Modification of Type A behavior through aerobic exercise

This psychophysiological evaluation of an aerobic exercise program examined specifically whether aerobic training modified Pattern A for those individuals at behavioral risk for developing coronary heart disease, i.e., young Type A individuals. At pretest and posttest of this secondary prevention study, Type A and Type B subjects were assessed in three conditions: aerobic exercise program, nonaerobic activity (Aikido, a martial art) control, and notreatment control. After 10 weeks, Type A but not Type B subjects exhibited lower Pattern A behavior in the aerobic program than in control conditions. Average workout pulse rates and differentially reliable increases in aerobic capacity indicated that aerobic training was indeed aerobic, whereas aikido activity was not. Even though selected nonaerobic factors, such as locus of control and group participation, did not mediate the Pattern A decrease for Type A's when comparing aikido and aerobic conditions, changes in aerobic capacity may have been the mediator. Generalizability of the results and implications for theoretical development and clinical intervention are discussed.     

Structure and process in semantic memory: new evidence based on speed-accuracy decomposition

Reaction-time and accuracy data obtained from studies of sentence verification have not been rich enough to answer certain important theoretical questions about structures and processes in human semantic memory. However, a new technique called speed-accuracy decomposition (Meyer, Irwin, Osman, & Kounios, 1986) may help solve this problem. The technique allows intermediate products of sentence verification to be analyzed more precisely. Three experiments with speed-accuracy decomposition indicate that verification processes produce useful partial information before they are completed. Such information appears to accumulate continuously at a rate whose magnitude depends on the degree of relatedness between semantic categories. This outcome is consistent with continuous computational (e.g., semantic-feature comparison) models of semantic memory. An analysis of reaction-time minima suggests that a discrete all-or-none search process may also contribute at least occasionally to sentence verification. Further details regarding the nature of these processes and the memory structures on which they operate can be inferred from additional results obtained through speed-accuracy decomposition.     

Long-term memory formation in chicks is blocked by 2-deoxygalactose, a fucose analog

When day-old chicks are trained on a passive avoidance task there is enhanced synthesis of glycoproteins. Bilateral intracerebral injections of 20 mumole of 2-deoxygalactose (2-D-gal), administered just before and just after training on the task, produce amnesia for the avoidance. Amnesia develops slowly over the first hour and persists for at least 24 h subsequently. If 2-D-gal injections are administered 4 h prior to the training or delayed for 3 h after training, no amnesia occurs. Apart from a brief initial suppression of pecking following injection there are no effects of 2-D-gal on other observed behaviors of the birds. Within the first hour this dose of 2-D-gal inhibits [3H]fucose incorporation into acid-insoluble material by 26% (or 68%, calculated relative to free pool fucose). The amnestic effect of 2-D-gal is not shown by galactose, glucose, fucose, or 2-D-glucose. Injecting 40 mumole of galactose simultaneously with the 2-D-gal abolishes the 2-D-gal-induced amnesia; 40 mumole of fucose, however, does not abolish the amnesia. The utility of 2-D-gal as an agent for analyzing the role of glycoproteins in memory formation is discussed.     

Hippocampal associative cellular responses: dissociation with behavioral responses revealed by a transfer-of-control technique

Multiunit activity was recorded in the CA3 field of the dorsal hippocampus in freely moving rats during classical conditioning and subsequent presentation of the CS on operant baselines for food reward as well as shock avoidance. Rats were first trained in a nonsignaled bar-pressing-dependent shock omission task and in a food-motivated lever-pressing task (60-s VI). Five sessions with presentations of a previously habituated tone as a CS paired with footshock as a US were then given. Testing was carried out by presenting the CS alone while behavioral responses were maintained by reinforcement in both instrumental tasks on alternate sessions. As expected, the CS induced a marked suppression of lever pressing for food reward and a marked enhancement of bar-pressing for shock avoidance. The analysis of the frequency of multiunit discharges to the CS revealed that the hippocampal cellular responses established during classical conditioning were maintained while two different behavioral responses were exhibited to the CS. The results showed that the associative response of hippocampal neurons may be dissociated from the Pavlovian conditioned responses the CS elicits. They support the hypothesis that hippocampal cellular responses represent a neural index of the acquired CS-US associative representation.     

Eyeheight-scaled information about affordances: a study of sitting and stair climbing

Previous work has shown that both the perceived and actual critical (maximum) heights of surfaces that afford "sitting on " and "climbing on" can be expressed as constant proportions of each actor's leg length. The current study provides evidence that these judgments of critical action boundaries are based on an existing source of size and distance information that is already scaled with reference to the actor's eyeheight. In Experiment 1 changes in judgments of "perceived eyeheight" (an index of the intrinsic scalar) as a function of viewing distance were shown to be highly correlated with changes in the maximum height that was perceived to afford sitting on or climbing on. In Experiments 2 and 3 observers wore 10-cm blocks and made judgments about whether the heights of various surfaces afforded sitting or climbing. The use of eyeheight-scaled information as the basis for their estimates predicted the obtained pattern of errors in these judgments. With a modicum of experience wearing the blocks, however, observers were able to retune accurately their critical action boundary to a degree that would not have been predicted from their consistent overestimation of the height of the block on which they were standing. These results have implications for understanding how observers obtain information about their specific action boundary.     

Rigidity in cinema seen from the front row, side aisle

Pictures and cinema seen at a slant present the optics of virtual objects that are distorted and inconsistent with their real counterparts. In particular, it should not be possible for moving objects on slanted film and television screens to be seen as rigid, at least according to rules of linear perspective. Previous approaches to this problem have suggested that some process (perhaps cognitive) rectifies the optics of objects in slanted pictures to derive true shape and preserve shape constancy. The means for this rectification is usually thought to be based on recovery of true screen slant. In three experiments I show that this account is unnecessary and insufficient to explain the perception of rotating, rectangular objects in slanted cinema. I present data in favor of an alternate view, one in which the information is sufficient for perceivers to determine rigidity in an object on slanted screens, at least for parallel projections. In the human visual system, local measurements of objects are apparently made according to projective geometry; in those measurements, small amounts of certain distortions in projection are tolerated. Stimuli that appear nonrigid are ones that violate certain local principles, known as Perkins's laws, of projections of rectangular solids.     

Perceptual normalization of vowels produced by sinusoidal voices

When listeners hear a sinusoidal replica of a sentence, they perceive linguistic properties despite the absence of short-time acoustic components typical of vocal signals. Is this accomplished by a postperceptual strategy that accommodates the anomalous acoustic pattern ad hoc, or is a sinusoidal sentence understood by the ordinary means of speech perception? If listeners treat sinusoidal signals as speech signals however unlike speech they may be, then perception should exhibit the commonplace sensitivity to the dimensions of the originating vocal tract. The present study, employing sinusoidal signals, raised this issue by testing the identification of target /bVt/, or b-vowel-t, syllables occurring in sentences that differed in the range of frequency variation of their component tones. Vowel quality of target syllables was influenced by this acoustic correlate of vocal-tract scale, implying that the perception of these nonvocal signals includes a process of vocal-tract scale, implying that the perception of these nonvocal signals includes a process of vocal-tract normalization. Converging evidence suggests that the perception of sinusoidal vowels depends on the relation among component tones and not on the phonetic likeness of each tone in isolation. The findings support the general claim that sinusoidal replicas of natural speech signals are perceptible phonetically because they preserve time-varying information present in natural signals.     

Strategies for visual word recognition and orthographical depth: a multilingual comparison

We investigated the psychological reality of the concept of orthographical depth and its influence on visual word recognition by examining naming performance in Hebrew, English, and Serbo-Croatian. We ran three sets of experiments in which we used native speakers and identical experimental methods in each language. Experiment 1 revealed that the lexical status of the stimulus (high-frequency words, low-frequency words, and nonwords) significantly affected naming in Hebrew (the deepest of the three orthographies). This effect was only moderate in English and nonsignificant in Serbo-Croatian (the shallowest of the three orthographies). Moreover, only in Hebrew did lexical status have similar effects on naming and lexical decision performance. Experiment 2 revealed that semantic priming effects in naming were larger in Hebrew than in English and completely absent in Serbo-Croatian. Experiment 3 revealed that a large proportion of nonlexical tokens (nonwords) in the stimulus list affects naming words in Hebrew and in English, but not in Serbo-Croatian. These results were interpreted as strong support for the orthographical depth hypothesis and suggest, in general, that in shallow orthographies phonology is generated directly from print, whereas in deep orthographies phonology is derived from the internal lexicon.     

Intimate homicide: An analysis of violent social relationships

Homicide which occurs in intimate social relationships was studied using data from three Western Canadian cities. Variables which may be related to the relationship and homicide are also examined. Unstable relationships are clearly differentiated from other relationships and are more likely to result in homicide. Implications for future research are discussed.