fixation preference paradigm. The results indicated noteworthy development between 1 and 3 months particularly in sensitivity to high spatial frequencies (fine stripes). The low-frequency attenuation characteristic of adult vision is observed at 2 and 3 months but not always at 1. In Experiment 2, CSFs of 2-month infants were measured at a lower luminance level. The results indicated that low-frequency attenuation became less pronounced as would be predicted if it were a manifestation of lateral inhibitory processing. The manner in which the CSF can be used to make general predictions is described. The CSFs of Experiment 1 are then used to successfully predict infants' detection of patterns used in two frequently cited experiments. We also propose a simple model of infant pattern preference and show that the model accurately predicts the results of a number of well-known experiments.     

The self-attention-induced feedback loop and social facilitation

It has been proposed that self-directed attention leads to the engagement of a cybernetic feedback loop, by which discrepancies between present behavior and a standard of comparison are reduced. This analysis is applied to performance facilitation effects, which are more typically explained in terms of drive theories. Though these two approaches to motivation make similar behavioral predictions in this context, they assume different mediating states. Support is noted for the assumptions that mirror presence and audience presence induce self-focus, and that they lead to comparison with salient behavioral standards. Support for the assumption that these manipulations increase arousal is also reviewed, and is challenged on methodological grounds. The attentional analysis is used to derive predictions regarding changes in physiological state over the course of a typical social facilitation procedure. An experiment is reported which confirmed these predictions. Discussion centers on how to interpret physiological changes in terms that are compatible with control theory, how to account for social impairment phenomena in terms of the present model, and the conceptual relationship between mirror presence and audience presence as experimental manipulations.     

Intelligence and teachers' ratings as predictors of abstract and concrete learning

This study concerned the prediction of children's learning with an individual measure of intelligence and teachers' evaluations. Eight abstract and eight concrete nouns were paired with nonsense geometric figures and presented to 60 elementary school children in a three-trial paired-associate (PA) learning task. Subjects' IQ scores on the Wechsler Intelligence Scale for Children-Revised and teachers' ratings of learning proficiency were used to predict children's performance on the PA task. Multiple correlations favored abstract learning with verbal scale intelligence, accounting for the majority of the variability. Teachers' ratings provided a surprising degree of predictive efficiency for abstract recall which was redundant with verbal intelligence.     

Multiple sessions of systolic blood pressure biofeedback: Its effects on ability to control systolic pressure during training,after training,and its effects on pulse rate

Seventy-one normotensive subjects participated in four training sessions in which they were either (a) instructed to increase their blood pressure, (b) instructed to decrease their blood pressure, or (c) not instructed to change their blood pressure. The subjects either (a) were provided with biofeedback concerning systolic blood pressure or (b) were not provided with biofeedback concerning systolic blood pressure. After the last training session, subjects participated in a transfer session in which they were again instructed concerning changes in pressure but were not provided with biofeedback. Analyses conducted on data from the training and transfer sessions indicated that subjects who were instructed to increase pressure and given biofeedback to aid them showed higher pressure than subjects in other conditions and that there were no differences among those other conditions; that is, biofeedback was effective for teaching subjects to increase pressure but was not effective for teaching subjects to decrease pressure. Additional training sessions did not add to the effect achieved in the first training session. During training sessions, subjects who were instructed to increase pressure showed higher heart rates than subjects in other conditions. The results raise questions concerning the interpretation of earlier experiments that did not include no-treatment, instructions-only, and attention control conditions.