55 research outputs found

    Face-space: A unifying concept in face recognition research

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    The concept of a multidimensional psychological space, in which faces can be represented according to their perceived properties, is fundamental to the modern theorist in face processing. Yet the idea was not clearly expressed until 1991. The background that led to the development of face-space is explained, and its continuing influence on theories of face processing is discussed. Research that has explored the properties of the face-space and sought to understand caricature, including facial adaptation paradigms, is reviewed. Face-space as a theoretical framework for understanding the effect of ethnicity and the development of face recognition is evaluated. Finally, two applications of face-space in the forensic setting are discussed. From initially being presented as a model to explain distinctiveness, inversion, and the effect of ethnicity, face-space has become a central pillar in many aspects of face processing. It is currently being developed to help us understand adaptation effects with faces. While being in principle a simple concept, face-space has shaped, and continues to shape, our understanding of face perception

    Do intoxicated witnesses produce poor facial composite images?

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    The effect of alcohol intoxication on witness memory and performance has been the subject of research for some time, however, whether intoxication affects facial composite construction has not been investigated. Intoxication was predicted to adversely affect facial composite construction. Thirty-two participants were allocated to one of four beverage conditions consisting of factorial combinations of alcohol or placebo at face encoding, and later construction. Participants viewed a video of a target person and constructed a composite of this target the following day. The resulting images were presented as a full face composite, or a part face consisting of either internal or external facial features to a second sample of participants who provided likeness ratings as a measure of facial composite quality. Intoxication at face encoding had a detrimental impact on the quality of facial composites produced the following day, suggesting that alcohol impaired the encoding of the target faces. The common finding that external compared to internal features are more accurately represented was demonstrated, even following alcohol at encoding. This finding was moderated by alcohol and target face gender such that alcohol at face encoding resulted in reduced likeness of external features for male composite faces only. Moderate alcohol intoxication impairs the quality of facial composites, adding to existing literature demonstrating little effect of alcohol on line-up studies. The impact of intoxication on face perception mechanisms, and the apparent narrowing of processing to external face areas such as hair, is discussed in the context of alcohol myopia theory

    An evaluation of US systems for facial composite production

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    Witness and victims of serious crime are normally requested to construct a facial composite of a suspect’s face. While modern systems for constructing composites have been evaluated extensively in the UK, this is not the case in the US. In the current work, two popular computerized systems in the US, FACES and Identikit 2000, were evaluated against a ‘reference’ system, PRO-fit, where performance is established. In Experiment 1, witnesses constructed a composite with both PRO-fit and FACES using a realistic procedure. The resulting composites were very poorly named, but the PRO-fit emerged best in ‘cued’ naming and two supplementary measures: composite sorting and likeness ratings. In Experiment 2, PRO-fit was compared with Identikit 2000, a sketch-like feature system. Spontaneous naming was again very poor, but both cued naming and sorting suggested that the systems were similar. The results support previous findings that modern systems do not produce identifiable composites

    Familiarity effects in the construction of facial-composite images using modern software systems

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    We investigate the effect of target familiarity on the construction of facial composites, as used by law enforcement to locate criminal suspects. Two popular software construction methods were investigated. Participants were showna target face that was either familiar or unfamiliar to them and constructed a composite of it from memoryusing a typical ‘feature’ system, involving selection of individual facial features, or one of the newer ‘holistic’ types, involving repeated selection and breeding from arrays of whole faces. This study found that composites constructed of a familiar face were named more successfully than composites of an unfamiliar face; also, naming of composites of internal and external features was equivalent for construction of unfamiliar targets, but internal features were better named than the external features for familiar targets. These findings applied to both systems, althoughbenefit emerged for the holistic type due to more accurate construction of internal features and evidence for a whole-face advantage

    The impact of irrelevant auditory facial descriptions on memory for target faces: implications for eyewitness memory

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    Purpose – The purpose of this paper is to investigate the potential susceptibility of eyewitness memory to the presence of extraneous background speech that comprises a description consistent with, or at odds with, a target face. Design/methodology/approach – A between-participants design was deployed whereby participants viewed an unfamiliar target face in the presence of quiet, or extraneous to-be-ignored speech comprising a verbal description that was either congruent or incongruent with the target face. After a short distractor task, participants were asked to describe the target face and construct a composite of the face using PRO-fit software. Further participants rated the likeness of the composites to the target. Findings – Recall of correct facial descriptors was facilitated by congruent to-be-ignored speech and inhibited by incongruent to-be-ignored speech compared to quiet. Moreover, incorrect facial descriptors were reported more often in the incongruent speech condition compared with the congruent speech and quiet conditions. Composites constructed after exposure to incongruent speech were rated as worse likenesses to the target than those created after exposure to congruent speech and quiet. Whether congruent speech facilitated or impaired composite construction was found to depend on the distinctiveness of the target face. Practical implications – The results suggest that the nature of to-be-ignored background speech has powerful effects on the accuracy of information verbally reported from having witnessed a face. Incongruent speech appears to disrupt the recognition processes that underpin face construction while congruent speech may have facilitative or detrimental effects on this process, depending on the distinctiveness of the target face. Originality/value – This is one of the first studies to demonstrate that extraneous speech can produce adverse effects on the recall and recognition of complex visual information: in this case, the appearance of a human face. </jats:sec

    Chatting in the face of the eyewitness: The impact of extraneous cell-phone conversation on memory for a perpetrator.

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    Cell-phone conversation is ubiquitous within public spaces. The current study investigates whether ignored cell-phone conversation impairs eyewitness memory for a perpetrator. Participants viewed a video of a staged crime in the presence of 1 side of a comprehensible cell-phone conversation (meaningful halfalogue), 2 sides of a comprehensible cell-phone conversation (meaningful dialogue), 1 side of an incomprehensible cell-phone conversation (meaningless halfalogue), or quiet. Between 24 and 28 hr later, participants freely described the perpetrator's face, constructed a single composite image of the perpetrator from memory, and attempted to identify the perpetrator from a sequential lineup. Further, participants rated the likeness of the composites to the perpetrator. Face recall and lineup identification were impaired when participants witnessed the staged crime in the presence of a meaningful halfalogue compared to a meaningless halfalogue, meaningful dialogue, or quiet. Moreover, likeness ratings showed that the composites constructed after ignoring the meaningful halfalogue resembled the perpetrator less than did those constructed after experiencing quiet or ignoring a meaningless halfalogue or a meaningful dialogue. The unpredictability of the meaningful content of the halfalogue, rather than its acoustic unexpectedness, produces distraction. The results are novel in that they suggest that an everyday distraction, even when presented in a different modality to target information, can impair the long-term memory of an eyewitnes

    The impact of external facial features on the construction of facial composites

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    Witnesses may construct a composite face of a perpetrator using a computerised interface. Police practitioners guide witnesses through this unusual process, the goal being to produce an identifiable image. However, any changes a perpetrator makes to their external facial-features may interfere with this process. In Experiment 1, participants constructed a composite using a holistic interface one day after target encoding. Target faces were unaltered, or had altered external-features: (i) changed hair, (ii) external-features removed or (iii) naturally-concealed external-features (hair, ears, face-shape occluded by a hooded top). These manipulations produced composites with more error-prone internal-features: participants’ familiar with a target’s unaltered appearance less often provided a correct name. Experiment 2 applied external-feature alterations to composites of unaltered targets; although whole-face composites contained less error-prone internal-features, identification was impaired. Experiment 3 replicated negative effects of changing target hair on construction and tested a practical solution: selectively concealing hair and eyes improved identification

    The impact of weapons and unusual objects on the construction of facial composites

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    The presence of a weapon in the perpetration of a crime can impede an observer’s ability to describe and/or recognise the person responsible. In the current experiment, we explore whether weapons when present at encoding of a target identity interfere with the construction of a facial composite. Participants encoded an unfamiliar target face seen either on its own or paired with a knife. Encoding duration (10 or 30 s) was also manipulated. The following day, participants recalled the face and constructed a composite of it using a holistic system (EvoFIT). Correct naming of the participants’ composites was found to reduce reliably when target faces were paired with the weapon at 10 s but not at 30 s. These data suggest that the presence of a weapon reduces the effectiveness of facial composites following a short encoding duration. Implications for theory and police practice are discussed

    Identification of Stable Resistance to Smut in Pearl Millet

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    More than 1,500 accessions from a germ plasm working collection and 6,200 advanced breeding lines were screened to identify resistance to smut in pearl millet. All advanced breeding lines were susceptible, but resistance was detected in several germ plasm accessions originating from Nigeria, Senegal, Mali, Cameroon, Uganda, Lebanon, and India. To combine resistance with agronomic eliteness, crosses were made between smut-resistant lines and agronomically elite inbred lines, and pedigree selection was carried out in the segregating generations up to the F6 generation under high disease pressure. Stability of resistance was tested through a multilocational testing program, the International Pearl Millet Smut Nursery (IPMSN). Selections from six germ plasm accessions (SSC FS 252-S-4, ICI 7517-S-1, ExB 132-2-S-5-2-DM-1, ExB 46-1-2-S-2, ExB 112-1-S-1-1, and P-489-S-3) and four, newly developed, smut-resistant, agronomically elite lines (ICMPS 100-5-1, 900-9-3, 1600-2-4, and 2000-5-2) showed consistently high levels of smut resistance for 1–6 yr at six or seven locations in India and West Africa. These lines had across-location mean smut severities of less than 5% compared with 35% or more in the susceptible checks. These lines were also resistant to downy mildew in India

    EvoFIT: A holistic, evolutionary facial imaging technique for creating composites

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    EvoFIT, a computerized facial composite system is being developed as an alternative to current systems. EvoFIT faces are initially presented to a witness with random characteristics, but through a process of selection and breeding, a composite is “evolved.” Comparing composites constructed with E-FIT, a current system, a naming rate of 10% was found for EvoFIT and 17% for E-FIT. Analysis revealed that target age was limiting factor for EvoFIT and a second study with age-appropriate targets visible during composite construction produced a naming rate similar to E-FIT. Two more-realistic studies were conducted that involved young target faces and two current systems (E-FIT and PROfit). Composites from both of these experiments were poorly named but a significant benefit emerged for EvoFIT
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