Several studies have suggested that both affective valence and arousal affect the perception of time. However, in previous experiments, the two affective dimensions have not been systematically controlled. In this study, standardized photographic slides rated for emotional valence and arousal were projected to two groups of subjects for 2, 4, and 6 sec. One group of subjects estimated the projection duration on an analog scale, whereas the second group of subjects reproduced the intervals by pushing a button. Heart rate and skin conductance responses were also recorded during stimulus presentation as indices of attention and arousal. Time estimation results showed neither a main effect of valence nor a main effect of arousal. A highly significant valence X arousal interaction affected duration judgments. For low-arousal stimuli, the duration of negative slides was judged relatively shorter than the duration of positive slides. For high-arousal stimuli, the duration of negative slides was judged longer than the duration of positive slides. The same interaction pattern was observed across judgment modalities. These results are interpreted in terms of a model of action tendency, in which the level of arousal controls two different motivational mechanisms, one emotional and the other attentional.In everyday life, human beings are continually engaged in emotionally driven behaviors. Such behaviors are so highly pervasive that the recent psychological literature has pointed out the centrality ofemotional factors in cognitive processes such as learning a second language (Schumann, 1990(Schumann, , 1994. Damasio (1994) has recently documented a remarkable body of neuropsychological evidence supporting the assumption that emotions are involved in most, if not all, cognitive processes.Although an increasing number of studies have investigated the role of emotions in cognitive activity, only a limited number of studies have analyzed the relationship between emotional states and estimation of time durations. Furthermore, these studies have typically yielded inconclusive results regarding the precise nature of the relationship between emotions and time perception. These inconsistent findings may originate from the use of nonstandardized emotional manipulations that make the quantification and replication of the results rather problematic.A leading theoretical approach in the current literature involves the dimensional analysis of emotions. Dimensional theories of emotion differ from basic emotions theories (Argyle, 1975;Chance, 1980;Plutchik, 1962) in that they do not classify emotions on the basis ofthe presence or absence of independent and specific emotional states (e.g., fear, anger, or joy). Instead, they assume that emotions can be represented in a multidimensional space We wish to thank G. B. Vicario, P. 1. Lang, L. Stegagno, D. Palomba, P. Bressan, R. Mucha, and L. Krueger (associate editor), and the referees for their helpful suggestions and comments. Correspondence should be addressed to Alessandro Angrilli, Antone...

Fourteen patients with stable acquired brain injuries exhibiting attention and working memory deficits were given 10 weeks of attention process training (APT) and 10 weeks of brain injury education in a cross-over design. Structured interviews and neuropsychological tests were used prior to rehabilitation and after both treatments to determine the influence of the interventions on tasks of daily life and performance on attentional networks involving vigilance, orienting, and executive function. The overall results showed that most patients made improvements. Some of these gains were due to practice from repetitive administration of the tests. In addition, the type of intervention also influenced the results. The brain injury education seemed to be most effective in improving self-reports of psychosocial function. APT influenced self-reports of cognitive function and had a stronger influence on performance of executive attention tasks than was found with the brain injury education therapy. Vigilance and orienting networks showed little specific improvement due to therapy. However, vigilance level influenced the improvement with therapy on some tests of executive attention. We consider the implications of these results for future studies of the locus of attentional improvement and for the design of improved interventions.

In a series of three experiments requiring selection of real objects for action, we investigated whether characteristics of the planned action and/or the "affordances" of target and distractor objects affected interference caused by distractors. In all of the experiments, the target object was selected on the basis of colour and was presented alone or with a distractor object. We examined the effect of type of response (button press, grasping, or pointing), object affordances (compatibility with the acting hand, affordances for grasping or pointing), and target/distractor positions (left or right) on distractor interference (reaction time differences between trials with and without distractors). Different patterns of distractor interference were associated with different motor responses. In the button-press conditions of each experiment, distractor interference was largely determined by perceptual salience (e.g., proximity to initial visual fixation). In contrast, in tasks requiring action upon the objects in the array, distractors with handles caused greater interference than those without handles, irrespective of whether the intended action was pointing or grasping. Additionally, handled distractors were relatively more salient when their affordances for grasping were strong (handle direction compatible with the acting hand) than when affordances were weak. These data suggest that attentional highlighting of specific target and distractor features is a function of intended actions.

Thirty undergraduates participated in an experiment investigating the effect of the arithmetic difference between stimulus identity and stimulus numerosity in a numerical version of the Stroop task. It was found that digits symbolically close to the enumeration response reliably produced larger interference than digits that were farther from the enumeration response. This semantic distance effect was found with different numerosities (1-9) and different enumeration processes (counting and subitizing), and it increased as a function of numerosity in the subitizing range. These findings suggest that digit identity autonomously activates a magnitude representation organized as a compressed number line.

Pavese and UmiltaÁ found that, in an enumeration task, Stroop-like interference is larger when the digit identity is symbolically close to the enumeration response than when it is symbolically far. In two experiments testing 49 undergraduates, we further explored this phenomenon using Francolini and Egeth's paradigm. We found that symbolic distance aected interference even when the stimulus was brie¯y presented and masked. In Exp. 2, which tested numerosities outside the subitizing range, individuals used a dierent enumeration strategy but showed the same symbolic distance eect. These results support the hypothesis that Stroop interference found in enumeration tasks depends on a rapid and automatic activation of digits' magnitude representation.