Christopher A. Longmore

Learning faces from photographs.

Previous studies examining face learning have mostly used only a single exposure to 1 image of each of the faces to be learned. However, in daily life, faces are usually learned from multiple encounters. These 6 experiments examined the effects on face learning of repeated exposures to single or multiple images of a face. All experiments provided evidence for image-specific picture learning taking place over and above any invariant face learning, with recognition accuracy always highest for the image studied and performance falling across transformations between study and test images. The relative roles of pictorial and structural codes in mediating learning faces from photographs need to be reconsidered.

Processes of overall similarity sorting in free classification.

The processes of overall similarity sorting were investigated in 5 free classification experiments. Experiments 1 and 2 demonstrated that increasing time pressure can reduce the likelihood of overall similarity categorization. Experiment 3 showed that a concurrent load also reduced overall similarity sorting. These findings suggest that overall similarity sorting can be a time-consuming analytic process. Such results appear contrary to the idea that overall similarity is a nonanalytic process (e.g., T. B. Ward, 1983) but are in line with F. N. Milton and A. J. Willss (2004) dimensional summation hypothesis and with the stochastic sampling assumptions of the extended generalized context model (K. Lamberts, 2000). Experiments 4 and 5 demonstrated that the relationship between stimulus presentation time and overall similarity sorting is nonmonotonic, and the shape of the function is consistent with the idea that the three aforementioned processes operate over different parts of the time course.

Is overall similarity classification less effortful than single-dimension classification?

It is sometimes argued that the implementation of an overall similarity classification is less effortful than the implementation of a single-dimension classification. In the current article, we argue that the evidence securely in support of this view is limited, and report additional evidence in support of the opposite proposition—overall similarity classification is more effortful than single-dimension classification. Using a match-to-standards procedure, Experiments 1A, 1B and 2 demonstrate that concurrent load reduces the prevalence of overall similarity classification, and that this effect is robust to changes in the concurrent load task employed, the level of time pressure experienced, and the short-term memory requirements of the classification task. Experiment 3 demonstrates that participants who produced overall similarity classifications from the outset have larger working memory capacities than those who produced single-dimension classifications initially, and Experiment 4 demonstrates that instructions to respond meticulously increase the prevalence of overall similarity classification.

The importance of internal facial features in learning new faces

For familiar faces, the internal features (eyes, nose, and mouth) are known to be differentially salient for recognition compared to external features such as hairstyle. Two experiments are reported that investigate how this internal feature advantage accrues as a face becomes familiar. In Experiment 1, we tested the contribution of internal and external features to the ability to generalize from a single studied photograph to different views of the same face. A recognition advantage for the internal features over the external features was found after a change of viewpoint, whereas there was no internal feature advantage when the same image was used at study and test. In Experiment 2, we removed the most salient external feature (hairstyle) from studied photographs and looked at how this affected generalization to a novel viewpoint. Removing the hair from images of the face assisted generalization to novel viewpoints, and this was especially the case when photographs showing more than one viewpoint were studied. The results suggest that the internal features play an important role in the generalization between different images of an individuals face by enabling the viewer to detect the common identity-diagnostic elements across non-identical instances of the face.

Covert Detection of Attractiveness among the Neurologically Intact: Evidence from Skin-Conductance Responses

Several studies have shown that participants, without a deficit in face recognition, give an increased skin conductance response (SCR) to familiar faces when presented subliminally, hence suggesting covert recognition of these faces. In the experiment presented here we manipulated familiarity and attractiveness and tested whether participants distinguished between faces for these variables when presented too fast to allow conscious recognition. Three sets of faces were presented: famous attractive; unfamiliar attractive; and unfamiliar less attractive. SCRs were the same for each category of faces whether presented subliminally or supraliminally, and were the same for attractive faces, whether famous or unfamiliar; however, SCRs differed between the attractive and less attractive faces. The findings support those of Stone et al (2001 Cognitive, Affective and Behavioral Neuroscience 1 183–191) and suggest that higher SCRs to famous faces are not necessarily due to covert recognition, but may be a response to the positive affective valence of the stimuli.

SKOOL versus ZOOL: Effects of orthographic and phonological long-term memory on nonword immediate serial recall

In a now-classic study Besner and Davelaar (1982) reported an advantage of pseudohomophone (PSH) over nonword recall in a visual immediate serial recall (ISR) task, which remained under articulatory suppression (AS), and interpreted the findings as indicating PSH items obtain support from stored phonological long-term memory (LTM) representations even when phonological rehearsal is disrupted. However, one key question relating to this PSH effect remains: could the results have been contaminated by a potential confound of orthographic familiarity (i.e., PSH items often look like the word they sound like)? As a result, the present study examined the impact of orthography on PSH ISR. Our findings indicate that PSH accuracy was consistently higher for items that had an orthographic similarity to the parent word, and this effect did not interact with concurrent task. We therefore argue that PSH items in ISR obtain independent support from both orthographic and phonological LTM representations. The present study demonstrates the critical impact of orthographic LTM representations on visual nonword ISR, and we suggest that this may be a fruitful avenue for further research.

Image dependency in the recognition of newly learnt faces

Research investigating the effect of lighting and viewpoint changes on unfamiliar and newly learnt faces has revealed that such recognition is highly image dependent and that changes in either of these leads to poor recognition accuracy. Three experiments are reported to extend these findings by examining the effect of apparent age on the recognition of newly learnt faces. Experiment 1 investigated the ability to generalize to novel ages of a face after learning a single image. It was found that recognition was best for the learnt image with performance falling the greater the dissimilarity between the study and test images. Experiments 2 and 3 examined whether learning two images aids subsequent recognition of a novel image. The results indicated that interpolation between two studied images (Experiment 2) provided some additional benefit over learning a single view, but that this did not extend to extrapolation (Experiment 3). The results from all studies suggest that recognition was driven primarily by pictorial codes and that the recognition of faces learnt from a limited number of sources operates on stored images of faces as opposed to more abstract, structural, representations.

Social influences on unconscious plagiarism and anti-plagiarism.

People are more likely to unconsciously plagiarise ideas from a same-sex partner than a different-sex partner, and more likely to unconsciously plagiarise if recalling alone rather than in the presence of their partner [Macrae, C. N., Bodenhausen, G. V., & Calvini, G. (1999). Contexts of cryptomnesia: May the source be with you. Social Cognition, 17, 273–297. doi:10.1521/soco.1999.17.3.273]. Two sets of experiments explore these phenomena, using extensions of the standard unconscious plagiarism paradigm. In Experiment 1A participants worked together in same- or different-sex dyads before trying to recall their own ideas or their partners ideas. More source errors were evident for same-sex dyads (Experiment 1A), but this effect was absent when participants recalled from both sources simultaneously (Experiment 1B). In Experiment 2A, participants recalled ideas from a single source either alone or in the presence of the partner, using an extended-recall task. Partner presence did not affect the availability of ideas, but did reduce the propensity to report them as task compliant, relative to a partner-present condition. Simultaneous recall from both sources removed this social effect (Experiment 2B). Thus social influences on unconscious plagiarism are apparent, but are influenced by the salience of the alternate source at retrieval.