Sentence processing strategies in healthy seniors with poor comprehension: an fMRI study

We used fMRI to examine patterns of brain recruitment in 22 healthy seniors, half of whom had selective comprehension difficulty for grammatically complex sentences. We found significantly reduced recruitment of left posterolateral temporal [Brodmann area (BA) 22/21] and left inferior frontal (BA 44/6) cortex in poor comprehenders compared to the healthy seniors with good sentence comprehension, cortical regions previously associated with language comprehension and verbal working memory, respectively. The poor comprehenders demonstrated increased activation of left prefrontal (BA 9/46), right dorsal inferior frontal (BA 44/6), and left posterior cingulate (BA 31/23) cortices for the grammatically simpler sentences that they understood. We hypothesize that these brain regions support an alternate, nongrammatical strategy for processing complex configurations of symbolic information. Moreover, these observations emphasize the crucial role of the left perisylvian network for grammatically guided sentence processing in subjects with good comprehension.     

A meta‐analysis of serotonin metabolite 5‐HIAA and antisocial behavior

During the past 25 years, researchers have examined the relationship between neurochemical variables and antisocial behavior in human adults, but none has been studied more intensely than the serotonin metabolite 5‐hydroxyindoleacetic acid (5‐HIAA). The goal of the current study was to employ meta‐analytic procedures to quantitatively evaluate selected evidence on the relationship between 5‐HIAA and antisocial behavior. It was expected that antisocial groups would show reduced cerebrospinal fluid 5‐HIAA compared with non–antisocial groups. This study also aimed to assess moderators that could influence the relationship between 5‐HIAA and antisociality. An electronic search and strict inclusion criteria identified 20 reports used in this meta‐analysis. Results showed a significant overall mean effect size (ES = –.45, P < .05) in the direction of lowered 5‐HIAA in antisocial vs. non–antisocial groups. A significant moderating effect for age indicated that groups comprised of antisocial individuals younger than 30 years exhibited larger negative effect sizes (ES = –1.37, P < .05) than groups with older subjects (ES = –.31, P < .05). There were no moderating effects for gender, target of violence, history of suicide, and alcoholism. Age effects may help explain age‐related declines in crime. The fact that effects did not differ based on other moderating variables supports models of reduced serotonin in antisocial individuals, regardless of type of crime or psychiatric problems. Aggr. Behav. 28:299–316, 2002. © 2002 Wiley‐Liss, Inc.     

Awareness of action: Inference and prediction

This study investigates whether the conscious awareness of action is based on predictive motor control processes, or on inferential "sense-making" process that occur after the action itself. We investigated whether the temporal binding between perceptual estimates of operant actions and their effects depends on the occurrence of the effect (inferential processes) or on the prediction that the effect will occur (predictive processes). By varying the probability with which a simple manual action produced an auditory effect, we showed that both the actual and the predicted occurrence of the effect played a role. When predictability of the effect of action was low, temporal binding was found only on those trials where the auditory effect occurred. In contrast, when predictability of the effect of action was high, temporal binding occurred even on trials where the action produced no effect. Further analysis showed that the predictive process is modulated by recent experience of the action-effect relation. We conclude that the experience of action depends on a dynamic combination of predictive and inferential processes.     

Meditation,mindfulness and cognitive flexibility

This study investigated the link between meditation, self-reported mindfulness and cognitive flexibility as well as other attentional functions. It compared a group of meditators experienced in mindfulness meditation with a meditation-naïve control group on measures of Stroop interference and the “d2-concentration and endurance test”. Overall the results suggest that attentional performance and cognitive flexibility are positively related to meditation practice and levels of mindfulness. Meditators performed significantly better than non-meditators on all measures of attention. Furthermore, self-reported mindfulness was higher in meditators than non-meditators and correlations with all attention measures were of moderate to high strength. This pattern of results suggests that mindfulness is intimately linked to improvements of attentional functions and cognitive flexibility. The relevance of these findings for mental balance and well-being are discussed.     

Modulating the sense of agency with external cues

We investigate the processes underlying the feeling of control over one’s actions (“sense of agency”). Sense of agency may depend on internal motoric signals, and general inferences about external events. We used priming to modulate the sense of agency for voluntary and involuntary movements, by modifying the content of conscious thought prior to moving. Trials began with the presentation of one of two supraliminal primes, which corresponded to the effect of a voluntary action participants subsequently made. The perceived interval between movement and effect was used as an implicit measure of sense of agency. Primes modulated perceived intervals for both voluntary and involuntary movements, but the modulation was greatest for involuntary movements. A second experiment showed that this modulation depended on prime–movement (temporal) contiguity. We propose that sense of agency is based on a combination of internal motoric signals and external sensory evidence about the source of actions and effects.     

Spatial associations in relational reasoning: evidence for a SNARC-like effect

Relational reasoning (A > B, B > C, therefore A > C) shares a number of similarities with numerical cognition, including a common behavioural signature, the symbolic distance effect. Just as reaction times for evaluating relational conclusions decrease as the distance between two ordered objects increases, people need less time to compare two numbers when they are distant (e.g., 2 and 8) than when they are close (e.g., 3 and 4). Given that some remain doubtful about such analogical representations in relational reasoning, we determine whether numerical cognition and relational reasoning have other overlapping behavioural effects. Here, using relational reasoning problems that require the alignment of six items, we provide evidence showing that the subjects' linear mental representation affects motor performance when evaluating conclusions. Items accessible from the left part of a linear representation are evaluated faster when the response is made by the left, rather than the right, hand and the reverse is observed for items accessible from the right part of the linear representation. This effect, observed with the prepositions to the left of and to the right of as well as with above and below, is analogous to the SNARC (Spatial Numerical Association of Response Codes) effect, which is characterized by an interaction between magnitude of numbers and side of response.     

Infants perceive human point-light displays as solid forms

While five-month-old infants show orientation-specific sensitivity to changes in the motion and occlusion patterns of human point-light displays, it is not known whether infants are capable of binding a human representation to these displays. Furthermore, it has been suggested that infants do not encode the same physical properties for humans and material objects. To explore these issues we tested whether infants would selectively apply the principle of solidity to upright human displays. In the first experiment infants aged six and nine months were repeatedly shown a human point-light display walking across a computer screen up to 10 times or until habituated. Next, they were repeatedly shown the walking display passing behind an in-depth representation of a table, and finally they were shown the human display appearing to pass through the table top in violation of the solidity of the hidden human form. Both six- and nine-month-old infants showed significantly greater recovery of attention to this final phase. This suggests that infants are able to bind a solid vertical form to human motion. In two further control experiments we presented displays that contained similar patterns of motion but were not perceived by adults as human. Six- and nine-month-old infants did not show recovery of attention when a scrambled display or an inverted human display passed through the table. Thus, the binding of a solid human form to a display in only seems to occur for upright human motion. The paper considers the implications of these findings in relation to theories of infants' developing conceptions of objects, humans and animals.     

Second-order beliefs about intention and children's attributions of sociomoral judgment

Predicting how another person will evaluate the intention underlying an action involves consideration of second-order mental states. Children (ages 5-10 years) and college students (N=105) predicted an observer's belief about an actor's intention and evaluated the actor from both their own perspectives and the perspective of the observer. Younger children were more likely than older children and adults to attribute a belief to the observer that mismatched the actor's prior intention. Attributed beliefs about intention were more likely to match negative prior intentions than to match positive prior intentions and were also more likely to match prior intentions when the observer knew the actor's prior intention than when the observer did not know the actor's prior intention. The judgments attributed to the observer were based on the beliefs about intention attributed to the observer, showing use of second-order mental states to infer another's sociomoral judgments.     

Libertarian Free Will and the Physical Indeterminism Luck Objection

Libertarian free will is, roughly, the view that agents (or, agent-involving events) cause actions to occur or not occur: Maddy’s decision to get a beer causes her to get up off her comfortable couch to get a beer, though she almost chose not to get up. Libertarian free will notoriously faces the luck objection, according to which agential states do not determine whether an action occurs or not, so it is beyond the control of the agent, hence lucky, whether an action occurs or not: Maddy’s reasons for getting beer in equipoise with her reasons to remain in her comfortable seat do not determine that she will get up or stay seated, so it seems beyond her control, hence lucky, that she gets up. In this paper I consider a sub-set of the luck objection called the Physical Indeterminism Luck Objection, according to which indeterministic physical processes cause actions to occur or not, and agent’s lack control over these indeterministic physical processes, so agent’s lack control over, hence it is lucky, whether action occurs or not. After motivating the physical indeterminism luck objection, I consider responses from three recent event-causal libertarian models, and conclude that they fail to overcome the problem, though one promising avenue is opened up.

This paper is divided into six parts. In Section One, I minimally define libertarian free will as accepting agential indeterminism, which is the conjunction of indeterminism and agential causation, where agential indeterminism occurs when an agent’s reasons, efforts or character indeterministically cause actions. In Sections Two and Three I outline the physical indeterminism luck objection to libertarian free will, which states that sub-agential physical processes in the brain indeterministically cause actions to occur, and agents lack control over these indeterministic physical causes, so agent’s lack control over whether their actions occur. If agent’s lack control over whether actions occur, the occurrence of these actions is lucky, where this luck jeopardizes free will and moral responsibility. In Sections Four through Six I consider three recent libertarian responses to this objection—Mark Balaguer in Section Four, Chris Franklin in Section Five, and Robert Kane in Section Six. I conclude that none of these models satisfactorily overcomes the physical indeterminism luck objection, though one interpretation of Kane yields a promising avenue of reply.

     

Sex task and processing strategy effects in hemispheric alpha asymmetries for the recall and recognition of arousal words: results from perceptual and motor tasks in males and females

Hemispheric alpha asymmetries of males and females were observed during perceptual and motor tasks requiring recall and recognition of words controlled for level of arousal (positive, negative, and neutral). Verbal reports of individual processing strategy were collected and analyzed relative to hemispheric alpha ratios. Results showed greater alpha suppression in the left relative to right hemisphere for recall as compared to recognition tasks and for word presentation when contrasted with motor conditions. High positive correlations were found between narrative report of processing strategy and hemispheric alpha data. A separate analysis revealed that seven subjects identified as highly analytic processors showed greater alpha suppression in the left relative to right hemisphere across tasks, conditions, and stimuli than did seven highly visual processors who, in contrast, demonstrated greater right hemispheric alpha suppression. Task difficulty and individual differences in processing style that modify cerebral laterality effects are discussed.