Preferential processing of visual trauma-film reminders predicts subsequent intrusive memories

This study used an analogue design to test the hypothesis that preferential processing of visual trauma reminders in the aftermath of a stressful or traumatic event gives rise to subsequent intrusive memories. Shortly after the presentation of a stressful film fragment, participants (n=36) were asked to detect neutral targets (rotated buildings or nature scenes) in a single target rapid serial visual presentation (RSVP) paradigm. During half of the streams, the target was preceded by a distracter. The distracters consisted of visual images extracted from an earlier presented stressful film (e.g., persons and objects that figured in the film). The degree of interference by these film reminders predicted subsequent intrusions recorded in a one-week diary. The results provide evidence that a deficient ability to obtain attentional control over perceptual “trauma” reminders during goal-directed behaviour may set people at risk for persistent intrusive memories. Implications for research investigating attentional bias and intrusive memories in context of posttraumatic stress disorder (PTSD) are discussed.     

Thomas Aquinas and Antonio de Córdoba on self-defence: saving yourself as a private end

ABSTRACT

Revisionists about Aquinas’ teaching on private self-defence take the standard reading to hold that Aquinas applies a version of the Doctrine of Double Effect (DDE) according to which the intentional killing of a wrongful attacker by a private person is morally prohibited while the non-intentional but foreseeable killing of the attacker is permitted. Revisionists dispute this reading and argue that Aquinas permits the intentional killing of wrongful attackers. I argue that revisionists mischaracterize the standard reading of Aquinas. I consider one of its main proponents, Antonio de Córdoba (1485–1579). When Córdoba condemned the intentional killing of wrongful attackers by private persons, he was not applying DDE. Rather, he was arguing that when you decide to kill an attacker you treat the attacker as a resource for the private end of saving your life. Killing a member of your community is a form of irrevocable social exclusion. This decision ought to be left to the public authorities. The disagreement between the authors defending the standard view and their critics was not about DDE but rather about the moral limits that membership in a community sets on the pursuit of private ends, including the private end of staying alive.     

The pigeon's discrimination of shape and location information

Two groups of pigeons (n = 4) were trained with 16 line drawings portraying a fixed shape and a variable shape. The four variable shapes (a wedge, a cone, a cylinder, and a handle) appeared to the left of, to the right of, above, or below the fixed shape (a cube). Group Shape (S) was required to discriminate the identity of the variable shape that was mated with the cube, whereas Group Location (L) was required to discriminate where the variable shape appeared relative to the cube. Three of the four pigeons in each group mastered their respective tasks. Later tests revealed that the two groups of pigeons had attended to different aspects of the shape pairs, even though the visual stimuli and general procedures they had been given were the same. Group S had attended to the identity of the variable shape and had ignored the identity and location of the cube, whereas Group L had attended to the configuration of the two shapes. The methods and stimuli could be useful in delineating the biological bases of shape and location perception.     

Accurate identification but no priming and chance recognition memory for pictures in RSVP sequences

In 1969, Potter and Levy reported that recognition memory of accurately perceived RSVP pictures was extremely low, an effect that they attributed to disruption of memory consolidation. Here we report that the repetition of an RSVP picture (72-126 msec/picture) up to 31 times prior to when it became a target had no effect on identification accuracy. At these rates, forced-choice recognition memory was at chance. Single presentations of the pictures outside of the RSVP sequences readily resulted in substantial priming of their identification within the sequences. We offer a neural interpretation of Potter and Levy's explanation, as well as contemporary two-stage accounts of RSVP memory and attentional phenomena, based on the recent finding (Tovee & Rolls, 1995) that most of the information in inferior temporal cells is conveyed in the first 50msec of firing but the cells continue their activity for an additional 350msec. The additional activity, by our account, is required for memory and it is this activity that may be disrupted by attention to the next image during RSVP presentations. The critical factor for priming, if not memory in general, may be attention to the stimulus for a few hundred milliseconds beyond that required for its identification. Single-trial presentations thus manifest robust memory and priming effects - even when the stimulus cannot be identified - whereas RSVP conditions in which the stimulus can be identified result in poor memory.     

Stimulus-specific dynamics of learning in conjunction search tasks

We investigated the time course of learning in visual search for within-dimension conjunctions in homogeneous (inverted V in Vs) or heterogeneous distractors (L in 90° counterclockwise-rotated Ls and 180° rotated Ls), and for across-dimension conjunctions search (green\in green/s and red\s). Two learning sessions of 10 and 5 blocks each took place three months apart. In the first session, the reduction in mean search time was greater for within-dimension conjunctions with heterogeneous distractors. Learning endured from one session to the other for all stimuli, suggesting that learning can be long-term in search for feature conjunctions. However, when the positional regularity between elements was perturbed, the effect of prior learning was reduced for homogeneous within-dimension conjunctions. This suggests that, for these stimuli, learning facilitates grouping by positional regularity. Finally, the learning effect with homogeneous withindimension conjunctions disappeared when both target and distractors were rotated to modify the orientation of conjunction patterns. This suggests that learning improves a grouping mechanism selective for the relative orientations of combined form features.     

Aging Extends the Time Required to Switch Cognitive Set

ABSTRACT

The Attentional Blink (AB) refers to a decrease in the chance of detecting a second target in a rapid sequence of items if it occurs within approximately 500 ms of a first target. In this study the efficiency of establishing and switching cognitive set for older adults (mean age 71.62 years) relative to young adults (mean age 21.33 years) was investigated. Three increasingly complex conditions of the AB paradigm were employed, each of which required participants to identify a coloured square (T1) and a letter (T2) within a stream of distracters. Accuracy of identification of T2 decreased for both young and older adults as complexity increased. In Condition 1, selection criteria for both targets were fully specified, while T1 acted as a direct cue to the selection criteria for T2 in Condition 2. Older participants took longer to establish cognitive set in this condition. Condition 3 contained an added requirement to activate a pre-determined rule for T2 selection. The basic requirement to establish cognitive set ‘online’, however, seemed to disguise any additional potential problems associated with the additional load required for Condition 3 for older adults. Younger adults were cognitively slowed in Condition 3 relative to Condition 2, suggesting that it is the need to use an internally generated cue to switch cognitive set that requires extra time for them. The significantly larger AB demonstrated by the older participants indicated an impaired ability to rapidly establish cognitive set. The findings are discussed in light of the current literature on cognitive aging, the AB and task switching.     

Attention bias modification for reducing speech anxiety

The mechanisms mediating the anxiolytic effects of attention bias modification (ABM) remain unclear. Accordingly, we randomly assigned speech-anxious subjects to receive four sessions of one of three training conditions: ABM, inverse ABM, and control. In the ABM condition, subjects viewed pairs of photographs of models displaying facial expressions of disgust and joy on a computer screen. Probes always replaced the positive face, and subjects pushed a button to indicate the identity of the probe (E or F) as rapidly as possible. In the inverse condition, the probes always replaced the negative face, and in the control condition, the probes replaced each face type equally often. After four training sessions, all groups exhibited statistically indistinguishable, but significant, reductions on self-report, behavioral, and physiological measures of speech anxiety. Self-report and behavioral measures of attentional control improved likewise. Contrary to early studies, ABM was not superior to control procedures in producing reductions on measures of social anxiety.     

Experiencing malevolent voices is associated with attentional dysfunction in psychotic patients

Inattention in people with schizophrenia is common. However, there has been little research on the association between inattention and auditory hallucinations. The aim of the study was to investigate how inattention is affected by beliefs about voices as benevolent and malevolent and perceived control of voices. A total of 31 patients who experienced auditory hallucinations and who met the criteria for schizophrenia or other psychosis completed the attention subscale of the Scale for the Assessment of Negative Symptoms (SANS) and the Connors’ Continuous Performance Test II (CCPT‐II). The revised Beliefs About Voices Questionnaire (BAVQ‐R) was used to assess malevolent and benevolent beliefs about voices, and severity of auditory hallucinations (the Psychotic Symptom Rating Scales; PSYRATS) was used to assess perceived control of voices and frequency of voices. Levels of depression (the Beck Depression Inventory; BDI), anxiety (the Beck Anxiety Inventory; BAI), severity of overall psychiatric symptoms (the Brief Psychiatric Rating Scale; BPRS), and severity of negative symptoms (SANS) were assessed to control for their potential confounding effects. The relations between the variables were explored with correlations and multiple hierarchical regression analyses. The results indicated that more malevolent, but not more benevolent, beliefs about voices predicted lower levels of attention, independently of general psychiatric symptoms and various other psychotic symptoms such as frequency of and perceived control of voices. These findings suggest an important relationship between malevolent beliefs about voices and levels of inattention. The possible impact of changing beliefs about voices to improve attentional functioning is discussed.     

Proteus效应：虚拟世界研究的新视角

随着虚拟世界的迅速发展,特别是虚拟现实环境与现实生活的日趋融合,虚拟现实环境对用户的影响引起了研究者的重视。在基于自我呈现的线上互动中,化身特点会有意或无意地影响到用户的知觉、态度和行为,即普罗透斯效应（Proteus Effect）。近年来,有研究者围绕着普罗透斯效应进行了一系列研究,对这一效应的概念、潜在发生机制、影响因素以及对用户个体和群体水平的影响等方面进行了一些探讨,并取得一定进展,这为国内学者开展虚拟世界中心理现象的探究提供了新的切入点。在未来研究中,普罗透斯效应的研究方法和范式仍需拓展,研究样本仍需丰富,本土化研究、跨文化研究以及应用研究也有待逐步展开。     

Online attention modification for social anxiety disorder: replication of a randomized controlled trial

Social anxiety disorder (SAD) models posit vigilance for external social threat cues and exacerbated self-focused attention as key in disorder development and maintenance. Evidence indicates a modified dot-probe protocol may reduce symptoms of SAD; however, the efficacy when compared to a standard protocol and long-term maintenance of treatment gains remains unclear. Furthermore, the efficacy of such protocols on SAD-related constructs remains relatively unknown. The current investigation clarified these associations using a randomized control trial replicating and extending previous research. Participants with SAD (n = 113; 71% women) were randomized to complete a standard (i.e. control) or modified (i.e. active) dot-probe protocol consisting of 15-min sessions twice weekly for four weeks. Self-reported symptoms were measured at baseline, post-treatment, and 4-month and 8-month follow-ups. Hierarchical linear modeling indicated significant self-reported reductions in symptoms of social anxiety, fear of negative evaluation, trait anxiety, and depression, but no such reductions in fear of positive evaluation. Symptom changes did not differ based on condition and were maintained at 8-month follow-up. Attentional biases during the dot-probe task were not related to symptom change. Overall, our results replicate support for the efficacy of both protocols in reducing symptoms of SAD and specific related constructs, and suggest a role of exposure, expectancy, or practice effects, rather than attention modification, in effecting such reductions. The current results also support distinct relationships between fears of negative and positive evaluation and social anxiety. Further research focused on identifying the mechanisms of change in attention modification protocols appears warranted.