Revisiting the link between horizontal tuning and face processing ability with independent measures.

In recent years, horizontal spatial information has received attention for its role in face perception. One study, for instance, has reported an association between horizontal tuning for faces and face identification ability measured within the same task. A possible consequence of this is that the correlation could have been overestimated. In the present study, we wanted to reexamine this question. We first measured face processing ability on the Cambridge Face Memory Test +, the Cambridge Face Perception Test, and the Glasgow Face Matching Test. A single ability score was extracted using a principal components analysis. In a separate task, participants also completed an identification task in which faces were randomly filtered on a trial basis using orientation bubbles. This task allowed the extraction of individual orientation profiles and horizontal tuning scores for faces. We then measured the association between horizontal tuning for faces and the face-processing ability score and observed a significant positive correlation. Importantly, this relation could not be accounted for by other factors such as object-processing ability, horizontal tuning for cars, or greater sensitivity to horizontal gratings. Our data give further credence to the hypothesis that horizontal facial structure plays a crucial role in face processing. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Dual-task interference on left eye utilization during facial emotion perception.

There is an ongoing debate in the literature about whether facial emotion perception is carried automatically-that is, without effort or attentional resources. While it is generally accepted that spatial attention is necessary for the perception of emotional facial expressions, the picture is less clear for central attention. Using the bubbles method, we provide results that were obtained by measuring the effect of the psychological refractory period on diagnostic information for the basic facial expressions. Based on previous findings that linked spatial attention with processing of the eyes and of high spatial frequencies in the visual periphery, we hypothesized that reliance on the eyes might decrease when central resources were monopolized by a difficult prioritized auditory task. Central load led to a marked decrease in left eye utilization that was generalized across emotions; on the contrary, utilization of the mouth was unaffected by central load. Thus, processing of the left eye might be nonautomatic, and processing of the mouth might be automatic. Interestingly, we also observed a reduction in reliance on the left side of the face under central load that was accompanied by a commensurate increase in reliance on the right side of the face. We end with a discussion of how hemispheric asymmetries might account for these peculiar findings. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Orientations for the successful categorization of facial expressions and their link with facial features.

Horizontal information was recently suggested to be crucial for face identification. In the present paper, we expand on this finding and investigate the role of orientations for all the basic facial expressions and neutrality. To this end, we developed orientation bubbles to quantify utilization of the orientation spectrum by the visual system in a facial expression categorization task. We first validated the procedure in Experiment 1 with a simple plaid-detection task. In Experiment 2, we used orientation bubbles to reveal the diagnostic-i.e., task relevant-orientations for the basic facial expressions and neutrality. Overall, we found that horizontal information was highly diagnostic for expressions-surprise excepted. We also found that utilization of horizontal information strongly predicted performance level in this task. Despite the recent surge of research on horizontals, the link with local features remains unexplored. We were thus also interested in investigating this link. In Experiment 3, location bubbles were used to reveal the diagnostic features for the basic facial expressions. Crucially, Experiments 2 and 3 were run in parallel on the same participants, in an interleaved fashion. This way, we were able to correlate individual orientation and local diagnostic profiles. Our results indicate that individual differences in horizontal tuning are best predicted by utilization of the eyes.

Mapping the impairment in decoding static facial expressions of emotion in prosopagnosia.

Acquired prosopagnosia is characterized by a deficit in face recognition due to diverse brain lesions, but interestingly most prosopagnosic patients suffering from posterior lesions use the mouth instead of the eyes for face identification. Whether this bias is present for the recognition of facial expressions of emotion has not yet been addressed. We tested PS, a pure case of acquired prosopagnosia with bilateral occipitotemporal lesions anatomically sparing the regions dedicated for facial expression recognition. PS used mostly the mouth to recognize facial expressions even when the eye area was the most diagnostic. Moreover, PS directed most of her fixations towards the mouth. Her impairment was still largely present when she was instructed to look at the eyes, or when she was forced to look at them. Control participants showed a performance comparable to PS when only the lower part of the face was available. These observations suggest that the deficits observed in PS with static images are not solely attentional, but are rooted at the level of facial information use. This study corroborates neuroimaging findings suggesting that the Occipital Face Area might play a critical role in extracting facial features that are integrated for both face identification and facial expression recognition in static images.

Boron carboxylate catalysis of homoallylboration.

Boron tris(trifluoroacetate) is identified as the first effective catalyst for the homoallyl- and homocrotylboration of aldehydes by cyclopropylcarbinylboronates. NMR spectroscopic studies and theoretical calculations of key intermediates and transition states both suggest that a ligand-exchange mechanism, akin to our previously reported PhBCl2-promoted homoallylations, is operative. Our experimental and theoretical results also suggest that the catalytic activity of boron tris(trifluoroacetate) might originate from more facile catalytic turnover of the trifluoroacetate ligands (in agreement with DFT calculations) or from a lower propensity for formation of off-pathway reservoir intermediates (as observed by (1)H NMR). This work shows that carboxylates are viable catalytic ligands for homoallyl- and homocrotylations of carbonyl compounds and opens the door to the development of catalytic asymmetric versions of this transformation.