Paradoxical effects of testing: retrieval enhances both accurate recall and suggestibility in eyewitnesses

Although retrieval practice typically enhances memory retention, it can also impair subsequent eyewitness memory accuracy (Chan, Thomas, & Bulevich, 2009). Specifically, participants who had taken an initial test about a witnessed event were more likely than nontested participants to recall subsequently encountered misinformation—an effect we called retrieval-enhanced suggestibility (RES). Here, we sought to test the generality of RES and to further elucidate its underlying mechanisms. To that end, we tested a dual mechanism account, which suggests that RES occurs because initial testing (a) enhances learning of the later misinformation by reducing proactive interference and (b) causes the reactivated memory trace to be more susceptible to later interference (i.e., a reconsolidation account). Three major findings emerged. First, RES was found after a 1-week delay, where a robust testing benefit occurred for event details that were not contradicted by later misinformation. Second, blockage of reconsolidation was unnecessary for RES to occur. Third, initial testing enhanced learning of the misinformation even when proactive interference played a minimal role.     

An observation on the spontaneous noticing of prospective memory event-based cues

In event-based prospective memory, current theories make differing predictions as to whether intention-related material can be spontaneously noticed (i.e., noticed without relying on preparatory attentional processes). In 2 experiments, participants formed an intention that was contextually associated to the final phase of the experiment, and lures that overlapped to differing degrees with the features of the intention-related cues were embedded in the initial phase. When participants were outside of the appropriate responding context (i.e., the initial phase), they exhibited slower latencies to lures that exactly matched the features of their intention compared with other types of lures and control words. In addition, on a final remember/know recognition test, participants reported having greater subjective recollection for the occurrence of the exact-match lures. These results suggest that exact-match lures were spontaneously noticed and differentially processed in the absence of any observable preparatory attentional processes. The findings have implications for the theoretical debate over whether preparatory attention must always be relied upon to notice intention-related material.     

Effects of audio-visual integration on the detection of masked speech and non-speech sounds

Integration of simultaneous auditory and visual information about an event can enhance our ability to detect that event. This is particularly evident in the perception of speech, where the articulatory gestures of the speaker's lips and face can significantly improve the listener's detection and identification of the message, especially when that message is presented in a noisy background. Speech is a particularly important example of multisensory integration because of its behavioural relevance to humans and also because brain regions have been identified that appear to be specifically tuned for auditory speech and lip gestures. Previous research has suggested that speech stimuli may have an advantage over other types of auditory stimuli in terms of audio-visual integration. Here, we used a modified adaptive psychophysical staircase approach to compare the influence of congruent visual stimuli (brief movie clips) on the detection of noise-masked auditory speech and non-speech stimuli. We found that congruent visual stimuli significantly improved detection of an auditory stimulus relative to incongruent visual stimuli. This effect, however, was equally apparent for speech and non-speech stimuli. The findings suggest that speech stimuli are not specifically advantaged by audio-visual integration for detection at threshold when compared with other naturalistic sounds.     

Mental illness, criminal risk factors and parole release decisions

Research has not examined whether higher rates of parole denial among inmates with mental illness (MI) are the result of the increased presence of criminal risk factors among this population. Employing a representative sample of inmates with (n = 219) and without (n = 184) MI receiving parole release decisions in 2007, this study tested whether the central eight risk factors for recidivism considered in parole release decisions intervened in the relationship between MI and parole release. MI was associated with possession of a substance use disorder, antisocial personality disorder and violent charges while incarcerated; however, these factors were not related to release decisions. MI was found to have neither a direct nor an indirect effect on release decisions. While results indicate that release decisions appear, to some extent, to be evidence-based, they also suggest considerable discretion is being implemented by parole board members in release decisions above and beyond consideration of criminal risk factors.     

Social influence modulates the neural computation of value

Social influence--individuals' tendency to conform to the beliefs and attitudes of others--has interested psychologists for decades. However, it has traditionally been difficult to distinguish true modification of attitudes from mere public compliance with social norms; this study addressed this challenge using functional neuroimaging. Participants rated the attractiveness of faces and subsequently learned how their peers ostensibly rated each face. Participants were then scanned using functional MRI while they rated each face a second time. The second ratings were influenced by social norms: Participants changed their ratings to conform to those of their peers. This social influence was accompanied by modulated engagement of two brain regions associated with coding subjective value--the nucleus accumbens and orbitofrontal cortex--a finding suggesting that exposure to social norms affected participants' neural representations of value assigned to stimuli. These findings document the utility of neuroimaging to demonstrate the private acceptance of social norms.     

Do Research Intermediaries Reduce Perceived Coercion to Enter Research Trials Among Criminally Involved Substance Abusers?

We examined the efficacy of including a research intermediary (RI) during the consent process in reducing participants' perceptions of coercion to enroll in a research study. Eighty-four drug court clients being recruited into an ongoing study were randomized to receive a standard informed consent process alone (standard condition) or with an RI (intermediary condition). Before obtaining consent, RIs met with clients individually to discuss remaining concerns. Findings provided preliminary evidence that RIs reduced client perceptions that their participation might influence how clinical and judicial staff view them. This suggests that using RIs may improve participant autonomy in clinical studies.     

Very brief exposure II: the effects of unreportable stimuli on reducing phobic behavior

This experiment compared the effects of exposure to masked phobic stimuli at a very brief stimulus-onset asynchrony on spider-phobic and non-phobic individuals. Participants were identified through a widely used questionnaire and a Behavioral Avoidance Test (BAT) with a live, caged tarantula to establish baseline levels of avoidance. One week later, they were individually administered one of two continuous series of masked images: spiders or flowers. Preliminary masking experiments showed that independent samples of participants from the same populations failed to recognize these stimuli. Participants in the main experiment reported ratings of subjective distress immediately before and after the exposure manipulation. Then they engaged in the BAT once again. Very brief exposure to images of spiders reduced phobic participants' avoidance of the tarantula. No effects were evidenced on subjective distress, or on non-phobic participants. Theoretical implications for the non-conscious basis of fear are discussed.     

The psychometric properties and utility of the Short Sadistic Impulse Scale (SSIS)

Sadistic personality disorder (SPD) has been underresearched and often misunderstood in forensic settings. Furthermore, personality disorders in general are the subject of much controversy in terms of their classification (i.e., whether they should be categorical or dimensional). The Sadistic Attitudes and Behaviors Scale (SABS; Davies & Hand, 2003; O'Meara, Davies, & Barnes-Holmes, 2004) is a recently developed scale for measuring sadistic inclinations. Derived from this is the Short Sadistic Impulse Scale (SSIS), which has proved to be a strong unidimensional measure of sadistic inclination. Through cumulative scaling, it was investigated whether the SSIS could measure sadism on a continuum of interest, thus providing a dimensional view of the construct. Further, the SSIS was administered along with a number of other measures related to sadism in order to assess the validity of the scale. Results showed that the SSIS has strong construct and discriminant validity and may be useful as a screening measure for sadistic impulse.     

Strengths of Aboriginal Foster Parents

The purpose of the study was to identify the strengths of Aboriginal foster parents according to the foster parents themselves. A total of 83 Aboriginal foster parents participated in over the phone interviews that included the question “What are the main strengths you have as a foster parent?”. Responses to the questions were sorted by the participants and the sorted data were analyzed using multidimensional scaling and cluster analysis. Four clusters emerged from the responses to the question: (1) awareness abilities and skills, (2) cultural experience, (3) personal qualities, and (4) child as part of family. The clusters were compared and contrasted with available literature.     

The dark side of testing memory: repeated retrieval can enhance eyewitness suggestibility

Eyewitnesses typically recount their experiences many times before trial. Such repeated retrieval can enhance memory retention of the witnessed event. However, recent studies (e.g., Chan, Thomas, & Bulevich, 2009) have found that initial retrieval can exacerbate eyewitness suggestibility to later misleading information--a finding termed retrieval-enhanced suggestibility (RES). Here we examined the influence of multiple retrieval attempts on eyewitness suggestibility to subsequent misinformation. In four experiments, we systematically varied the number of initial tests taken (between zero and six), the delay between initial testing and misinformation exposure (~30 min or 1 week), and whether initial testing was manipulated between- or within-subjects. University undergraduate students were used as participants. Overall, we found that eyewitness suggestibility increased as the number of initial tests increased, but this RES effect was qualified by the delay and by whether initial testing occurred in a within- or between-subjects manner. Specifically, the within-subjects RES effect was smaller than the between-subjects RES effect, possibly because of the influence of retrieval-induced forgetting/facilitation (Chan, 2009) when initial testing was manipulated within subjects. Moreover, consistent with the testing effect literature (Roediger & Karpicke, 2006), the benefits of repeated testing on later memory were stronger after a 1-week delay than after a 30-min delay, thus reducing the negative impact of RES in long-term situations. These findings suggest that conditions that are likely to occur in criminal investigations can either increase (repeated testing) or reduce (delay) the influence of RES, thus further demonstrating the complex relationship between eyewitness memory and repeated retrieval.