Geoffrey Loftus - Academia.edu (original) (raw)

Papers by Geoffrey Loftus

10 Response Time versus Accuracy in Human Memory Michael Kahana and Geoffrey Loftus One of the fi... more 10 Response Time versus Accuracy in Human Memory Michael Kahana and Geoffrey Loftus One of the first decisions confronting a behavioral scientist is the choice of a measurement instrument that appropriately captures some relevant aspect of human behavior. Consider a typical ...

Journal of experimental psychology. Human learning and memory, 1979

Subjects participated in a yes/no picture recognition experiment in which exposure time varied fr... more Subjects participated in a yes/no picture recognition experiment in which exposure time varied from 50 to 1,000 msec at the time of initial study. Following each study trial, half of the subjects, the detail at study and test (ST) group, reported whether they had observed a detail in the picture that they thought might help in subsequent recognition. The other half of the subjects, the detail at test only (T) group, did not attempt to name details during study. All of the subjects reported at the time of each test picture whether they were basing their yes/no recognition response on a specific detail in the picture or on the picture's general familiarity. The data provided strong support for a model which assumed that (a) there is a constant probability of encoding a detail during each successive unit of time at study and (b) a detail is named at test either if it was encoded at study or with some bias probability. ST subjects showed superior recognition memory performance relat...

Law and Human Behavior, 1987

Journal of experimental psychology. Human perception and performance, 2004

We test 3 theories of global and local scene information acquisition, defining global and local i... more We test 3 theories of global and local scene information acquisition, defining global and local in terms of spatial frequencies. By independence theories, high- and low-spatial-frequency information are acquired over the same time course and combine additively. By global-precedence theories, global information acquisition precedes local information acquisition, but they combine additively. By interactive theories, global information also affects local-information acquisition rate. We report 2 digit-recall experiments. In the 1st, we confirmed independence theories. In the 2nd, we disconfirmed both independence theories and interactive theories, leaving global-precedence theories as the remaining alternative. We show that a specific global-precedence theory quantitatively accounted for Experiments 1-2 data as well as for past data. We discuss how their spatial-frequency definition of spatial scale comports with definitions used by others, and we consider the suggestion by P. G. Schyn...

Journal of experimental psychology. Human learning and memory, 1980

In four experiments, pictures of complex, naturalistic scenes were shown, followed by a two-alter... more In four experiments, pictures of complex, naturalistic scenes were shown, followed by a two-alternative forced-choice recognition test in which the targets and distractors differed in only a single, critical detail. Eye movements were recorded at the time of study in the first two experiments. In Experiment 1 we investigated eye movements during short initial exposure times and found that if the nearest fixation to the critical detail was further than about 2 degrees of visual angle, performance was no better than chance. Experiment 2 replicated Experiment 1 using longer exposure times and an expanded set of pictures. Performance was still found to decrease with increase in distance of the nearest fixation to the critical detail, but not quite to chance. In Experiments 3 and 4 we controlled where the subject's first fixation occurred using a prefixation point of light. The results indicated that the performance again decreases with increasing distance from the critical detail; h...

Journal of experimental psychology. General, 1989

We investigated the effects of semantic priming on initial encoding of briefly presented pictures... more We investigated the effects of semantic priming on initial encoding of briefly presented pictures of objects and scenes. Pictures in four experiments were presented for varying durations and were followed immediately by a mask. In Experiments 1 and 2, pictures of simple objects were either preceded or not preceded by the object's category name (e.g., dog). In Experiment 1 we measured immediate object identification; in Experiment 2 we measured delayed old/new recognition in which targets and distractors were from the same categories. In Experiment 3 naturalistic scenes were either preceded or not preceded by the scene's category name (e.g., supermarket). We measured delayed recognition in which targets and distractors were described by the same category names. In Experiments 1-3, performance was better for primed than for unprimed pictures. Experiment 4 was similar to Experiment 2 in that we measured delayed recognition for simple objects. As in Experiments 1-3, a prime that...

Journal of Experimental Psychology: Human Learning & Memory, 1975

It is assumed that recognition memory for pictures is based on two types of information. The firs... more It is assumed that recognition memory for pictures is based on two types of information. The first is information about specific details in a picture. The process of encoding this type of information is identified with what N. H. Mackworth and others have termed looking at &amp;quot;informative areas&amp;quot; in pictures. The second informational component is designated as &amp;quot;general visual information.&amp;quot; Two experiments were carried out investigating (a) the extent to which recognition responses to pictures are based on specific detail vs. general visual information, (b) whether the amount of specific detail information may be manipulated by varying the complexity of a target picture, and (c) the rate at which the two types of information are acquired. The results indicate that the rate of encoding specific details varies with the number of potential informative areas in a pictures and, given that a detail is encoded, memory performance is not substantially affected by target complexity, exposure time, or presence or absence of a mask.

Zeitschrift für Psychologie / Journal of Psychology, 2009

Psychonomic Bulletin & Review, 2005

Psychonomic Bulletin & Review, 1999

Psychonomic Bulletin & Review, 1994

We argue that to best comprehend many data sets, plotting judiciously selected sample statistics ... more We argue that to best comprehend many data sets, plotting judiciously selected sample statistics with associated confidence intervals can usefully supplement, or even replace, standard hypothesis-testing procedures. We note that most social science statistics textbooks limit discussion of confidence intervals to their use in between-subject designs. Our central purpose in this article is to describe how to compute an analogous confidence interval that can be used in within-subject designs. This confidence interval rests on the reasoning that because between-subject variance typically plays no role in statistical analyses of within-subject designs, it can legitimately be ignored; hence, an appropriate confidence interval can be based on the standard within-subject error term-that is, on the variability due to the subject × condition interaction. Computation of such a confidence interval is simple and is embodied in Equation 2 on p. 482 of this article. This confidence interval has two useful properties. First, it is based on the same error term as is the corresponding analysis of variance, and hence leads to comparable conclusions. Second, it is related by a known factor (√2) to a confidence interval of the difference between sample means; accordingly, it can be used to infer the faith one can put in some pattern of sample means as a reflection of the underlying pattern of population means. These two properties correspond to analogous properties of the more widely used between-subject confidence interval.

Psychological Science, 2004

Journal of Neurology, Neurosurgery & Psychiatry, 2001

Journal of Experimental Psychology: Learning, Memory, and Cognition, 2004

Upon learning the outcome to a problem, people tend to believe that they knew it all along (hinds... more Upon learning the outcome to a problem, people tend to believe that they knew it all along (hindsight bias). Here, we report the first study to trace the development of hindsight bias across the life span. One hundred ninety-four participants aged 3 to 95 years completed 3 tasks designed to measure visual and verbal hindsight bias. All age groups demonstrated hindsight bias on all 3 tasks; however, preschoolers and older adults exhibited more bias than older children and younger adults. Multinomial processing tree analyses of these data revealed that preschoolers' enhanced hindsight bias resulted from them substituting the correct answer for their original answer in their recall (a qualitative error). Conversely, older adults' enhanced hindsight bias resulted from them forgetting their original answer and recalling an answer closer to, but not equal to, the correct answer (a quantitative error). We discuss these findings in relation to mechanisms of memory, perspective taking, theory of mind, and executive function.

Journal of Experimental Psychology: Learning, Memory, and Cognition, 1991

Journal of Experimental Psychology: Human Perception and Performance, 2004

Journal of Experimental Psychology: Human Perception and Performance, 1992

A briefly presented visual stimulus engenders an available-information function that lags behind ... more A briefly presented visual stimulus engenders an available-information function that lags behind the physical stimulus. We report two experiments that focus on the iconic-decay portion of this function, which falls to 0 over a 200-300 ms period following stimulus offset. In each experiment, to-be-reported digit strings were shown for varying durations followed by a noise mask at varying poststimulus intervals. We found the shape of the performance curve relating digit-report probability to stimulus exposure duration to be independent of stimulus-mask interstimulus interval. This finding is consistent with the proposition that the iconic-decay function's shape is independent of stimulus duration and allows us to identify this shape. We rejected exponential iconic decay for 6 of 8 observers; however, all observers' decay functions could be adequately fit by gamma decay, a generalization of exponential decay.