Local and Relational Aspects of Face Distinctiveness

Distinctiveness contributes strongly to the recognition and rejection of faces in memory tasks. In four experiments we examine the role played by local and relational information in the distinctiveness of upright and inverted faces. In all experiments subjects saw one of three versions of a face: original faces, which had been rated as average in distinctiveness in a previous study (Hancock, Burton, & Bruce, 1996), a more distinctive version in which local features had been changed ( D-local ), and a more distinctive version in which relational features had been changed ( D-rel ). An increase in distinctiveness was found for D-local and D-rel faces in Experiment 1 (complete faces) and 3 and 4 (face internals only) when the faces had to be rated in upright presentation, but the distinctiveness of the D-rel faces was reduced much more than that of the D-local versions when the ratings were given to the faces presented upside-down (Experiments 1 and 3). Recognition performance showed a similar pattern: presented upright, both D-local and D-rel revealed higher performance compared to the originals, but in upside-down presentation the D-local versions showed a much stronger distinctiveness advantage. When only internal features of faces were used (Experiments 3 and 4), the D-rel faces lost their advantage over the Original versions in inverted presentation. The results suggest that at least two dimensions of facial information contribute to a face's apparent distinctiveness, but that these sources of information are differentially affected by turning the face upside-down. These findings are in accordance with a face processing model in which face inversion effects occur because a specific type of information processing is disrupted, rather than because of a general disruption of performance.     

Are We In or Are We Out? Ingroup Prototypicality Effects in Implicit Ethnic‐American Associations

The goal of the present research was to document ingroup prototypicality effects in implicit associations between ethnic groups and the American identity. Across four studies, we compared implicit associations displayed by perceivers who either belonged to or did not belong to the target ethnic groups. In Studies 1 and 2, African, Asian, Latino, and European American participants were randomly assigned to complete an Implicit Association Test contrasting either their ingroup and an outgroup or two outgroups (third‐party perspective). Data yielded evidence for ingroup prototypicality effects in all interethnic comparisons. Studies 3 and 4 used large datasets available through Project Implicit. We examined whether ingroup prototypicality effects were restricted to U.S. residents or generalized to participants living in other regions of the world. Results showed that ingroup prototypicality effects did not presuppose immersion in the U.S. context, but at the same time patterns of implicit associations varied according to region of residence. Implicit ethnic‐American associations are at least partially the reflection of the perceivers’ positioning in interethnic comparisons.     

Hand preference in attention deficit hyperactivity disorder

In our Outpatient Department, we studied 56 subjects (41 males, 15 females; aged 5-16 yr.) with Attention Deficit Hyperactivity Disorder (ADHD) with respect to hand use in functional tasks via parental report. Left-hand use was markedly preferred, compared to that of a control group, more for complex than simple and for external (touching food and objects) than internal (scratching, rubbing eyes) tasks, suggesting a deficit in cerebral control of right-hand use. More patients were reported to have a left-hand preference than in the non-ADHD population. Furthermore, extent of laterality was greater for complex than simple external tasks and for external than for internal.     

When feature information comes first! Early processing of inverted faces

We investigated the early stages of face recognition and the role of featural and holistic face information. We exploited the fact that, on inversion, the alienating disorientation of the eyes and mouth in thatcherised faces is hardly detectable. This effect allows featural and holistic information to be dissociated and was used to test specific face-processing hypotheses. In inverted thatcherised faces, the cardinal features are already correctly oriented, whereas in undistorted faces, the whole Gestalt is coherent but all information is disoriented. Experiment 1 and experiment 3 revealed that, for inverted faces, featural information processing precedes holistic information. Moreover, the processing of contextual information is necessary to process local featural information within a short presentation time (26 ms). Furthermore, for upright faces, holistic information seems to be available faster than for inverted faces (experiment 2). These differences in processing inverted and upright faces presumably cause the differential importance of featural and holistic information for inverted and upright faces.     

The Wall inside the brain: Overestimation of distances crossing the former Iron Curtain

A study of distance estimations between German cities investigated the organization of mental maps and their specific deviations from reality. Potential factors for the deviation of mental maps from reality are physical barriers, emotional involvement, and semantic unity. Distance estimations between cities situated in different former parts of Germany (East or West) were systematically overestimated compared to distances of cities located in the same parts of Germany. This trend was strengthened when participants had a negative attitude toward the reunification of Germany. The impact of these results is far reaching, because overestimated distances between both German parts indicate that there still exists a mental gap between East and West—even in young people—15 years after the German reunification.     

Histidine-decarboxylase knockout mice show deficient nonreinforced episodic object memory, improved negatively reinforced water-maze performance, and increased neo- and ventro-striatal dopamine turnover

The brain's histaminergic system has been implicated in hippocampal synaptic plasticity, learning, and memory, as well as brain reward and reinforcement. Our past pharmacological and lesion studies indicated that the brain's histamine system exerts inhibitory effects on the brain's reinforcement respective reward system reciprocal to mesolimbic dopamine systems, thereby modulating learning and memory performance. Given the close functional relationship between brain reinforcement and memory processes, the total disruption of brain histamine synthesis via genetic disruption of its synthesizing enzyme, histidine decarboxylase (HDC), in the mouse might have differential effects on learning dependent on the task-inherent reinforcement contingencies. Here, we investigated the effects of an HDC gene disruption in the mouse in a nonreinforced object exploration task and a negatively reinforced water-maze task as well as on neo- and ventro-striatal dopamine systems known to be involved in brain reward and reinforcement. Histidine decarboxylase knockout (HDC-KO) mice had higher dihydrophenylacetic acid concentrations and a higher dihydrophenylacetic acid/dopamine ratio in the neostriatum. In the ventral striatum, dihydrophenylacetic acid/dopamine and 3-methoxytyramine/dopamine ratios were higher in HDC-KO mice. Furthermore, the HDC-KO mice showed improved water-maze performance during both hidden and cued platform tasks, but deficient object discrimination based on temporal relationships. Our data imply that disruption of brain histamine synthesis can have both memory promoting and suppressive effects via distinct and independent mechanisms and further indicate that these opposed effects are related to the task-inherent reinforcement contingencies.     

Monotone Majorizable Functionals

Several properties of monotone functionals (MF) and monotone majorizable functionals (MMF) used in the earlier work by the author and van de Pol are proved. It turns out that the terms of the simply typed lambda-calculus define MF, but adding primitive recursion, and even monotonic primitive recursion changes the situation: already Z.Z(1 — sg) is not MMF. It is proved that extensionality is not Dialectica-realizable by MMF, and a simple example of a MF which is not hereditarily majorizable is given.