Flanker compatibility effects in patients with Parkinson's disease: impact of target onset delay and trial-by-trial stimulus variation

Parkinson’s disease (PD) patients and healthy controls were administered a flanker task that consisted of the presentation of colored targets and distractors. Participants were required to attend to the center target and identify its color. The stimulus displays were either congruent (i.e., the target and flankers were the same color) or incongruent. The time between the onset of the flanker and the target color (the target onset delay) was either short or long. Results indicated that PD patients and controls did not differ in the magnitude of the flanker effect within individual trials in that both groups demonstrated a typical flanker effect at the short target onset delay and neither group demonstrated a flanker effect at the longer delay. However, when performance was examined on a trial-by-trial basis, PD patients demonstrated a slowing of reaction time relative to controls when having to make the same response across consecutive trials at longer inter-trial intervals when the flankers were incongruent across consecutive trials and the display on the second of two trials was incongruent. These results indicate that PD patients are impaired in inhibiting the distractors over an extended delay and that this deficit may impact motor responding in these patients, suggesting that the basal ganglia contribute to the interface of attention and action.     

Differential susceptibility to discipline: the moderating effect of child temperament on the association between maternal discipline and early childhood externalizing problems.

This study investigated the interaction of child temperament and maternal discipline in the prediction of externalizing problems in early childhood. Interaction effects were evaluated in a sample of 227 one- to three-year-old children with relatively high externalizing problems scores on the Child Behavior Checklist/1 1/2-5. Child temperament was reported by the mothers, maternal discipline was observed in a laboratory session, and child outcome measures included both mother-reported externalizing problems and observed physical aggression. Results indicate that children with difficult temperaments are more susceptible to negative discipline (i.e., they showed more externalizing problems) as well as more susceptible to positive discipline (i.e., they showed fewer externalizing problems and less physical aggression), as compared with children with relatively easy temperaments. These findings provide empirical evidence for the differential susceptibility hypothesis and suggest directions for enhancing the effectiveness of interventions aimed at reducing early childhood externalizing problems.     

Ignorance is bliss: the role of observer expectation in dynamic spatial tuning of the attentional focus

When two sequential targets (T1, T2) are inserted in an RSVP stream of distractors, perception of T2 is impaired at intertarget lags shorter than 700 msec. Paradoxically, this deficit disappears when T2 is presented directly after T1 (lag-1 sparing). Visser, Bischof, and Di Lollo (1999) found that lag-1 sparing occurs only when T1 and T2 are presented in the same stream. In contrast, Shih (2000) obtained lag-1 sparing with targets insepa-rate streams. Four experiments addressed this inconsistency and revealed lag-1 sparing with targets in different streams, but only when observers had no foreknowledge of T1's location. We hypothesized that when T1 location is known, attention is focused narrowly on that stream; if T2 then appears in the other stream it is missed, and lag-1 sparing does not occur. When T1 location is not known, attention is focused broadly, encompassing both streams, and lag-1 sparing ensues.     

The time required for perceptual (nonmotoric) processing in IOR

In an inhibition of return (IOR) paradigm, we used a threshold-tracking procedure combined with backward masking to measure the speed of perceptual processing in IOR independent of motoric factors. Instead of the conventional reaction time measure, this procedure yielded the critical exposure duration (DUR_c) that is required in order for a target to be identified reliably before the onset of a trailing mask. In Experiment 1, the facilitation effects conventionally found at short cue—target onset asynchrony (CTOA) were evidenced by shorter values of DUR_c at cued relative to uncued locations. Conversely, the retardation effects conventionally found at long CTOA were evidenced by correspondingly longer values of DUR_c. In Experiment 2, the DUR_c results strongly suggest that the directional reading bias previously observed in IOR studies is due, at least in part, to perceptual rather than motoric factors.     

Authoritarianism, social dominance orientation and prejudice: Effects of various self-categorization conditions

One hundred and seventy nine students first answered RWA and SDO scales were assigned to experimental conditions that primed different forms of self-categorization, and finally responded for prejudice scales for three target ethnic groups. The results showed first, that RWA and SDO correlate with prejudice in a control condition. Second, RWA and SDO correlated differently with prejudice depending on the way in which membership to social group was primed. When a prime as member of a group oriented to devotion to the in-group norms and values was used, the correlation of RWA and in-group identification with prejudice was significant, but when a prime as member of a competitive group was used, only SDO correlated significantly with prejudice. The results were discussed as identifying two different schemas of social categorization according to which RWA and SDO expressed sets of social beliefs and attitudes relevant for inter-group relations.     

Are spatial selection and identity extraction separable when attention is controlled endogenously?

Visual search for a target involves two processes: spatial selection and identity extraction. Ghorashi, Enns, and Di Lollo (2008) found these processes to be independent and surmised that they were carried out along distinct visual pathways: dorsal and ventral, respectively. The two experiments that are described in the present article evaluated this hypothesis. Attentional-blink methodology was combined with voluntary spatial cuing in a visual search task: Intertarget lag was used to manipulate identity extraction; predictive cues were used to signal target locations. Central digit cues in Experiment 1 required participants to identify digits before voluntarily directing attention to a corresponding location, whereas flashed dots in Experiment 2 (indicating an opposite location) required attentional redeployment without prior cue identification. Consistent with the dual-pathway hypothesis, cuing was impaired only when the first target and the number cue competed for ventral-pathway mechanisms. Collectively, the results support the dual-pathway account of the separability of spatial selection and identity extraction.     

The nature of skilled adult reading varies with type of instruction in childhood

Does the type of reading instruction experienced during the initial years at school have any continuing effect on the ways in which adults read words? The question has arisen in current discussions about computational models of mature word-reading processes. We tested predicted continuing effects by comparing matched samples of skilled adult readers of English who had received explicit phonics instruction in childhood and those who had not. In responding to nonwords that can receive alternative legitimate pronunciations, those adults having childhood phonics instruction used more regular grapheme-phoneme correspondences that were context free and used fewer vocabulary-based contextually dependent correspondences than did adults who had no phonics instruction. These differences in regularization of naming responses also extended to some low-frequency words. This apparent cognitive footprint of childhood phonics instruction is a phenomenon requiring consideration when researchers attempt to model adult word reading and when they select participants to test the models.     

When do primes prime? The moderating role of the self-concept in individuals’ susceptibility to priming effects on social behavior

Using cooperative behavior in economic decision-making settings, we predicted and found that people’s susceptibility to priming influences is moderated by two factors: people’s chronic accessibility to a behavioral repertoire and people’s self-concept activation. In Experiment 1, we show that individuals highly consistent in their social value orientation (SVO) assimilate their behavior to their dispositions rather than to the primes, whereas the opposite effect is obtained among individuals with a low consistent SVO. In Experiment 2, we show that low consistent SVO individuals become less susceptible to priming influences when their self-concept is activated. These studies shed new light on individuals’ susceptibility to priming influences on social behavior.     

DEVELOPMENTAL SEX DIFFERENCES IN THE RELATION OF NEUROANATOMICAL CONNECTIVITY TO INTELLIGENCE

Recent neuroimaging research has shown sex-related differences in the relationship between brain structure and cognitive function. Anatomical studies have shown a greater reliance for cognitive function on white matter structure in adult females, and a greater reliance on gray matter structure in adult males. Functional neuroimaging studies have also shown a greater correlation between brain connectivity and cognitive function in females. However, this relationship is not present in young childhood (5 years old) but appears during the developmental period. Here sex differences in structure–function relationships and their developmental trajectory are investigated using diffusion tensor imaging (DTI) on a large cohort of over 100 normal children ages 5–18. Significant sex–X–IQ interactions on fractional anisotropy (FA), a marker for white matter organization, were seen in the left frontal lobe, in fronto-parietal areas bilaterally, and in the arcuate fasciculus bilaterally, with girls showing positive correlations of FA with IQ, and boys showing a negative correlation. Significant sex–X–IQ–X–age interactions on FA were also seen in the left frontal lobe and in fronto-parietal areas bilaterally, showing a developmental effect. These results strongly corroborate previous findings regarding sex differences in structure–function relationships regarding intelligence. Results also indicate that a naïve interpretation of “more is better” with respect to FA may not be accurate, especially in adult males.