Chris Donkin

UNSW Sydney | UNSW · School of Psychology

Much recent research has aimed to establish whether visual working memory (WM) is better characterized by a limited number of discrete all-or-none slots or by a continuous sharing of memory resources. To date, however, researchers have not considered the response-time (RT) predictions of discrete-slots versus shared-resources models. To complement...

A classic law of cognition is that forgetting curves are closely approximated by power functions. This law describes relations between different empirical dependent variables and the retention interval, and the precise form of the functional relation depends on the scale used to measure each variable. In the research reported here, we conducted a r...

A classic question in cognitive psychology concerns the nature of memory search in short-term recognition. Despite its long history of investigation, however, there is still no consensus on whether memory search takes place serially or in parallel or is based on global access. In the present investigation, we formalize a variety of models designed...

Many real-world decisions must be made on basis of experienced outcomes. However, there is little consensus about the mechanisms by which people make these decisions from experience (DfE). Across five experiments, we identified several factors influencing DfE. We also introduce a novel computational modeling framework, the memory for exemplars mode...

When making risky choices, two kinds of information are crucial: outcome values and outcome probabilities. Here, we demonstrate that the juncture at which value and probability information is provided has a fundamental effect on choice. Across four experiments involving 489 participants, we compare two decision making scenarios: one where value inf...

The key implication argued by proponents of preregistration is that it improves the diagnosticity of statistical tests [1]. In the strong version of this argument, preregistration does this by solving statistical problems, such as family-wise error rates. In the weak version, it nudges people to think more deeply about their theories, methods, and...

The target article on robust modeling (Lee et al. in review) generated a lot of commentary. In this reply, we discuss some of the common themes in the commentaries; some are simple points of agreement while others are extensions of a practical or abstract nature. We also address a small number of disagreements or confusions.

Starting from the view that progress in science consists of the improvement of our theories, in the current paper we ask two questions: what makes a theory good, and how much do the current method-oriented solutions to the replication crisis contribute to the development of good theories? Based on contemporary philosophy of science, we argue that g...

The target article on robust modeling (Lee et al.) generated a lot of commentary. In this reply, we discuss some of the common themes in the commentaries; some are simple points of agreement while others are extensions of a practical or abstract nature. We also address a small number of disagreements or confusions.

How useful are methods aiming to make research findings more replicable—particularly preregistration—for developing good psychological theories? We distinguish between two kinds of flexibility—the flexibility of a theory and the flexibility of a model—and argue that even when attempts are made to reduce model flexibility, the lack of attention to t...

Medical informed consent is the process by which a ‘competent’, non-coerced individual receives sufficient information including risks of a medical procedure and gives permission for it to occur. The capacity to give an informed consent might be impaired during labour. This study aimed to examine women’s abilities to understand and remember during...

We investigated previous findings suggesting a paradoxical inconsistency of people's beliefs and choices: When making decisions under uncertainty, people seem to both overestimate the probability of rare events in their judgments and underweight the probability of the same rare events in their choices. In our reexamination, we found that people's b...

In an attempt to increase the reliability of empirical findings, psychological scientists have recently proposed a number of changes in the practice of experimental psychology. Most current reform efforts have focused on the analysis of data and the reporting of findings for empirical studies. However, a large contingent of psychologists build mode...

We investigated previous findings suggesting a paradoxical inconsistency of people’s beliefs and choices: When making decisions under uncertainty, people seem to both overestimate the probability of rare events in their judgments and underweight the probability of the same rare events in their choices. In our re-examination, we found that people’s...

In an attempt to increase the reliability of empirical findings, psychological scientists have recently proposed a number of changes in the practice of experimental psychology. Most current reform efforts have focused on the analysis of data and the reporting of findings for empirical studies. However, a large contingent of psychologists build mode...

We respond to the comments of Logie and Vandierendonck to our article proposing benchmark findings for evaluating theories and models of short-term and working memory. The response focuses on the two main points of criticism: (a) Logie and Vandierendonck argue that the scope of the set of benchmarks is too narrow. We explain why findings on how wor...

Any mature field of research in psychology-such as short-term/working memory-is characterized by a wealth of empirical findings. It is currently unrealistic to expect a theory to explain them all; theorists must satisfice with explaining a subset of findings. The aim of the present article is to make the choice of that subset less arbitrary and idi...

How does the process of information transmission affect the cultural or linguistic products that emerge? This question is often studied experimentally and computationally via iterated learning, a procedure in which participants learn from previous participants in a chain. Iterated learning is a powerful tool because, when all participants share the...

How does the process of information transmission affect the cultural or linguistic products that emerge? This question is often studied experimentally and computationally via iterated learning: a procedure in which participants learn from previous participants in a chain. Iterated learning is a powerful tool because, when all participants share the...

Past research indicates that individuals respond adaptively to contextual factors in multi-attribute choice tasks. Yet it remains unclear how this adaptation is cognitively governed. In this paper, empirically testable implementations of two prominent competing theoretical frameworks are developed and compared across two multi-attribute choice expe...

We describe and demonstrate an empirical strategy useful for discovering and replicating empirical effects in psychological science. The method involves the design of a metastudy, in which many independent experimental variables—that may be moderators of an empirical effect—are indiscriminately randomized. Radical randomization yields rich datasets...

Response times have been very informative for the understanding of mental processes, for many years. The most useful analyses of response times have been those based on cognitive theories of decision making, known as evidence accumulation models. We review the history of decision‐making models, and the empirical phenomena that have guided their dev...

Most data analyses rely on models. To complement statistical models, psychologists have developed cognitive models, which translate observed variables into psychologically interesting constructs. Response time models, in particular, assume that response time and accuracy are the observed expression of latent variables including 1) ease of processin...

With immediate repetition priming of forced choice perceptual identification, short prime durations produce positive priming (i.e., priming the target leads to higher accuracy, while priming the foil leads to lower accuracy). Many theories explain positive priming following short duration primes as reflecting increased perceptual fluency for the pr...

When people consider a series of random binary events, such as tossing an unbiased coin and recording the sequence of heads (H) and tails (T), they tend to erroneously rate sequences with less internal structure or order (such as HTTHT) as more probable than sequences containing more structure or order (such as HHHHH). This is traditionally explain...

We describe and demonstrate an empirical strategy useful for discovering and replicating empirical effects in psychological science. The method involves the design of a meta-study, in which many independent experimental variables—that may be moderators of an empirical effect—are indiscriminately randomized. Radical randomization yields rich data se...

There is growing interest in modelling how people make choices that involve both risks and delays, i.e., risky inter-temporal choices. We investigated an untested assumption underlying several proposed risky inter-temporal choice models: that pure risky choices and pure inter-temporal choices are special cases of risky inter-temporal choice. We tes...

In two experiments, we demonstrate that despite indicating indifference when probed about risk or delay in isolation, when forced to explicitly trade-off between the two, participants prefer delayed over risky rewards. This pattern of findings sets a boundary condition for any common utility-based comparison process involving both risk and delay. F...

Debate continues over whether visual working memory has a single, fixed capacity. Empirically, performance in working memory tasks worsens as the complexity of stimuli increases. However, there exist two explanations for this result. One proposal is that visual working memory is capable of holding fewer complex stimuli. The alternative proposal is...

We investigated the relationship between psychometrically-defined schizotypy and the ability to detect a visual target pattern. Target detection is typically impaired by a surrounding pattern (context) with an orientation that is parallel to the target, relative to a surrounding pattern with an orientation that is orthogonal to the target (orientat...

Raw data and best-fitting psychometric functions for all participants The blue circles represent the proportion of correct responses within a given target contrast bin, with an area that is proportional to the number of trials. The solid black lines represent the best-fitting psychometric function, with the grey surrounding region capturing the boo...

Comparison of the O-LIFE scores reported by Mason & Claridge (1996) and the current study Panels show the different subscales of the O-LIFE questionnaire, and boxplots show the 25th, 50th, 75th, and 90th percentiles for the “<22” age group norms reported by Mason & Claridge (1996) and for those obtained in the current study, separated by gender.

Distribution of orientation-dependent contextual modulation effects for the two testing booths Boxplots show the difference between the contrast detection thresholds for parallel and orthogonal contexts for simultaneous presentation, separately for the two physical testing booths that were used in this study.

Distribution of participant ages, after application of exclusion criteria

Re-analysis of previous orientation-dependent surround suppression schizophrenia studies

Distribution of orientation-dependent contextual modulation effects for females and males Boxplots show the difference between the contrast detection thresholds for parallel and orthogonal contexts for simultaneous presentation, separately for females and males.

Pairwise correlations between the ranked scores on the O-LIFE subscales Correlation coefficients and p values refer to the Pearson correlation on the ranked values (Spearman’s correlation).

Comparison of O-LIFE score and the magnitude of the orientation-dependent effect of context during simultaneous presentation Each point shows a single participant’s O-LIFE subscale score and orientation-dependent context effect (the difference between the contrast detection threshold with a parallel surround and that with an orthogonal surround, bo...

Comparison of ranked schizotypy score and the ranked contrast detection threshold with orthogonal context during simultaneous presentation

Comparison of ranked schizotypy score and the ranked magnitude of the difference between contrast detection thresholds with parallel and orthogonal context for the ’leading surround’ condition

Consumer behavior can often be framed as decision making in multi-attribute choice tasks where several options (products) are described on a number of attributes, which serve as cues. Past research indicates that individuals adaptively apply different amount of cognitive effort depending on contextual factors. Yet it remains unclear how this adapti...

Most data analyses rely on models. To complement statistical models, psychologists have developed cognitive models, which translate observed variables into psychologically interesting constructs. Response time models, in particular, assume that response time and accuracy are the observed expression of latent variables including 1) ease of processin...

Over the last four decades, sequential accumulation models for choice response times have spread through cognitive psychology like wildfire. The most popular style of accumulator model is the diffusion model (Ratcliff Psychological Review, 85, 59–108, 1978), which has been shown to account for data from a wide range of paradigms, including perceptu...

Previous research with the ratio-bias task found larger response latencies for conflict trials where the heuristic- and analytic-based responses are assumed to be in opposition (e.g., choosing between 1/10 and 9/100 ratios of success) when compared to no-conflict trials where both processes converge on the same response (e.g., choosing between 1/10...

The long-held popular notion of intuition has garnered much attention both academically and popularly. Although most people agree that there is such a phenomenon as intuition, involving emotionally charged, rapid, unconscious processes, little compelling evidence supports this notion. Here, we introduce a technique in which subliminal emotional inf...

We report an experiment designed to provide a qualitative contrast between knowledge-limited versions of mixed-state and variable-resources (VR) models of visual change detection. The key data pattern is that observers often respond "same" on big-change trials, while simultaneously being able to discriminate between same and small-change trials. Th...

Reasoning and inference are well-studied aspects of basic cognition that have been explained as statistically optimal Bayesian inference. Using a simplified experimental design, we conducted quantitative comparisons between Bayesian inference and human inference at the level of individuals. In 3 experiments, with more than 13,000 participants, we a...

Does the similarity between two items change over time? Previous studies (Goldstone & Medin, 1994; Gentner & Brem, 1999) have found suggestive results but have relied on interpreting complex interaction effects from " deadline " decision tasks in which the decision making process is not well understood (Luce, 1986). Using a self-paced simple decisi...

At the core of every decision-making task are two simple features; outcome values and probabilities. Over the past few decades, many models have developed from von Neumann' and Morgenstern's (1945) Expected Utility Theory to provide a thorough account of people's subjective value and probability weighting functions. In particular, one such model th...

a.luckman@unsw.edu.au) Chris Donkin (c.donkin@unsw.edu.au) Ben R. Newell (ben.newell@unsw.edu.au) Abstract Utility based models are common in both the risky and inter-temporal choice literatures. Recently there have been efforts to formulate models of choices which involve both risks and time delays. An important question then is whether the concep...

Working memory capacity (WMC) is typically measured by the amount of task-relevant information an individual can keep in mind while resisting distraction or interference from task-irrelevant information. The current research investigated the extent to which differences in WMC were associated with performance on a novel redundant memory probes (RMP)...

Two experiments investigated the extent to which value-modulated oculomotor capture is subject to top-down control. In these experiments, participants were never required to look at the reward-related stimuli; indeed, doing so was directly counterproductive because it caused omission of the reward that would otherwise have been obtained. In Experim...

Absolute identification is a deceptively simple task that has been the focus of empirical investigation and theoretical speculation for more than half a century. Observers are shown a set of N stimuli varying on a single dimension (e.g., length or loudness) and each stimulus is given a label (e.g., 1, .., N). They then attempt to identify stimuli p...

Absolute identification is a deceptively simple task that has been the focus of empirical investigation and theoretical speculation for more than half a century. Observers are shown a set of N stimuli varying on a single dimension (e.g., length or loudness) and each stimulus is given a label (e.g., 1, .., N). They then attempt to identify stimuli p...

Many theories of visual search assume that the features composing a target are detected by distinct processors, unaffected by the presence of other target features. Here we show that the detection of a target feature is affected by the presence of other target features. In the experiment, we trained participants to perform two tasks, a visual searc...

The strength of conclusions about the adoption of different categorization strategies-and their implications for theories about the cognitive and neural bases of category learning-depend heavily on the techniques for identifying strategy use. We examine performance in an often-used "information-integration" category structure and demonstrate that s...

In the redundant target effect, participants respond faster with two (redundant) targets. We compared the magnitude of this effect in younger and older adults, with and without distractors, in a simple visual-detection task. We employed additional measures that allow non-parametric assessment of performance (Townsend's capacity coefficient) and par...

The slots model of visual working memory, despite its simplicity, has provided an excellent account of data across a number of change detection experiments. In the current research, we provide a new test of the slots model by investigating its ability to account for the increased prevalence of errors when there is a potential for confusion about th...

Significance One of the more intriguing but controversial ideas in psychology is that unconscious information can influence our decisions without us even knowing it. Here, we explicitly tested these controversial ideas with a novel behavioral task and computational models of decision-making. We report that unconscious information can be accumulated...

Sequential effects are ubiquitous in decision-making, but no more than in the absolute identification task where participants must identify stimuli from a set of items that vary on a single dimension. A number of competing explanations for these sequential effects have been proposed, and recently Matthews and Stewart [(2009a). The effect of inter-s...

The long-held popular notion of intuition, despite lacking strong scientific support has garnered much attention both academically and conversationally. While most agreed on intuition involving emotionally charged, rapid, unconscious processes, little compelling evidence exists in its support. Here, we employ a novel empirical paradigm and diffusio...

Zhang and Luck (Psychological Science, 20, 423-428, 2009) found that perceptual memories are lost over time via sudden death rather than gradual decay. However, they acknowledged that participants may have instead lost memory for the locations of objects. We required observers to recall only a single object. Although the paradigm eliminated the nee...

Decision-makers effortlessly balance the need for urgency against the need for caution. Theoretical and neurophysiological accounts have explained this tradeoff solely in terms of the quantity of evidence required to trigger a decision (the "threshold"). This explanation has also been used as a benchmark test for evaluating new models of decision m...

The ability to trade accuracy for speed is fundamental to human decision making. The speed-accuracy trade-off (SAT) effect has received decades of study, and is well understood in relatively simple decisions: collecting more evidence before making a decision allows one to be more accurate but also slower. The SAT in more complex paradigms has been...

Externalizing psychopathology (EXT) is associated with low executive working memory (EWM) capacity and problems with inhibitory control and decision-making; however, the specific cognitive processes underlying these problems are not well known. This study used a linear ballistic accumulator computational model of go/no-go associative-incentive lear...

We examined the conditions under which sampling information from different probability distributions reduces base-rate neglect in intuitive probability judgments. To assess the impact of our manipulations, we employed a novel Bayesian latent-mixture model analysis that allowed us to quantify evidence for base-rate neglect. Experience with samples f...

As a fundamental part of our daily lives, visual word processing has received much attention in the psychological literature. Despite the well established advantage of perceiving letters in a word or in a pseudoword over letters alone or in random sequences using accuracy, a comparable effect using response times has been elusive. Some researchers...

A fundamental issue concerning visual working memory is whether its capacity limits are better characterized in terms of a limited number of discrete slots (DSs) or a limited amount of a shared continuous resource. Rouder et al. (2008) found that a mixed-attention, fixed-capacity, DS model provided the best explanation of behavior in a change detec...

We focus on two issues: (1) an unusual, counterintuitive prediction that quantum probability (QP) theory appears to make regarding multiple sequential judgments, and (2) the extent to which QP is an appropriate and comprehensive benchmark for assessing judgment. These issues highlight how QP theory can fall prey to the same problems of arbitrarines...

Interference resolution is improved for stimuli presented in contexts (e.g., locations) associated with frequent conflict. This phenomenon, the context-specific proportion congruent (CSPC) effect, has challenged the traditional juxtaposition of “automatic” and “controlled” processing because it suggests that contextual cues can prime top-down contr...

A classic distinction in perceptual information processing is whether stimuli are composed of separable dimensions, which are highly analyzable, or integral dimensions, which are processed holistically. Previous tests of a set of logical-rule models of classification have shown that separable-dimension stimuli are processed serially if the dimensio...