Hemispheric asymmetry in the efficiency of attentional networks

Despite the fact that hemispheric asymmetry of attention has been widely studied, a clear picture of this complex phenomenon is still lacking. The aim of the present study was to provide an efficient and reliable measurement of potential hemispheric asymmetries of three attentional networks, i.e. alerting, orienting and executive attention. Participants (N=125) were tested with the Lateralized Attention Network Test (LANT) that allowed us to investigate the efficiency of the networks in both visual fields (VF). We found a LVF advantage when a target occurred in an unattended location, which seems to reflect right hemisphere superiority in control of the reorienting of attention. Furthermore, a LVF advantage in conflict resolution was observed, which may indicate hemispheric asymmetry of the executive network. No VF effect for alerting was found. The results, consistent with the common notion of general right hemisphere dominance for attention, provide a more detailed account of hemispheric asymmetries of the attentional networks than previous studies using the LANT task.     

Quality of Life Before and After Cataract Surgery: Research in a Sample of Polish Patients

The goal of this paper is to present possible change in quality of life (QoL) in older sample of people with vision disturbances. The patients were investigated twice: before (N = 193) and 4 month after the cataract surgery (N = 69), by means of the scale for vision functioning, and the Life Quality Questionnaire (Schalock & Keith, 1993) extend with the items measuring health related quality of life (HRQoL). Two problems were formulated: To what extent are visual defects associated with the decreased subjective QoL? What changes are observed in perceived QoL during the period of treatment of visual defects? The patients reported significant increase of HRQoL, however they did not report similar increase of a general QoL. Few reasons are considered: overlapping of the content of visual function scales and HRQoL and different indices of a general QoL and HRQoL, lack of a proper postoperative care, low socio-economic status of the participants, and too high expectation concerning better functioning after the surgery.     

Temporal-order judgments and reaction time for stimuli of different modalities

Summary Reaction times and the relative latency evaluated by the temporal-order-judgment method for two stimuli of different modalities (visual and auditory) were measured. The difference between reaction times for visual and auditory stimuli was about 40 ms. The relative latency was slightly shorter, however; in conflict with Rutschmann and Link's (1964) previous result, the auditory stimulus must be delayed to be perceived simultaneously with the visual one.     

Effects of Perceptual Fluency on Affective Judgments

According to a two-step account of the mere-exposure effect, repeated exposure leads to the subjective feeling of perceptual fluency, which in turn influences liking. If so, perceptual fluency manipulated by means other than repetition should influence liking. In three experiments, effects of perceptual fluency on affective judgments were examined. In Experiment 1, higher perceptual fluency was achieved by presenting a matching rather than nonmatching prime before showing a target picture. Participants judged targets as prettier if preceded by a matching rather than nonmatching prime. In Experiment 2, perceptual fluency was manipulated by figure-ground contrast. Stimuli were judged as more pretty, and less ugly, the higher the contrast. In Experiment 3, perceptual fluency was manipulated by presentation duration. Stimuli shown for a longer duration were liked more, and disliked less. We concluded (a) that perceptual fluency increases liking and (b) that the experience of fluency is affectively positive, and hence attributed to positive but not to negative features, as reflected in a different impact on positive and negative judgments.     

On structural completeness of implicational logics

We consider the notion of structural completeness with respect to arbitrary (finitary and/or infinitary) inferential rules. Our main task is to characterize structurally complete intermediate logics. We prove that the structurally complete extension of any pure implicational in termediate logic C can be given as an extension of C with a certain family of schematically denned infinitary rules; the same rules are used for each C. The cardinality of the family is continuum and, in the case of (the pure implicational fragment of) intuitionistic logic, the family cannot be reduced to a countable one. It means that the structurally complete extension of the intuitionistic logic is not countably axiomatizable by schematic rules.This work was supported by the Polish Academy of Sciences, CPBP 08.15, Struktura logiczna rozumowa niesformalizowanych.     

Temporal order judgment in dyslexia

Hari et al. (Brain 174:1373-1380, 2001) demonstrated that dyslexics showed a sluggish attention capture in both visual hemifields. Additionally, they indicated a left-right asymmetry in the perception of temporal order of two visual stimuli (they performed worse than controls only if the stimulus in the left hemifield preceded that in right hemifield). They suggested that a left-sided minineglect is associated with dyslexia. We hypothesized that if a kind of neglect syndrome is responsible for the asymmetry they found, dyslexics should not only show a left-right asymmetry in temporal order judgment of two laterally presented stimuli but also perform equally well as controls when the stimuli are vertically aligned. Our results indicated that in both tasks dyslexics performed generally worse than normal readers. The results suggest that dyslexics suffer from a more general problem of order discrimination.     

The negative compatibility effect with nonmasking flankers: a case for mask-triggered inhibition hypothesis

Visual targets which follow a prime stimulus and a mask can be identified faster when they are incompatible rather than compatible with the prime (negative compatibility effect--NCE). According to the self-inhibition hypothesis, the initial activation of the motor response is elicited by the prime based on its identity. This activation leads to benefits for compatible trials and costs for incompatible trials. This motor activation is followed by an inhibition phase, leading to an NCE if perceptual evidence of the prime is immediately removed by the mask. The object-updating and mask-triggered inhibition hypotheses emphasize the role of the mask content (i.e. whether the mask possesses target-like features). We show that the NCE may appear even if nonmasking neutral flankers are presented instead of a mask. Moreover, although with target-like flankers the NCE is larger, it occurred if flankers and targets are built from dissimilar elements. Therefore, masks/flankers can evoke an inhibition phase independently of whether or not they remove evidence for the prime and whether they are similar to the targets.     

Conscious contributions to subliminal priming

Choice reaction times to visual stimuli (targets) may be influenced by preceding subliminal stimuli (primes). Some authors reported a straight priming effect i.e., responses were faster when primes and targets called for the same response than when they called for different responses. Others found the reversed pattern of results. Eimer and Schlaghecken [Eimer, M. & Schlaghecken, F. (2002). Links between conscious awareness and response inhibition: evidence from masked priming. Psychonomic Bulletin &Review, 9, 514-520.] showed recently that straight priming occurs whenever a prime is not efficiently masked thereby the information provided by the prime is accessible for consciousness. In the present study, a hypothesis is tested that straight priming is due to mediation of consciousness. To test this hypothesis, prime validity was manipulated. We showed that even when no mask was used so that participants could fully and consciously perceive the prime and participants were informed that primes were mostly invalid, for the short prime-target ISI interval (100 ms) straight priming occurred. The priming was inverse when the ISI was 800 ms. This indicates that participants were able to use the information provided by the prime to prepare the response opposite to that cued by the prime but only if the time between the prime and the target was long enough.