Stopping speech suppresses the task-irrelevant hand

Some situations require one to quickly stop an initiated response. Recent evidence suggests that rapid stopping engages a mechanism that has diffuse effects on the motor system. For example, stopping the hand dampens the excitability of the task-irrelevant leg. However, it is unclear whether this ‘global suppression’ could apply across wider motor modalities. Here we tested whether stopping speech leads to suppression of the task-irrelevant hand. We used Transcranial Magnetic Stimulation over the primary motor cortex with concurrent electromyography from the hand. We found that when speech was successfully stopped the motor evoked potential from the task-irrelevant hand was significantly reduced compared to when the participant failed to stop speaking, or responded on non stop signal trials, or compared to baseline. This shows that when speech is quickly stopped, there is a broad suppression across the motor system. This has implications for the neural basis of speech control and stuttering.     

An Examination of Network Position and Childhood Relational Aggression: Integrating Resource Control and Social Exchange Theories

Applying resource control theory and social exchange theory, we examined the social network conditions under which elementary age children were likely to engage in relational aggression. Data on classroom peer networks and peer‐nominated behaviors were collected on 671 second‐ through fourth‐grade children in 34 urban, low‐income classrooms. Nested regression models with robust cluster standard errors demonstrated that the association between children's number of relationships and their levels of relational aggression was moderated by the number of relationships that their affiliates had. Children with more peer relationships (i.e., higher network centrality) exhibited higher levels of relational aggression, but only when these relationships were with peers who had fewer connections themselves (i.e., poorly connected peers). This finding remained significant even when controlling for common predictors of relational aggression including gender, overt aggression, prosocial behavior, victimization, social preference, and perceived popularity. Results are discussed in terms of their implications for advancing the literature on childhood relational aggression and their practical applications for identifying children at risk for these behaviors.     

Social Issues,Authoritarianism, and Ideological Conceptualization: How Policy Dimensions and Psychological Factors Influence Ideological Labeling

Ideology's crucial theoretical and empirical role in explaining political behavior makes it imperative that scholars understand how individuals conceptualize and apply ideological labels. The existing literature on this topic is quite limited, however, because it relies almost exclusively upon data from the 1970s and 1980s, and it does not examine how psychological factors influence conceptualizations of ideological labels. This article uses data from two original laboratory experiments to test the relative impact of four major policy dimensions on participants' evaluations of candidate ideology and to test authoritarianism's role in shaping ideological conceptualization. These analyses indicate that individuals most often define liberalism and conservatism primarily in terms of social policies closely associated with religious values, each of which invert traditional ideological orientations toward the appropriate size and role of government. The causal mechanism shaping this relationship is authoritarianism, because, I argue, the religious social policy dimension most clearly evokes the deep‐seated value conflicts associated with an authoritarian view of political conflict.     

Neural activation underlying cognitive control in the context of neutral and affectively charged pictures in children

The neural correlates of cognitive control for typically developing 9-year-old children were examined using dense-array ERPs and estimates of cortical activation (LORETA) during a go/no-go task with two conditions: a neutral picture condition and an affectively charged picture condition. Activation was estimated for the entire cortex after which data were exported for four regions of interests (ROIs): ventrolateral prefrontal cortex (VLPFC), dorsal anterior cingulate cortex (dACC), dorsolateral prefrontal cortex (DLPFC), and orbitofrontal/ventromedial prefrontal cortex (OFC/VMPFC). Results revealed faster reaction times, greater N2 activation, and greater prefrontal activation for the affectively charged picture condition than the neutral picture condition. The findings are discussed in reference to the impact of affective stimuli on recruitment of specific brain regions involved in cognitive control.     

"Princess Alice is watching you": children's belief in an invisible person inhibits cheating

Two child groups (5-6 and 8-9 years of age) participated in a challenging rule-following task while they were (a) told that they were in the presence of a watchful invisible person (“Princess Alice”), (b) observed by a real adult, or (c) unsupervised. Children were covertly videotaped performing the task in the experimenter’s absence. Older children had an easier time at following the rules but engaged in equal levels of purposeful cheating as the younger children. Importantly, children’s expressed belief in the invisible person significantly determined their cheating latency, and this was true even after controlling for individual differences in temperament. When “skeptical” children were omitted from the analysis, the inhibitory effects of being told about Princess Alice were equivalent to having a real adult present. Furthermore, skeptical children cheated only after having first behaviorally disconfirmed the “presence” of Princess Alice. The findings suggest that children’s belief in a watchful invisible person tends to deter cheating.     

Profiles of anger control in second-grade children: examination of self-report, observational, and physiological components

The current study used latent profile analysis (LPA) to examine anger control in 257 second-grade children (∼8 years of age). Anger was induced through losing a game and prize to a confederate who cheated. Three components of anger control were assessed: self-report of awareness of anger, observed intensity of angry facial expressions, and skin conductance reactivity. These components served as indicators in an LPA conducted to determine whether distinct groups of children who differed in anger control profiles would emerge. Five groups were found: (a) Physiology-and-Expression Controllers (high self-report, low expression, low physiological arousal), (b) Expression-Only Controllers (high self-report, low expression, high physiological arousal), (c) Non-controllers (high self-report, high expression, medium physiological arousal), (d) Non-reactive (low self-report, low expression, low physiological arousal), and (e) Non-reporters (low self-report, medium expression, medium physiological arousal). These findings are discussed in terms of implications for the assessment of children’s anger control skills and intervention programs for children’s anger management.     

The effects of a concurrent task on human optimization and self control

Memory deficits have been shown to hamper decision making in a number of populations. In two experiments, participants were required to select one of three alternatives that varied in reinforcer amount and delay, and the effect of a concurrent task on a behavioral choice task that involved making either an impulsive, self-controlled, or optimal response was studied. The studies aimed to see whether or not individuals were capable of optimizing when confronted with a three-alternative choice paradigm, and if a concurrent task could induce over-selectivity toward a self-controlled, or impulsive, choice, rather than an optimal choice. Various factors which could possibly influence optimization were also explored. The results suggest that some, but not all, individuals are capable of optimizing in a three-alternative choice paradigm, especially when there is a great differential between reinforcement rates of optimal versus non-optimal behaviors. Participants with a concurrent task (continuously subtracting seven from a large number) displayed over-selectivity, evidenced by the high proportion of self-controlled responses.     

Reinforcing saccadic amplitude variability

Saccadic endpoint variability is often viewed as the outcome of neural noise occurring during sensorimotor processing. However, part of this variability might result from operant learning. We tested this hypothesis by reinforcing dispersions of saccadic amplitude distributions, while maintaining constant their medians. In a first experiment we reinforced the least frequent saccadic amplitudes to increase variability, and then reinforced the central part of the amplitude distributions to reduce variability. The target was placed at a constant distance from the fovea after the saccade to maintain the postsaccadic visual signal constant and an auditory reinforcement was delivered depending on saccadic amplitude. The second experiment tested the effects of the contingency. We reinforced high levels of variability in 4 participants, whereas 4 other participants were assigned to a yoked control group. On average, saccadic amplitude standard deviations were doubled while the medians remained mostly unchanged in the experimental participants in both experiments, and variability returned to baseline level when low variability was reinforced. In the control group no consistent changes in amplitude distributions were observed. These results, showing that variability can be reinforced, challenge the idea of a stochastic neural noise. We instead propose that selection processes constrain saccadic amplitude distributions.     

Some determinants of remote behavioral history effects in humans

Undergraduates were exposed to a series of reinforcement schedules: first, to a fixed-ratio (FR) schedule in the presence of one stimulus and to a differential-reinforcement-of-low-rate (DRL) schedule in the presence of another (multiple FR DRL training), then to a fixed-interval (FI) schedule in the presence of a third stimulus (FI baseline), next to the FI schedule under the stimuli previously correlated with the FR and DRL schedules (multiple FI FI testing), and, finally, to a single session of the multiple FR DRL schedule again (multiple FR DRL testing). Response rates during the multiple FI FI schedule were higher under the former FR stimulus than under the former DRL stimulus. This effect of remote histories was prolonged when either the number of FI-baseline sessions was small or zero, or the time interval between the multiple FR DRL training and the multiple FI FI testing was short. Response rates under these two stimuli converged with continued exposure to the multiple FI FI schedule in most cases, but quickly differentiated when the schedule returned to the multiple FR DRL.     

Delay discounting: I'm a k, you're a k

Delay discounting is the decline in the present value of a reward with delay to its receipt. Across a variety of species, populations, and reward types, value declines hyperbolically with delay. Value declines steeply with shorter delays, but more shallowly with longer delays. Quantitative modeling provides precise measures to characterize the form of the discount function. These measures may be regarded as higher-order dependent variables, intervening variables, or hypothetical constructs. I suggest the degree of delay discounting may be a personality trait. In the end, the ontological status of measures of delay discounting is irrelevant. Whatever delay discounting may be, its study has provided the field of behavior analysis and other areas measures with robust generality and predictive validity for a variety of significant human problems. Research on moderating the degree of delay discounting has the potential to produce substantial societal benefits.