Investigating the face inversion effect in a deaf population using the Dimensions Tasks

Early experience can change the way people process faces. Early deafness provides deaf children with the opportunity to learn sign language, which is likely to alter their face processing strategy. The goal of the current study was to investigate whether early deafness, combined with the sign language experience, was able to change the face processing strategy using the Dimensions Task. In the Face Dimensions Task, configural and featural information were parametrically and independently manipulated in the eye and mouth region of the face. The manipulations for configural information involved changing the distance between the eyes or the distance between the mouth and the nose. The manipulations for featural information involved changing the size of the eyes or the size of the mouth. Similar manipulations were applied in the House Dimensions Task, with top and bottom windows treated as eyes and mouth. In the Face Dimensions Task, both the signing deaf and hearing participants showed a larger inversion effect in the mouth condition than the eye condition. However, as compared to hearing participants, deaf participants showed smaller inversion effect in the mouth condition, because their performance in the inverted mouth condition was not compromised by inversion to the same extent as the hearing participants. In the House Dimensions Task, this effect was not present, suggesting that it was face specific. This effect could be explained by the redistributed attentional resources from the centre to peripheral visual fields of deaf participants.     

Renewal of Extinguished Lever-Press Responses upon Return to the Training Context

Two experiments with rats explored renewal effects in operant conditioning preparations. When pressing a lever was trained in one context and then extinguished in a second context, the responding was renewed by returning to the original context (ABA renewal) in Experiment 1. This finding was replicated in Experiment 2 with discriminative operant performance signaled by a localized light cue. In spite of the successful demonstration of ABA renewal effect in these experiments, AAB renewal was detected in neither experiment: When the responses had been extinguished in the context of acquisition, testing the rats in a second context did not renew the responses. The demonstration of ABA renewal but no AAB renewal suggests that extinction in another context and/or a return to the original context are critical for renewal of extinguished operant performance.     

Parts and wholes in face recognition

Are faces recognized using more holistic representations than other types of stimuli? Taking holistic representation to mean representation without an internal part structure, we interpret the available evidence on this issue and then design new empirical tests. Based on previous research, we reasoned that if a portion of an object corresponds to an explicitly represented part in a hierarchical visual representation, then when that portion is presented in isolation it will be identified relatively more easily than if it did not have the status of an explicitly represented part. The hypothesis that face recognition is holistic therefore predicts that a part of a face will be disproportionately more easily recognized in the whole face than as an isolated part, relative to recognition of the parts and wholes of other kinds of stimuli. This prediction was borne out in three experiments: subjects were more accurate at identifying the parts of faces, presented in the whole object, than they were at identifying the same part presented in isolation, even though both parts and wholes were tested in a forced-choice format and the whole faces differed only by one part. In contrast, three other types of stimuli--scrambled faces, inverted faces, and houses--did not show this advantage for part identification in whole object recognition.     

An Infinitary Extension of Jankov’s Theorem

It is known that for any subdirectly irreducible finite Heyting algebra A and any Heyting algebra B, A is embeddable into a quotient algebra of B, if and only if Jankov’s formula χ _A for A is refuted in B. In this paper, we present an infinitary extension of the above theorem given by Jankov. More precisely, for any cardinal number κ, we present Jankov’s theorem for homomorphisms preserving infinite meets and joins, a class of subdirectly irreducible complete κ-Heyting algebras and κ-infinitary logic, where a κ-Heyting algebra is a Heyting algebra A with # ≥  κ and κ-infinitary logic is the infinitary logic such that for any set Θ of formulas with # Θ ≥  κ, ∨Θ and ∧Θ are well defined formulas.     

Race-specific perceptual discrimination improvement following short individuation training with faces

This study explores the effect of individuation training on the acquisition of race-specific expertise. First, we investigated whether practice individuating other-race faces yields improvement in perceptual discrimination for novel faces of that race. Second, we asked whether there was similar improvement for novel faces of a different race for which participants received equal practice, but in an orthogonal task that did not require individuation. Caucasian participants were trained to individuate faces of one race (African American or Hispanic) and to make difficult eye-luminance judgments on faces of the other race. By equating these tasks we are able to rule out raw experience, visual attention, or performance/success-induced positivity as the critical factors that produce race-specific improvements. These results indicate that individuation practice is one mechanism through which cognitive, perceptual, and/or social processes promote growth of the own-race face recognition advantage.     

Composites, compromises, and CHARM: what is the evidence for blend memory representations?

Metcalfe's (1990) distributed memory model simulates many misinformation effects by assuming representations that superimpose information from multiple sources. In the present article, two types of evidence are reviewed for such "blend" representations: composite recollections, including items from both the original and postevent sources (e.g., a previously seen intersection is remembered with a subsequently suggested stop sign), and compromise recollections, including features that cannot be exclusively associated with either source (e.g., a green car that was later suggested to be blue is remembered as bluish green). The considerable evidence for composite recollections provides little support for blend representations. Compromise recollections, though seemingly more persuasive, are both rare and interpretable without postulating blend representations. Speculation is made about potential findings that would support blend representations.     

Exploring the perceptual spaces of faces, cars and birds in children and adults

While much developmental research has focused on the strategies that children employ to recognize faces, less is known about the principles governing the organization of face exemplars in perceptual memory. In this study, we tested a novel, child-friendly paradigm for investigating the organization of face, bird and car exemplars. Children ages 3-4, 5-6, 7-8, 9-10, 11-12 and adults were presented with 50/50 morphs of typical and atypical face, bird and car parent images. Participants were asked to judge whether the 50/50 morph more strongly resembled the typical or the atypical parent image. Young and older children and adults showed a systematic bias to the atypical faces and birds, but no bias toward the atypical cars. Collectively, these findings argue that by the age of 3, children encode and organize faces, birds and cars in a perceptual space that is strikingly similar to that of adults. Category organization for both children and adults follows Krumhansl's (1978) distance-density principle in which the similarity between two exemplars is jointly determined by their physical appearance and the density of neighboring exemplars in the perceptual space.     

The preferred level of face categorization depends on discriminability

People usually categorize objects more quickly at the basic level (e.g., “dog”) than at the subordinate (e.g., “collie”) or superordinate (e.g., “animal”) levels. Notable exceptions to this rule include objects of expertise, faces, or atypical objects (e.g., “penguin,” “poodle”), all of which show faster than normal subordinate-level categorization. We hypothesize that the subordinate-level reaction time advantage for faces is influenced by their discriminability relative to other faces in the stimulus set. First, we replicated the subordinate-level advantage for faces (Experiment 1) and then showed that a basic-level advantage for faces can be elicited by increasing the perceptual similarity of the face stimuli, making discrimination more difficult (Experiment 2). Finally, we repeated both effects within subjects, showing that individual faces were slower to be categorized in the context of similar faces and more quickly categorized among diverse faces (Experiment 3).     

Enhanced recognition of emotional stimuli in the chimpanzee (<Emphasis Type="Italic">Pan troglodytes</Emphasis>)

Humans often have a better memory of emotional events than neutral events. From the comparative-cognitive perspective, we explored the enhancement of recognition memory by emotion in chimpanzees (Pan troglodytes) using a serial probe recognition task. In this task, we sequentially presented a list of pictures to subjects and then tested their recognition of specific pictures from within the list. We selected pictures of aggressive chimpanzees as emotional stimuli and less tensed, relaxed chimpanzees as neutral stimuli. In Experiment 1, we gave four-item lists to two young chimpanzees; one showed significantly greater recognition of pictures depicting aggressive chimpanzees than neutral ones. In Experiment 2, this chimpanzee was further tested using a recognition task with eight-item lists. The subject again showed better recognition of emotional stimuli than neutral. Furthermore, the presence of an emotional stimulus in the list also facilitated recognition of the neutral item immediately following it. Overall, although only one of the two chimpanzees showed enhanced recognition memory by emotional stimuli, this is the first demonstration of such a response in the chimpanzee. The findings are discussed in comparison with those of human studies.     

Subjectively divided tone components in the gap transfer illusion

When a long glide with a short temporal gap in its middle crosses with a continuous short glide at the temporal midpoint of both glides, the gap is perceived in the short glide instead of in the long glide. In the present article, we tested possible explanations for this "gap transfer illusion" by obtaining points of subjective equality of the pitches and durations of the two short tones that are subjectively divided by the gap. The results of two experiments showed that neither an explanation in terms ofenvelope patterns nor explanations in terms of combinationtones or acoustic beats could account for the perception of the short tones in the gap transfer illusion. Rather, the results were compatible with the idea that the illusory tones were formed by the perceptual integration of onsets and offsets of acoustically different sounds. Implications for the perceptual construction of auditory events are discussed.