Reducing Facial Stereotype Bias in Consequential Social Judgments: Intervention Success With White Male Faces.

Initial impressions of others based on facial appearances are often inaccurate yet can lead to dire outcomes. Across four studies, adult participants underwent a counterstereotype training to reduce their reliance on facial appearance in consequential social judgments of White male faces. In Studies 1 and 2, trustworthiness and sentencing judgments among control participants predicted whether real-world inmates were sentenced to death versus life in prison, but these relationships were diminished among trained participants. In Study 3, a sequential priming paradigm demonstrated that the training was able to abolish the relationship between even automatically and implicitly perceived trustworthiness and the inmates' life-or-death sentences. Study 4 extended these results to realistic decision-making, showing that training reduced the impact of facial trustworthiness on sentencing decisions even in the presence of decision-relevant information. Overall, our findings suggest that a counterstereotype intervention can mitigate the potentially harmful effects of relying on facial appearance in consequential social judgments.

Domain-specific experience determines individual differences in holistic processing.

Holistic processing refers to the processing of objects as wholes rather than in a piecemeal, part-based fashion. Despite a suggested link between expertise and holistic processing, the role of experience in determining holistic processing of both faces and objects has been questioned. Here, we combine an individual differences approach with an experimental training study and parametrically manipulate experience with novel objects to examine the determinants of holistic processing. We also measure object-recognition ability. Our results show that although domain-general visual ability is a predictor of the ability to match object parts, it is the amount of experience people have individuating objects of a category that determines the extent to which they process new objects of this category in a holistic manner. This work highlights the benefits of dissociating the influences of domain-general ability and domain-specific experience, typically confounded in measures of performance or "expertise." Our findings are consistent with those in recent work with faces showing that variability specific to experience is a better predictor of domain-specific effects than is variability in performance. We argue that individual differences in holistic processing arise from domain-specific experience and that these effects are related to similar effects of experience on other measures of selective attention. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Prevention of ischemia/reperfusion-induced cardiac apoptosis and injury by melatonin is independent of glutathione peroxdiase 1.

Free-radical generation is one of the primary causes of myocardial ischemia/reperfusion (I/R) injury. Melatonin is an efficient free-radical scavenger and induces the expression of antioxidant enzymes. We have previously shown that melatonin can prevent free-radical-induced myocardial injury. To date, the mechanism underlying melatonin's cardioprotective effect is not clear. In this study, we assessed the ability of melatonin to protect against I/R injury in mice deficient in glutathione peroxidase 1 (Gpx1). Mice hearts were subjected to 40 min of global ischemia in vitro followed by 45 min of reperfusion. Myocardial I/R injury (expressed as % of recovery of left ventricular developed pressure x heart rate) was exacerbated in mice deficient in Gpx1 (51 +/- 3% for Gpx1+/+ mice versus 31 +/- 6% for Gpx1(-/-) mice, P < 0.05). Administration of melatonin for 30 min protected against I/R injury in both Gpx1+/+ mice (72 +/- 4.8%) and Gpx1(-/-) mice (63 +/- 4.7%). This protection was accompanied by a significant improvement in left ventricular end-diastolic pressure and a twofold decrease in lactate dehydrogenase (LDH) level released from melatonin-treated hearts. In another set of experiments, mice were subjected to 50 min of ligation of the left descending anterior coronary artery in vivo followed by 4 hr of reperfusion. The infarct sizes, expressed as the percentage of the area at risk, were significantly larger in Gpx1(-/-) mice than in Gpx1+/+ mice (75 +/- 9% versus 54 +/- 6%, P < 0.05) and were reduced significantly in melatonin-treated mice (31 +/- 3.7% Gpx1(-/-) mice and 33 +/- 6.0% Gpx1+/+ mice). In hearts subjected to 30 min of coronary artery occlusion followed by 3 hr of reperfusion, melatonin-treated hearts had significantly fewer in situ oligo ligation-positive myocytes and less protein nitration. Our results demonstrate that the cardioprotective function of melatonin is independent of Gpx1.

Neuroprotective effect of humanin on cerebral ischemia/reperfusion injury is mediated by a PI3K/Akt pathway.

Humanin (HN) is an anti-apoptotic peptide that suppresses neuronal cell death induced by Alzheimer's disease, prion protein fragments, and serum deprivation. Recently, we demonstrated that Gly14-HN (HNG), a variant of HN in which the 14th amino acid serine is replaced with glycine, can decrease apoptotic neuronal death and reduce infarct volume in a focal cerebral ischemia/reperfusion mouse model. In this study, we postulate that the mechanism of HNG's neuroprotective effect is mediated by the PI3K/Akt pathway. Oxygen-glucose deprivation (OGD) was performed in cultured mouse primary cortical neurons for 60 min. The effect of HNG and PI3K/Akt inhibitors on OGD-induced cell death was examined at 24 h after reperfusion. HNG increased cell viability after OGD in primary cortical neurons, whereas the PI3K/Akt inhibitors wortmannin and Akti-1/2 attenuated the protective effect of HNG. HNG rapidly increased Akt phosphorylation, an effect that was inhibited by wortmannin and Akti-1/2. Mouse brains were injected intraventricularly with HNG before being subjected to middle cerebral artery occlusion (MCAO). HNG treatment significantly elevated p-Akt levels after cerebral I/R injury and decreased infarct volume. The protective effect of HNG on infarct size was attenuated by wortmannin and Akti-1/2. Taken as a whole, these results suggest that PI3K/Akt activation mediates HNG's protective effect against hypoxia/ischemia reperfusion injury.

How holistic processing of faces relates to cognitive control and intelligence.

The Vanderbilt Holistic Processing Test for faces (VHPT-F) is the first standard test designed to measure individual differences in holistic processing. The test measures failures of selective attention to face parts through congruency effects, an operational definition of holistic processing. However, this conception of holistic processing has been challenged by the suggestion that it may tap into the same selective attention or cognitive control mechanisms that yield congruency effects in Stroop and Flanker paradigms. Here, we report data from 130 subjects on the VHPT-F, several versions of Stroop and Flanker tasks, as well as fluid IQ. Results suggested a small degree of shared variance in Stroop and Flanker congruency effects, which did not relate to congruency effects on the VHPT-F. Variability on the VHPT-F was also not correlated with Fluid IQ. In sum, we find no evidence that holistic face processing as measured by congruency in the VHPT-F is accounted for by domain-general control mechanisms.

Grasp representations depend on knowledge and attention.

Seeing pictures of objects activates the motor cortex and can have an influence on subsequent grasping actions. However, the exact nature of the motor representations evoked by these pictures is unclear. For example, action plans engaged by pictures could be most affected by direct visual input and computed online based on object shape. Alternatively, action plans could be influenced by experience seeing and grasping these objects. We provide evidence for a dual-route theory of action representations evoked by pictures of objects, suggesting that these representations are influenced by both direct visual input and stored knowledge. We find that that familiarity with objects has a facilitative effect on grasping actions, with knowledge about the object's canonical orientation or its name speeding grasping actions for familiar objects compared to novel objects. Furthermore, the strength of contributions from each route to action can be modulated by the manner in which the objects are attended. Thus, evocation of grasping representations depends on an interaction between one's familiarity with perceived objects and how those objects are attended while making grasp actions. (PsycINFO Database Record

Category-specific learned attentional bias to object parts.

Humans can selectively attend to information in visual scenes. Learning from previous experiences plays a role in how visual attention is subsequently deployed. For example, visual search times are faster in areas that are statistically more likely to contain a target (Jiang and Swallow in Cognition, 126(3), 378-390, 2013). Here, we examined whether similar attentional biases can be created for different locations on complex objects as a function of their category, based on a history of these locations containing a target. Subjects performed a visual search task in the context of novel objects called Greebles. The target appeared in one half (e.g., top) of the Greebles 89 % of the time and in the other half (e.g., bottom) 11 % of the time. We found a reaction time advantage when the target was located in a "target-rich" region, even after target location probabilities were equated. This indicates that attentional biases can be associated not only with regions of space but also with specific object features, or at least with locations in an object-based frame of reference.

Holistic processing from learned attention to parts.

Attention helps us focus on what is most relevant to our goals, and prior work has shown that aspects of attention can be learned. Learned inattention to parts can abolish holistic processing of faces, but it is unknown whether learned attention to parts is sufficient to cause a change from part-based to holistic processing with objects. We trained subjects to individuate nonface objects (Greebles) from 2 categories: Ploks and Glips. Diagnostic information was in complementary halves for the 2 categories. Holistic processing was then tested with Plok-Glip composites that combined the kind of part that was diagnostic or nondiagnostic during training. Exposure to Greeble parts resulted in general failures of selective attention for nondiagnostic composites, but face-like holistic processing was only observed for diagnostic composites. These results demonstrated a novel link between learned attentional control and the acquisition of holistic processing.

Becoming a Lunari or Taiyo expert: learned attention to parts drives holistic processing of faces.

Faces are processed holistically, but the locus of holistic processing remains unclear. We created two novel races of faces (Lunaris and Taiyos) to study how experience with face parts influences holistic processing. In Experiment 1, subjects individuated Lunaris wherein the top, bottom, or both face halves contained diagnostic information. Subjects who learned to attend to face parts exhibited no holistic processing. This suggests that individuation only leads to holistic processing when the whole face is attended. In Experiment 2, subjects individuated both Lunaris and Taiyos, with diagnostic information in complementary face halves of the two races. Holistic processing was measured with composites made of either diagnostic or nondiagnostic face parts. Holistic processing was only observed for composites made from diagnostic face parts, demonstrating that holistic processing can occur for diagnostic face parts that were never seen together. These results suggest that holistic processing is an expression of learned attention to diagnostic face parts.

Antioxidant activity of 7,8-dihydroxyflavone provides neuroprotection against glutamate-induced toxicity.

Glutamate, an excitatory neurotransmitter in the central nervous system, plays an important role in neurological disorders. Previous studies have shown that excess glutamate can cause oxidative stress in a hippocampal HT-22 cell line. 7,8-Dihydroxyflavone (7,8-DHF), a member of the flavonoid family, is a selective tyrosine kinase receptor B (TrkB) agonist that has neurotrophic effects in various neurological diseases such as stroke and Parkinson's disease. In this study, we found that there is no TrkB receptor in HT-22 cells. Despite this, our data demonstrate that 7,8-DHF still protects against glutamate-induced toxicity in HT-22 cells in a concentration-dependent manner, indicating that 7,8-DHF prevents cell death through other mechanisms rather than TrkB receptors in this cell model. We further show that 7,8-DHF increases cellular glutathione levels and reduces reactive oxygen species (ROS) production caused by glutamate in HT-22 cells. Finally, our data demonstrate that 7,8-DHF protects against hydrogen peroxide and menadione-induced cell death, suggesting that 7,8-DHF has an antioxidant effect. In summary, although 7,8-DHF is considered as a selective TrkB agonist, our results demonstrate that 7,8-DHF can still confer neuroprotection against glutamate-induced toxicity in HT-22 cells via its antioxidant activity.

Synergistic protective effects of humanin and necrostatin-1 on hypoxia and ischemia/reperfusion injury.

Since several different pathways are involved in cerebral ischemia/reperfusion injury, combination therapy rather than monotherapy may be required for efficient neuroprotection. In this study, we examined the protective effects of an apoptosis inhibitor Gly(14)-humanin (HNG) and a necroptosis inhibitor necrostatin-1 (Nec-1) on hypoxia/ischemia/reperfusion injury. Cultured mouse primary cortical neurons were incubated with Nec-1, HNG or both in a hypoxia chamber for 60 min. Cell viability was determined by MTS assay at 24h after oxygen-glucose deprivation (OGD) treatment. Mice underwent middle cerebral artery occlusion for 75 min followed by 24h reperfusion. Mice were administered HNG and/or Nec-1 (i.c.v.) at 4h after reperfusion. Neurological deficits were evaluated and the cerebral infarct volume was determined by TTC staining. Nec-1 or HNG alone had protective effects on OGD-induced cell death. Combined treatment with Nec-1 and HNG resulted in more neuroprotection than Nec-1 or HNG alone. Treatment with HNG or Nec-1 reduced cerebral infarct volume from 59.3 ± 2.6% to 47.0 ± 2.3% and 47.1 ± 1.5%, respectively. Combined treatment with HNG and Nec-1 improved neurological scores and decreased infarct volume to 38.6 ± 1.5%. In summary, we demonstrated that the combination treatment of HNG and Nec-1 conferred synergistic neuroprotection on hypoxia/ischemia/reperfusion injury in vitro and in vivo. These findings provide a novel therapeutic strategy for the treatment of stroke by combining anti-apoptosis and anti-necroptosis therapy.