Attention shifts produce spatial stimulus codes

Summary In the Simon task the spatial position of the stimulus, though task irrelevant, influences speed of response. We (Umiltà & Nicoletti, 1992) proposed that the orienting of attention to the imperative stimulus produces a Stroop-like interference. This paper reports the results of three experiments that provide empirical support for two predictions of this hypothesis. One is that the stimulus spatial code is formed with relation to the position to which attention is directed. The other prediction is that the Simon effect is obtained on condition that attention can orient to the stimulus.Some of the results of Experiments 1 and 2 were reported briefly in Umiltà and Nicoletti (1992)     

Interference and conflict monitoring in individuals with amnestic mild cognitive impairment: A structural study of the anterior cingulate cortex

Amnestic mild cognitive impairment (aMCI) is a clinical condition characterized by memory impairment in the absence of any other cognitive impairment and is commonly associated with high conversion to Alzheimer's disease. Recent evidence shows that executive functions and selective attention mechanisms could also be impaired in aMCI. In this study, we investigated performance differences (i.e., reaction times [RTs] and accuracy) between a group of aMCI participants and a group of age‐matched healthy individuals on the attentional network task (ANT) focusing on situations with increased interference. In particular, we assessed the relationship between interference and conflict effects and grey matter volumes (GMVs) of the anterior cingulate cortex (ACC)/pre‐supplementary motor area in the entire sample because of its crucial role in conflict monitoring. When compared with controls, aMCI participants were less accurate on the ANT, showing increased interference and conflict effects, but no differences in RTs. In addition, aMCI participants exhibited lower GMV in the ACC than controls. While better accuracy for interference and conflict effects was associated with an increase of GMV in the ACC for both groups, RTs from the interference effect were negatively correlated with GMV of the ACC only in aMCI participants. In other words, lower GMV values of the ACC were paralleled with significantly impaired performance in terms of interference resolution. In conclusion, our study suggests the presence of a selective impairment in interference and conflict monitoring in aMCI, which in turn is associated with decreased GMVs in the ACC.     

Differences in dimensionality of electroencephalogram during awake and deeper sleep stages

The nonlinear dynamical systems theory provides some tools for the analysis of electroencephalogram (EEG) at different sleep stages. Its use could allow the automatic monitoring of the states of the sleep and it would also contribute an explanatory level of the differences between stages. The goal of the present paper is to address this type of analysis, focusing on the most different stages. Estimations of dimensionality were compared when six subjects were awake and in a deep sleep stage. Greater dimensionality involves more complexity because the system receives more external influences. If this dimensionality is maximum, we can consider that the time series is a noisy one. A smaller dimensionality involves lower complexity because the system receives fewer inputs. We hypothesized that we would find greater dimensionality when subjects were awake than in a deep sleep stage. Results show a noisy time series during the awake stage, whereas in the sleep stage, dimensionality is smaller, confirming our hypothesis. This result is similar to the findings reached previously by other authors.     

Global/local processing and negative priming: the influence of selection difficulty and stimulus exposure

Negative priming is a decrement in performance observed when a previously ignored stimulus is re-presented as a target. The present study examined the relation between selection difficulty and negative priming in five experiments that used hierarchical stimuli (large letters made up by small letters). The results show that negative priming is greater when subjects direct attention to the local level (more difficult selection) than when they direct attention to the global level (less difficult selection). However, that occurs only when exposure of prime and probe is sufficiently long. With shorter presentations, negative priming is still observed but is no longer modulated by selection difficulty. These results suggest that both anticipatory and reactive mechanisms are responsible for the occurrence of negative priming and that instantiation of the reactive mechanism depends on the time available for prime and probe selection. Received: 17 January 2000 / Accepted: 3 July 2000     

Dialectical behaviour therapy skills training compared to standard group therapy in borderline personality disorder: A 3-month randomised controlled clinical trial

Dialectical behaviour therapy (DBT) has proven to be an effective treatment in borderline personality disorder (BPD). However, the effectiveness in BPD of DBT skills training (DBT-ST) alone is not known. This study aimed at comparing the efficacy of DBT-ST and standard group therapy (SGT) for outpatients with BPD. Sixty patients meeting the DSM-IV diagnostic criteria for BPD, as assessed by two semi-structured diagnostic interviews, were included in a 3-month, single-blind randomised controlled trial. A total of 13 weekly group psychotherapy sessions of 120 min of either SGT or DBT-ST were conducted. Assessments were carried out every 2 weeks by two blinded evaluators. Observer-rater, self-report scales and behavioural reports were used as outcome measures. DBT-ST was associated with lower dropout rates, 34.5% compared to 63.4% with SGT. It was superior to SGT in improving several mood and emotion areas, such as: depression, anxiety, irritability, anger and affect instability. A reduction in general psychiatric symptoms was also observed. Three-months weekly DBT-ST proved useful. This therapy was associated with greater clinical improvements and lower dropout rates than SGT. DBT-ST seems to play a role in the overall improvement of BPD seen with standard DBT intervention. It allows straightforward implementation in a wide range of mental health settings and provides the additional advantage that it is cost effective.     

Extended multisensory space in blind cane users

In the present work, we investigated whether an auditory peripersonal space exists around the hand and whether such a space might be extended by a brief tool-use experience or by long-term experience using a tool in everyday life. To this end, we studied audio-tactile integration in the space around the hand and in far space, in blind subjects who regularly used a cane to navigate and in sighted subjects, before and after brief training with the cane. In sighted subjects, auditory peripersonal space was limited to around the hand before tool use, then expanded after tool use, and contracted backward after a resting period. In contrast, in blind subjects, peri-hand space was immediately expanded when they held the cane but was limited to around the hand when they held a short handle. These results suggest that long-term experience with the cane induces a durable extension of the peripersonal space.     

The measurement of left—right asymmetries in the Simon effect: A fine-grained analysis

The spatial Simon effect is often asymmetric, being greater on one side than on the other. To date, not much attention has been paid to these asymmetries, and explanations of the Simon effect do not take them into account. In the present article, we attempt to clarify the statistical implications of the asymmetries so as to provide a useful tool for future empirical investigation. Starting with examples from our laboratory and previous well-known studies, we point out the consequences of ignoring the asymmetries in the Simon effect. We suggest an alternative data analysis that might render the results clearer. Finally, through a comparison of left- and right-handed subjects, we demonstrate that asymmetries in the Simon effect are linked to the lateralization of processes involved in the Simon task—that is, attention and response selection. This approach provides a strong argument against collapsing data from the two sides to measure the Simon effect.     

The ontogeny of continuous quantity discrimination in zebrafish larvae (Danio rerio)

Animal Cognition - Several studies have investigated the ontogeny of the capacity to discriminate between discrete numerical information in human and non-human animals. Contrarily, less attention...