When sound affects vision: effects of auditory grouping on visual motion perception

Two identical visual targets moving across each other can be perceived either to bounce off or to stream through each other. A brief sound at the moment the targets coincide biases perception toward bouncing. We found that this bounce-inducing effect was attenuated when other identical sounds (auditory flankers) were presented 300 ms before and after the simultaneous sound. The attenuation occurred only when the simultaneous sound and auditory flankers had similar acoustic characteristics and the simultaneous sound was not salient. These results suggest that there is an aspect of auditory-grouping (saliency-assigning) processes that is context-sensitive and can be utilized by the visual system for solving ambiguity. Furthermore, control experiments revealed that such auditory context did not affect the perceptual qualities of the simultaneous sound. Because the attenuation effect is not manifest in the perception of acoustic characteristics of individual sound elements, we conclude that it is a genuine cross-modal effect.     

Pigeons (<Emphasis Type="Italic">Columba livia</Emphasis>) know when they will need hints: prospective metacognition for reference memory?

Despite their impressive cognitive abilities, avian species have shown less evidence for metacognition than mammals. We suspect that commonly used tasks such as matching to sample might be too demanding to allow metacognitive processing within birds’ working memory. Here, we examined whether pigeons could control their behavior as a function of knowledge levels on a three-item sequence learning task, a reference memory task supposedly requiring fewer working memory resources. The experiment used two types of lists differing in familiarity. One was familiar to the pigeons through repeated exposure, whereas the other was novel in every new session. In test sessions, pigeons could choose between a trial with a hint specifying the next item to peck and one with no hint. However, successful responses in trials with a hint resulted in lowered rates of primary reinforcement: .60 in the first test and .75 in the second. Results showed that two of four pigeons chose the trial with a hint significantly more often before receiving a novel list than the familiar list in the four sessions of the first test, and three did so in the second test. Impressively, one bird showed robust evidence in the very first sessions in both tests. These results suggest that pigeons may monitor their long-term knowledge states and thereby control their environment before starting to solve a task.     

Differentiation of international terrorism: attack as threat,means, and violence

This study examined whether international terrorism could be differentiated into different behavioural themes related to the way of using force. The sample consisted of 217 international terrorist organisations that had perpetrated five or more terrorist incidents. A non‐metric multidimensional scaling analysis revealed that all of the terrorist incidents could be assigned to one of three themes reflecting different styles of the use of force: ‘attack as threat’, ‘attack as means’, and ‘attack as violence’. In the current sample, 189 of the terrorist organisations repeated one theme in more than 50% of their series of incidents, suggesting their preference for one of the three themes. Copyright © 2008 John Wiley & Sons, Ltd.     

Offender and crime characteristics of female serial arsonists in Japan

This study of Japanese female serial arsonists examined their crimes and background characteristics. The data were a sample from the national police register containing arson cases resulting in charges in Japan between 1982 and 2005. Serial arsonists were 6% of the arson offenders and 12% of these were female, resulting in 83 female serial arsonist data sets. The mean age was 37.6 years and 43% were unemployed. Nearly half were married. Only 28% had a documented history of mental problems and 22% had a prior arrest, usually for theft (19%). Female serial arsonists are characterised by going to a place near their home with a lighter and setting fire directly to combustible materials. Non‐metric multidimensional scaling was used to analyse 33 variables related to the offences. The arsons could be differentiated in terms of either expressive or instrumental sources of action. Expressive arsons were opportunistic and impulsive acts, motivated by emotional distress. The fires were mostly set close to home. Expressive arsons were characteristic of 66% of the females. Instrumental arsons were often motivated by revenge and involved planned and goal‐directed behaviours. They were committed by 13% of the females. Instrumental arsonists tended to travel further from home. Copyright © 2007 John Wiley & Sons, Ltd.     

Temporal dissociation between category-based and item-based processes in rejecting distractors

Presenting a target-like distractor in an RSVP task deteriorates the detection of a trailing target, because the visual system has difficulties in rejecting the erroneously accepted distractor. We investigated whether the rejection process is influenced by observers’ knowledge regarding possible distractors. Observers identified a letter (target) embedded in a stream of line patterns, rejecting a preceding distractor (digit). We informed the observers about either the category of distractors (“digit”) or the identity of the distractor (e.g., “5”). The distractors with certain distractor–target lags increased identification errors, indicating that the distractor rejection process temporarily interfered with the target identification. When the observers knew the distractor identity, the rejection process started later than when they knew only the distractor category. These results suggest that the rejection process may operate at either the category or the individual-item level; however, the setting of the rejection level is not under the observers’ control.     

Short-term memory for event duration: Modality specificity and goal dependency

Time perception is involved in various cognitive functions. This study investigated the characteristics of short-term memory for event duration by examining how the length of the retention period affects inter- and intramodal duration judgment. On each trial, a sample stimulus was followed by a comparison stimulus, after a variable delay period (0.5?C5?s). The sample and comparison stimuli were presented in the visual or auditory modality. The participants determined whether the comparison stimulus was longer or shorter than the sample stimulus. The distortion pattern of subjective duration during the delay period depended on the sensory modality of the comparison stimulus but was not affected by that of the sample stimulus. When the comparison stimulus was visually presented, the retained duration of the sample stimulus was shortened as the delay period increased. Contrarily, when the comparison stimulus was presented in the auditory modality, the delay period had little to no effect on the retained duration. Furthermore, whenever the participants did not know the sensory modality of the comparison stimulus beforehand, the effect of the delay period disappeared. These results suggest that the memory process for event duration is specific to sensory modality and that its performance is determined depending on the sensory modality in which the retained duration will be used subsequently.     

Spatial distortion induced by imperceptible visual stimuli

Previous studies have explored the effects of attention on spatial representation. Specifically, in the attentional repulsion effect, a transient visual cue that captures attention has been shown to alter the perceived position of a target stimulus to the direction away from the cue. The effect is also susceptible to retrospective influence, that attention appears to attract the target when the cue appears afterwards. This study examined the necessity of visual awareness of the cue in these phenomena. We found that when the cues were rendered invisible by backward visual masks, both repulsion and attraction effects were weakened but still observed. The results suggest that the effects possibly depend on processes that are not necessarily associated with conscious visual awareness of the cues. We conjecture that attentional shift produced by the weak, invisible cues may play a role in spatial distortion; but other possible accounts including non-attentional ones are also discussed.     

Influence of gender membership on sequential decisions of face attractiveness

Responses in a current trial are biased by the stimulus and response in the preceding trial. In a mixed-category sequence, the sequential dependency is weaker when the stimuli of the current and preceding trials fall under different categories. In the present study, we investigated the influence of the gender membership of faces on the sequential dependency. Forty-eight pictures of male and female faces were presented successively. Participants rated the attractiveness, roundness, or intelligence of each face on a 7-point scale. The sequential effect was robustly observed, irrespective of the property to be judged. However, between-gender sequential dependency was weaker than within-gender dependency only in the attractiveness judgment. These findings suggest that the gender of faces serves as a cue for forming category representations when face attractiveness is of interest, and hence that the formation of categories in sequential decisions is an adaptive process that depends on the property to be judged.     

Psychometric Properties of the Revised Chen Internet Addiction Scale (CIAS-R) in Chinese Adolescents

The Revised Chen Internet Addiction Scale (CIAS-R) was developed to assess Internet addiction in Chinese populations, but its psychometric properties in adolescents have not been examined. This study aimed to evaluate the factor structure and psychometric properties of CIAS-R in Hong Kong Chinese adolescents. 860 Grade 7 to 13 students (38 % boys) completed the CIAS-R, the Young’s Internet Addiction Test (IAT), and the Health of the Nation Outcome Scales for Children and Adolescents (HoNOSCA) in a survey. The prevalence of Internet addiction as assessed by CIAS-R was 18 %. High internal consistency and inter-item correlations were reported for the CIAS-R. Results from the confirmatory factor analysis suggested a four-factor structure of Compulsive Use and Withdrawal, Tolerance, Interpersonal and Health-related Problems, and Time Management Problems. Moreover, results of hierarchical multiple regression supported the incremental validity of the CIAS-R to predict mental health outcomes beyond the effects of demographic differences and self-reported time spent online. The CIAS is a reliable and valid measure of internet addiction problems in Hong Kong adolescents. Future study is warranted to validate the cutoffs of the CIAS-R for identification of adolescents with Internet use problems who may have mental health needs.     

Visual snake aversion in Octodon degus and C57BL/6 mice

Animal Cognition - Phobia against spiders or snakes is common in humans, and similar phobia-like behaviors have been observed in non-human animals. Visual images of snakes elicit phobia in humans,...