Perceptually Equivalent Judgments Made Visually and via Haptic Sensory-Substitution Devices

ABSTRACT

According to the ecological theory of perception–action, perception is primarily of affordances, which are directly perceivable opportunities for behavior. The current study evaluated participants’ ability to use vision and haptic sensory-substitution devices to support perceptual judgments of affordances involving the task of passing through apertures. Sighted participants made perceptual judgments about whether they could walk through apertures of various widths and their level of confidence in each judgment, using unrestricted vision and, when blindfolded, using two haptic sensory-substitution instruments: a cane-like wooden rod and the Enactive Torch, a device that converts distance information into vibrotactile stimuli. The boundary between aperture widths that were judged as pass-through-able versus non-pass-through-able was statistically equivalent across sensory modalities. However, participants were not as confident in their judgments using the rod or Enactive Torch as they were using vision. Additionally, participants’ judgments with the haptic instruments were significantly more accurate than with vision. The results underscore the need to assess sensory-substitution devices in the context of functional behaviors.     

A non‐representational approach to imagined action

This study addresses the dynamical nature of a “representation‐hungry” cognitive task involving an imagined action. In our experiment, participants were handed rods that systematically increased or decreased in length on subsequent trials. Participants were asked to judge whether or not they thought they could reach for a distant object with the hand‐held rod. The results are in agreement with a dynamical model, extended from Tuller, Case, Ding, and Kelso (1994). The dynamical effects observed in this study suggest that predictive judgments regarding the possibility or impossibility of a certain action can be understood in terms of dynamically evolving basins of attraction instead of as depending on representational structures.     

Dissociating cognitive and motor interference effects on kinesthetic short-term memory

In two experiments, we investigated how short-term memory of kinesthetically defined spatial locations suffers from either motor or cognitive distraction. In Exp. 1, 22 blindfolded participants moved a handle with their right hand towards a mechanical stop and back to the start and then reproduced the encoded stop position by a second movement. The retention interval was adjusted to approximately 0 and 8 s. In half of the trials participants had to provide a verbal judgment of the target distance after encoding (cognitive distractor). Analyses of constant and variable errors indicated that the verbal judgments interfered with the motor reproduction only, when the retention interval was long. In Exp. 2, 22 other participants performed the same task but instead of providing verbal distance estimations they performed an additional movement either with their right or left hand during the retention interval. Constant error was affected by the side of the interpolated movement (right vs. left hand) and by the delay interval. The results show that reproduction of kinesthetically encoded spatial locations is affected differently in long- and short-retention intervals by cognitive and motor interference. This suggests that reproduction behavior is based on distinct codes during immediate vs. delayed recall.     

Apparent movement and metacontrast suppression: A decisional analysis

Three test and three mask energies were varied orthogonally and randomly over trials. The stimulus onset asynchrony (ISOA) separating test and mask was varied between trial blocks within each of two display conditions, apparent movement (two-object) and metacontrast (threeobject). Subjects were required to makebrightness judgments of both test and mask energies by responding “bright,” “medium,” or “dim” with respect to the apparent intensity of each stimulus. The accuracy and the coherence lconsistencyt of test judgments were U-shaped functions of SOA for both apparent movement and metacontrast situations. However, the accuracy and the coherence of mask judgments did not vary with SOA for either apparent movement or metacontrast. It was noted that substantially the same results have been reported previously when subjects were required to makecontour judgments. Hence, it is argued that apparent movement and metacontrast suppression are intimately related.     

The Effect of Evidential Impact on Perceptual Probabilistic Judgments

In a series of three behavioral experiments, we found a systematic distortion of probability judgments concerning elementary visual stimuli. Participants were briefly shown a set of figures that had two features (e.g., a geometric shape and a color) with two possible values each (e.g., triangle or circle and black or white). A figure was then drawn, and participants were informed about the value of one of its features (e.g., that the figure was a “circle”) and had to predict the value of the other feature (e.g., whether the figure was “black” or “white”). We repeated this procedure for various sets of figures and, by varying the statistical association between features in the sets, we manipulated the probability of a feature given the evidence of another (e.g., the posterior probability of hypothesis “black” given the evidence “circle”) as well as the support provided by a feature to another (e.g., the impact, or confirmation, of evidence “circle” on the hypothesis “black”). Results indicated that participants’ judgments were deeply affected by impact, although they only should have depended on the probability distributions over the features, and that the dissociation between evidential impact and posterior probability increased the number of errors. The implications of these findings for lower and higher level cognitive models are discussed.     

Binding “what” and “where” in auditory working memory: An asymmetrical association between sound identity and sound location

Contrasting results in visual and auditory working memory studies suggest that the mechanisms of association between location and identity of stimuli depend on the sensory modality of the input. In this auditory study, we tested whether the association of two features both encoded in the “what” stream is different from the association between a “what” and a “where” feature. In an old–new recognition task, blindfolded participants were presented with sequences of sounds varying in timbre, pitch and location. They were required to judge if either the timbre, pitch or location of a single-probe stimulus was identical or different to the timbre, pitch or location of one of the sounds of the previous sequence. Only variations in one of the three features were relevant for the task, whereas the other two features could vary, with task-irrelevant changes. Results showed that task-irrelevant variations in the “what” features (either timbre or pitch) caused an impaired recognition of sound location and in the other task-relevant “what” feature, whereas changes in sound location did not affect the recognition of either one of the “what” features. We conclude that the identity of sounds is incidentally processed even when not required by the task, whereas sound location is not maintained when task irrelevant.     

What Do People Find Incompatible With Causal Determinism?

Four studies explored people's judgments about whether particular types of behavior are compatible with determinism. Participants read a passage describing a deterministic universe, in which everything that happens is fully caused by whatever happened before it. They then assessed the degree to which different behaviors were possible in such a universe. Other participants evaluated the extent to which each of these behaviors had various features (e.g., requiring reasoning). We assessed the extent to which these features predicted judgments about whether the behaviors were possible in a deterministic universe. Experiments 1 and 2 found that people's judgments about whether a behavior was compatible with determinism were not predicted by their judgments about whether that behavior relies on physical processes in the brain and body, is uniquely human, is unpredictable, or involves reasoning. Experiment 3, however, found that a distinction between what we call “active” and “passive” behaviors can explain people's judgments. Experiment 4 extended these findings, showing that we can measure this distinction in several ways and that it is robustly predicted by two different cues. Taken together, these results suggest that people carve up mentally guided behavior into two distinct types—understanding one type to be compatible with determinism, but another type to be fundamentally incompatible with determinism.     

Dynamic Touch by Hand and Head During Walking: Protective Behavior for the Head?

We investigated perception of the extent of an object held in the hand or attached to the head during walking. Participants wielded an occluded, weighted rod by hand and by head and reported the perceived location of the rod end (relative to a virtual vertical line) while walking and while standing. There was an unexpected effect of body part on perceived location of the rod end. In particular, participants stood or walked so that the rod end was farther away from the vertical line when wielding with the head than wielding with the hand. It is possible that differences between the tasks and the relative costs of a collision influenced the locomotory behavior in each condition.     

Advice conditionals about tips and warnings: interpretations and inferences

Two experiments examine how people interpret and reason about advice conditionals, such as tips, for example, “if you study more your grades will improve”, and warnings, for example, “if you stop exercising you will gain weight”. Experiment 1 showed that when participants reason about whether a tip or warning could be true in different situations, their judgments correspond to a biconditional or conditional interpretation on about half of all trials, but to an enabling or tautology interpretation on many others. Experiment 2 showed that participants make few modus ponens and tollens inferences from tips and warnings, and more modus ponens inferences from tips than warnings. The implications for alternative theories are discussed.     

反应选项对时序知觉重复启动效应的影响

先前研究采用两项反应任务发现了时序知觉重复启动效应, 这可能是反应选项导致的虚假效应, 本研究采用三项反应任务对此进行了检验。实验1运用三项判断任务以消除缺乏中间选项所致的反应偏向, 结果发现重复启动显著影响“哪个图形先出现”和“两个图形同时出现”的时序判断; 实验2在实验1的基础上对“同时出现”反应选项进行两种指导语操作, 实验结果不仅与实验1一致, 而且“有把握时判断为同时出现”和“有无把握都判断为同时出现”之间没有显著差异, 说明被试能够识别时序加以判断, 不支持反应偏向的前提条件。因此, 时序知觉重复启动效应不是反应选项产生的反应偏向引发的虚假效应, 重复启动对“系列性”和“同时性”时序知觉都存在显著影响。     

Multimodal Perception of Reachability Expressed Through Locomotion

We investigated the information that supports perception of whether an object is within reach using a locomotor task. Participants adjusted their own position relative to a fixed target by stepping or by propelling a wheelchair until they judged it to be within reach. The to-be-reached object was presented in virtual reality. The display of the target was driven in real time as a function of the observer's movement, thus depicting a stationary virtual object at a definite distance only through the relation across optical and nonoptical patterns of stimulation. We asked participants to judge the distance they could reach with their unaided hand or when holding a rod that extended their effective reach. They could see neither their body nor the rod thereby limiting available visual information about “reachability.” As expected, our results showed that despite the limited information that was available, participants' locomotor adjustments were influenced by (a) their simulated distance from the target, (b) their arm length, and (c) the presence or absence of the rod. The type of motion (stepping or wheelchair) had little influence. However, judgment accuracy was influenced by participants' initial simulated distance from the target. We compare the performance obtained in our locomotor judgment task with previous studies that have used different methods for measuring perceived reaching-ability. We discuss perceptual information that could have supported performance within the framework of the global array.     

Nodding in dis/agreement: a tale of two cultures

Head movement is commonly used to communicate positive versus negative response. However, whereas in US culture, vertical head movement denotes positivity (nodding to say “yes”) and horizontal head movement is associated with negativity (shaking heads to say “no”), in Bulgaria, this response pattern is reversed, that is, horizontal head movement means “yes” and vertical head movement means “no.” Thus, these two cultures spatially “embody” agreement via different movement directions. We examined the effect of such cultural differences on cognitive processing that has no communicative intent by comparing ratings of likeability, brightness, and positive feeling associated with different color moving dots. Participants followed the dots’ movement with their heads in a 2 (direction: vertical vs. horizontal) by 2 (speed: fast vs. slow) design. We found a two-way country by speed of movement interaction such that Bulgarian participants associated colors with more positive feeling when those were perceived in combination with slower head movement irrespective of movement direction. US participants, on the other hand, rated color dots as better mood-enhancing in combination with faster head movement. There was a similar two-way country by movement speed interaction for likeability ratings but none for brightness. Findings are discussed in terms of variability in gestural meaning and culture-specific embodiment patterns.     

The covariation of independent and dependant variables in neurofeedback: A proposal framework to identify cognitive processes and brain activity variables

This methodological article proposes a framework for analysing the relationship between cognitive processes and brain activity using variables measured by neurofeedback (NF) carried out by functional Magnetic Resonance Imagery (fMRI NF). Cognitive processes and brain activity variables can be analysed as either the dependant variable or the independent variable. Firstly, we propose two traditional approaches, defined in the article as the “neuropsychological” approach (NP) and the “psychophysiology” approach (PP), to extract dependent and independent variables in NF protocols. Secondly, we suggest that NF can be inspired by the style of inquiry used in neurophenomenology. fMRI NF allows participants to experiment with his or her own cognitive processes and their effects on brain region of interest (ROI) activations simultaneously. Thus, we suggest that fMRI NF could be improved by implementing “the elicitation interview method”, which allows the investigator to gather relevant verbatim from participants’ introspection on subjective experiences.     

Measurement and the mental map

In order to test between subtractive and ratio theories of stimulus comparison, judges were asked to estimate “ratios” and “differences” of easterliness and westerliness of U.S. cities. “Difference” judgments fit the subtractive model, and “ratio” judgments fit the ratio model. However, “ratios” and “differences” were monotonically related, contrary to the theory that judges compute both relations on a common scale. Results are consistent with the theory that there is but one operation for both “ratios” and “differences.” To assume that the single operation is a ratio requires the complex interpretation that easterliness and westerliness are nonlinearly related. A simpler interpretation is provided by a subtractive theory, in which all four types of judgments are monotonically related to subjective differences on a single cognitive map.     

The role of animacy in spatial transformations

We present evidence that different mental spatial transformations are used to reason about three different types of items representing a spectrum of animacy: human bodies, nonhuman animals, and inanimate objects. Participants made two different judgments about rotated figures: handedness judgments (“Is this the left or right side?”) and matching judgments (“Are these figures the same?”). Perspective-taking strategies were most prevalent when participants made handedness judgments about human bodies and animals. In contrast, participants generally did not imagine changes in perspective to perform matching judgments. Such results suggest that high-level information about semantic categories, including information about a thing’s animacy, can influence how spatial representations are transformed when performing online problem solving. Supplemental materials for this article may be downloaded from http://mc.psychonomic-journals.org/content/supplemental.     

Factors that affect action possibility judgments: The assumed abilities of other people

Judging what actions are possible and impossible to complete is a skill that is critical for planning and executing movements in both individual and joint actions contexts. The present experiments explored the ability to adapt action possibility judgments to the assumed characteristics of another person. Participants watched alternating pictures of a person's hand moving at different speeds between targets of different indexes of difficulty (according to Fitts' Law) and judged whether or not it was possible for individuals with different characteristics to maintain movement accuracy at the presented speed. Across four studies, the person in the pictures and the background information about the person were manipulated to determine how and under what conditions participants adapted their judgments. Results revealed that participants adjusted their possibility judgments to the assumed motor capabilities of the individual they were judging. However, these adjustments only occurred when participants were instructed to take the other person into consideration suggesting that the adaption process is a voluntary process. Further, it was observed that the slopes of the regression equations relating movement time and index of difficulty did not differ across conditions. All differences between conditions were in the y-intercept of the regression lines. This pattern of findings suggests that participants formed the action possibility judgments by first simulating their own performance, and then adjusted the “possibility” threshold by adding or subtracting a correction factor to determine what is and is not possible for the other person to perform.     

Identifying and individuating cognitive systems: a task-based distributed cognition alternative to agent-based extended cognition

This article argues for a task-based approach to identifying and individuating cognitive systems. The agent-based extended cognition approach faces a problem of cognitive bloat and has difficulty accommodating both sub-individual cognitive systems (“scaling down”) and some supra-individual cognitive systems (“scaling up”). The standard distributed cognition approach can accommodate a wider variety of supra-individual systems but likewise has difficulties with sub-individual systems and faces the problem of cognitive bloat. We develop a task-based variant of distributed cognition designed to scale up and down smoothly while providing a principled means of avoiding cognitive bloat. The advantages of the task-based approach are illustrated by means of two parallel case studies: re-representation in the human visual system and in a biomedical engineering laboratory.     

Mind,Soul and Spirit: Conceptions of Immaterial Identity in Different Cultures

The cognitive science of religion has recently focused attention on whether concepts of mind, soul, and spirit derive from the same or different intuitive foundations of immaterial identity. The present research is the first to look at intuitions about these three concepts simultaneously in different cultures. Methodologically, hypothetical transplants or transfers of minds or brains have been commonly used to examine the development of inferences about the continuity of mental identity despite bodily displacement. The present research extends the transfer paradigm to compare inferences about transfers of “soul” and “spirit” as well as the “mind.” American, Brazilian, and Indonesian undergraduate participants were presented with a series of scenarios in which a character's soul, mind, or spirit is transferred to another character's body. Participants made judgments about the consequences of such transfers on behaviors selected to potentially differentiate underlying intuitive categories. Results indicate that intuitions of soul, spirit, and mind do appear to draw from different but overlapping intuitions, which are recruited in different ways depending on religion and country. For American and Indonesian participants, the mind transfer was judged more often to result in a displacement of cognitive attributes compared to bodily, social, and moral attributes. Across the three countries, the transfer of spirit led more frequently to judgments about displacement of passion than of ability; religiosity was associated with giving more weight to the transfer of the soul, thus resulting in a greater displacement of all types of attributes. The results emphasize the importance of considering how different intuitive foundations, such as essentialism, intuitive psychology, and vitalism, might be recruited by culture to highlight different aspects of immaterial identity.     

Enhanced embodied response following ambiguous emotional processing

It has generally been assumed that high-level cognitive and emotional processes are based on amodal conceptual information. In contrast, however, “embodied simulation” theory states that the perception of an emotional signal can trigger a simulation of the related state in the motor, somatosensory, and affective systems. To study the effect of social context on the mimicry effect predicted by the “embodied simulation” theory, we recorded the electromyographic (EMG) activity of participants when looking at emotional facial expressions. We observed an increase in embodied responses when the participants were exposed to a context involving social valence before seeing the emotional facial expressions. An examination of the dynamic EMG activity induced by two socially relevant emotional expressions (namely joy and anger) revealed enhanced EMG responses of the facial muscles associated with the related social prime (either positive or negative). These results are discussed within the general framework of embodiment theory.