Face Recognition without Identification
Anne M. Cleary · InTech eBooks · 2011
Most people have had the experience of recognizing a person's face as familiar despite failing to identify who the person is or where the person was seen before.Many domains of research have aimed to study this phenomenon; thus, there exist many research paradigms for attempting to tap it in laboratory settings.Among these paradigms are dual-process recognition memory paradigms within the recognition memory literature (e.g., Yonelinas, 2002), feeling-of-knowing paradigms within the metacognition literature (Koriat, 1995), and face identification paradigms within the more general face recognition literature (e.g., Burton, Bruce & Hancock, 1999). Dual process methods of studying recognition memory Familiarity-based recognitionRecognition memory is the type of memory that enables people to determine that they have experienced something previously.Dual process theories of recognition memory hold that it can be based on either of two processes: Recollection or familiarity (see Diana et al., 2006, or Yonelinas, 2002, for reviews).Recollection-based recognition occurs when one recognizes having experienced something before based on the retrieval of specifics about the prior occurrence.For example, one might pass someone on the sidewalk and recognize that the person has been seen before by calling to mind the specific instance in which the person was seen before: This person was the receptionist at the dentist the other day.In contrast, familiarity-based recognition occurs when one recognizes having experienced something before based only on a gut feeling or sense about the situation.For example, one might pass someone on the sidewalk and only recognize that the person is familiar without recalling where that person was seen before.The person simply seems familiar.From a dual-process perspective, studying recognition that is familiarity-based requires teasing apart instances of familiarity-based recognition and instances of recollection-based recognition.Over the years, researchers have developed many methods of doing so within list-learning paradigms (see Yonelinas, 2002, or Mandler, 2008, for reviews).Some existing methods are: The process dissociation procedure (e.g., Jacoby, Toth, & Yonelinas, 1993), the tasks procedure (e.g., Cleary & Greene, 2001;Yonelinas, 1997), analyses of receiver operating characteristics (ROCs, Yonelinas, 1994, 1997), the signal-lag procedure (e.g., Hintzman & Curran, 1994) and the remember-know procedure (e.g., Rajaram, 1993).By separating familiarity from recollection in studies of recognition, presumably the characteristics of familiarity can be studied.Indeed, much has been learned about www.intechopen.comReviews, Refinements and New Ideas in Face Recognition 318 familiarity from dual-process methods.Yonelinas (1994) combined the process-dissociation procedure with the analysis of receiver operating characteristics (ROCs) and found that although overall recognition memory tends to lead to a z-ROC slope of significantly less than 1.0, when the contribution of familiarity is isolated, the slope of the z-ROC approximates 1.0, as would be predicted by simple signal detection theory; this suggests that familiarity may be well-described by simple single detection theory when it is isolated.Rajaram (1993) used the remember-know procedure (whereby subjects simply indicate whether the basis for each "yes" response on a recognition test was recollection or familiarity) to show that familiarity, but not recollection, is affected by manipulations of perceptual fluency, such as the rapid presentation of a test stimulus prior to presenting it for the recognition decision.Jacoby, et al. (1993) found similar results using the processdissociation procedure.Rajaram and Geraci (2000) used the remember-know technique to show that familiarity is affected by manipulations of conceptual fluency, such as the presentation of a semantically related word prior to presenting the recognition test stimulus.Unlike recollection, familiarity is unaffected by divided attention at encoding, as has been shown using the process-dissociation procedure (Jacoby, et al., 1993) and the rememberknow paradigm (Gardiner & Parkin, 1990).Research using the signal-lag procedure, in which subjects are given varying response deadlines across recognition test trials, has shown that familiarity-based old-new discrimination emerges sooner in the processing stream than recollection-based old-new discrimination.This has been shown with such tasks as the plurality task, in which subjects must discriminate between words that remain the same from study to test (e.g., frog) and words that changed plurality from study to test (e.g., frogs).Subjects can discriminate which root words were studied versus unstudied significantly earlier than they can discriminate between correct and incorrect pluralities, suggesting that familiarity becomes available earlier on in processing than recollection (Hintzman & Curran, 1994).This finding is consistent with studies of event-related potentials (ERPs) during recognition testing (e.g., Curran, 2000;Curran & Cleary, 2003), which have suggested that the brain electrophysiological correlate to familiarity occurs earlier (300-500 ms) than that of recollection (e.g., 500-800 ms).Mathematical models often describe familiarity in terms of features (e.g., Clark & Gronlund, 1996).Memory traces for encoded items each exist as a set of the separable features that composed the item itself.At the time of the recognition test, the features in the test item are matched, on a feature by feature basis, with all of the features that have been stored in memory.From this perspective, features should play a critical role in familiarity-based recognition.Indeed, many studies have shown that there are various features that, when isolated, can produce familiarity-based recognition.Among the features that have been shown to play a role in familiarity are: Letters of words (Cleary & Greene, 2000, 2001), phonemes (Cleary, Winfield & Kostic, 2007), geometric shapes within pictures (Cleary, Langley & Seiler, 2004), song notes (Kostic & Cleary, 2009) and song rhythm (Kostic & Cleary, 2009).Finally, familiarity appears to be left intact with certain forms of memory impairment and with aging.Many amnesics have been shown to be impaired on recollection with familiarity relatively spared (e.g., Aggleton & Brown, 1999;Vann et al., 2009), suggesting that whereas recollection involves the hippocampus proper, familiarity may involve other regions of the medial temporal lobe (MTL) that are often spared in amnesics.Functional neuroimaging How to referenceIn order to correctly reference this scholarly work, feel free to copy and paste the following: