Biomedical subjects

Timothy J Perfect

Publications and source records attributed to Timothy J Perfect.

7 recordsLinked to original sources

PubMed2007

Visual memory for shapes in deaf signers and nonsigners and in hearing signers and nonsigners: atypical lateralization and enhancement.

Deaf and hearing individuals who either used sign language (signers) or not (nonsigners) were tested on visual memory for objects and shapes that were difficult to describe verbally with a same/different matching paradigm. The use of 4 groups was designed to permit a separation of effects related to sign language use (signers vs. nonsigners) and effects related to auditory deprivation (deaf vs. hearing). Forty deaf native signers and nonsigners and 51 hearing signers and nonsigners participated in the study. Signing individuals (both deaf and hearing) were more accurate than nonsigning individuals (deaf and hearing) at memorizing shapes. For the shape memory task but not the object task, deaf signers and nonsigners displayed right hemisphere (RH) advantage over the left hemisphere (LH). Conversely, both hearing groups displayed a memory advantage for shapes in the LH over the RH. Results indicate that enhanced memory performance for shapes in signers (deaf and hearing) stems from the visual skills acquired through sign language use and that deafness, irrespective of language background, leads to the use of a visually based strategy for memory of difficult-to-describe items.

Adult↗

PubMed2005

When elaboration leads to appropriation: unconscious plagiarism in a creative task.

Brown and Murphy's (1989) three-stage paradigm (generation, recall-own, generate-new) was used to assess the effects of participant elaboration on rates of unconscious plagiarism in two experiments using a creative task. Following the generation phase, participants imagined and rated a quarter of the ideas (imagery elaboration), generated improvements to another quarter (generative elaboration), and listened to a quarter of the ideas again without elaboration, with the remaining ideas acting as control. A week later, participants attempted to recall their own ideas, and generate new solutions to the same cues. In Experiment 1 both forms of elaboration equally increased correct recall, and decreased plagiarism in the generate-new task. However, generative elaboration led to significantly greater plagiarism in the recall-own task, but imagery elaboration did not. Participants in Experiment 2 were encouraged not to plagiarise by means of a financial incentive. However, they showed the same pattern as seen in Experiment 1. Therefore, contrary to a simple strength account, the probability of a person plagiarising another's ideas is linked to the particular nature of the elaboration carried out on that idea, rather than its familiarity.

Awareness↗

PubMed2005

Effects of processing bias on the recognition of composite face halves.

Research has shown that face recognition accuracy can be improved by prior global processing and impaired by prior local processing (Macrae & Lewis, 2002). The aim of this study was to test the processing bias account of face recognition, using the composite face task (Young, Hellawell, & Hay, 1987), a test of featural recognition. Undergraduate volunteers (N = 75) participated in a between-subjects design that tested their ability to recognize face halves within a composite, following either global or local Navon processing or a control task. Results showed that, as compared with the control task, local processing speeded ability to recognize face halves. These results provide support for the processing bias account of face recognition.

Cognition↗

PubMed2003

Local processing bias impairs lineup performance.

Evidence suggests that lineup performance by witnesses can be influenced by inducing a prior local or global processing bias. In this study, 90 witnesses attempted to identify a perpetrator from a lineup. Prior to the lineup, 30 participants completed a global processing task followed by a local processing task; 30 did the same tasks in reverse order; and 30 acted as controls. Analysis indicated that the last task completed influenced subsequent lineup performance.

Humans↗

PubMed2003

Adult age differences in unconscious transference: source confusion or identity blending?

Eyewitnesses are known often to falsely identify a familiar but innocent bystander when asked to pick out a perpetrator from a lineup. Such unconscious transference errors have been attributed to either identity confusions at encoding or source retrieval errors. Three experiments contrasted younger and older adults in their susceptibility to such misidentifications. Participants saw photographs of perpetrators, then a series of mug shots of innocent bystanders. A week later, they saw lineups containing bystanders (and others containing perpetrators in Experiment 3) and were asked whether any of the perpetrators were present. When younger faces were used as stimuli (Experiments 1 and 3), older adults showed higher rates of transference errors. When older faces were used as stimuli (Experiments 2 and 3), no such age effects in rates of unconscious transference were apparent. In addition, older adults in Experiment 3 showed an own-age bias effect for correct identification of targets. Unconscious transference errors were found to be due to both source retrieval errors and identity confusions, but age-related increases were found only in the latter.

Adult↗

PubMed2002

Retrieval-induced forgetting in Alzheimer's disease.

It is claimed that Alzheimer's disease (AD) patients show reduced inhibitory processing and this has been put forward as a reason why AD patients make intrusion errors at recall. However, the evidence to date has been equivocal, because non-inhibitory mechanisms can account for the pattern of findings. Recently, however, a paradigm has been developed that is claimed to give a purer measure of inhibitory processing in episodic memory, the retrieval-induced forgetting (RIF) paradigm [Inhibitory Processes in Attention, Memory and Language, Academic Press, San Diego, 1994, p. 265; J. Exp. Psychol.: Learning, Memory Cognition 20 (1994) 1063; Psychol. Rev. 102 (1995) 68]. Thus, we were interested whether AD patients would show a deficit in inhibitory processing using this procedure. Participants studied lists of category cue-exemplar pairs (e.g. fruit-orange) then practised retrieval for a subset of items from a subset of categories before taking a final memory test for all studied items. As in previous work, inhibition was measured as the difference between final memory performance for unpractised items from practised categories, and unpractised items from unpractised categories. The results show that AD patients showed normal levels of inhibition with both tests of cued recall and category generation (CG). This suggests that a deficit in inhibitory processes during retrieval is not behind the high levels of intrusion errors made in recall in AD.

Aged↗

PubMed2002

Assessing the inhibitory account of retrieval-induced forgetting with implicit-memory tests.

Five experiments examined whether retrieval-induced-forgetting effects are observed for implicit tests of memory. In each experiment participants first studied category-exemplar paired associates, then practiced retrieval for a subset of items from a subset of categories before finally completing memory tests for all the studied items. In standard fashion, inhibition was measured as the performance difference of unpracticed items from practiced categories and unpracticed items from unpracticed categories. Across the 5 experiments poorer performance for unpracticed items was seen in conceptual implicit memory (category generation and category matching) but not in perceptual implicit memory (stem completion, perceptual identification). Thus, retrieval-induced-forgetting effects are limited to tests of conceptual memory.

Adult↗