S-R compatibility between response position and destination of apparent motion: Evidence of the detection of affordances.

In choice reaction time, stimuli and responses in some combinations (e.g., based on spatial arrangement) are faster than in other combinations. To test whether motion toward a position yields faster responses at that position, a computer-generated square in front of one hand appeared to move either toward that hand or toward the other hand. Compatible responses (e.g., motion toward left hand/left response) were faster than incompatible responses, even when that opposed traditional positional compatibility. In Experiment 2, subjects responded to the same stimuli but with both hands left, right, or on the body midline. Medial responses were the fastest, showing that destination, rather than mere relative position, was a critical variable. It was suggested that spatial compatibility effects are not unique to position but apply to a variety of task situations, describable by J. J. Gibson's theory of affordances, in which he claims that one perceives the actions (e.g., catching) permitted in a situation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive operations and the generation effect.

The present experiments were designed to test a cognitive operations hypothesis of the generation effect, or memorial advantage for stimuli that are generated rather than simply read. In two experiments two aspects of generation were manipulated independently: (a) whether the to-be-remembered stimulus was absent (and therefore produced by the subject) or present (and therefore not produced) and (b) whether the relevant cognitive operations were performed by the subject or were instead performed by another agent. Specifically, subjects were given simple multiplication problems with the answers either absent or present in the original problems and with the calculations performed either by themselves or by another agent (either the experimenter or a calculator). The first experiment tested immediate recall of the answers, and the second experiment tested both recall and recognition of the answers after retention intervals up to a week. In all cases, a highly significant retention advantage was found for the tasks requiring multiplication operations by the subjects themselves as opposed to another agent, but there was no main effect for whether the answer was absent or present in the original problem. We discuss the theoretical implications of these results with respect to the generation effect as well as the practical implications with respect to using a calculator in learning the multiplication facts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Birth order and hand preference in chimpanzees (Pan troglodytes): Implications for pathological models of handedness in humans.

The effect of birth order on hand preference was assessed in a sample of 154 captive-born chimpanzees. Subjects were classified as first, middle, or latter born using 2 classification criteria based on their birth order. Hand preference was measured using a task that elicited coordinated bimanual actions. Significant birth-order effects were found for both classification criteria, with first- and latter-born subjects exhibiting a lesser degree of right-handedness compared with middle-born subjects. These data suggest that biological rather than sociological factors play a greater role in explaining the observed birth-order effects on hand preference in humans. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual load alters visual excitability.

Increasing perceptual load reduces the processing of visual stimuli outside the focus of attention, but the mechanism underlying these effects remains unclear. Here we tested an account attributing the effects of perceptual load to modulations of visual cortex excitability. In contrast to stimulus competition accounts, which propose that load should affect simultaneous, but not sequential, stimulus presentations, the visual excitability account makes the novel prediction that load should affect detection sensitivity for both simultaneous and sequential presentations. Participants fixated a stimulus stream, responding to targets defined by either a color (low load) or color and orientation conjunctions (high load). Additionally, detection sensitivity was measured for a peripheral critical stimulus (CS) presented occasionally. Increasing load at fixation reduced sensitivity to the peripheral CSs; this effect was similar regardless of whether CSs were presented simultaneously with central stimuli or during the (otherwise empty) interval between them. Controls ruled out explanations of the results in terms of strategic task prioritization. These findings support a cortical excitability account for perceptual load, challenging stimulus competition accounts. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Misattribution, preparatory information, and speech anxiety.

In two experiments with undergraduate subjects, I compared the effects of misattribution versus information manipulations on speech anxiety. In Experiment 1, some subjects were allegedly exposed to subliminal noise while reading a speech in front of a camera. These subjects were told that subliminal noise makes people feel either unpleasantly aroused or pleasantly relaxed or that it has no effect. Subjects in a fourth condition were given accurate information about how they would feel (unpleasantly aroused) but were not exposed to the subliminal noise misattribution source. In Experiment 2, I replicated the arousing noise and accurate information conditions from the first study and added two new groups incorporating a delay that should preclude misattribution. In both experiments, the alleged presence of arousing subliminal noise reduced subjects' speech dysfluencies during the speech task, whereas the presentation of accurate information alone did not have a comparable ameliorative effect. Thus, both experiments supported the misattribution interpretation of why neutral labels for arousal can reduce emotionality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Meta-Analytic Review of Gender Variations in Children's Language Use: Talkativeness, Affiliative Speech, and Assertive Speech.

Three sets of meta-analyses examined gender effects on children's language use. Each set of analyses considered an aspect of speech that is considered to be gender typed: talkativeness, affiliative speech, and assertive speech. Statistically significant average effect sizes were obtained with all three language constructs. On average, girls were slightly more talkative and used more affiliative speech than did boys, whereas boys used more assertive speech than did girls. However, the average effect sizes were either negligible (talkativeness, d=0.11; assertive speech, d=0.11) or small (affiliative speech, d=0.26). Larger effect sizes were indicated for some language constructs depending on either the operational definition of the language measure, the method of recording, the child's age level, the interaction partner (adult or peer), group size, gender composition, observational setting, or type of activity. The results are interpreted in relation to social-developmental and social-constructionist approaches to gender; these views are presented as complementary--rather than competing--meta-theoretical viewpoints. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of the effects of morphine and immobilization stress on discrimination performance of rats.

Compared the effects of morphine and immobilization stress (IMS) on performance of 24 male Sprague-Dawley rats in discrete-trial, 2-choice discrimination tasks. In Exps I and II, 2 shocks of different intensities were discriminative stimuli (DSs) for choices in a T-maze. In Exps III and IV, responses were right and left leverpresses in an operant chamber, where correct responses were signaled by either shocks of different intensities (shock discrimination task) or by the position of a brief light flash (light discrimination task). In Exp I, both 70-min IMS and 5 mg/kg morphine induced greater disruptions in trials in which the higher shock was the DS and there were no significant differences between treatments. However, in Exp II, only the effects of morphine were blocked by 10 mg/kg naltrexone. In Exp III, the effects of IMS and morphine were not selective with respect to shock level in the shock discrimination task, nor were they task (shock vs light) selective. The effect of morphine was significantly greater than the effect of IMS in both tasks. Exp IV indicated that effects induced by actual alterations in the intensities of the DS shocks did not mimic those induced by either morphine or IMS but that abrupt decreases in the duration of the DS lights induced effects similar to those of morphine. Results indicate that (a) different mechanisms mediate the effects of IMS and morphine and (b) many of their behavioral effects in shock discrimination tasks are due to dissociative processes rather than alterations in perceived shock intensity. (52 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial stimulus-response compatibility in callosotomy patients and subjects with callosal agenesis

Subjects with partial or complete defects of the corpus callosum, either congenital or acquired, performed a choice reaction time (RT) task involving a right or left key-press response to a light presented at random in the right or left hemifield. Like normal subjects, all of them exhibited two additive effects typical of these tasks: the spatial stimulus-response compatibility effect (faster RT for stimuli and responses matched for side), and the hand placement effect (longer RT for responses performed with crossed hands). Two subjects with a complete callosal defect, one acquired and the other congenital, showed a third effect, not present in normal subjects, consisting of a marked advantage for RT of responses with hand anatomically ipsilateral to the stimulus, independent of both stimulus-response compatibility and hand placement. These findings can be interpreted according to a hierarchical model of information processing assuming that, in the absence of the corpus callosum, the matching of the mental codes for the stimulus and response sets takes place solely in the hemisphere receiving the stimulus, with a subsequent rapid-intrahemispheric or slow-interhemispheric transmission of the response command to the appropriate motor centers.     

Testing the influence of external and internal cues on smoking motivation using a community sample.

Exposing smokers to either external cues (e.g., pictures of cigarettes) or internal cues (e.g., negative affect induction) can induce urge to smoke and other behavioral and physiological responses. However, little is known about whether the two types of cues interact when presented in close proximity, as is likely the case in the real word. Additionally, potential moderators of cue reactivity have rarely been examined. Finally, few cue-reactivity studies have used representative samples of smokers. In a randomized 2 × 2 crossed factorial between-subjects design, the current study tested the effects of a negative affect cue intended to produce anxiety (speech preparation task) and an external smoking cue on urge and behavioral reactivity in a community sample of adult smokers (N = 175), and whether trait impulsivity moderated the effects. Both types of cues produced main effects on urges to smoke, despite the speech task failing to increase anxiety significantly. The speech task increased smoking urge related to anticipation of negative affect relief, whereas the external smoking cues increased urges related to anticipation of pleasure; however, the cues did not interact. Impulsivity measures predicted urge and other smoking-related variables, but did not moderate cue-reactivity. Results suggest independent rather than synergistic effects of these contributors to smoking motivation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Greater reinforcement from alcohol for those at risk: Parental risk, personality risk, and sex.

The effects of a high dose of alcohol (1 g ethanol/kg body weight) on physiological and self-report responses to two stressors (electric shock and self-disclosing speech) were compared with the effects of a placebo in three groups of nonalcoholic subjects considered to be at heightened risk for alcoholism by virtue of their (a) having an alcoholic parent (parental risk) or (b) matching a prealcoholic personality profile (personality risk), or (c) having an alcoholic parent and matching a prealcoholic personality profile. These high-risk groups were contrasted with a low-risk group that had neither risk factor. Male and female subjects were tested in each group with appropriate controls for drinking experience and, for female subjects, phase of menstrual cycle. Results indicated that a potentially reinforcing effect of alcohol (its capacity to attenuate physiological responses to stress) was more pronounced in high-risk subjects than in low-risk subjects. This relation was found for both parental risk and personality risk factors and in both male and female subjects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

That's easy for you to say: Action identification and speech fluency.

Action identification theory holds that an action can be identified by the performer in different ways, and that these various act identities differ in their appropriateness for maintaining the action effectively. Optimal action identification exists when a personally easy action is identified in relatively high-level terms (i.e., the action's effects and implications) or a personally difficult action is identified in relatively low-level terms (i.e., the action's mechanical details). To test the optimality hypothesis with respect to speech fluency, subjects were asked to deliver a speech to either an easy-to-persuade audience or a difficult-to-persuade audience and induced to think about the action in either high-level or low-level terms. As predicted, subjects made fewer speech errors and felt more satisfied with their performance when the task was personally easy and identified at high level and when the task was personally difficult and identified at low level. Optimal action identification made things easier for them to say. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Response coding and visuomotor transformation in the Simon task: The role of action goals.

Manual responses can be defined by differing response parameters. Any of them may generate a Simon effect. For all those response parameters, the same implementation of the Simon effect (in terms of subserving mechanism) is assumed. In 3 experiments, subjects had to respond with either fingers or sticks. Temporal properties of the Simon effect changed with response parameters relevant in a task. The Simon effect for manual responses decayed. For stick responses, in which the action goal differed from the anatomical mapping of the acting hand, a sustained Simon effect was observed. However, if the action goal for stick responses was not instrumental for selecting the correct response, the Simon effect decayed. The findings are consistent with the notion of different mechanisms involved in generating a Simon effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of benzodiazepines and flumazenil on motor cortical excitability in the human brain

In the present study, the effects of benzodiazepines (diazepam) were evaluated in terms of cortical excitability changes, as tested with transcranial magnetic simulation (TMS). In particular, analyzed were drug-induced changes regarding two selected parameters of TMS: (1) the cortical excitability threshold and (2) the silent period duration (SP). For this purpose, we evaluated the effects of long-term therapy with diazepam in the patients affected by anxiety disorders and the changes induced by single oral doses of diazepam in both healthy controls and patients. In addition, we tested cortical excitability changes in two 'extreme conditions' where a considerable concentration of serum benzodiazepine-like activity was reached, as represented by diazepam overdose and idiopathic recurrent stupor (IRS). In both groups of patients, a significant increment of motor threshold was found, while in the overdose patients, the SP was also increased. The administration of flumazenil in these two conditions was followed by a prompt reversal effect, consisting of a return to normal cortical excitability parameters. The long-term usage of diazepam in patients with anxiety disorders is associated with significantly increased threshold; the increased value of these parameters was temporarily further enhanced by the administration of a single oral dose of diazepam, which, in normal control subjects, is not associated with changes of cortical excitability. The results of this study reveal that different physio-pathological conditions induced by the influence of benzodiazepine and its antagonist are reflected in excitability changes which attest to the involvement and modification of cortical GABAergic activity.     

Cortical hyperexcitability in progressive myoclonus epilepsy: a study with transcranial magnetic stimulation

In progressive myoclonus epilepsy (PME), responses to afferent input are frequently abnormal. It is unclear whether the abnormality lies at the cortical, subcortical, or segmental level. To obtain evidence for an exaggerated effect on motor cortical excitability, we used peripheral nerve and transcranial magnetic stimulation in controls and subjects with idiopathic generalized epilepsy and PME. Mean threshold intensity was higher in those with idiopathic generalized epilepsy and PME than in controls, probably as a result of anticonvulsant treatment. A long-latency response to peripheral stimulation and an exaggerated facilitatory effect of peripheral stimulation on the motor evoked potential was present in subjects with PME. Latency differences between the late responses in the upper and lower limbs provided evidence against a segmental reflex and implicated rapidly conducting fibers in the spinal cord. Both the late response and the facilitatory effect had onset latencies consistent with a transcortical pathway, suggesting an exaggerated effect of afferent input on motor cortical excitability in PME.     

The unattended speech effect: Perception or memory?

D. E. Broadbent (1983) has suggested that the influence of unattended speech on immediate serial recall is a perceptual phenomenon rather than a memory phenomenon. In order to test this, 40 undergraduates were required to classify visually presented pairs of consonants on the basis of either case or rhyme. They were tested both in silence and against a background of continuous spoken Arabic presented at 75 db(A). No effect of unattended speech was observed on either the speed or accuracy of processing. A further study required 20 undergraduates to decide whether visually presented nonwords were homophonous with real words. Again, performance was not impaired by unattended speech, although a clear effect was observed on an immediate serial memory task. It is concluded that the results give no support to the perceptual interpretation of the unattended speech effect. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Grasping beer mugs: On the dynamics of alignment effects induced by handled objects.

We examined automatic spatial alignment effects evoked by handled objects. Using color as the relevant cue carried by an irrelevant handled object aligned or misaligned with the response hand, responses to color were faster when the handle aligned with the response hand. Alignment effects were observed only when the task was to make a reach and grasp response. No alignment effects occurred if the response involved a left?right key press. Alignment effects emerged over time, becoming more apparent either when the color cue was delayed or when relatively long, rather than short, response times were analyzed. These results are consistent with neurophysiological evidence indicating that the cued goal state has a modulatory influence on sensorimotor representations, and that handled objects initially generate competition between neural populations coding for a left- or right-handed action that must be resolved before a particular hand is favored. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Failure to remap visuotactile space across the midline in the split-brain.

Examined the effect of posture change on the representation of visuotactile space in a 47-yr-old male split-brain patient using a cross-modal congruency task. The patient made speeded elevation discrimination responses (up vs down) to a series of tactile targets presented to the index finger or thumb of his right hand. The authors report congruency effects elicited by irrelevant visual distractors placed either close to, or far from, the stimulated hand. These cross-modal congruency effects followed the right hand as it moved within the right hemispace, but failed to do so when the hand crossed the midline into left hemispace. These results support claims that interhemispheric connections are required to maintain an accurate representation of visuotactile space. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Validity and boundary conditions of automatic response activation in the Simon task.

Three experiments were conducted to determine whether spatial stimulus-response compatibility effects are caused by automatic response activation by stimulus properties or by interference between codes during translation of stimulus into response coordinates. The main evidence against activation has been that in a Simon task with hands crossed, responses are faster at the response location ipsilateral to the stimulus though manipulated by the hand contralateral to the stimulus. The experiments were conducted with hands in standard and in crossed positions and electroencephalogram measures showed coactivation of the motor cortex induced by stimulus position primarily during standard hand positions with visual stimuli. Only in this condition did the Simon effect decay with longer response times. The visual Simon effect appeared to be due to specific mechanisms of visuomotor information transmission that are not responsible for the effects obtained with crossed hands or auditory stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of generation on indirect measures of memory.

Subjects either read words (CHIMP) or generated words ("a small ape—C') during the study phase of three experiments. The effects of these encoding tasks on performance in two indirect, priming tests—word completion and word identification—were observed. The word completion test is a version of word stem completion in which subjects are shown the initial four letters of a five-letter word (e.g., CHIM_: CHIMP, CHIME) and are asked to add one letter to produce the first word that comes to mind. In word identification, subjects are shown a word briefly and are asked to identify it. Systematic comparisons of the two tests within single experiments showed that generation, either to semantic cues or to orthographic cues, had different effects on performance in the two tests: Word identification performance was lower for words generated rather than read, whereas word completion performance for words generated was indistinguishable from performance for words read. These results suggest that performance in different indirect tests depends on the processing of different types of information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)