Age and Mouth Color in Common Ravens

Bernd Heinrich; John Marzluff

doi:10.2307/1369233

Attending to Faces: Change Detection, Familiarization, and Inversion Effects

Perception ◽

10.1068/p3460 ◽

2003 ◽

Vol 32 (1) ◽

pp. 15-28 ◽

Cited By ~ 26

Author(s):

Jason J S Barton ◽

Shaunak Deepak ◽

Numaan Malik

Keyword(s):

Change Detection ◽

Spatial Relations ◽

Eye Position ◽

Short Term ◽

Four Dimensions ◽

Eye Color ◽

Color Changes ◽

Mouth Color ◽

And Inversion ◽

Inversion Effects

We tested detection of changes to eye position, eye color (brightness), mouth position, and mouth color in frontal views of faces. Two faces were presented sequentially for 555 ms each, with a blank screen of 120 ms separating the two. Faces were presented either both upright or both inverted. Measures of detection ( d') were calculated for several different degrees of change for each of the four dimensions of change. We first compared results to an earlier experiment that used an oddity design, in which subjects indicated which of three simultaneously viewed and otherwise identical faces had been altered on one of these four dimensions. Subjects in both of these experiments were partially cued, in that they knew the four possible types of changes that could occur on a given trial. The change-detection results correlated well with the oddity data. They confirmed that face inversion had little effect upon detection of changes in eye color, a moderate effect upon detection of eye-position or mouth-color changes, and caused a drastic reduction in the detection of mouth-position changes. An experiment in which uncued and fully cued subjects were compared showed that cueing significantly improved detection of feature color changes, but there was little difference between upright and inverted faces. Full cueing eliminated all effects of inversion. Compared to partial cueing, changes in mouth color were poorly detected by uncued subjects. Last, a change in the frequency of the base (unaltered) face in an experiment from 75% to 40% showed that increased short-term familiarity decreased the detection of eye changes and increased the detection of mouth changes, regardless of face orientation and the type of change made (color or position). We conclude that uncued subjects encode the spatial relations of features more than the colors of features, that mouth color in particular is not considered a relevant dimension for encoding, and that familiarization redistributes attention from more to less salient facial regions. Inversion effects are not simply an exaggeration of the salience effects revealed by withdrawing cueing, but represent an interaction of spatial encoding with salience, in that the greatest inversion effects occur for spatial shifts in less salient facial regions, and can be eliminated through the use of focused attention.

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How Birds and Other Adults Get Their Color Back

10.31219/osf.io/twm7j ◽

2019 ◽

Author(s):

Brian M Coyle

Keyword(s):

Direct Perception ◽

Pilot Training ◽

Underlying Structure ◽

Adult Bird ◽

Human Infants ◽

Color Displays ◽

The Face ◽

Mouth Color ◽

Control Flight ◽

Different Color

Lorenz's Kinderchenschema can lead to genetic repurposing (pleiotropy) as mutations that help infants survive are later used for adult mating. Around 2014 it was discovered that blue eyes and blond hair appeared first among human infants. Color attracts, essential for infant mammal survival. Pleiotroptic regulators were selected to enable these attribute to be retained in adults, as attraction capacity also increases mating success.Nestlings birds have beaks with internal membranes called gapes, frequently colorful and/or patterned. Beaks conserve vital genetic information, useful over 30 million years of radiation. Colorful gapes are present in monochromatic as well as species with colorful plumage. Gapes and the beak's cere are the only colored part of many raptors, a broad group related to ancestors of many landbirds. Gapes are bird Kinderchenschema, an infant display feature that compels parent behavior.Birds move in extradimensional space, with bifurcated visual systems that lets one side control flight in the face of distraction. Bright, bold displays aid navigation. Ecological psychology, developed for pilot training, established motion perception as the core of direct perception. Bird gapes serve as landing pads.Mammalian Kinderchenschema is dominated by superficial features of the head, such as eye and forehead size, to transact emotion that encourages protection and feeding. Atricial bird kinderchenschema also promotes protection and feeding. When nestlings are vulnerable to predation, internal mouth color remains hidden, protecting them. When nestling parents approach, the internal mouth color is exposed, enabling feeding.For a nestling color to be repurposed in plumage, it may trigger a conditioned response that aids selection. Nestling displays trigger adult bird neurotransmitters. Color can be disassociated from underlying structure and transferred, along with hormone release.There's a strong correlation between gape and plumage color. Adaptionist explanations of gape and feather colors emphasize nutrient conditions, but these increase saturation, not brilliance. It is color's attention-grabbing aspect that makes it so important for nestlings, and transferable for mating. Given changing environments, that require birds to evolve different color displays, the conserved resource of gape color is important.

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