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Filmmakers’ efforts not only advance film as an art form, they also provide insights about basic perception. This research was designed to uncover commonalities between the aesthetic appreciation of viewers of films and the perceptual capacities of observers of environmental events. We assessed whether the temporal structure of events in the environment is reflected in the temporal structure of events in film. Participants in Study 1 segmented neutral environmental events to establish a benchmark temporal structure. Study 2 compared the temporal structure of editing in amateur and professionally made films. Results from these two studies suggest a particular fractal structure common to environmental event perception and the editing structure of professional films. This hypothesis was then tested in an experiment that reedited one film so as to produce four different versions, each with a different fractal structure. These versions were evaluated by audiences in terms of aesthetics (e.g., general likability, comprehension, technical aspects of craft). The results suggest that the fractal structure typical of environmental event perception is preferred, even when it is not the original, artistically intended version. It is argued that narrative films succeed, at least in part, because their temporal structure reflects the temporal structure of environmental event perception.

In addressing the character of the haptic system, James Gibson (1966) noted, “The study of useful sensitivity, as distinguished from theoretically basic sensitivities, is only just beginning” (p. 116). Whereas the preceding 150 years had gotten mired in an inventory of isolated sensations, the ensuing 50 years have revealed a good deal about the capabilities of a perceptual system that detects information about the self, the environment, and self-environment relations by means of muscular effort. That research is summarized with special attention to the kind of medium that could ground the useful dimensions of haptic sensitivity.

The emerging understanding of the behavioral transitions that accompany the ascending and descending method of limits is in terms of "functional distance" - the degree to which a perceiver is disengaged from ordinary exploratory activities. Increasing functional distance results in negative hysteresis in contrast to the classical positive hysteresis more typical of ongoing activity. In the present study of human gait transitions on a treadmill, the functional distance between a perceiver and ordinary exploratory activities was manipulated in two ways: (1) "Active" participants, walking or running on a treadmill, were asked to anticipate the gait that would be required if treadmill speed were increased or decreased; and (2) "passive" participants, standing off a moving treadmill, were asked to report the gait they would use if they were on the treadmill at its current speed. As expected, the increase of functional distance from (1) to (2) reduced the amount of classical hysteresis and promoted negative hysteresis, that is, a lower transition speed for walk-to-run transitions (ascending trials) than for run-to-walk transitions (descending trials). These results complement empirical findings in other behavioral transition experiments. More broadly, they signify the role of perception-action cycles for grounding natural on-going perception. In particular, they support the assertion that perception and action are intertwined and that lack of information about an impending action has consequences for perceptual judgments.

Research on dynamic touch has shown that when a rod strapped to the shoulders is wielded via axial rotations, flexions-extensions, and lateral bending of the trunk, participants can selectively perceive whole rod length and partial rod length (e.g., a leftward segment) with precision comparable to wielding by hand (Palatinus, Carello & Turvey, 2011). The present research addressed whether this haptic ability is preserved in quiet standing, when postural control is limited to center of pressure (COP) fluctuations at the mm/ms scale, and, if so, whether the intentions ("perceive partial," "perceive whole") are distinguishable within the fluctuations. Given standard manipulations of rod length and attached mass, participants provided significantly distinct, appropriately scaled, whole and partial estimates of rod length. COP displacement time series were subjected to multifractal, detrended fluctuation analysis. The resultant spectrum of fractal scaling exponents for gradually different-sized fluctuations revealed that "perceive partial" was manifest as larger exponents for progressively smaller fluctuations than "perceive whole." Our results indicate (a) that the significant mechanical variables for haptically perceiving object extent are available in the small scale of normal body sway, and (b) that these seemingly "passive" movements reflect the intention of the perceiver.

We investigated fractality in the segmentation of cinematic and live events. Four movies from distinct genres were first analyzed and found to be fractal, albeit in different regions of the fractal range. In Experiment 1, viewers parsed the films' events, attending to short or long timescales, using a button box to indicate break points. The temporal structure of film viewing was found to be fractal regardless of the scale of attention and to reflect the differing fractal editing structure of the films. Experiment 2 found event segmentation to be fractal in a natural setting, a basketball game, as well. An additional parallel between reel and real events was uncovered: fractal indices were at the higher end of the range for both the film genre intended to be anxiogenic and the more suspenseful portion of the basketball game. We argue that the fractal structure of perception reflects the fractal structure of events whether the events are in film or in nature. We speculate that fractal structure has implica...

Gibson's (1966, 1979/1986) ecological approach to perception, action, and cognition is patently non-representational and non-computational. In the place of these commonly assumed neural endowments, ecological psychology seeks to expose the laws that underlie intelligent capabilities. It is argued that this is the goal for understanding the directed behavior of not just humans, not just animals, and not just the living. We argue that an approach to intelligence that is physically grounded is completely consistent with—and is even a natural consequence of—the central tenets of ecological psychology. We identify two dozen guidelines for seeking intelligence in first principles.

Dynamic touching is effortful touching. It entails deformation of muscles and fascia and activation of the embedded mechanoreceptors, as when an object is supported and moved by the body. It is realized as exploratory activities that can vary widely in spatial and temporal extents (a momentary heft, an extended walk). Research has revealed the potential of dynamic touching for obtaining non-visual information about the body (e.g. limb orientation), attachments to the body (e.g. an object's height and width) and the relation of the body both to attachments (e.g. hand's location on a grasped object) and surrounding surfaces (e.g. places and their distances). Invariants over the exploratory activity (e.g. moments of a wielded object's mass distribution) seem to ground this ‘information about’. The conception of a haptic medium as a nested tensegrity structure has been proposed to express the obtained information realized by myofascia deformation, by its invariants and transformations. The tensegrity proposal rationalizes the relative indifference of dynamic touch to the site of mechanical contact (hand, foot, torso or probe) and the overtness of exploratory activity. It also provides a framework for dynamic touching's fractal nature, and the finding that its degree of fractality may matter to its accomplishments.

The haptic subsystem of dynamic touch expresses a novel form of part–whole selective perception. When wielding a nonvisible rod grasped at some intermediate point along its length, an individual can attend to and report the length of a part of the rod (e.g., the segment forward of the hand) or the length of the whole rod. Both perceptions relate to the rod's mass moments about the point of grasp but in systematically different ways. Previous demonstrations of this part–whole selectivity have been in respect to rods grasped by hand or attached to a foot. The authors demonstrated the part–whole selectivity for nonvisible rods attached to the shoulder girdle and wielded primarily by movements of the trunk with benchmark performance provided by the same rods grasped and wielded by hand. Their results suggest that part–whole selectivity is a haptic capability general to the body.

LW, an individual with a stroke-related motor impairment, was asked to perceive the lengths of rods of different mass distributions by dynamic touch. His impairment dictated that wielding was primarily about the shoulder rather than the wrist. Although perceived rod lengths were in the range of actual rod lengths, scaling to the objects' mass moments was atypical for both the affected and unaffected limbs. A group of healthy young adults asked to mimic his wielding style yielded the same atypical scaling. The typical scaling was restored when LW's wielding was fixed about a mechanical axis. Discussion considered what frame of reference is suitable for revealing an object's mass moments relevant to a given task. In particular, it appears that individuals can exploit alternative forms of interaction with environmental objects that leave invariant the parameters specifying to-be-perceived properties. Perception by dynamic touch is not a function of particular neuromuscular patterns but of information made av...

Two experiments evaluated change in the perception of an environmental property (object length) in each of 3 perceptual modalities (vision, audition, and haptics) when perceivers were provided with the opportunity to experience the same environmental property by means of an additional perceptual modality (e.g., haptics followed by vision, vision followed by audition, or audition followed by haptics). Experiment 1 found that (a) posttest improvements in perceptual consistency occurred in all 3 perceptual modalities, regardless of whether practice included experience in an additional perceptual modality and (b) posttest improvements in perceptual accuracy occurred in haptics and audition but only when practice included experience in an additional perceptual modality. Experiment 2 found that learning curves in each perceptual modality could be accommodated by a single function in which auditory perceptual learning occurred over short time scales, haptic perceptual learning occurred over middle time scales, a...

Nonvisual perceptions of a wielded object's spatial properties are based on the quantities expressing the object's mass distribution, quantities that are invariant during the wielding. The mechanoreceptors underlying the kind of haptic perception involved in wielding - referred to as effortful, kinesthetic, or dynamic touch - are those embedded in the muscles, tendons, and ligaments. The present experiment's focus was the selectivity of this muscle-based form of haptic perception. For an occluded rod grasped by the hand at some intermediate position along its length, participants can attend to and report selectively the rod's full length, its partial lengths (fore or aft of the hand), and the position of the grip. The present experiment evaluated whether participants could similarly attend selectively when wielding by foot. For a given rod attached to and wielded by foot or attached to (i.e. grasped) and wielded by hand, participants reported (by magnitude production) the rod's whole length or fractional length leftward of the point of attachment. On measures of mean perceived length, accuracy, and reliability, the degree of differentiation of partial from full extent achieved by means of the foot matched that achieved by means of the hand. Despite their neural, anatomical, and experiential differences, the lower and upper limbs seem to abide by the same principles of selective muscle-based perception and seem to express this perceptual function with equal facility.

According to the International Classification of Functioning, Disability and Health, effective rehabilitation requires interventions that go beyond minimizing pathological conditions and associated symptoms. The scope of practice must include promoting an individual's activity within relevant contexts. We argue that best practice requires decisions that are not only evidence-based but also theory-based. Perception and action theories are essential for interpreting evidence and clinical phenomena as well as for developing new interventions. It is our contention that rehabilitation goals can best be achieved if inspired by the ecological approach to perception and action, an approach that focuses on the dynamics of interacting constraints of performer, task and environment. This contrasts with organism-limited motor control theories that have important influence in clinical practice. Parallels between such theories and the medical model of care highlight their fundamental inconsistency with the current understanding of functioning. We contend that incorporating ecological principles into rehabilitation research and practice can help advance our understanding of the complexity of action and provide better grounding for the development of effective functional practice. Implications and initial suggestions for an ecologically grounded functional practice are outlined.

The sensibility associated with muscles contributes little to the conceptual content of current psychology. In part, this is because perceptions achieved through the muscle sense typically go unnoticed. Nonetheless, researchers have discovered a rich variety of muscle-based perceptual capabilities—such as those relating to held objects, probed objects, and body segments—that seem to depend on quantities well known in physics, quantities that reflect how the mass of an object or limb is distributed. The conceptual and technical issues posed by these capabilities warrant study by psychologists interested in the general problems of space perception, action, and selective attention.

Various object properties are perceptible by wielding. We asked whether the dynamics of wielding differed as a function of the to-be-perceived property. Wielding motions were analyzed to determine if they differed under the intention to perceive or not perceive rod length (experiment 1), to perceive object height versus object width (experiment 2), and to perceive the length forward of where the rod was grasped versus the position of the grasp (experiment 3). Perceiving these different properties is known to depend on different components of the object's inertia tensor. Analyses of the subtle recurrent patterns in the phase space of the hand motions revealed differences in wielding across the different perceptual intentions. Haptic exploratory procedures may exhibit distinct exploratory dynamics.

Whether an object can be used to satisfy a given tool user's intention depends on, among other things, the object's inertial properties. Overcoming an object's rotational inertia is key in controlling a handheld object with respect to a given intention. Manipulating an object by means of muscular exertion is the domain of dynamic touch. Thus, the affordances of a given object as a tool should be perceivable by means of dynamic touch. In 3 experiments, we investigated the inertial variables that support perception of 2 potential affordances of handheld tools: hammer-with-ability and poke-with-ability. The results suggest that ratings of hammers are dependent on the volume of the inertial ellipsoid in such a way that supports the transference of power to the struck surface. Ratings of pokers are dependent on the same quantity but in a way that supports controllability of the poking object. Additionally, results suggest that minimal experience in a given tool-using task may "tune" tool users to the inertial ...

Young adults are able to perceive an implement's center of percussion (CP) or “sweet spot,” and to distinguish it from the implement's length, simply on the basis of wielding. Given the known changes in mechanoreceptors with aging, two experiments assessed these perceptual abilities in older adults (ranging in age from 62 to 89 years with an average of 69.2). They, too, distinguished length from the sweet spot simply on the basis of wielding, both for tennis rackets (Experiment 1) and for bats contrived from wooden rods with attached masses (Experiment 2). Results conformed to previous research on dynamic touch in showing that perceiving the extents of wielded objects is constrained by the moments of the objects' mass distributions. Moreover, so-called young–old plots were linear – older peoples' perceptions were predicted by younger peoples' perceptions – implicating a common underlying mechanism for the two age groups. Nonetheless, the perceived-to-actual functions were generally flatter for elderly participants. How aging might compromise the functioning of dynamic touch was discussed in terms of fractal organization and functional limitations.

(1999). Further Evidence of Perceptual Independence (Specificity) in Dynamic Touch. Ecological Psychology: Vol. 11, No. 4, pp. 269-281.

Many sports involve aligning a hitting implement with a ball trajectory such that contact is made at the implement's center of percussion or ‘sweet spot’. This spot is not visibly distinct; its perception must be haptic. Although it is functionally defined with respect to contact—it is the point of impact that produces the least vibration in the hand holding the implement—hitting success requires appreciating the location of the sweet spot prior to contact. Two experiments verified that perceivers (novices as well as expert tennis players) distinguished perception of length from perception of the position of the sweet spot simply on the basis of wielding, both for tennis rackets and for bats contrived from wooden rods with attached masses. Results conformed to previous research on dynamic touch in showing that perceiving the lengths of wielded objects, including selectively perceiving partial lengths, is constrained by inertial properties of the object.

Although hearing is classically considered a temporal sense, everyday listening suggests that subtle spatial properties constitute an important part of what people know about the world through sound. Typically neglected in psychoacoustics research, the ability to perceive the precise sizes of objects on the basis of sound was investigated during the routine event of dropping wooden dowels of different lengths onto a hard surface. In two experiments, the ordinal and metrical success of naive listeners was related to length but not to the simple acoustic variables (duration, amplitude, frequency) likely to be related to it. Additional analysis suggests the potential relevance of an object's inertia tensor in constraining perception of that object's length, analogous to the case that has been made for perceiving length by effortful touch.

When a rod is grasped at a place intermediate between its ends, the nonvisible perception of length by wielding can be directed to either side of the hand. The selective perception of the lengths of rod segments relative to the hand is hypothesized to depend jointly on the rod's inertia tensor about a fixed rotation point and on the 2-valued attitude spinor connecting the rod's reference frame to the hand's. That hypothesis was tested in 3 experiments m which 8-10 subjects participated; asymmetry in the rod's mass distribution relative to the hand was induced either by the addition of a metal ring to one end or by grasping the rod at a place other than its midpoint. Planes of wielding, style of wielding, and object size were varied across the experiments. The results conformed to expectation: For a given asymmetric rod configuration, perceived length for attending to one direction from the hand (e g., above or left) differed from perceived length for attending to the other direction (below or right); for a given segment of an asymmetric rod, perception of its length did not differ as a function of us direction from the hand. In each experiment, variance in perceived partial length was accommodated by the rod's major eigenvalue and the spinor rotation angle, with rotation sense dictated by the direction of attention.

Two experiments examined perception of the extent of a target rod that is contacted and wielded by a second probe rod. The equations that define the dynamics of the probe-target system suggest a higher order moment of inertia as the relevant perceptual variable. The particular inertial term implicates parameters of both the target and probe rod. Experiment 1 manipulated the inertia of the target rod and Experiment 2 manipulated the inertia of the probe rod. In both experiments, perceived length was a function of the complex inertial term. Results were discussed in terms of haptic perception at a distance, the equivalence of inert and neural appendages, and the scaling of perceived to actual variables.

Perceiving the length of a rod by dynamic touch is tied to the inertia tensor Iij, a quantification of its resistance to rotational acceleration. Perception of the portion extending in front of the grasp has previously been ascribed to decomposing one component of Iij by attention. The tensorial nature of dynamic touch suggests that this ability must be anchored wholly in the tensor. Three experiments show that perceived partial length is a function of two components of the tensor, one tied primarily to magnitude and the other tied primarily to direction, whereas perceived whole length is a function of a magnitude component alone. Dynamic touch is characterized in terms of a haptic perceptual instrument that softly assembles to exploit Iij differently depending on the intention, producing 1:1 maps that are appropriately scaled for each intention.

In the haptic perception of the size of frontoparallel intervals achieved by probing between two objects with a handheld stick, perceived size decreases with distance, with the rate of decrease greater for greater sizes. Analysis and experimentation have shown that these perceptual results are predicted by a quantity that is invariant over probing and specific to the physical conditions defined by the spatial layout and the probe. In this article, we conjecture that an analogous quantity may be involved in the visual perception of size at a distance. Preliminary to the pursuit of this analogous quantity is the demonstration that visual perception reveals the same dependencies on size and distance as extended haptic perception. In Experiment 1, the haptic and visual perceptions of frontoparallel intervals were compared under similar conditions, and in Experiment 2, the range of such intervals to be perceived visually was extended. The standard results for extended haptic perception were replicated and the ...

Perception of whether a slanted surface supports upright stance was evaluated visually and haptically. Observers stood approximately 1 m from a 1 m by 1 m plywood board whose angle of inclination varied randomly among seven settings (12, 17, 22, 27, 33, 39, and 45 deg.). For visual trials, observers looked at the surface. For haptic trials, the observers were blindfolded and explored the surface with a hand-held wooden dowel. The perceived behavioral category boundary (i.e., the slope that received 50% yes responses) did not differ for visual and haptic judgments. Although the two perceptual systems did not differ in the mean, participants took longer to make haptic judgments and were less confident in doing so. For both perceptual systems, response time increased and confidence decreased at the category boundary. A second experiment used ascending and descending methods of limits and found both enhanced contrast and hysteresis effects for both perceptual systems. Differences between perceptual systems we...

James Gibson introduced the concept of affordance to emphasize the importance of behavior in constraining perception. In this view, perception is not judged in terms of sensitivities to properties that are measured by physical instruments (photometers for brightness, scales for weight, etc.) but in terms of properties that matter to behaving systems (whether an object is appropriate to carry out some task). The affordance notion is brought to bear on understanding and motivating a variety of experimental phenomena in the study of dynamic touch, the domain of touch most concerned with using objects and interacting with surfaces.

James Gibson introduced the concept of affordance to emphasize the importance of behavior in constraining perception. In this view, perception is not judged in terms of sensitivities to properties that are measured by physical instruments (photometers for brightness, scales for weight, etc.) but in terms of properties that matter to behaving systems (whether an object is appropriate to carry out some task). The affordance notion is brought to bear on understanding and motivating a variety of experimental phenomena in the study of dynamic touch, the domain of touch most concerned with using objects and interacting with surfaces.

BACKGROUND: Muscle-based perception of the spatial properties of limbs constrains the patterning, timing and magnitude of muscle forces while performing motor activities. The centrality of muscle-based perception to both ordinary and skilled actions warrants attention from the rehabilitation community, since deficits in its functioning would be related to important functional limitations. In this overview, we summarize a body of research that may be used to guide the development of effective assessment tools and rehabilitation programs that are specifically directed towards such deficits. OBJECTIVES: There were four specific aims: first, to present an information-based approach to muscle-based perception that is grounded in physical laws; second to identify central principles underlying muscle-based perception that have been revealed and supported by empirical work; third, to summarize reports that have investigated whether the principles identified can be generalized to muscle-based perception in individuals with sensory-motor impairments; and fourth to provide a preliminary discussion of the potential implications of the research presented here for issues relating to rehabilitation. INTRODUÇÃO: A percepção muscular das propriedades espaciais dos membros restringe o padrão, período e magnitude das forças exercidas durante a execução de atividades motoras. A importância central da percepção muscular, tanto para ações rotineiras quanto para ações especializadas, merece atenção da comunidade envolvida na área de reabilitação, uma vez que alterações em suas funções podem estar relacionadas a importantes limitações funcionais. Nesta revisão, os autores apresentam um resumo da pesquisa que pode ser utilizada para guiar o desenvolvimento de ferramentas de avaliação eficazes bem como programas de reabilitação que sejam especificamente direcionados para estas disfunções. OBJETIVOS: Quatro pontos específicos foram incluídos: primeiro, a apresentação da abordagem com base em informações relativas à percepção muscular de acordo com as leis da física; segundo, a identificação dos princípios centrais determinantes da percepção muscular que vem sendo revelada e apoiada por trabalhos empíricos; terceiro, um resumo dos relatos que investigaram e se os princípios identificados poderiam ser generalizados para a percepção muscular dos indivíduos com alterações motoras e sensitivas; e quarto, uma discussão preliminar sobre as implicações potenciais da pesquisa aqui apresentada, no tocante aos assuntos relacionados à reabilitação.

The spatial extents of hand-held objects can be perceived nonvisually by wielding them. This ability of effortful or dynamic touch to exploit the mass moments of an object to perceive its length was evaluated with a 40-years old right-handed woman with surgically treated Arnold-Chiari Type 1 Malformation and cervical syrinx. At the time of the experiment she presented with loss of discriminative touch in the left arm but no comparable sensory deficits in the right arm or the lower extremities. She could neither identify objects in her left hand nor tell that they were in the hand while manipulating them. She could, however, grasp an object tightly and wield it on request. In the experiment she wielded weighted rods of 45, 60, and 80 cm length about the wrist. There were two main results. First, her nonvisual perception of rod length by the insensate left arm scaled systematically with rod moment of inertia. The scaling matched that of the intact right arm and the nondominant arm of haptically unimpaired controls tested with rods of similar dimensions. Second, her right arm was superior in accuracy and reliability than her insensate left arm and was equal to or better than the dominant arm of the control group on key measures of nonvisual length perception. The first result was evaluated in respect to the notions of numb touch and differences in the neural bases of discriminative and effortful touch. The second result was discussed in terms of contralateral cortical enhancement by deafferentation.

It is hypothesized that heaviness perception for a freely wielded nonvisible object can be mapped to a point in a three-dimensional heaviness space. The three dimensions are mass, the volume of the inertia ellipsoid, and the symmetry of the inertia ellipsoid. Within this space, particular combinations yield heaviness metamers (objects of different mass that feel equally heavy), whereas other combinations yield analogues to the size-weight illusion (objects of the same mass that feel unequally heavy). Evidence for the two types of combinations was provided by experiments in which participants wielded occluded hand-held objects and estimated the heaviness of the objects relative to a standard. Further experiments with similar procedures showed that metamers of heaviness were metamers of moveableness but not metamers of length. A promising conjecture is that the haptic perceptual system maps the combination of an object’s inertia for translation and inertia for rotation to a perception of the object’s maneuverability.

Perception of the extent of hand-held rods was examined when the mode of exploration was dynamic touch and the mode of report was either a subsystem of the same mode (haptic touch) or a different mode (vision). Moment of inertia was manipulated by the position of an attached mass along the lengths of the rods. Results showed no difference between the report modes, with log of perceived length being a linear function of log of moment of inertia in both cases. This similarity between ipsemodal and cross-modal matches for perceived extent supports the generality of examinations of dynamic touch that use visual magnitude production (e.g., Solomon & Turvey, 1988; Solomon, Turvey, & Burton, 1989a, 1989b).

The haptic perceptual sybsystem of dynamic touch is prominent in manipulating and transporting objects, providing a nonvisible awareness of their linear dimensions. The hypothesis that perceptions of object width and height by dynamic touch are different functions of the inertia tensor is addressed. In two experiments heights and widths of nonvisible wielded objects were judged separately. Experiment 1 used solid rectangular parallelepipeds of different sizes; Experiment 2 used objects of identical mass and linear dimensions but nonidentical inertia ellipsoids. Width and height perceptions of comparable reliability and accuracy were found to vary as distinct functions of the objects' inertial eigenvalues. Discussion focused on the notion of tangible shape and on the selectivity of attention within dynamic touch.

A synergy is taken to refer to independent things acting together to produce an ordered macroscopic state. It is argued that perception and action act synergistically, with the macroscopic state being the perceiving-acting cycle. This perspective entails a rethinking of perception along the lines suggested by J. J. Gibson: the appropriate observables are at the ecologicalscale (i.e., they are intrinsically coarse); the appropriate organ of sensitivity is a perceptual system (not a receptor or nerve); and the appropriate treatment of information is as specificational (i.e., it is lawfully related to its source). With this reformulation, the idea of a perceiving-acting cycle is elaborated, especially with reference to the relationship among intentional states, exploratory states, and informational states. The basic theme is that perception constrains action which, in turn, “sets up” perception. Examples of perceptually constrained exploratory and performatory activities are provided to illustrate the kinds of macroscopic variables that have been identified as being relevant to understanding perceiving-acting cycles.

Much of the work on sound localization has focused on sound sources in the horizontal plane. This study looks at the auditory perception of distance using a reaching task [L. D. Rosenblum, A. P. Wuestefeld, and K. L. Anderson, Ecological Psych. 8, 1–24 (1996)]. In this task, blindfolded participants judged the reachability of a rattle based on a straight right arm reach. In order to investigate visual influences on auditory distance perception, in another condition, participants judged the reachability of an ‘‘auditory’’ rattle while simultaneously viewing a ‘‘visual’’ rattle that did not produce sound. The ‘‘visual’’ rattle was placed 8 cm in front of the ‘‘auditory’’ rattle or 8 cm behind it. Compared to an auditory alone condition, participants were more likely to judge that the rattle was within reach when the visual stimulus was closer to the participant than the auditory stimulus. These results show that vision influences the perception of sound source distance.

Serbo-Croatian is transcribed in two partially overlapping alphabets. Some shared letters are pronounced differently in the two alphabets. Consequently, a word composed of shared ambiguous and unambiguous letters and no alphabetically unique letters is phonologically ambiguous. Ordinarily, visual recognition of such words is slowed relative to appropriately controlled, phonologically unambiguous words. Experiments showed that this phonological ambiguity effect is reduced substantially and equally by either a consonant string or a word that immediately precedes the target and specifies its alphabet. Alphabetic priming was also found for targets that contain both ambiguous and unique letters but not for targets without ambiguous letters. Other evidence showed, however, that alphabet priming can be offset by accessed lexical information. Results were discussed in terms of a connectionist model.

The Serbo-Croatian language is transcribed in two partially overlapping alphabets. Some of the shared letters are pronounced differently in the two alphabets. Consequently, when the alphabet is not specified, some letter strings are phonologically ambiguous. Lexical decision and naming are much slower for such letter strings relative to appropriately controlled, phonologically unambiguous letter strings. Lexical decision and rapid naming experiments are reported, directed at contextually reducing this phonological ambiguity effect. For words, the phonological ambiguity effect was reduced by alphabetically related contexts in both tasks. Associatively related contexts also contributed to the effect's reduction in the rapid naming of words. For pseudowords, alphabet specification reduced the effect in lexical decision but not naming. Results were discussed in terms of their implications for an account of Serbo-Croatian word recognition.