Aftereffects generally occur after a prolonged exposure (adaptation) to a first stimulus possessing one given property followed by presentation of a stimulus bearing a neutral value of that property. The aftereffect consists in a change in appearance of the neutral stimulus following the adapter, compared to the appearance of the neutral stimulus when it is perceived without any previous exposure to the adapter. The transient phenomena of perceptual aftereffects are believed to depend on the activation of neuron populations that respond selectively to a given property of the stimuli (Webster, 2011). Studying how adaptation occurs (which stimulus properties are sensitive to it, which timings are necessary, whether individual differences modulate its occurrence) has thus become an indirect way to probe the plasticity of sensory functions in the nervous system, recently extending to more cognitive and representational aspects of neural coding.
In the last two decades, indeed, it has been demonstrated that aftereffects occur not only for low-level properties of stimuli (such as motion, color, or orientation) but also for high-level properties. Many studies have proven that high-level proprieties of the stimuli, e.g. gender (Rhodes et al., 2004; Webster et al., 2004), identity (Leopold et al., 2001), ethnicity (Webster et al., 2004), or age (O’Neil & Webster, 2011; Schweinberger et al., 2010) of a face or a voice, are sensitive to this phenomenon. It has been shown, for example, that the prolonged exposure to a female or male face produces a gender misperception in the opposite direction when an androgynous face is shown after the adapter (Webster, 2004). Furthermore, recent studies have also shown that aftereffects are not strictly contingent upon the physical features that make up stimuli, but they seem to run across the high-level proprieties subjects are adapted to. These evidences are supported by cross-category adaptation studies, which underlie how aftereffects occur even across stimuli that do not share physical features (e.g. bodies and faces) but that instead, share common higher-level properties, such as gender (Clifford & Rhodes, 2005; Palumbo et al. 2014).
Given the growing body of research focused on adaptation and aftereffects in high-level perception at the boundaries with perceptual learning, attention and cognition, our purpose is to provide a picture of the state of the art relative to the specific phenomena of adaptation in high-level perceptual processing.
Suggested contributions are solicited that include empirical studies, focused reviews, theoretical and modeling proposals dealing with, but not limited to, adaptation to properties of social stimuli (faces, bodies, voices, scents, etc.), cross-modal and cross-category adaptation and aftereffects, adaptation and categorization and studies on the biological underpinnings of these phenomena. Studies that attempt to explain the functional role of adaptation (the “adaptive value of adaptation”) suggesting new hypotheses and directions are also welcome. We are open to empirical work (from psychophysics, perceptual science, behavioral and cognitive neuroscience, brain theory, etc.) conforming to rigorous methodological and statistical standards that help to advance understanding on the mechanisms and the role of adaptation in high-level perception and its neural correlates.
Aftereffects generally occur after a prolonged exposure (adaptation) to a first stimulus possessing one given property followed by presentation of a stimulus bearing a neutral value of that property. The aftereffect consists in a change in appearance of the neutral stimulus following the adapter, compared to the appearance of the neutral stimulus when it is perceived without any previous exposure to the adapter. The transient phenomena of perceptual aftereffects are believed to depend on the activation of neuron populations that respond selectively to a given property of the stimuli (Webster, 2011). Studying how adaptation occurs (which stimulus properties are sensitive to it, which timings are necessary, whether individual differences modulate its occurrence) has thus become an indirect way to probe the plasticity of sensory functions in the nervous system, recently extending to more cognitive and representational aspects of neural coding.
In the last two decades, indeed, it has been demonstrated that aftereffects occur not only for low-level properties of stimuli (such as motion, color, or orientation) but also for high-level properties. Many studies have proven that high-level proprieties of the stimuli, e.g. gender (Rhodes et al., 2004; Webster et al., 2004), identity (Leopold et al., 2001), ethnicity (Webster et al., 2004), or age (O’Neil & Webster, 2011; Schweinberger et al., 2010) of a face or a voice, are sensitive to this phenomenon. It has been shown, for example, that the prolonged exposure to a female or male face produces a gender misperception in the opposite direction when an androgynous face is shown after the adapter (Webster, 2004). Furthermore, recent studies have also shown that aftereffects are not strictly contingent upon the physical features that make up stimuli, but they seem to run across the high-level proprieties subjects are adapted to. These evidences are supported by cross-category adaptation studies, which underlie how aftereffects occur even across stimuli that do not share physical features (e.g. bodies and faces) but that instead, share common higher-level properties, such as gender (Clifford & Rhodes, 2005; Palumbo et al. 2014).
Given the growing body of research focused on adaptation and aftereffects in high-level perception at the boundaries with perceptual learning, attention and cognition, our purpose is to provide a picture of the state of the art relative to the specific phenomena of adaptation in high-level perceptual processing.
Suggested contributions are solicited that include empirical studies, focused reviews, theoretical and modeling proposals dealing with, but not limited to, adaptation to properties of social stimuli (faces, bodies, voices, scents, etc.), cross-modal and cross-category adaptation and aftereffects, adaptation and categorization and studies on the biological underpinnings of these phenomena. Studies that attempt to explain the functional role of adaptation (the “adaptive value of adaptation”) suggesting new hypotheses and directions are also welcome. We are open to empirical work (from psychophysics, perceptual science, behavioral and cognitive neuroscience, brain theory, etc.) conforming to rigorous methodological and statistical standards that help to advance understanding on the mechanisms and the role of adaptation in high-level perception and its neural correlates.
