Eyewitness memory following discussion: using the MORI technique with a Western sample

Researchers studying memory conformity have made significant advances in our understanding of the phenomenon, but have used methods with significant shortcomings. Mori's three‐stage method addresses many of these concerns. To date the technique has not been replicated on a Western sample. We present such a study, and discuss two significant improvements to Mori's method. We found that subjects were more likely to report the correct answer for non‐discussed critical details than discussed critical details. Our data also suggested that when subjects agreed with their partner's information during the discussion, they did so because they thought that information was accurate; only a minority of the time did they go along with their partner during discussion and revert to their own answer at the test. We draw parallels between the unknown mechanisms driving memory conformity effects and the search for mechanisms driving the misinformation effect two decades ago. Copyright © 2007 John Wiley & Sons, Ltd.     

A scaling analysis of the snake lightness illusion

Logvinenko and Maloney (2006) measured perceived dissimilarities between achromatic surfaces placed in two scenes illuminated by neutral lights that could differ in intensity. Using a novel scaling method, they found that dissimilarities between light surface pairs could be represented as a weighted linear combination of two dimensions, "surface lightness" (a perceptual correlate of the difference in the logarithm of surface albedo) and "surface brightness" (which corresponded to the differences of the logarithms of light intensity across the scenes). Here we attempt to measure the contributions of these dimensions to a compelling lightness illusion (the "snake illusion"). It is commonly assumed that this illusion is a result of erroneous segmentation of the snake pattern into regions of unequal illumination. We find that the illusory shift in the snake pattern occurs along the surface lightness dimension, with no contribution from surface brightness. Thus, even if an erroneous segmentation of the snake pattern into strips of unequal illumination does happen, it reveals itself, paradoxically, as illusory changes in surface lightness rather than as surface brightness. We conjecture that the illusion strength depends on the balance between two groups of illumination cues signaling the true (uniform) illumination and the pictorial (uneven) illumination.     

The relationship between susceptibility to false memories, dissociativity, and paranormal belief and experience

One hundred participants completed a News Coverage Questionnaire concerning personal memories of where they were, what they were doing and who they were with when footage of dramatic news events was first shown on television, as well as asking them to recall details of the footage itself. These news items included four events that are known to have been captured on film and one item concerning non-existent footage of the bombing of a nightclub in Bali. Overall, 36% of respondents reported false memories of the alleged footage of the Bali bombing. Participants reporting false memories were found to score significantly higher than those who did not report such memories on the Australian Sheep–Goat Scale, on various subscales of the Anomalous Experiences Inventory (Belief, Experience and Ability) and on the Dissociative Experiences Scale, supporting the hypothesis that believers in the paranormal may be more susceptible to false memories than non-believers.     

The Turing Test: the first 50 years

The Turing Test, originally proposed as a simple operational definition of intelligence, has now been with us for exactly half a century. It is safe to say that no other single article in computer science, and few other articles in science in general, have generated so much discussion. The present article chronicles the comments and controversy surrounding Turing's classic article from its publication to the present. The changing perception of the Turing Test over the last 50 years has paralleled the changing attitudes in the scientific community towards artificial intelligence: from the unbridled optimism of 1960s to the current realization of the immense difficulties that still lie ahead. I conclude with the prediction that the Turing Test will remain important, not only as a landmark in the history of the development of intelligent machines, but also with real relevance to future generations of people living in a world in which the cognitive capacities of machines will be vastly greater than they are now.     

The sibling familiarity effect: Is within-person facial variability shared across siblings?

Humans are experts at familiar face recognition, but poor at unfamiliar face recognition. Familiarity is created when a face is encountered across varied conditions, but the way in which a person’s appearance varies is identity-specific, so familiarity with one identity does not benefit recognition of other individuals. However, the faces of biological siblings share structural similarities, so we explored whether the benefits of familiarity are shared across siblings. Results show that familiarity with one half of a sibling pair improves kin detection (experiment 1), and that unfamiliar face matching is more accurate when targets are the siblings of familiar versus unfamiliar individuals (experiment 2). PCA applied to facial images of celebrities and their siblings demonstrates that faces are generally better reconstructed in the principal components of a same-sex sibling than those of an unrelated individual. When we encounter the unfamiliar sibling of someone we already know, our pre-existing representation of their familiar relation may usefully inform processing of the unfamiliar face. This can benefit both kin detection and identity processing, but the benefits are constrained by the degree to which facial variability is shared.     

Aging and strategic retrieval in a cued-recall test: the role of executive functions and fluid intelligence

Cued-recall in episodic memory was investigated in relation to low and high cognitive support at retrieval, executive function level and fluid intelligence level in 81 healthy adults divided first into two age groups (young and elderly adults). The first analyses showed that age-related differences were greater when a low cognitive support was provided to recall the words. An individual index of loss of performance when the number of cues was decreased was then calculated. Hierarchical regression analysis revealed that the executive functions measure (perseverative errors on the Wisconsin Card Sorting Test) was a better candidate than the fluid intelligence measure (Cattell's culture fair test) to account for the age-related variance of the size of performance loss. These findings suggest that age differences in implementing strategic retrieval may be mainly due to a decline in executive functions.     

Metacognitive beliefs across the continuum of psychosis: comparisons between patients with psychotic disorders, patients at ultra-high risk and non-patients

BACKGROUND: Recent models of emotional disorders and psychosis implicate metacognitive beliefs in the development and maintenance of psychological distress. We predicted that patients with established psychotic disorders and those meeting at risk mental state (ARMS) criteria (and, thus, at increased risk of developing psychosis) would show higher levels of metacognitive beliefs than non-patient controls. Furthermore, we predicted that patients with psychosis would show higher levels of such beliefs than the at risk group. METHOD: The Metacognitions Questionnaire was administered to 73 patients with psychotic disorders, 43 ARMS patients and 188 non-patients. RESULTS: As predicted, patients with psychotic diagnoses and those at risk scored higher on metacognitive belief dimensions than non-patients. Patients with psychosis showed higher positive metacognitive beliefs than the at risk patients, indicating a greater range of unhelpful metacognitions overall, when compared to non-patients. CONCLUSIONS: These findings are consistent with metacognitive conceptualisations of psychological disorders. The implications of these findings for clinical practice are discussed.     

Age differences in resistance to peer influence

Prior research describes the development of susceptibility to peer pressure in adolescence as following an inverted U-shaped curve, increasing during early adolescence, peaking around age 14, and declining thereafter. This pattern, however, is derived mainly from studies that specifically examined peer pressure to engage in antisocial behavior. In the present study, age differences and developmental change in resistance to peer influence were assessed using a new self-report instrument that separates susceptibility to peer pressure from willingness to engage in antisocial activity. Data from four ethnically and socioeconomically diverse samples comprising more than 3,600 males and females between the ages of 10 and 30 were pooled from one longitudinal and two cross-sectional studies. Results show that across all demographic groups, resistance to peer influences increases linearly between ages 14 and 18. In contrast, there is little evidence for growth in this capacity between ages 10 and 14 or between 18 and 30. Middle adolescence is an especially significant period for the development of the capacity to stand up for what one believes and resist the pressures of one's peers to do otherwise.