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Amina Memon

Publications and source records attributed to Amina Memon.

11 recordsLinked to original sources
PubMed2006

False claims about false memory research.

Pezdek and Lam [Pezdek, K. & Lam, S. (2007). What research paradigms have cognitive psychologists used to study "False memory," and what are the implications of these choices? Consciousness and Cognition] claim that the majority of research into false memories has been misguided. Specifically, they charge that false memory scientists have been (1) misusing the term "false memory," (2) relying on the wrong methodologies to study false memories, and (3) misapplying false memory research to real world situations. We review each of these claims and highlight the problems with them. We conclude that several types of false memory research have advanced our knowledge of autobiographical and recovered memories, and that future research will continue to make significant contributions to how we understand memory and memory errors.

Child↗
PubMed2006

I saw it for longer than you: the relationship between perceived encoding duration and memory conformity.

The memory conformity effect is when people's memories become similar to one another's following a discussion. The present study examined whether an individual's beliefs in the quality of their memory, relative to another person's, mediates susceptibility to memory conformity. Perceived encoding duration was manipulated by telling dyad members that one person had encoded a set of pictures for either half or twice as long as their partner. In fact, actual encoding duration was the same for all participants. Dyad members each encoded slightly different versions of otherwise identical pictures and discussed them prior to an individual free recall test. Participants who believed that they had encoded the pictures for half as long as their partner were more susceptible to memory conformity, as indicated by their increased tendency to report errant items at test that had been encountered from their partner rather than items that they had actually seen. This effect of perceived encoding duration on memory conformity was mediated through response order. A source monitoring test found that these unseen items were errantly attributed to the pictures approximately 50% of the time. The findings are discussed in relation to the role of metamemory in susceptibility to memory conformity.

Adult↗
PubMed2006

Pre-event stereotypes and misinformation effects in young children.

This study examined the effects of pre-event stereotypes on 5-year-old children's memories for the visit of an adult male to their school. Children were read three stories in which this man was described in positive, negative, or neutral terms. Following the visit, children were read post-event narratives which contained positive and negative misinformation that was consistent and inconsistent with the pre-event stereotype. Children were then given a recognition test under inclusion and exclusion instructions. Negative misinformation was correctly rejected more often than positive misinformation. Children given a positive pre-event stereotype were more likely to accept positive misinformation than those in the other stereotype conditions. Process dissociation analyses revealed that recollection for negative misinformation was larger than for positive misinformation; the opposite was the case for familiarity.

Analysis of Variance↗
PubMed2006

Memory conformity: disentangling the steps toward influence during a discussion.

When two people see the same event and discuss it, one person's memory report can influence what the other person subsequently claims to remember. We refer to this as memory conformity. In the present article, two factors underlying the memory conformity effect are investigated. First, are there any characteristics of the dialogue that predict memory conformity? Second, is memory conformity differentially affected when information is encountered that omits, adds to, or contradicts originally encoded items? Participants were tested in pairs. The two members of each pair encoded slightly different versions of complex scenes and discussed them prior to an individual free recall test. The discussions were audiotaped, transcribed, and analyzed. Our most striking finding was that the witness initiating the discussion was most likely to influence the other witness's memory report. Furthermore, witnesses were most likely to be influenced when an additional (previously unseen) item of information was encountered in the discussion.

Adolescent↗
PubMed2004

Understanding pretrial publicity: predecisional distortion of evidence by mock jurors.

Prejudicial pretrial publicity (PTP) constitutes a serious source of juror bias. The current study examined differences in predecisional distortion for mock jurors exposed to negative PTP (N-PTP) versus nonexposed control participants. According to work by K. A. Carlson and J. E. Russo (2001), predecisional distortion occurs when jurors bias new evidence in favor of their current leading party (prosecution or defense) rather than evaluating this information for its actual probative properties. Jury-eligible university students (N=116) acted as jurors in a mock trial. Elevated rates of guilty verdicts were observed in the N-PTP condition. Predecisional distortion scores were significantly higher in the N-PTP condition and reflected a proprosecution bias. The effect of prejudicial PTP on verdict outcomes was mediated by predecisional distortion in the evaluation of testimony. Results are discussed in relation to motivated decision making and confirmation biases.

Adolescent↗
PubMed2003

Improving the identification accuracy of senior witnesses: do prelineup questions and sequential testing help?

Eyewitness research has identified sequential lineup testing as a way of reducing false lineup choices while maintaining accurate identifications. The authors examined the usefulness of this procedure for reducing false choices in older adults. Young and senior witnesses viewed a crime video and were later presented with target present orabsent lineups in a simultaneous or sequential format. In addition, some participants received prelineup questions about their memory for a perpetrator's face and about their confidence in their ability to identify the culprit or to correctly reject the lineup. The sequential lineup reduced false choosing rates among young and older adults in target-absent conditions. In target-present conditions, sequential testing significantly reduced the correct identification rate in both age groups.

Adolescent↗
PubMed2003

The aging eyewitness: effects of age on face, delay, and source-memory ability.

As a way to examine the nature of age-related differences in lineup identification accuracy, young (16-33 years) and older (60-82 years) witnesses viewed two similar videotaped incidents, one involving a young perpetrator and the other involving an older perpetrator. The incidents were followed by two separate lineups, one for the younger perpetrator and one for the older perpetrator. When the test delay was short (35 min), the young and older witnesses performed similarly on the lineups, but when the tests were delayed by 1 week, the older witnesses were substantially less accurate. When the target was absent from the lineups, the older witnesses made more false alarm errors, particularly when the faces were young. When the target was present in the lineups, correct identifications by both young and older witnesses were positively correlated with a measure of source recollection derived from a separate face-recognition task. Older witnesses scored poorly on this measure, suggesting that source-recollection deficits are partially responsible for age-related differences in performance on the lineup task.

Adolescent↗
PubMed2003

Exposure duration: effects on eyewitness accuracy and confidence.

The current study examined the relationship between the length of exposure to a face in an eyewitness setting and identification accuracy and confidence. A sample of 164 young (ages 17-25) and older (ages 59-81) adults viewed a simulated crime in which they saw the culprit's face for a short (12 s) or long (45 s) duration. They were then tested with a target absent (a line-up not containing the culprit) or target present line-up. Identification accuracy rates for both young and older participants were significantly higher under the long exposure condition. In the short exposure condition, witnesses who had made a correct identification of the target were more confident than incorrect witnesses. In the long exposure condition the confidence ratings of accurate and inaccurate witnesses did not differ. Discussion focuses on the extent to which extended exposure may inflate confidence judgments and variables that may moderate the relationship between exposure duration and face recognition accuracy.

Adolescent↗
PubMed2002

Eyewitness recognition errors: the effects of mugshot viewing and choosing in young and old adults.

Eyewitness memory is vulnerable to information encountered prior to a lineup. Young (18-30 years) and older (60-80 years) witnesses viewed a crime video. Some witnesses were then exposed to mugshots of innocent suspects that included a critical foil. After a 48-h delay, all the witnesses took part in a target-absent lineup that included the critical foil and five new foils. Witnesses who picked one of the mugshots as the likely perpetrator showed inflated rates of choosing the critical foil from the lineup. Context reinstatement instructions did not reduce choices of innocent foils following mugshot exposure. Despite age-related increases in false choosing, age did not qualify other effects. The results are discussed in terms of commitment, source memory, and gist-based processing.

Adult↗
PubMed1999

Point mutations in the guanine phosphoribosyltransferase from Giardia lamblia modulate pyrophosphate binding and enzyme catalysis.

Guanine phosphoribosyltransferase (GPRTase) from Giardia lamblia, an enzyme required for guanine salvage and necessary for the survival of this parasitic protozoan, has been kinetically characterized. Phosphoribosyltransfer proceeds through an ordered sequential mechanism common to many related purine phosphoribosyltransferases (PRTases) with alpha-D-5-phosphoribosyl-1-pyrophosphate (PRPP) binding to the enzyme first and guanosine monophosphate (GMP) dissociating last. The enzyme is a highly unique purine PRTase, recognizing only guanine as its purine substrate (K(m) = 16.4 microM) but not hypoxanthine (K(m) > 200 microM) nor xanthine (no reaction). It also catalyzes both the forward (kcat = 76.7 s-1) and reverse (kcat = 5.8.s-1) reactions at significantly higher rates than all the other purine PRTases described to date. However, the relative catalytic efficiencies favor the forward reaction, which can be attributed to an unusually high K(m) for pyrophosphate (PPi) (323.9 microM) in the reverse reaction, comparable only with the high K(m) for PPi (165.5 microM) in Tritrichomonas foetus HGXPRTase-catalyzed reverse reaction. As the latter case was due to the substitution of threonine for a highly conserved lysine residue in the PPi-binding loop [Munagala et al. (1998) Biochemistry 37, 4045-4051], we identified a corresponding threonine residue in G. lamblia GPRTase at position 70 by sequence alignment, and then generated a T70K mutant of the enzyme. The mutant displays a 6.7-fold lower K(m) for PPi with a twofold increase in the K(m) for PRPP. Further attempts to improve PPi binding led to the construction of a T70K/A72G double mutant, which displays an even lower K(m) of 7.9 microM for PPi. However, mutations of the nearby Gly71 to Glu, Arg, or Ala completely inactivate the GPRTase, suggesting the requirement of flexibility in the putative PPi-binding loop for enzyme catalysis, which is apparently maintained by the glycine residue. We have thus tentatively identified the PPi-binding loop in G. lamblia GPRTase, and attributed the relatively higher catalytic efficiency in the forward reaction to the unusual loop structure for poor PPi binding in the reverse reaction.

Animals↗