Kelly Goedert | Seton Hall University (original) (raw)

Papers by Kelly Goedert

Research paper thumbnail of Priming interdependence affects processing of context information in causal inference—But not how you might think

Acta Psychologica, 2014

Cultural mindset is related to performance on a variety of cognitive tasks. In particular, studie... more Cultural mindset is related to performance on a variety of cognitive tasks. In particular, studies of both chronic and situationally-primed mindsets show that individuals with a relatively interdependent mindset (i.e., an emphasis on relationships and connections among individuals) are more sensitive to background contextual information than individuals with a more independent mindset. Two experiments tested whether priming cultural mindset would affect sensitivity to background causes in a contingency learning and causal inference task. Participants were primed (either independent or interdependent), and then saw complete contingency information on each of 12 trials for two cover stories in Experiment 1 (hiking causing skin rashes, severed brakes causing wrecked cars) and two additional cover stories in Experiment 2 (school deadlines causing stress, fertilizers causing plant growth). We expected that relative to independent-primed participants, those interdependent-primed would give more weight to the explicitly-presented data indicative of hidden alternative background causes, but they did not do so. In Experiment 1, interdependents gave less weight to the data indicative of hidden background causes for the car accident cover story and showed a decreased sensitivity to the contingencies for that story. In Experiment 2, interdependents placed less weight on the observable data for cover stories that supported more extra-experimental causes, while independents' sensitivity did not vary with these extra-experimental causes. Thus, interdependents were more sensitive to background causes not explicitly presented in the experiment, but this sensitivity hurt rather than improved their acquisition of the explicitlypresented contingency information.

Research paper thumbnail of Priming interdependence affects processing of context information in causal inference—But not how you might think

Acta Psychologica, 2014

Cultural mindset is related to performance on a variety of cognitive tasks. In particular, studie... more Cultural mindset is related to performance on a variety of cognitive tasks. In particular, studies of both chronic and situationally-primed mindsets show that individuals with a relatively interdependent mindset (i.e., an emphasis on relationships and connections among individuals) are more sensitive to background contextual information than individuals with a more independent mindset. Two experiments tested whether priming cultural mindset would affect sensitivity to background causes in a contingency learning and causal inference task. Participants were primed (either independent or interdependent), and then saw complete contingency information on each of 12 trials for two cover stories in Experiment 1 (hiking causing skin rashes, severed brakes causing wrecked cars) and two additional cover stories in Experiment 2 (school deadlines causing stress, fertilizers causing plant growth). We expected that relative to independent-primed participants, those interdependent-primed would give more weight to the explicitly-presented data indicative of hidden alternative background causes, but they did not do so. In Experiment 1, interdependents gave less weight to the data indicative of hidden background causes for the car accident cover story and showed a decreased sensitivity to the contingencies for that story. In Experiment 2, interdependents placed less weight on the observable data for cover stories that supported more extra-experimental causes, while independents' sensitivity did not vary with these extra-experimental causes. Thus, interdependents were more sensitive to background causes not explicitly presented in the experiment, but this sensitivity hurt rather than improved their acquisition of the explicitlypresented contingency information.

Research paper thumbnail of Discounting and Conditionalization: Dissociable Cognitive Processes in Human Causal Inference

Psychological Science, 2005

Research paper thumbnail of Causal Necessity and Alternative Strength Differentially Influence Predictions and Causal Judgments

Research paper thumbnail of Comparison Then Computation: A Model of Independent Causal Efficacy

This paper introduces the Comparison Then Computation (CTC) model, which describes how individual... more This paper introduces the Comparison Then Computation (CTC) model, which describes how individuals assess the causal efficacy of a target event when simultaneously learning of multiple potential causes of the same outcome. The CTC is a two step model that entails an initial comparison between the probability of an outcome given the target alone and that given the joint occurrence of the target and other explicitly represented alternatives. The first step determines the computation to be performed in the second step. This computation heavily weights sufficiency information over necessity information. Two experiments testing novel predictions of the CTC model favored that model over causal power and weighted averaging . Strengths and weaknesses of the CTC model will be discussed.

Research paper thumbnail of Prism adaptation differently affects motor-intentional and perceptual-attentional biases in healthy individuals

Neuropsychologia, 2011

Prism adaptation (PA) has been shown to affect performance on a variety of spatial tasks in healt... more Prism adaptation (PA) has been shown to affect performance on a variety of spatial tasks in healthy individuals and neglect patients. However, little is still known about the mechanisms through which PA affects spatial cognition. In the present study we tested the effect of PA on the perceptual-attentional “where” and motor-intentional “aiming” spatial systems in healthy individuals. Eighty-four participants performed a line bisection task presented on a computer screen under normal or right-left reversed viewing conditions, which allows for the fractionation of “where” and “aiming” bias components (Schwartz et al., 1997). The task was performed before and after a short period of visuomotor adaptation either to left- or right-shifting prisms, or control goggles fitted with plain glass lenses. Participants demonstrated initial leftward “where” and “aiming” biases, consistent with previous research. Adaptation to left-shifting prisms reduced the leftward motor-intentional “aiming” bias. By contrast, the “aiming” bias was unaffected by adaptation to the right-shifting prisms or control goggles. The leftward “where” bias was also reduced, but this reduction was independent of the direction of the prismatic shift. These results mirror recent findings in neglect patients, who showed a selective amelioration of right motor-intentional “aiming” bias after right prism exposure (0150 and 0510). Thus, these findings indicate that prism adaptation primarily affects the motor-intentional “aiming” system in both healthy individuals and neglect patients, and further suggest that improvement in neglect patients after PA may be related to changes in the aiming spatial system.► Fragmentation of motor and perceptual line bisection biases in healthy individuals. ► Adaptation to left-shifting prism selectively reduces motor-intentional aiming bias. ► Non-directionally specific prism adaptation (PA) effects on the perceptual bias. ► PA primarily affects the motor-intentional aiming system. ► Neglect improvement after PA may be related to changes in the aiming spatial system.

Research paper thumbnail of Psychometric Evaluation of Neglect Assessment Reveals Motor-Exploratory Predictor of Functional Disability in Acute-Stage Spatial Neglect

Archives of Physical Medicine and Rehabilitation

Goedert KM, Chen P, Botticello A, Masmela JR, Adler U, Barrett AM. Psychometric evaluation of neg... more Goedert KM, Chen P, Botticello A, Masmela JR, Adler U, Barrett AM. Psychometric evaluation of neglect assessment reveals motor-exploratory predictor of functional disability in acute-stage spatial neglect.To determine the psychometric properties of 2 neglect measures, the Behavioral Inattention Test (BIT)-conventional and the Catherine Bergego Scale (CBS), in acute spatial neglect. Spatial neglect is a failure or slowness to respond, orient, or initiate action toward contralesional stimuli, associated with functional disability that impedes stroke recovery. Early identification of specific neglect deficits may identify patients likely to experience chronic disability. However, psychometric evaluation of assessments has focused on subacute/chronic populations.Correlational/psychometric study.Inpatient rehabilitation hospital.Screening identified 51 consecutive patients with a right-hemisphere stroke with left neglect (BIT score <129 or CBS score >11) tested an average of 22.3 days poststroke.Not applicable.We obtained BIT, CBS, and Barthel Index assessments for each participant and clinical and laboratory measures of perceptual-attentional and motor-intentional deficits.The BIT showed good reliability and loaded onto a single factor. Consistent with our theoretical prediction, principal components analysis of the CBS identified 2 underlying factors: Where perceptual-attentional items (CBS-PA) and embodied, motor-exploratory items (CBS-ME). The CBS-ME uniquely predicted deficits in activities of daily living (ADLs) assessed by using the Barthel Index, but did not predict clinical and laboratory assessments of motor-intentional bias. More severe neglect on the CBS-PA correlated with greater Where perceptual-attentional bias on clinical and laboratory tests, but did not uniquely predict deficits in ADLs.Our results indicate that assessments of spatial neglect may be used to detect specific motor-exploratory deficits in spatial neglect. Obtaining CBS-ME scores routinely might improve the detection of acute-stage patients with spatial action deficits requiring increased assistance that may persist to the chronic stage.

Research paper thumbnail of Asymmetrical Effects of Adaptation to Left and Right-Shifting Prisms Depends on Pre-existing Attentional Biases

Journal of The International Neuropsychological Society, 2010

Proposals that adaptation with left-shifting prisms induces neglect-like symptoms in normal indiv... more Proposals that adaptation with left-shifting prisms induces neglect-like symptoms in normal individuals rely on a dissociation between the post-adaptation performance of individuals trained with left-versus right-shifting prisms (e.g., . A potential problem with this evidence is that normal young adults have an a priori leftward bias (e.g., . In Experiment 1, we compared the line bisection performance of young adults to that of aged adults, who as a group may lack a leftward bias in line bisection. Participants trained with both left-and right-shifting prisms. Consistent with our hypothesis, while young adults demonstrated aftereffects for left, but not right prisms, aged adults demonstrated reliable aftereffects for both prisms. In Experiment 2, we recruited a larger sample of young adults, some of whom were right-biased at baseline. We observed an interaction between baseline bias and prism-shift, consistent with the results of Experiment 1: Left-biased individuals showed a reduced aftereffect when training with right-shifting prisms and right-biased individuals showed a reduced aftereffect when training with left-shifting prisms. These results suggest that previous failures to find generalizable aftereffects with right-shifting prisms may be driven by participants' baseline biases rather than specific effects of the prism itself.

Research paper thumbnail of The Pedagogical Value of Experimental Participation Paired With Course Content

Teaching of Psychology, 2005

Research paper thumbnail of Spacing practice sessions across days earlier rather than later in training improves performance of a visuomotor skill

Experimental Brain Research, 2008

Our goal was to determine whether the extent of off-line performance improvements on a visuomotor... more Our goal was to determine whether the extent of off-line performance improvements on a visuomotor task depends on the amount of practice individuals experience prior to a 24-h between-session break. Subjects completed ten trials of a mirror-tracing task over two days. On Day 1, subjects experienced either one, three or seven trials. Twenty-four hours later subjects completed the remainder of the ten trials. Despite experiencing an equivalent number of total training trials, subjects experiencing the 24-h delay after one or three trials demonstrated off-line performance improvements, but those experiencing the delay after seven trials did not. Furthermore, the one- and three-trial groups reached a superior level of performance by the end of training relative to the seven-trial group.

Research paper thumbnail of Causal discounting in the presence of a stronger cue is due to bias

Psychonomic Bulletin & Review, 2010

People use information about the covariation between a putative cause and an outcome to determine... more People use information about the covariation between a putative cause and an outcome to determine whether a causal relationship obtains. When there are two candidate causes and one is more strongly related to the effect than is the other, the influence of the second is underestimated. This phenomenon is called causal discounting. In two experiments, we adapted paradigms for studying causal learning in order to apply signal detection analysis to this phenomenon. We investigated whether the presence of a stronger alternative makes the task more difficult (indexed by differences in d′) or whether people change the standard by which they assess causality (measured by β). Our results indicate that the effect is due to bias.

Research paper thumbnail of The role of taxonomies in the study of human memory

Cognitive Affective & Behavioral Neuroscience, 2001

The idea that memory is not unitary but is instead composed of multiple systems has a long histor... more The idea that memory is not unitary but is instead composed of multiple systems has a long history and has been debated with particular vigor in the last 20 years. Nevertheless, whether or not there are multiple memory systems remains unsettled. In this article, we suggest that psychologists wishing to classify memory can learn from biological systematics, the discipline that creates taxonomies of species. In so doing, we suggest that psychologists have made two assumptions in classifying memory: that features of memory are perfectly correlated, and that there is a straightforward mapping between taxonomy and theory. We argue that these assumptions are likely to be incorrect, but we also argue that there is a place for taxonomy in the study of memory. Taxonomies of memory are organizational schemes for data—they are descriptive, not explanatory-and so can inspire theory, although they cannot serve as theories themselves.

Research paper thumbnail of Nonnormative discounting: There is more to cue interaction effects than controlling for alternative causes

Learning & Behavior, 2005

Several experiments on human causal reasoning have demonstrated “discounting”-that the presence o... more Several experiments on human causal reasoning have demonstrated “discounting”-that the presence of a strong alternative cause may decrease the perceived efficacy of a moderate target cause. Some, but not all, of these effects have been shown to be attributable to subjects’ use of conditional rather than unconditional contingencies (i.e., subjects control for alternative causes). We review experimental results that do not conform to the conditionalizing contingency account of causal judgment. In four experiments, we demonstrate that there is “nonnormative discounting” above what is accounted for by conditionalization, that discounting may depend on the nature of the question put to the subjects, and that discounting can be affected by motivation. We conclude that because nonnormative discounting occurs for summary presentations as well as trial-by-trial presentations of information and because nonnormative discounting depends on motivation, it is not a necessary result of cue competition during the contingency learning process.

Research paper thumbnail of Neural Substrates of Response-based Sequence Learning using fMRI

Journal of Cognitive Neuroscience, 2004

& Representation of sequential structure can occur with respect to the order of perceptual events... more & Representation of sequential structure can occur with respect to the order of perceptual events or the order in which actions are linked. Neural correlates of sequence retrieval associated with the order of motor responses were identified in a variant of the serial reaction time task in which training occurred with a spatially incompatible mapping between stimuli and finger responses. After transfer to a spatially compatible version of the task, performance enhancements indicative of learning were only present in subjects required to make finger movements in the same order used during training. In contrast, a second group of subjects performed the compatible task using an identical sequence of stimuli (and different order of finger movements) as in training. They demonstrated no performance benefit, indicating that learning was response based. Analysis was restricted to subjects demonstrating low recall of the sequence structure to rule out effects of explicit awareness. The interaction of group (motor vs. perceptual transfer) with sequence retrieval (sequencing vs. rest) revealed significantly greater activation in the bilateral supplementary motor area, cingulate motor area, ventral premotor cortex, left caudate and inferior parietal lobule for subjects in the motor group (illustrating successful sequence retrieval at the response level). Retrieval of sequential responses occurs within mesial motor areas and related motor planning areas. &

Research paper thumbnail of Patterns of Interference in Sequence Learning and Prism Adaptation Inconsistent With the Consolidation Hypothesis

Learning & Memory, 2002

The studies reported here used an interference paradigm to determine whether a long-term consolid... more The studies reported here used an interference paradigm to determine whether a long-term consolidation process (i.e., one lasting from several hours to days) occurs in the learning of two implicit motor skills, learning of a movement sequence and learning of a visuo-motor mapping. Subjects learned one skill and were tested on that skill 48 h later. Between the learning session and test session, some subjects trained on a second skill. The amount of time between the learning of the two skills varied for different subjects. In both the learning of a movement sequence and the learning of a visuo-motor mapping, we found that remote memories were susceptible to interference, but the passage of time did not afford protection from interference. These results are inconsistent with the long-term consolidation of these motor skills. A possible difference between these tasks and those that do show long-term consolidation is that the present tasks are not dynamic motor skills. 3 Corresponding author. E-MAIL goedert@plu.edu; FAX (253) 535-8305. Article and publication are at

Research paper thumbnail of Priming interdependence affects processing of context information in causal inference—But not how you might think

Acta Psychologica, 2014

Cultural mindset is related to performance on a variety of cognitive tasks. In particular, studie... more Cultural mindset is related to performance on a variety of cognitive tasks. In particular, studies of both chronic and situationally-primed mindsets show that individuals with a relatively interdependent mindset (i.e., an emphasis on relationships and connections among individuals) are more sensitive to background contextual information than individuals with a more independent mindset. Two experiments tested whether priming cultural mindset would affect sensitivity to background causes in a contingency learning and causal inference task. Participants were primed (either independent or interdependent), and then saw complete contingency information on each of 12 trials for two cover stories in Experiment 1 (hiking causing skin rashes, severed brakes causing wrecked cars) and two additional cover stories in Experiment 2 (school deadlines causing stress, fertilizers causing plant growth). We expected that relative to independent-primed participants, those interdependent-primed would give more weight to the explicitly-presented data indicative of hidden alternative background causes, but they did not do so. In Experiment 1, interdependents gave less weight to the data indicative of hidden background causes for the car accident cover story and showed a decreased sensitivity to the contingencies for that story. In Experiment 2, interdependents placed less weight on the observable data for cover stories that supported more extra-experimental causes, while independents' sensitivity did not vary with these extra-experimental causes. Thus, interdependents were more sensitive to background causes not explicitly presented in the experiment, but this sensitivity hurt rather than improved their acquisition of the explicitlypresented contingency information.

Research paper thumbnail of Priming interdependence affects processing of context information in causal inference—But not how you might think

Acta Psychologica, 2014

Cultural mindset is related to performance on a variety of cognitive tasks. In particular, studie... more Cultural mindset is related to performance on a variety of cognitive tasks. In particular, studies of both chronic and situationally-primed mindsets show that individuals with a relatively interdependent mindset (i.e., an emphasis on relationships and connections among individuals) are more sensitive to background contextual information than individuals with a more independent mindset. Two experiments tested whether priming cultural mindset would affect sensitivity to background causes in a contingency learning and causal inference task. Participants were primed (either independent or interdependent), and then saw complete contingency information on each of 12 trials for two cover stories in Experiment 1 (hiking causing skin rashes, severed brakes causing wrecked cars) and two additional cover stories in Experiment 2 (school deadlines causing stress, fertilizers causing plant growth). We expected that relative to independent-primed participants, those interdependent-primed would give more weight to the explicitly-presented data indicative of hidden alternative background causes, but they did not do so. In Experiment 1, interdependents gave less weight to the data indicative of hidden background causes for the car accident cover story and showed a decreased sensitivity to the contingencies for that story. In Experiment 2, interdependents placed less weight on the observable data for cover stories that supported more extra-experimental causes, while independents' sensitivity did not vary with these extra-experimental causes. Thus, interdependents were more sensitive to background causes not explicitly presented in the experiment, but this sensitivity hurt rather than improved their acquisition of the explicitlypresented contingency information.

Research paper thumbnail of Discounting and Conditionalization: Dissociable Cognitive Processes in Human Causal Inference

Psychological Science, 2005

Research paper thumbnail of Causal Necessity and Alternative Strength Differentially Influence Predictions and Causal Judgments

Research paper thumbnail of Comparison Then Computation: A Model of Independent Causal Efficacy

This paper introduces the Comparison Then Computation (CTC) model, which describes how individual... more This paper introduces the Comparison Then Computation (CTC) model, which describes how individuals assess the causal efficacy of a target event when simultaneously learning of multiple potential causes of the same outcome. The CTC is a two step model that entails an initial comparison between the probability of an outcome given the target alone and that given the joint occurrence of the target and other explicitly represented alternatives. The first step determines the computation to be performed in the second step. This computation heavily weights sufficiency information over necessity information. Two experiments testing novel predictions of the CTC model favored that model over causal power and weighted averaging . Strengths and weaknesses of the CTC model will be discussed.

Research paper thumbnail of Prism adaptation differently affects motor-intentional and perceptual-attentional biases in healthy individuals

Neuropsychologia, 2011

Prism adaptation (PA) has been shown to affect performance on a variety of spatial tasks in healt... more Prism adaptation (PA) has been shown to affect performance on a variety of spatial tasks in healthy individuals and neglect patients. However, little is still known about the mechanisms through which PA affects spatial cognition. In the present study we tested the effect of PA on the perceptual-attentional “where” and motor-intentional “aiming” spatial systems in healthy individuals. Eighty-four participants performed a line bisection task presented on a computer screen under normal or right-left reversed viewing conditions, which allows for the fractionation of “where” and “aiming” bias components (Schwartz et al., 1997). The task was performed before and after a short period of visuomotor adaptation either to left- or right-shifting prisms, or control goggles fitted with plain glass lenses. Participants demonstrated initial leftward “where” and “aiming” biases, consistent with previous research. Adaptation to left-shifting prisms reduced the leftward motor-intentional “aiming” bias. By contrast, the “aiming” bias was unaffected by adaptation to the right-shifting prisms or control goggles. The leftward “where” bias was also reduced, but this reduction was independent of the direction of the prismatic shift. These results mirror recent findings in neglect patients, who showed a selective amelioration of right motor-intentional “aiming” bias after right prism exposure (0150 and 0510). Thus, these findings indicate that prism adaptation primarily affects the motor-intentional “aiming” system in both healthy individuals and neglect patients, and further suggest that improvement in neglect patients after PA may be related to changes in the aiming spatial system.► Fragmentation of motor and perceptual line bisection biases in healthy individuals. ► Adaptation to left-shifting prism selectively reduces motor-intentional aiming bias. ► Non-directionally specific prism adaptation (PA) effects on the perceptual bias. ► PA primarily affects the motor-intentional aiming system. ► Neglect improvement after PA may be related to changes in the aiming spatial system.

Research paper thumbnail of Psychometric Evaluation of Neglect Assessment Reveals Motor-Exploratory Predictor of Functional Disability in Acute-Stage Spatial Neglect

Archives of Physical Medicine and Rehabilitation

Goedert KM, Chen P, Botticello A, Masmela JR, Adler U, Barrett AM. Psychometric evaluation of neg... more Goedert KM, Chen P, Botticello A, Masmela JR, Adler U, Barrett AM. Psychometric evaluation of neglect assessment reveals motor-exploratory predictor of functional disability in acute-stage spatial neglect.To determine the psychometric properties of 2 neglect measures, the Behavioral Inattention Test (BIT)-conventional and the Catherine Bergego Scale (CBS), in acute spatial neglect. Spatial neglect is a failure or slowness to respond, orient, or initiate action toward contralesional stimuli, associated with functional disability that impedes stroke recovery. Early identification of specific neglect deficits may identify patients likely to experience chronic disability. However, psychometric evaluation of assessments has focused on subacute/chronic populations.Correlational/psychometric study.Inpatient rehabilitation hospital.Screening identified 51 consecutive patients with a right-hemisphere stroke with left neglect (BIT score <129 or CBS score >11) tested an average of 22.3 days poststroke.Not applicable.We obtained BIT, CBS, and Barthel Index assessments for each participant and clinical and laboratory measures of perceptual-attentional and motor-intentional deficits.The BIT showed good reliability and loaded onto a single factor. Consistent with our theoretical prediction, principal components analysis of the CBS identified 2 underlying factors: Where perceptual-attentional items (CBS-PA) and embodied, motor-exploratory items (CBS-ME). The CBS-ME uniquely predicted deficits in activities of daily living (ADLs) assessed by using the Barthel Index, but did not predict clinical and laboratory assessments of motor-intentional bias. More severe neglect on the CBS-PA correlated with greater Where perceptual-attentional bias on clinical and laboratory tests, but did not uniquely predict deficits in ADLs.Our results indicate that assessments of spatial neglect may be used to detect specific motor-exploratory deficits in spatial neglect. Obtaining CBS-ME scores routinely might improve the detection of acute-stage patients with spatial action deficits requiring increased assistance that may persist to the chronic stage.

Research paper thumbnail of Asymmetrical Effects of Adaptation to Left and Right-Shifting Prisms Depends on Pre-existing Attentional Biases

Journal of The International Neuropsychological Society, 2010

Proposals that adaptation with left-shifting prisms induces neglect-like symptoms in normal indiv... more Proposals that adaptation with left-shifting prisms induces neglect-like symptoms in normal individuals rely on a dissociation between the post-adaptation performance of individuals trained with left-versus right-shifting prisms (e.g., . A potential problem with this evidence is that normal young adults have an a priori leftward bias (e.g., . In Experiment 1, we compared the line bisection performance of young adults to that of aged adults, who as a group may lack a leftward bias in line bisection. Participants trained with both left-and right-shifting prisms. Consistent with our hypothesis, while young adults demonstrated aftereffects for left, but not right prisms, aged adults demonstrated reliable aftereffects for both prisms. In Experiment 2, we recruited a larger sample of young adults, some of whom were right-biased at baseline. We observed an interaction between baseline bias and prism-shift, consistent with the results of Experiment 1: Left-biased individuals showed a reduced aftereffect when training with right-shifting prisms and right-biased individuals showed a reduced aftereffect when training with left-shifting prisms. These results suggest that previous failures to find generalizable aftereffects with right-shifting prisms may be driven by participants' baseline biases rather than specific effects of the prism itself.

Research paper thumbnail of The Pedagogical Value of Experimental Participation Paired With Course Content

Teaching of Psychology, 2005

Research paper thumbnail of Spacing practice sessions across days earlier rather than later in training improves performance of a visuomotor skill

Experimental Brain Research, 2008

Our goal was to determine whether the extent of off-line performance improvements on a visuomotor... more Our goal was to determine whether the extent of off-line performance improvements on a visuomotor task depends on the amount of practice individuals experience prior to a 24-h between-session break. Subjects completed ten trials of a mirror-tracing task over two days. On Day 1, subjects experienced either one, three or seven trials. Twenty-four hours later subjects completed the remainder of the ten trials. Despite experiencing an equivalent number of total training trials, subjects experiencing the 24-h delay after one or three trials demonstrated off-line performance improvements, but those experiencing the delay after seven trials did not. Furthermore, the one- and three-trial groups reached a superior level of performance by the end of training relative to the seven-trial group.

Research paper thumbnail of Causal discounting in the presence of a stronger cue is due to bias

Psychonomic Bulletin & Review, 2010

People use information about the covariation between a putative cause and an outcome to determine... more People use information about the covariation between a putative cause and an outcome to determine whether a causal relationship obtains. When there are two candidate causes and one is more strongly related to the effect than is the other, the influence of the second is underestimated. This phenomenon is called causal discounting. In two experiments, we adapted paradigms for studying causal learning in order to apply signal detection analysis to this phenomenon. We investigated whether the presence of a stronger alternative makes the task more difficult (indexed by differences in d′) or whether people change the standard by which they assess causality (measured by β). Our results indicate that the effect is due to bias.

Research paper thumbnail of The role of taxonomies in the study of human memory

Cognitive Affective & Behavioral Neuroscience, 2001

The idea that memory is not unitary but is instead composed of multiple systems has a long histor... more The idea that memory is not unitary but is instead composed of multiple systems has a long history and has been debated with particular vigor in the last 20 years. Nevertheless, whether or not there are multiple memory systems remains unsettled. In this article, we suggest that psychologists wishing to classify memory can learn from biological systematics, the discipline that creates taxonomies of species. In so doing, we suggest that psychologists have made two assumptions in classifying memory: that features of memory are perfectly correlated, and that there is a straightforward mapping between taxonomy and theory. We argue that these assumptions are likely to be incorrect, but we also argue that there is a place for taxonomy in the study of memory. Taxonomies of memory are organizational schemes for data—they are descriptive, not explanatory-and so can inspire theory, although they cannot serve as theories themselves.

Research paper thumbnail of Nonnormative discounting: There is more to cue interaction effects than controlling for alternative causes

Learning & Behavior, 2005

Several experiments on human causal reasoning have demonstrated “discounting”-that the presence o... more Several experiments on human causal reasoning have demonstrated “discounting”-that the presence of a strong alternative cause may decrease the perceived efficacy of a moderate target cause. Some, but not all, of these effects have been shown to be attributable to subjects’ use of conditional rather than unconditional contingencies (i.e., subjects control for alternative causes). We review experimental results that do not conform to the conditionalizing contingency account of causal judgment. In four experiments, we demonstrate that there is “nonnormative discounting” above what is accounted for by conditionalization, that discounting may depend on the nature of the question put to the subjects, and that discounting can be affected by motivation. We conclude that because nonnormative discounting occurs for summary presentations as well as trial-by-trial presentations of information and because nonnormative discounting depends on motivation, it is not a necessary result of cue competition during the contingency learning process.

Research paper thumbnail of Neural Substrates of Response-based Sequence Learning using fMRI

Journal of Cognitive Neuroscience, 2004

& Representation of sequential structure can occur with respect to the order of perceptual events... more & Representation of sequential structure can occur with respect to the order of perceptual events or the order in which actions are linked. Neural correlates of sequence retrieval associated with the order of motor responses were identified in a variant of the serial reaction time task in which training occurred with a spatially incompatible mapping between stimuli and finger responses. After transfer to a spatially compatible version of the task, performance enhancements indicative of learning were only present in subjects required to make finger movements in the same order used during training. In contrast, a second group of subjects performed the compatible task using an identical sequence of stimuli (and different order of finger movements) as in training. They demonstrated no performance benefit, indicating that learning was response based. Analysis was restricted to subjects demonstrating low recall of the sequence structure to rule out effects of explicit awareness. The interaction of group (motor vs. perceptual transfer) with sequence retrieval (sequencing vs. rest) revealed significantly greater activation in the bilateral supplementary motor area, cingulate motor area, ventral premotor cortex, left caudate and inferior parietal lobule for subjects in the motor group (illustrating successful sequence retrieval at the response level). Retrieval of sequential responses occurs within mesial motor areas and related motor planning areas. &

Research paper thumbnail of Patterns of Interference in Sequence Learning and Prism Adaptation Inconsistent With the Consolidation Hypothesis

Learning & Memory, 2002

The studies reported here used an interference paradigm to determine whether a long-term consolid... more The studies reported here used an interference paradigm to determine whether a long-term consolidation process (i.e., one lasting from several hours to days) occurs in the learning of two implicit motor skills, learning of a movement sequence and learning of a visuo-motor mapping. Subjects learned one skill and were tested on that skill 48 h later. Between the learning session and test session, some subjects trained on a second skill. The amount of time between the learning of the two skills varied for different subjects. In both the learning of a movement sequence and the learning of a visuo-motor mapping, we found that remote memories were susceptible to interference, but the passage of time did not afford protection from interference. These results are inconsistent with the long-term consolidation of these motor skills. A possible difference between these tasks and those that do show long-term consolidation is that the present tasks are not dynamic motor skills. 3 Corresponding author. E-MAIL goedert@plu.edu; FAX (253) 535-8305. Article and publication are at