Signal-detection methods in personality and perception.

Discusses methodological problems encountered in the use of traditional threshold measures in the study of personality and perception. The threshold is shown to: (1) yield results dependent upon the psychophysical method used, (2) be arbitrary in definition, (3) be unimproved by corrections for guessing, and (4) confound the O's sensory capabilities with his criterion for reporting a given stimulus event. Methods derived from signal-detection theory are described. Studies using the logic and methods of signal-detection analysis in personality and perception research are reviewed and their implications discussed. (35 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Strong memories are hard to scale.

People are generally skilled at using a confidence scale to rate the strength of their memories over a wide range. Specifically, low-confidence recognition decisions are often associated with close-to-chance accuracy, whereas high-confidence recognition decisions can be associated with close-to-perfect accuracy. However, using a 20-point rating scale, the authors found that the ability to scale memory strength had its limitations in that a high proportion of list items received the highest rating of 20. Efforts to induce participants to differentiate between these strong memories using emphatic instructions and alternative scales were not successful. Remember/know judgments indicated that these strong and hard-to-scale memories were often based on familiarity (not just recollection). Providing error feedback on a plurals discrimination task finally produced a high-confidence criterion shift. The authors suggest that the ability to scale strong (and almost perfectly accurate) memories may be limited because of the absence of differential error feedback for very strong memories in the past (the kind of differential error feedback that may account for the memory-scaling expertise that participants otherwise exhibit). (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Testing signal-detection models of yes/no and two-alternative forced-choice recognition memory.

The current study compared 3 models of recognition memory in their ability to generalize across yes/no and 2-alternative forced-choice (2AFC) testing. The unequal-variance signal-detection model assumes a continuous memory strength process. The dual-process signal-detection model adds a thresholdlike recollection process to a continuous familiarity process. The mixture signal-detection model assumes a continuous memory strength process, but the old item distribution consists of a mixture of 2 distributions with different means. Prior efforts comparing the ability of the models to characterize data from both test formats did not consider the role of parameter reliability, which can be critical when comparing models that differ in flexibility. Parametric bootstrap simulations revealed that parameter regressions based on separate fits of each test type only served to identify the least flexible model. However, simultaneous fits of receiver-operating characteristic data from both test types with goodness-of-fit adjusted with Akaike’s information criterion (AIC) successfully recovered the true model that generated the data. With AIC and simultaneous fits to real data, the unequal-variance signal-detection model was found to provide the best account across yes/no and 2AFC testing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A signal-detection analysis of fast-and-frugal trees.

Models of decision making are distinguished by those that aim for an optimal solution in a world that is precisely specified by a set of assumptions (a so-called “small world”) and those that aim for a simple but satisfactory solution in an uncertain world where the assumptions of optimization models may not be met (a so-called “large world”). Few connections have been drawn between these 2 families of models. In this study, the authors show how psychological concepts originating in the classic signal-detection theory (SDT), a small-world approach to decision making, can be used to understand the workings of a class of simple models known as fast-and-frugal trees (FFTs). Results indicate that (a) the setting of the subjective decision criterion in SDT corresponds directly to the choice of exit structure in an FFT; (b) the sensitivity of an FFT (measured in d′) is reflected by the order of cues searched and the properties of cues in an FFT, including the mean and variance of cues' individual d′s, the intercue correlation, and the number of cues; and (c) compared with the ideal and the optimal sequential sampling models in SDT and a majority model with an information search component, FFTs are extremely frugal (i.e., do not search for much cue information), highly robust, and well adapted to the payoff structure of a task. These findings demonstrate the potential of theory integration in understanding the common underlying psychological structures of apparently disparate theories of cognition. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Size constancy in schizophrenia: A reanalysis.

Perceptual differences between normals and schizophrenics revealed by traditional size-constancy experiments are questionable because of S variability, procedural difficulties, and problems inherent in traditional psychophysical methods. A review of the literature reveals few consistent results. The present study compared normals, paranoid schizophrenics, and nonparanoid schizophrenics on a size-constancy task which allowed derivation of additional dependent variables from signal-detection and uncertainty analysis. No group differences were revealed using the size-constancy procedure, but signal-detection analysis indicated nonparanoid schizophrenics were significantly lower in perceptual sensitivity. Uncertainty analysis revealed additional response dispositions characteristic of the schizophrenic groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)