Philip L. Smith's research while affiliated with University of Melbourne and other places

Publications (100)

Preprint
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Previous research has characterized source retrieval as a thresholded process, which fails on a proportion of trials and leads to guessing, as opposed to a continuous process, where response precision varies across trials but is never zero. The thresholded view of source retrieval is largely based on the observation of heavy tailed distributions of...
Preprint
Continuous-outcome decisions, in which responses are made on continuous scales, are increasingly used to study perception and memory for stimulus attributes like color, orientation, and motion. This interest has led to the development of models of continuous-outcome decision processes like the circular diffusion model that predict joint distribution...
Article
Continuous-outcome decisions, in which responses are made on continuous scales, are increasingly used to study perception and memory for stimulus attributes like color, orientation, and motion. This interest has led to the development of models of continuous-outcome decision processes like the circular diffusion model that predict joint distributio...
Article
Ratcliff, Voskuilen, and McKoon (2018) presented data and model-based analyses that provided strong evidence for across-trial variability in evidence entering the decision process in several perceptual tasks. They did this using a double-pass procedure in which exactly the same stimuli are presented on two widely-separated trials. If there were onl...
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Using a simulated negotiation, we test how negotiators’ decision frames (gain vs loss) influence their social utilities. Recognizing that utilities are shaped by both economic and social concerns, we measure four attributes of negotiator satisfaction: satisfaction with own economic outcomes, satisfaction with self, other’s satisfaction with outcome...
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Diffusion models of evidence accumulation have successfully accounted for the distributions of response times and choice probabilities from many experimental tasks, but recently their assumption that evidence is accumulated at a constant rate to constant decision boundaries has been challenged. One model assumes that decision-makers seek to optimiz...
Article
Purpose Negotiators are offered limited advice on how to overcome adverse events. Drawing on resilience and coping literatures, this study aims to test the impact of three cognitive processing strategies on negotiators’ subjective and economic value following adversity. Design/methodology/approach Participants completed two negotiations with the s...
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A circular analogue of the diffusion model adapted for continuous response tasks is applied to a continuous-outcome source memory task. In contrast to existing models of source retrieval that attribute all of the variability in responding to memory, the circular diffusion model decomposes noise into variability arising from memory and from decision...
Article
Investigations into the way that information is held and integrated within the visual system provides some basis for understanding how visual information is represented and processed. Just over sixty years ago, Swets, Shipley, McKey, and Green (1959) demonstrated that performance within an auditory detection task increases as a function of the squa...
Article
When searching for a target briefly presented among distractors how do people combine information across display locations to make a decision and how does the quality of the evidence entering the decision process vary with the type of items in the display? Research on accuracy in near-threshold visual search has had difficulty in distinguishing bet...
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Evidence accumulation models like the diffusion model are increasingly used by researchers to identify the contributions of sensory and decisional factors to the speed and accuracy of decision-making. Drift rates, decision criteria, and nondecision times estimated from such models provide meaningful estimates of the quality of evidence in the stimu...
Preprint
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A circular analogue of the diffusion model adapted for continuous response tasks is applied to a continuous-outcome source memory task. In contrast to existing models of source retrieval that attribute all variability in responding to memory, the circular diffusion model decomposes noise into variability arising from memory and decision-making proc...
Article
The circular diffusion model is extended to provide a theory of the speed and accuracy of continuous outcome color decisions and used to characterize eye-movement decisions about the hues of noisy color patches in an isoluminant, equidiscriminability color space. Heavy-tailed distributions of decision outcomes were found with high levels of chromat...
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A crisis in psychology has provoked researchers to seek remedies for bad practices that might damage the integrity of the discipline as a whole. The ardor for wholesale reform has led to a suite of proposed technical solutions, some of which are considered in the context of computational modeling by the target article. Any technical solution, howev...
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Visual short-term memory (VSTM) has been described as being limited by the number of discrete visual objects, the aggregate quantity of information across multiple visual objects, or some combination of the two. Many recent studies examining these capacity limitations have shown that increasing the number of items in VSTM increases the frequency an...
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Negotiation scholars know relatively little about how negotiators can overcome adverse circumstances and end negotiations with an enhanced sense of satisfaction. Using a series of two negotiations simulations, we tested whether cognitive reappraisal influences negotiators' responses to adverse experiences. After completing a negotiation in which th...
Preprint
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Replication is already mainstream in areas of psychology that use small-N designs. Replication failures often result from weak theory, weak measurement, and weak control over error variance. These are hallmarks of phenomenon-based research with sparse data. Small-N designs, which focus on understanding processes, treat the individual rather than th...
Article
Replication is already mainstream in areas of psychology that use small- N designs. Replication failures often result from weak theory, weak measurement, and weak control over error variance. These are hallmarks of phenomenon-based research with sparse data. Small- N designs, which focus on understanding processes, treat the individual rather than...
Article
We generalize the circular 2D diffusion model of Smith (Psychological Review, 123, 425-451: 2016) to provide a new model of speeded decision-making in multielement visual displays. We model decision-making in tasks with multielement displays as evidence accumulation by a vector-valued diffusion process in a hypersphere, whose radius represents the...
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In his commentary, Bundesen (2018) argued that limited encoding capacity can account for the near-equivalent set size effects on performance under conditions of simultaneous and sequential presentation reported by Sewell, Lilburn, and Smith (2014). While we agree that limited encoding capacity could, in principle, account for this equivalency, we a...
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Although negotiation research has systematically investigated the factors that contribute to negotiators’ satisfaction with economic outcomes, relatively less attention has been given to the factors that influence their satisfaction with social outcomes. In this research, we used a computer-based task to present pairs of outcomes (own outcome, othe...
Article
The quality or precision of stimulus representations in visual working memory can be characterized by a power law, which states that precision decreases as a power of the number of items in memory, with an exponent whose magnitude typically varies in the range 0.5 to 0.75. The authors show that the magnitude of the exponent is an index of the atten...
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The dominant paradigm for inference in psychology is a null-hypothesis significance testing one. Recently, the foundations of this paradigm have been shaken by several notable replication failures. One recommendation to remedy the replication crisis is to collect larger samples of participants. We argue that this recommendation misses a critical po...
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According to sequential sampling models, perceptual decision-making is based on accumulation of noisy evidence towards a decision threshold. The speed with which a decision is reached is determined by both the quality of incoming sensory information and random trial-by-trial variability in the encoded stimulus representations. To investigate those...
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How limited representational capacity is divided when multiple items need to be processed simultaneously is a fundamental question in cognitive psychology. The double-target deficit is the finding that, when monitoring multiple locations or information streams for targets, identification of 2 simultaneous targets is substantially worse than is pred...
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A central question in working memory research concerns the degree to which information in working memory is accessible to other cognitive processes (e.g., decision-making). Theories assuming that the focus of attention can only store a single object at a time require the focus to orient to a target representation before further processing can occur...
Chapter
In this chapter, we provide a tutorial review of the class of sequential sampling models of two-choice decision-making. These models, which have been developed in cognitive and mathematical psychology over the last 50 years, provide a detailed quantitative account of performance in simple, speeded choice tasks. The models explain the major findings...
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We investigated the capacity of visual short-term memory (VSTM) in a phase discrimination task that required judgments about the configural relations between pairs of black and white features. Sewell et al. (2014) previously showed that VSTM capacity in an orientation discrimination task was well described by a sample-size model, which views VSTM a...
Article
Optimality studies and studies of decision-making in monkeys have been used to support a model in which the decision boundaries used to evaluate evidence collapse over time. This article investigates whether a diffusion model with collapsing boundaries provides a better account of human data than a model with fixed boundaries. We compared the model...
Article
I present a diffusion model for decision making in continuous report tasks, in which a continuous, circularly distributed, stimulus attribute in working memory is matched to a representation of the attribute in the stimulus display. Memory retrieval is modeled as a 2-dimensional diffusion process with vector-valued drift on a disk, whose bounding c...
Article
There is growing interest in diffusion models to represent the cognitive and neural processes of speeded decision making. Sequential-sampling models like the diffusion model have a long history in psychology. They view decision making as a process of noisy accumulation of evidence from a stimulus. The standard model assumes that evidence accumulate...
Article
Diffusion and random walk processes comprise one of the main classes of sequential-sampling models for decision making and choice response time in psychology. The models assume that decisions are made by accumulating samples of noisy evidence to a response criterion, either in continuous or in discrete time. The models successfully predict the main...
Article
Diffusion models for simple two-choice decision-making have achieved prominence in psychology and neuroscience. The standard model views decision-making as a process in which noisy evidence is accumulated until one of the two response criteria is reached, at which point the associated response is made. The criteria represent the amount of evidence...
Chapter
Negotiators’ communication patterns can be analyzed at several levels. Most often, researchers focus on the cumulative use of cooperative and competitive strategies to characterize the dominant strategic orientation of a negotiation. This perspective is complemented by analyses of strategy sequences, that is, how negotiators respond to opponents’ i...
Article
A normalized coding condition is proposed that provides a theoretical link between the Poisson shot noise model of choice response time and a Poisson neuron model of the information capacity of visual short-term memory (VSTM). In both models, noise in the cognitive representations of stimuli is attributed to Poisson variability in the neural proces...
Article
The diffusion model assumes that two-choice decisions are made by accumulating successive samples of noisy evidence to a response criterion. The model has a pair of criteria that represent the amounts of evidence needed to make each response. The time taken to reach criterion determines the decision time and the criterion that is reached first dete...
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Normalization models of visual sensitivity assume that the response of a visual mechanism is scaled divisively by the sum of the activity in the excitatory and inhibitory mechanisms in its neighborhood. Normalization models of attention assume that the weighting of excitatory and inhibitory mechanisms is modulated by attention. Such models have pro...
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Jones and Dzhafarov (2014) claim that several current models of speeded decision making in cognitive tasks, including the diffusion model, can be viewed as special cases of other general models or model classes. The general models can be made to match any set of response time (RT) distribution and accuracy data exactly by a suitable choice of param...
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Research suggests that visual short-term memory (VSTM) has both an item capacity, of around 4 items, and an information capacity. We characterize the information capacity limits of VSTM using a task in which observers discriminated the orientation of a single probed item in displays consisting of 1, 2, 3, or 4 orthogonally oriented Gabor patch stim...
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Reports an error in "A competitive interaction theory of attentional selection and decision making in brief, multielement displays" by Philip L. Smith and David K. Sewell (Psychological Review, 2013[Jul], Vol 120[3], 589-627). In the article, the values of ( d=)2 in Figure 8 were calculated using the formula d' = z[P(C)] rather than the standard fo...
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We generalize the integrated system model of Smith and Ratcliff (2009) to obtain a new theory of attentional selection in brief, multielement visual displays. The theory proposes that attentional selection occurs via competitive interactions among detectors that signal the presence of task-relevant features at particular display locations. The outc...
Article
Context shapes negotiators’ actions, including their willingness to act unethically. Focusing on negotiators use of deception, we used a simulated two-party negotiation to test how three contextual variables—regulatory focus, power, and trustworthiness—interacted to shift negotiators’ ethical thresholds. We demonstrated that these three variables i...
Article
Using a simulated employment negotiation, we tested the conditional relationships among dyadic power profiles (symmetric high, symmetric low, and asymmetric), the choice and sequencing of strategies, and value creation. We showed that negotiators in symmetric high, symmetric low, and asymmetric power dyads took distinctly different paths to value c...
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Perceptual decision making is believed to be driven by the accumulation of sensory evidence following stimulus encoding. More controversially, some studies report that neural activity preceding the stimulus also affects the decision process. We used a multivariate pattern classification approach for the analysis of the human electroencephalogram (E...
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This forthcoming entry in the Encyclopaedia of Peace Psychology provides an overview of trust in negotiation
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The attention literature distinguishes two general mechanisms by which attention can benefit performance: gain (or resource) models and orienting (or switching) models. In gain models, processing efficiency is a function of a spatial distribution of capacity or resources; in orienting models, an attentional spotlight must be aligned with the stimul...
Article
Negotiators' communication can be analyzed at several levels: the frequency with which strategies are used, how negotiators sequence strategies, and how strategies evolve over time. Each level of analysis provides us with different kinds of information about the negotiation process. An important difference between these approaches is that analyses...
Article
One of the first decisions a negotiator makes is whether to adopt a broadly cooperative or broadly competitive approach. This decision is critical because it affects the boundaries that negotiators set (the range of acceptable outcomes), where they start the negotiation and their willingness to make concessions. It also shapes how negotiations unfo...
Article
An important class of psychological models of decision making assumes that evidence is accumulated by a diffusion process to a response criterion. These models have successfully accounted for reaction time (RT) distributions and choice probabilities from a wide variety of experimental tasks. An outstanding theoretical problem is how the integration...
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Simultaneous recordings were collected from between two and four buildup neurons from the left and right superior colliculi in rhesus monkeys in a simple two-choice brightness discrimination task. The monkeys were required to move their eyes to one of two response targets to indicate their decision. Neurons were identified whose receptive fields we...
Article
Constructing a veridical spatial map by touch poses at least two problems for a perceptual system. First, as the hand is moved through space, the locations of features may be displaced if there is an uncorrected lag between the moment the hand encounters a feature and the time that feature is encoded on a spatial map. Second, due to the sequential...
Article
In the diffusion model of decision-making, evidence is accumulated by a Wiener diffusion process. A neurally motivated account of diffusive evidence accumulation is given, in which diffusive accumulation arises from an interaction between neural integration processes operating on short and long time scales. The short time scale process is modeled a...
Article
Cooperative actions are central to a problem-solving approach in negotiation. In deciding how to approach a negotiation, individuals draw on multiple cues to assess the likelihood that the other party will reciprocate cooperative actions. Using a simulated business negotiation, we examined how two contextual variables, regulatory focus (RF) and int...
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The relationship between attention and visual masking was investigated in a cued detection task using a factorial masking manipulation. Stimuli were either unmasked, or were masked with simultaneous (integration) masks, or delayed (interruption) masks, or integration-interruption mask pairs. The cuing effects in detection sensitivity were smallest...
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The authors report 9 new experiments and reanalyze 3 published experiments that investigate factors affecting the time course of perceptual processing and its effects on subsequent decision making. Stimuli in letter-discrimination and brightness-discrimination tasks were degraded with static and dynamic noise. The onset and the time course of decis...
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Recent spatial cuing studies have shown that detection sensitivity can be increased by the allocation of attention. This increase has been attributed to one of two mechanisms: signal enhancement or uncertainty reduction. Signal enhancement is an increase in the signal-to-noise ratio at the cued location; uncertainty reduction is a reduction in the...
Article
Reports an error in "An integrated theory of attention and decision making in visual signal detection" by Philip L. Smith and Roger Ratcliff (Psychological Review, 2009[Apr], Vol 116[2], 283-317). There is an error on p. 284 in the right-hand column. In the sentence "On each trial, the angular position of the cue, α, (0 2009-04438-001.) The simples...
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A radial frequency (RF) stimulus is strongly masked by a second, surrounding RF stimulus that follows the first after a critical stimulus onset asynchrony (SOA) of around 100 ms. We sought to determine whether a mask-dependent attentional cuing effect, like that found when detecting pattern-masked sinusoidal gratings, would be obtained with RF stim...
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The simplest attentional task, detecting a cued stimulus in an otherwise empty visual field, produces complex patterns of performance. Attentional cues interact with backward masks and with spatial uncertainty, and there is a dissociation in the effects of these variables on accuracy and on response time. A computational theory of performance in th...
Article
The speed-accuracy trade-off (SAT) is a ubiquitous phenomenon in experimental psychology. One popular strategy for controlling SAT is to use the response signal paradigm. This paradigm produces time-accuracy curves (or SAT functions), which can be compared across different experimental conditions. The typical approach to analyzing time-accuracy cur...
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A number of studies have shown that certain events that occur during a negotiation can alter its course. Referred to as “turning points,” these events are precipitated by actions taken either outside or inside the talks that have consequences for outcomes. In this article, we report the results of two experiments designed to examine the impacts of...
Article
Using a simulated two-party negotiation, we examined how trustworthiness and power balance affected deception. In order to trigger deception, we used an issue that had no value for one of the two parties. We found that high cognitive trust increased deception whereas high affective trust decreased deception. Negotiators who expressed anxiety also u...
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Negotiators' social motives (cooperative vs. individualistic) influence their strategic behaviors. In this study, the authors used multilevel modeling and analyses of strategy sequences to test hypotheses regarding how negotiators' social motives and the composition of the group influence group members' negotiation strategies. Four-person groups ne...
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The attentional cuing effects in detection and some discrimination tasks depend on the use of backward masks and on the presence of external noise in the display. These effects have been attributed to an interruption masking mechanism, which terminates stimulus processing prematurely, and an external noise exclusion mechanism, which minimizes the p...
Article
This research examined how trust affected resource allocation in a three-party negotiation. Negotiators were presented with an empty core problem in which their theoretical share of resources exceeded the resources available for distribution. We tested which of three components of trust—reliability, predictability and empathy—predicted negotiators’...
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Attentional cues may increase the detectability of a stimulus by increasing its signal-to-noise ratio (signal enhancement) or by increasing the efficiency of the observer's decision making by reducing uncertainty about the location of the stimulus (uncertainty reduction). Although signal enhancement has typically been found in detection tasks only...
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Monkeys made saccades to one of two peripheral targets based on the brightness of a central stimulus. Task difficulty was manipulated by varying the ratio of stimulus black-and-white pixels. Correct response probability for two monkeys varied directly with difficulty. Deep layer SC neurons exhibited robust presaccadic activity the magnitude of whic...
Article
Using a simulated, two-party negotiation, we examined how characteristics of the factor, target and situation affected deception. We focused on how negotiators talked about an indifference issue, that is, an issue that had no value for them. We found that negotiators misrepresented the value of this issue (sin of commission) when the other party wa...
Article
Deal-making negotiations can be characterized as social exchanges in which individuals trade both tangible resources such as goods and information, and intangible resources such as favors and esteem. Representing negotiations in this way highlights both the implicit obligation for recipients to return resources, and the possibility that they will b...
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Models of decision making and response time (RT) are often formulated using stochastic differential equations (SDEs). Researchers often investigate these models using a simple Monte Carlo method based on Euler's method for solving ordinary differential equations. The accuracy of Euler's method is investigated and compared to the performance of more...
Article
Using a simulated, two-party negotiation, we examined how trustworthiness and power balance affected deception. To trigger deception, we used an issue that had no value for one of the two parties. We found that deception was lower when the other party was perceived as reliable, predictable or as having shared goals. Deception increased when the oth...
Article
This research tested the relationships between turning points, cognitive and affective trust, and negotiation outcomes. After completing a simulated negotiation, participants identified turning points from videotape. Turning points were then classified as substantive (interest, offer), characterization (positive, negative), or procedural (positive,...
Chapter
This chapter examines the effects of ageing on cognitive processes in two choice tasks. It fits the diffusion model to the response time and accuracy data for each task, and interprets the effects of ageing in terms of the components of processing identified by the model. The chapter addresses whether the interpretations are specific to the diffusi...
Article
Using a bilateral negotiation, we examined the relationship between motivational orientation, mental maps and negotiators' outcomes. Cooperative and competitive negotiators bargained with a counterpart who held either the same or a different orientation. Compared to negotiators in mixed dyads, those in same-orientation dyads placed greater emphasis...
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Markov chain analysis provides a way to investigate how the communication processes in dyadic negotiations are affected by features of the negotiating context and how, in turn, differences in communication processes among dyads affect the quality of the final settlement. In Markov models, the communication process is represented as a sequence of tr...
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This experiment examined the impact of negotiators' cooperative and competitive expectations on the interpretation of ambiguous messages. In a simulated bilateral negotiation, participants received an initial set of cooperative, competitive or ambiguous messages, followed by a set of ambiguous messages. Negotiators who received cooperative of compe...
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A spatial-cuing paradigm was used to test the hypothesis of Carrasco, Penpeci-Talgar, and Eckstein (2000) that the mask-dependent cuing effects found in visual signal detection by Smith (2000a) were caused by submaximal activation of the transient-orienting system. Mask-dependent cuing was found with a range of stimulus contrasts with pure peripher...
Article
Mask-dependent cuing effects, like those previously found in yes-no detection, were found in a task in which observers judged the orientations of orthogonally-oriented Gabor patches presented at cued or uncued locations. Attentional cues enhanced sensitivity for masked, but not unmasked, stimuli. Responses were faster to cued than to uncued stimuli...
Article
The authors evaluated 4 sequential sampling models for 2-choice decisions--the Wiener diffusion, Ornstein-Uhlenbeck (OU) diffusion, accumulator, and Poisson counter models--by fitting them to the response time (RT) distributions and accuracy data from 3 experiments. Each of the models was augmented with assumptions of variability across trials in t...
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Patterns of neural firing linked to eye movement decisions show that behavioral decisions are predicted by the differential firing rates of cells coding selected and nonselected stimulus alternatives. These results can be interpreted using models developed in mathematical psychology to model behavioral decisions. Current models assume that decision...
Article
A dichoptic masking procedure was used to test whether the mask-dependent cuing effects found in luminance detection by P. L. Smith (2000a) were due to integration masking or interruption masking. Attentional cuing enhanced detection sensitivity (d') when stimuli were backwardly masked with either dichoptic or monoptic masks, whereas no cuing effec...
Article
The examination of negotiation processes is seen by many researchers as an insurmountable task largely because the required methods are unfamiliar and labor-intensive. In this article, we shed light on a fundamental step in studying negotiation processes, the quantitative coding of data. Relying on videotapes as the primary source of data, we revie...
Article
Using a simulated employment negotiation, this experiment examined the relationship between dyad composition, negotiation strategies and levels of joint gain. Three dyad types were created on the basis of social value orientation, proself, prosocial and mixed. A log linear analysis showed that dyads were differentiated on the basis of the strategie...