Infants learn about objects from statistics and people.

In laboratory experiments, infants are sensitive to patterns of visual features that co-occur (e.g., Fiser & Aslin, 2002). Once infants learn the statistical regularities, however, what do they do with that knowledge? Moreover, which patterns do infants learn in the cluttered world outside of the laboratory? Across 4 experiments, we show that 9-month-olds use this sensitivity to make inferences about object properties. In Experiment 1, 9-month-old infants expected co-occurring visual features to remain fused (i.e., infants looked longer when co-occurring features split apart than when they stayed together). Forming such expectations can help identify integral object parts for object individuation, recognition, and categorization. In Experiment 2, we increased the task difficulty by presenting the test stimuli simultaneously with a different spatial layout from the familiarization trials to provide a more ecologically valid condition. Infants did not make similar inferences in this more distracting test condition. However, Experiment 3 showed that a social cue did allow inferences in this more difficult test condition, and Experiment 4 showed that social cues helped infants choose patterns among distractor patterns during learning as well as during test. These findings suggest that infants can use feature co-occurrence to learn about objects and that social cues shape such foundational learning in distraction-filled environments. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Stimulus Selectivity of Figural Aftereffects for Faces.

Viewing a distorted face induces large aftereffects in the appearance of an undistorted face. The authors examined the processes underlying this adaptation by comparing how selective the aftereffects are for different dimensions of the images including size, spatial frequency content, contrast, and color. Face aftereffects had weaker selectivity for changes in the size, contrast, or color of the images and stronger selectivity for changes in contrast polarity or spatial frequency. This pattern could arise if the adaptation is contingent on the perceived similarity of the stimuli as faces. Consistent with this, changing contrast polarity or spatial frequency had larger effects on the perceived identity of a face, and aftereffects were also selective for different individual faces. These results suggest that part of the sensitivity changes underlying the adaptation may arise at visual levels closely associated with the representation of faces. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rehabilitating patients with left spatial neglect by prism exposure during a visuomotor activity.

Objective: Adaptation to prisms displacing the visual scene rightward is a therapeutic tool for left unilateral spatial neglect (USN). We aimed at comparing the effects of the classic adaptation procedure (repeated pointing toward visual targets, control treatment, C), with those of a novel adaptation method, involving ecological visuomotor activities (experimental treatment, E). Method: In 10 right-brain-damaged USN patients, each treatment was given for 1 week, with a crossover design, for a total of 20 sessions, twice per day. USN was assessed by cancellation, reading, and drawing tasks, and by a standardized scale. Neurological severity was assessed by the National Institutes of Health (NIH) stroke scale (Brott et al., 1989), disability by the Functional Independence Measure (FIM) scale. Results: The 2-week treatments (EC, CE) were equally effective, improving both USN, confirming previous reports (Frassinetti, Angeli, Meneghello, Avanzi, & Làdavas, 2002) and, importantly, disability. The improvement was independent of baseline performance, duration of disease, and neurological severity. Recovery took place after the first week, continued in the second week, and was stable at the follow-up of 3 months. The improvement of USN, measured by cancellation performance, and, in part, that of disability, measured through the FIM scale, were mediated by the size of the leftward aftereffects, suggesting a causal relationship between prism exposure and recovery. The E protocol was better tolerated. Conclusions: Daily life visuomotor activities, associated with prism exposure, are a useful tool for rehabilitating USN patients. This new treatment may widen the compliance with prism exposure treatments and their feasibility within home-based programs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Is the figural aftereffect an aftereffect? A review of its intensity, onset, decay, and transfer characteristics.

It has been shown how figural aftereffects might be generated by the lateral inhibitory effects of the inspection figure, in the manner of a simultaneous illusion. The present effort reviews some evidence suggesting that a figural aftereffect is a simultaneous illusion: (1) Varying the intensity of the inducing figure affects the simultaneous illusion and figural aftereffect in similar ways. (2) Temporal characteristics—onset and decay—of light adaptation, of afterimages, and of figural aftereffects are considered. It is shown that they obey similar empirical equations and that the constants in those equations have similar values. (3) The argument that the use of an interocular presentation of inducing and test figures eliminates the possible influence of afterimages is reviewed. It is concluded that figural aftereffects are very closely related to 3 visual phenomena: simultaneous contrast (the result of lateral inhibition), light and dark adaptation, and ocular tremor. (2 p. ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cross-modal face identity aftereffects and their relation to priming.

We tested the magnitude of the face identity aftereffect following adaptation to different modes of adaptors in four experiments. The perceptual midpoint between two morphed famous faces was measured pre- and post-adaptation. Significant aftereffects were observed for visual (faces) and nonvisual adaptors (voices and names) but not nonspecific semantic information (e.g., occupations). Aftereffects were also observed following imagination and adaptation to an associated person. The strongest aftereffects were found adapting to facial caricatures. These results are discussed in terms of cross-modal adaptation occurring at various loci within the face-recognition system analogous to priming. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The importance of information localization in scene gist recognition.

People can recognize the meaning or gist of a scene from a single glance, and a few recent studies have begun to examine the sorts of information that contribute to scene gist recognition. The authors of the present study used visual masking coupled with image manipulations (randomizing phase while maintaining the Fourier amplitude spectrum; random image structure evolution [RISE]; J. Sadr & P. Sinha, 2004) to explore whether and when unlocalized Fourier amplitude information contributes to gist perception. In 4 experiments, the authors found that differences between scene categories in the Fourier amplitude spectrum are insufficient for gist recognition or gist masking. Whereas the global 1/f spatial frequency amplitude spectra of scenes plays a role in gist masking, local phase information is necessary for gist recognition and for the strongest gist masking. Moreover, the ability to recognize the gist of a target image was influenced by mask recognizability, suggesting that conceptual masking occurs even at the earliest stages of scene processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A functional theory of the McCollough effect.

Pattern-contingent color aftereffects, or McCollough effects (MEs), are used to probe the visual brain's operations psychophysically. Their neural substrate is unknown, however, and theories about them are weak. Our theory proposes a strong functional role for MEs and a neuropsychological basis that accounts for "top-down" (global) constraints ignored by other theories. The functional aspect of the theory is based on the concept of contingent adaptation level, following H. Helson (1964), and on the "error-correcting device" of D. P. Andrews (1964), which tracks and adjusts internal representation to external-world contingencies. The neuropsychological part of the theory postulates that global properties are the result of MEs being generated not at the individual detector level but in the vectorfields of which the detectors are elements. It is an implementation of Lie transformation group theory (W. C. Hoffman, 1966). Evidence for this model is assessed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Face aftereffects indicate dissociable, but not distinct, coding of male and female faces.

It has been claimed that exposure to distorted faces of one sex induces perceptual aftereffects for test faces that are of the same sex, but not for test faces of the other sex (A. C. Little, L. M. DeBruine, & B. C. Jones, 2005). This result suggests that male and female faces have separate neural coding. Given the high degree of visual similarity between faces of different sexes, this result is surprising. The authors reinvestigated male and female face coding using a different face distortion. In Experiment 1, participants adapted to distorted faces from one sex (e.g., male contracted faces) and were tested with faces of both sexes. Aftereffects were found for both male and female faces, suggesting the existence of common coding mechanisms. In Experiments 2 and 3, participants adapted to oppositely distorted faces from both sexes (male contracted and female expanded faces). Weak opposite aftereffects were found for male and female faces, suggesting the existence of sex-selective face coding mechanisms. Taken together, these results indicate that both common and sex-selective mechanisms code male and female faces. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Self-Motion Perception During Locomotor Recalibration: More Than Meets the Eye.

Do locomotor aftereffects depend specifically on visual feedback? In 7 experiments, 116 college students were tested, with closed eyes, at stationary running or at walking to a previewed target after adaptation, with closed eyes, to treadmill locomotion. Subjects showed faster inadvertent drift during stationary running and increased distance (overshoot) when walking to a target. Overshoot seemed to saturate (i.e., reach a ceiling) at 17% after as little as 1 min of adaptation. Sidestepping at test reduced overshoot, suggesting motor specificity. But inadvertent drift effects were decreased if the eyes were open and the treadmill was drawn through the environment during adaptation, indicating that these effects involve self-motion perception. Differences in expression of inadvertent drift and of overshoot after adaptation to treadmill locomotion may have been due to different sets of ancillary cues available for the 2 tasks. Self-motion perception is multimodal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How Different Spatial-Frequency Components Contribute to Visual Information Acquisition.

We test 3 theories of global and local scene information acquisition, defining global and local in terms of spatial frequencies. By independence theories, high- and low-spatial-frequency information are acquired over the same time course and combine additively. By global-precedence theories, global information acquisition precedes local information acquisition, but they combine additively. By interactive theories, global information also affects local-information acquisition rate. We report 2 digit-recall experiments. In the 1st, we confirmed independence theories. In the 2nd, we disconfirmed both independence theories and interactive theories, leaving global-precedence theories as the remaining alternative. We show that a specific global-precedence theory quantitatively accounted for Experiments 1-2 data as well as for past data. We discuss how their spatial-frequency definition of spatial scale comports with definitions used by others, and we consider the suggestion by P. G. Schyns and colleagues (e.g., D. J. Morrison & Schyns, 2001) that the visual system may act flexibly rather than rigidly in its use of spatial scales. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cortical conductivity and vocabulary.

The relationship of cortical activity to kinesthetic and visual aftereffects was investigated. Cortical activity was measured by Vocabulary test scores. The results do not support a previous finding (Livson & Krech, 1955) of an inverse relationship between these variables. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conjunction of color and form without attention: Evidence from an orientation-contingent color aftereffect.

According to A. Treisman and G. Gelade's (see record 1980-04685-001) feature-integration theory, separable features such as color and shape exist in separate maps in preattentive vision and can be integrated only through the use of spatial attention. However, many perceptual aftereffects, which are also assumed to reflect the features available in preattentive vision, are sensitive to conjunctions of features. One possible resolution of these views holds that adaptation to conjunctions depends on spatial attention. Exp I tested this proposition by presenting 24 undergraduates with gratings varying in color and orientation. The resulting McCollough aftereffects were independent of whether the adaptation stimuli were presented inside or outside of the focus of spatial attention. Therefore, color and shape appear to be conjoined preattentively when perceptual aftereffects are used as the measure. These same stimuli, however, appeared to be separable in Exps II and III, which required 24 Ss to search for gratings of a specified color and orientation. These results show that different experimental procedures may be tapping into different stages of preattentive vision. (63 ref) (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Extremely selective attention: Eye-tracking studies of the dynamic allocation of attention to stimulus features in categorization.

Humans have an extremely flexible ability to categorize regularities in their environment, in part because of attentional systems that allow them to focus on important perceptual information. In formal theories of categorization, attention is typically modeled with weights that selectively bias the processing of stimulus features. These theories make differing predictions about the degree of flexibility with which attention can be deployed in response to stimulus properties. Results from 2 eye-tracking studies show that humans can rapidly learn to differently allocate attention to members of different categories. These results provide the first unequivocal demonstration of stimulus-responsive attention in a categorization task. Furthermore, the authors found clear temporal patterns in the shifting of attention within trials that follow from the informativeness of particular stimulus features. These data provide new insights into the attention processes involved in categorization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Parental reports of changes and challenges that result from parenting a child with cancer

Aftereffects of azimuthal auditory motion may have two components. A sensory component is inferred from strong aftereffects, because they are spectrally dependent and have shallower response functions than those for non-adaptation. Neither property applies to weak aftereffects, suggesting a cognitive component. Two experiments determined whether changing-loudness aftereffects (CLA) might be understood similarly. In a single-interval forced-choice procedure, listeners responded "growing softer" or "growing louder" to test stimuli changing in intensity. In Exp. 1, adapting and test stimuli were diotic and had the same 1-kHz sinusoidal carrier. Although response functions following adaptation were displaced from response functions for non-adaptation-indicating CLA-their slopes were broadly similar. In Exp. 2, stimuli were monotic; adapting frequency was 1 kHz and test frequencies were between 0.5 and 2.0 kHz. CLA was present in most adaptation conditions, but was strongest when the test frequency was 1.0 kHz; functions' slopes again evinced no systematic variation. The two-component hypothesis for CLA is supported by spectral dependence alone. It is argued that the slope of response functions is due to the nulling procedures for measuring auditory aftereffects. The slope depends on whether the adapted property is processed by "direct" and "indirect" mechanisms; aftereffects tap "direct" mechanisms alone, which may affect sensitivity during measurement.     

Adaptation to visuomotor rotations in younger and older adults.

Adaptation to a visuomotor rotation is known to be impaired at older adult age. The authors examined whether the impairment is present already at preretirement age and whether it depends on the difficulty of the adaptation task. Moreover, the authors tested predictions of the hypothesis that the age-related impairment pertains primarily to strategic corrections and the explicit knowledge on which they are based but not to the acquisition of an (implicit) internal model of the novel visuomotor transformation. The authors found an age-related impairment of adaptation and explicit knowledge already at preretirement age but no age-related change of aftereffects. With an incremental simplification of the adaptation task, age-related changes were able to be eliminated. Individual differences of the quality of explicit knowledge were associated with differences of adaptation, but not of aftereffects. When age groups were matched by explicit knowledge, age-related impairments of adaptation largely disappeared. However, a reliable difference remained in one of the experiments, suggesting that other processes of adjustment to a visuomotor rotation might be affected by aging as well. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotion-induced trade-offs in spatiotemporal vision.

It is generally assumed that emotion facilitates human vision in order to promote adaptive responses to a potential threat in the environment. Surprisingly, we recently found that emotion in some cases impairs the perception of elementary visual features (Bocanegra & Zeelenberg, 2009b). Here, we demonstrate that emotion improves fast temporal vision at the expense of fine-grained spatial vision. We tested participants' threshold resolution with Landolt circles containing a small spatial or brief temporal discontinuity. The prior presentation of a fearful face cue, compared with a neutral face cue, impaired spatial resolution but improved temporal resolution. In addition, we show that these benefits and deficits were triggered selectively by the global configural properties of the faces, which were transmitted only through low spatial frequencies. Critically, the common locus of these opposite effects suggests a trade-off between magno- and parvocellular-type visual channels, which contradicts the common assumption that emotion invariably improves vision. We show that, rather than being a general “boost” for all visual features, affective neural circuits sacrifice the slower processing of small details for a coarser but faster visual signal. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Analysis of saccadic short-term plasticity in three dimensions

The capacity for short-term adaptation is a well-established property of the horizontal (H) and vertical (V) components of saccades. It allows these directional components, which clearly serve the goal of foveation, to maintain their precision even under changing circumstances. Torsional (T) saccade components, on the other hand, which deal with the orientation of the target on the fovea, have hardly been investigated in adaptation experiments. They appear to be severely restricted by Listing's law during fixations and saccades. The main purpose of Listing's law is far from obvious but could be visual or oculomotor. Better knowledge of the adaptive capacity of the saccadic system in the torsional direction could throw new light on the functional significance of this interesting neural strategy. To study short-term plasticity in the torsional components of saccades, binocular 3D-eye positions were measured, using magnetic search coils. Five normal human subjects were instructed to make uni-directional refixation saccades, while they viewed a large visual scene. To induce a change in the torsional component, the complete stimulus was rapidly rotated during these saccades. We thoroughly investigated the torsional responses of the saccadic system, to see if any short-term adaptive response in torsional direction was induced, in which case the notion of a visual purpose for Listing's law would be strengthened. In none of our experiments, however, did we find any clear adaptive response in torsional direction. To further investigate the reliability of this result and to ascertain that our experimental conditions allowed classical gain adaptation, we also did experiments designed to achieve a combination of torsional adaptation and classic gain shortening in one of the directional components. While gain adaptation was very obvious, none of the experiments provided evidence for a short-term effect in torsion. We conclude that our experiments do not support a purely visual basis for Listing's law.