Dual-process Signal Detection Model Research Articles

Familiarity or Conceptual Priming: Event-related Potentials in Name Recognition

Recent interest has been drawn to the separate components of recognition memory, as studied by event-related potentials (ERPs). In ERPs, recollection is usually accompanied by a late, parietal positive deflection. An earlier, frontal component has been suggested to be a counterpart, accompanying recognition by familiarity. However, this component, the FN400, has alternatively been suggested to reflect a form of implicit memory, conceptual priming. The present study examined the ERP components of recognition memory using an episodic memory task with a stimulus material consisting of names, half of which were famous. Along a different dimension, the names varied in how rare or common they were. These dimensions, frequency and fame, exerted powerful effects on memory accuracy, and dissociated the two recognition processes, such that frequency gave rise to familiarity and fame fostered recollection, when the receiver operating characteristics data were analyzed with Yonelinas' dual-process signal detection model. The ERPs corresponded fully to the behavioral data because frequency affected the frontal component exclusively, and fame affected the parietal component exclusively. Moreover, a separate behavioral experiment showed that conceptual priming was sensitive to fame, but not to frequency. Our data therefore indicate that the FN400 varies jointly with familiarity, but independently of conceptual priming.

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.

Modeling Guessing

Multinomial processing-tree modeling has had a major impact on process-dissociation theory. Buchner, Erdfelder, and Vaterrodt-Plünnecke (1995) added guessing parameters to the original model of Jacoby (1991) and created a class of process-dissociation models. Furthermore, Erfelder and Buchner (1998) formulated criterion values of the dual-process signal-detection model ( Yonelinas, 1994 ) as multinomial parameters. Buchner, Erdfelder, Steffens, and Martensen (1997) suggested a new approach by proposing a multinomial source-monitoring model for process-dissociation data. Two experiments described here demonstrated that dual-process signal-detection theory must assume different levels of familiarity in inclusion and exclusion tests. Similarly, in some cases the source-monitoring model must assume different levels of recognition guessing in the two tests. Reasons are given for preferring the source-monitoring model.

Recollective experience in alcohol dependence: a laboratory study

Alcohol dependence has been linked to dysfunction of fronto-temporo-striatal circuits which mediate memory and executive function. The present study aimed to explore the specificity of recognition memory changes in alcohol dependence. setting and participants Twenty hospitalized alcohol-dependent detoxified patients and 20 healthy control subjects completed a verbal list discrimination task. Measurements Hits and false alarm rates were analysed. Additionally, both the dual process signal detection model (DPSD) and the process dissociation procedure (PDP) were used to derive estimates of the contribution of recollection and familiarity processes to the recognition memory performance in patients and controls. Alcohol-dependent patients showed intact hit rates, but increased false alarm rates and an impaired ability to remember the learning context. Both the DPSD model and PDP estimates yielded significantly reduced recollection estimates in the alcohol-dependent compared to control subjects. Whether or not familiarity was impaired, depended upon the sensitivity of the estimation procedure. Taken together, the result pattern suggests a significant impairment in recollection and mild familiarity changes in recently detoxified, predominantly male, alcohol-dependent subjects.

Effects of amisulpride on emotional memory using a dual-process model in healthy male volunteers

Memory dysfunction occurs in a number of neuropsychiatric disorders. Therapeutic psychopharmacological agents may exacerbate such memory impairment. Detailed characterisation of drug-induced memory impairment is therefore important. We recently showed that the D(2)/D(3) antagonist amisulpride quantitatively impairs emotional memory in a randomised placebo-controlled study of 33 healthy volunteers. Current evidence suggests that two qualitatively different processes (recollection and familiarity) contribute to recognition memory and can be investigated using a Dual-Process Signal Detection model. Using such a model, we found that amisulpride levels at encoding were significantly inversely correlated with recollection estimates for emotional but not neutral stimuli or familiarity estimates in healthy male volunteers. This suggests that dopamine antagonism at encoding preferentially impairs the recollection component of emotional memory, relative to the familiarity component. This was supported by receiver operating characteristic analysis. We also found a significantly increased false recognition rate, associated with significantly shorter reaction times for emotional but not neutral stimuli in the amisulpride group. These findings have important implications for our understanding of recognition memory processes, as well as the interpretation of neuropsychological findings in medicated patients.

Impairment of verbal recollection following ischemic damage to the right anterior hippocampus

Damage to the left medial temporal lobe (MTL) leads to an impairment of verbal recognition memory, affecting both the process of conscious recollection and familiarity-based recognition. Neuroimaging evidence, on the other hand, suggests a bilateral MTL contribution to verbal recollection. We investigated verbal recognition memory in three patients with focal ischemic lesions to the right MTL. The dual-process signal detection model and the process-dissociation procedure were applied to assess the contributions of recollection and familiarity to recognition memory. Compared to a group of 27 healthy age-matched controls, patients were impaired at recollection while familiarity was intact, and this effect was found for both estimation procedures. Detailed single-case analyses confirmed this pattern in two of the three right MTL patients. The findings suggest that, when task demands are high, as during recollective recognition, the right anterior hippocampus may also contribute to verbal recollection, thereby confirming neuroimaging evidence of a joint involvement of the left and the right MTL in verbal recollection.

The Development of Recollection and Familiarity in Childhood and Adolescence: Evidence From the Dual‐Process Signal Detection Model

Two experiments examined the development of recollection (recalling qualitative details about an event) and familiarity (recognizing the event) using the dual-process signal detection model. In Experiment 1 (n = 117; ages 6, 8, 10, 14, and 18 years), recollection improved from childhood to adolescence after semantic encoding but not after perceptual encoding and familiarity improved from ages 6 to 8 regardless of encoding condition. In Experiment 2 (n = 56; ages 6, 8, and 10 years), long duration compared to short duration of semantic encoding increased familiarity but not recollection. Age-related differences replicated those of Experiment 1, except no age difference in familiarity was found with long study duration. Overall, recollection and familiarity showed distinct developmental and functional characteristics. The dual-process signal detection model proved promising for developmental investigations.

Moving beyond pure signal-detection models: Comment on Wixted (2007).

The dual-process signal-detection (DPSD) model assumes that recognition memory is based on recollection of qualitative information or on a signal-detection-based familiarity process. The model has proven useful for understanding results from a wide range of memory research, including behavioral, neuropsychological, electrophysiological, and neuroimaging studies. However, a number of concerns have been raised about the model over the years, and it has been suggested that an unequal-variance signal-detection (UVSD) model that incorporates separate recollection and familiarity processes (J. T. Wixted, 2007) may provide an equally good, or even better, account of the data. In this article, the authors show that the results of studies that differentiate these models support the predictions of the DPSD model and indicate that recognition does not reflect the summing of 2 signal-detection processes, as the new UVSD model assumes. In addition, the assumptions of the DPSD model are clarified in order to address some of the common misconceptions about the model. Although important challenges remain, hybrid models such as this provide a more useful framework within which to understand human memory than do pure signal-detection models.

Spotlighting the probative findings: Reply to Parks and Yonelinas (2007).

J. T. Wixted (2007) argued that nearly every recent study that was designed to differentially test the unequal-variance signal-detection (UVSD) and dual-process signal-detection (DPSD) models has yielded findings that strongly support the UVSD model. C. M. Parks and A. P. Yonelinas (2007) did not address these studies in detail and instead focused mainly on issues that are tangential to the debate (e.g., measurement issues and neuroimaging). What few responses they did offer to the more relevant model-comparison studies did not effectively address the difficulties they posed for the DPSD model.

Recollection and familiarity in negative schizophrenia

Using the “remember–know” procedure to assess recognition memory, previous studies yielded evidence of impaired recollection but intact familiarity in schizophrenia patients. However, so far, the recognition memory performance of schizophrenia patients has not yet been analysed using the dual-process signal detection model (DPSD) by Yonelinas [Yonelinas, A. P. (2001). Components of episodic memory: The contribution of recollection and familiarity. Philosophical Transactions of Royal Society of London. Series B: Biological Sciences, 356(1413), 1363–1374], which accurately accounts for response and memory bias. Also, clinical symptoms have not yet been taken into account. Based on findings from neuropsychological and neurobiological research we hypothesized that high negative symptoms might be associated with a profile of impaired recollection and spared familiarity. The recognition memory performance of 22 schizophrenia patients scoring higher or lower on the negative symptoms subscale of the Positive and Negative Syndrome Scale (PANSS) was assessed by means of a word list discrimination task. Following the rationale of the dual-process signal detection model, estimates of recollection and familiarity were derived. The recollection estimate, derived by the DPSD model, was lower in patients with more severe negative symptomatology compared with both the patients with lower negative symptoms scores and healthy individuals. Familiarity was not affected if IQ was partialled out. Furthermore, the results yielded increased false alarm rates in patients with negative schizophrenia. The findings confirm an association of negative symptoms and recollection impairment in schizophrenia.

Word-Imagery Effects on Recollection and Familiarity in Recognition Memory

The Remember/Know procedure was used to investigate the effects of word imageability on recognition memory. An experiment, using French-speaking undergraduate students (17 women and 3 men), replicated Dewhurst and Conway's 1994 finding that rated imageability significantly increased accurate Remember responses but not Know responses when analyzed in the traditional way, assuming that the response types are mutually exclusive. Data were also analyzed using the Yonelinas, et al. 1998 dual-process signal-detection model, for estimating recollection and familiarity while assuming that Remember and Know responses are independent. Analysis indicated significant enhancement of imageability for estimates of both recollection and familiarity. This was interpreted as meaning that imageability enhanced both item-specific and contextual information associated with studied words.

Involvement of the mediodorsal thalamic nucleus in mediating recollection and familiarity

The mediodorsal (MD) thalamic nucleus is thought to play an important role in memory processes. Distinct hippocampal-thalamic-prefrontal connections have been described as the potential neural substrate for both, recollection and familiarity. The aim of this study was to investigate whether the MD is part of the circuits underlying these two memory components. We assessed the effects of ischemic thalamic lesions with or without MD involvement on performance in a word list discrimination task and standard tests of memory and executive function. Estimates of recollection and familiarity were derived using the dual-process signal-detection model (DPSD). The results revealed impairments in both, recollection and familiarity, after unilateral thalamic damage, with recollection being more affected than familiarity. There were no significant differences in the memory performance of patients with MD lesions compared to patients with ventrolateral-thalamic lesions except for familiarity estimates, which were lower for the latter group. Lesions involving the MD led to recollection deficits, although inspection of individual cases suggested a decrease in both memory components after damage in the medial part of this nucleus. Executive dysfunction was associated with lateral MD lesions and also ventrolateral-thalamic damage. The findings suggest that MD contributes to recollection, with some preliminary evidence of a contribution of the medial MD to familiarity. The small sample size does, however, not yet allow any clear conclusions in this regard. Since damage in the ventrolateral thalamus leads to memory and executive dysfunction, further research is needed to elucidate the role of this thalamic region in cognition.

Predicting individual false alarm rates and signal detection theory: a role for remembering.

The relationships between hit, remember, and false alarm rates were examined across individual subjects in three remember-know experiments in order to determine whether signal detection theory would be consistent with the observed data. The experimental data differed from signal detection predictions in two critical ways. First, remember reports were unrelated, or slightly negatively related, to the commission of false alarms. Second, both response types (remembers and false alarms) were uniquely related to hit rates, which demonstrated that the hit rate cannot be viewed as the result of a single underlying strength process. These results are consistent with the dual-process signal detection model of Yonelinas (1994), in which performance is determined by two independent processes--retrieval of categorical context information (remembering) and discriminations based on continuous item strength. Remember and false alarm rates selectively tap these processes, whereas the hit rate is jointly determined. Monte Carlo simulations in which the dual-process model was used successfully reproduced the pattern in the experimental data, whereas simulations in which a signal detection model, with separate "old" and "remember" criteria, was used, did not. The results demonstrate the utility of examining individual differences in response types when one is evaluating memory models.

Recollection and familiarity deficits in amnesia: convergence of remember-know, process dissociation, and receiver operating characteristic data.

Previous studies using the process dissociation and the remember-know procedures led to conflicting conclusions regarding the effects of anterograde amnesia on recollection and familiarity. We argue that these apparent contradictions arose because different models were used to interpret the results and because differences in false-alarm rates between groups biased the estimates provided by those models. A reanalysis of those studies with a dual-process signal-detection model that incorporates response bias revealed that amnesia led to a pronounced reduction in recollection and smaller but consistent reduction in familiarity. To test the assumptions of the model and to further assess recognition deficits in amnesics, we examined receiver operating characteristics (ROCs) in amnesics and controls. The ROCs of the controls were curved and asymmetrical, whereas those of the amnesics were curved and symmetrical. The results supported the predictions of the model and indicated that amnesia was associated with deficits in both recollection and familiarity.

Recollection and familiarity deficits in amnesia: Convergence of remember-know, process dissociation, and receiver operating characteristic data.

Previous studies using the process dissociation and the remember-know procedures led to conflicting conclusions regarding the effects of anterograde amnesia on recollection and familiarity. We argue that these apparent contradictions arose because different models were used to interpret the results and because differences in false-alarm rates between groups biased the estimates provided by those models. A reanalysis of those studies with a dual-process signal-detection model that incorporates response bias revealed that amnesia led to a pronounced reduction in recollection and smaller but consistent reduction in familiarity. To test the assumptions of the model and to further assess recognition deficits in amnesics, we examined receiver operating characteristics (ROCs) in amnesics and controls. The ROCs of the controls were curved and asymmetrical, whereas those of the amnesics were curved and symmetrical. The results supported the predictions of the model and indicated that amnesia was associated with deficits in both recollection and familiarity.