Shift In Response Criterion Research Articles

Emotional false memories: the impact of response bias under speeded retrieval conditions

ABSTRACT Emotional false memory findings using the DRM paradigm have been marked by higher false alarms to negatively arousing compared to neutral critical lure items. Explanations for these findings have mainly focused on false memory-based accounts. However, here we address the question of whether a response bias for emotional stimuli can, at least in part, explain this phenomenon. Participants viewed both neutral and negative arousing DRM lists and completed a recognition test in speeded or self-paced conditions. Speeded test reduces the opportunity to adjust response bias. Analysis showed no significant difference in false recognition across critical lure types for the speeded condition, but false recognition was higher for negative compared to neutral critical lures in the self-paced condition. We argue that when retrieval does not allow for shifts in response criteria, false alarms to negative emotional critical lures appear more similar to neutral equivalents. The discussion explores memory-based and criterion-shift explanations for the enhanced emotional false memory finding.

Dorsal pulvinar inactivation leads to spatial selection bias without perceptual deficit

The dorsal pulvinar has been implicated in visuospatial attentional and perceptual confidence processing. Pulvinar lesions in humans and monkeys lead to spatial neglect symptoms, including an overt spatial saccade bias during free choices. However, it remains unclear whether disrupting the dorsal pulvinar during target selection that relies on a perceptual decision leads to a perceptual impairment or a more general spatial orienting and choice deficit. To address this question, we reversibly inactivated the unilateral dorsal pulvinar by injecting GABA-A agonist THIP while two macaque monkeys performed a color discrimination saccade task with varying perceptual difficulty. We used Signal Detection Theory and simulations to dissociate perceptual sensitivity (d-prime) and spatial selection bias (response criterion) effects. We expected a decrease in d-prime if dorsal pulvinar affects perceptual discrimination and a shift in response criterion if dorsal pulvinar is mainly involved in spatial orienting. After the inactivation, we observed response criterion shifts away from contralesional stimuli, especially when two competing stimuli in opposite hemifields were present. Notably, the d-prime and overall accuracy remained largely unaffected. Our results underline the critical contribution of the dorsal pulvinar to spatial orienting and action selection while showing it to be less important for visual perceptual discrimination.

Does Timbre Modulate Visual Perception? Exploring Crossmodal Interactions

Musical timbre is often described using terms from non-auditory senses, mainly vision and touch; but it is not clear whether crossmodality in timbre semantics reflects multisensory processing or simply linguistic convention. If multisensory processing is involved in timbre perception, the mechanism governing the interaction remains unknown. To investigate whether timbres commonly perceived as “bright-dark” facilitate or interfere with visual perception (darkness-brightness), we designed two speeded classification experiments. Participants were presented consecutive images of slightly varying (or the same) brightness along with task-irrelevant auditory primes (“bright” or “dark” tones) and asked to quickly identify whether the second image was brighter/darker than the first. Incongruent prime-stimulus combinations produced significantly more response errors compared to congruent combinations but choice reaction time was unaffected. Furthermore, responses in a deceptive identical-image condition indicated subtle semantically congruent response bias. Additionally, in Experiment 2 (which also incorporated a spatial texture task), measures of reaction time (RT) and accuracy were used to construct speed-accuracy tradeoff functions (SATFs) in order to critically compare two hypothesized mechanisms for timbre-based crossmodal interactions, sensory response change vs. shift in response criterion. Results of the SATF analysis are largely consistent with the response criterion hypothesis, although without conclusively ruling out sensory change.

A critical examination of the evidence for sensitivity loss in modern vigilance tasks.

It is well known that when human observers must monitor for rare but critical events, probability of detection tends to wane over time, a phenomenon known as the "vigilance decrement." Over 60 years of empirical study on this topic has culminated in the general consensus that performance suffers due to a loss in observers' ability to distinguish signal from noise (a loss in sensitivity) provided that the task loads memory and stimuli are presented at a relatively high rate. We challenge this assertion on 2 fronts: First, we contend on a theoretical level that the metrics employed to measure observer sensitivity in modern vigilance tasks (derived from signal detection theory) are inappropriate and largely uninterpretable. This contention is supported by an evaluation of recent empirical work in the vigilance domain. Second, we present the results of an experiment that demonstrates that shifts in response bias (the observer's "willingness to respond") over time can masquerade as a loss in sensitivity. Consequently, the basic underlying cause of the vigilance decrement is actually unclear, and may simply reflect a shift in response criterion rather than sensitivity. The theoretical, as well as practical implications of these conclusions are discussed with respect to sustained attention in general, and vigilance in particular.

Age and lineup type differences in the own-race bias

The own-race bias (ORB) suggests that recognition for faces of one's own race is superior to recognition of other-race faces. A popular explanation for the ORB is amount of interracial contact, which may have cohort effects for older and younger adults. We compared White younger and older adults on the ORB utilizing a hybrid facial recognition and full diagnostic lineup (i.e., simultaneous and sequential target absent and target present lineups) paradigm. Both younger and older adults demonstrated an ORB. Signal detection estimates suggest younger adults compared to older adults have better discrimination accuracy for own-race over other-race faces. Interracial contact did not explain recognition for younger adults, but was related to a shift in response criterion for older adults.

Inhibition of return to emotional faces

Inhibition of Return (IOR) refers to a phenomenon that reaction times are slowed to a target that appears at a previously attended location. To investigate whether the mechanism of IOR is modulated by emotional contents of stimuli, the current study examined IOR to angry, happy and neutral faces. The speed-accuracy trade-off (SAT) function was measured to assess IOR in terms of sensitivity and processing time related to targets. Participants were required to discriminate gender of faces presenting on the cued or uncued locations under various response speeds controlled by experimenter. We have three findings: Firstly IOR to neutral faces was associated with shifts in response criterion, in line with our previous findings (Zhao et al. 2011). Secondly, IOR to emotional (angry and happy) faces was evident only at an early stage of target processing. Moreover, it was eliminated at a later stage of target processing and was reversed into a facilitation effect. According to the evolutional view, the arousal state decreased the response criterion to emotional faces which are interesting and important to us. Finally, perceptual sensitivity of gender discrimination was decreased to angry compared to neutral faces and the levels of decrement were significantly correlated to participants’ state-trait anxiety. Negative stimuli may increase the attentional demand as they might threat our chance of survival. This may lead to less attentional resource available for the discrimination task and in turn performance was impaired. In conclusion, the findings extended the evidence of IOR reflecting a criterion shift from low-level signal (e.g. ‘+’ or ‘x’) to high-level socially relevant stimuli such as neutral faces. Furthermore, it suggests that the arousing dimension of emotion interacted IOR in the response level while the valence dimension of emotion affected discrimination in the attentional level. Meeting abstract presented at VSS 2013

Identification of Gustatory-Olfactory Flavor Mixtures: Effects of Linguistic Labeling

Two experiments, using different ranges and numbers of stimuli, examined how linguistic labels affect the identification of flavor mixtures containing different proportions of sucrose (gustatory flavorant) and citral (olfactory flavorant). Both experiments asked subjects to identify each stimulus as having either "mostly sugar" or "mostly citrus." In one condition, no labels preceded the flavor stimuli. In another condition, each flavor stimulus followed a label, either SUGAR or CITRUS, which, the subjects were informed, usually though not always named the stronger flavor component; that is, the labels were probabilistically valid. The results of both experiments showed that the labels systematically modified the identification responses: Subjects responded "sugar" or "citrus" more often when the flavor stimulus followed the corresponding label, SUGAR or CITRUS. But the labels hardly affected overall accuracy of identification. Accuracy was possibly limited, however, by both the confusability of the flavor stimuli per se and the way that confusability could limit the opportunity to discern the probabilistic associations between labels and individual flavor stimuli. We describe the results in terms of a decision-theoretic model, in which labels induce shifts in response criteria governing the identification responses, or possibly effect changes in the sensory representations of the flavorants themselves.

Two components in IOR: evidence for response bias and perceptual processing delays using the SAT methodology

Inhibition of return (IOR) occurs when reaction times (RTs) are slowed to respond to a target that appears at a previously attended location. We used the speed-accuracy trade-off (SAT) procedure to obtain conjoint measures of IOR on sensitivity and processing speed by presenting targets at cued and uncued locations. The results showed that IOR is associated with both delays in processing speed and shifts in response criterion. When the target was briefly presented, the results supported a criterion shift account of IOR. However, when the target was presented until response, the evidence indicated that, in addition to a response bias effect, there was an increase in the minimal time required for information about the target to accumulate above chance level. A hybrid account of IOR is suggested that describes effects on both response bias and perceptual processing.

Response-repetition effects in task switching—Dissociating effects of anatomical and spatial response discriminability

In task switching, response repetitions typically lead to performance benefits for task repetitions but costs for task switches. We examined whether this cost–benefit pattern is affected by response discriminability (RD), varying (a) the anatomical response separation (within-hand vs. between-hand responses) and (b) the spatial separation (close vs. far response keys). We assumed that anatomical RD increases response competition generally, whereas spatial RD increases the salience of left–right coding and thus facilitates response selection. In two experiments, we found that spatial RD increased the response-repetition costs in task switches but similarly decreased the response-repetition benefit in task repetitions. The effect of spatial RD was response-specific but did not interact with task switching. This data pattern is consistent with a recent account that proposed that facilitated response selection increases response “self-inhibition” after response execution. In contrast, the influence of anatomical RD primarily consisted of an overall increase of reaction-time level in all conditions, whereas error rates decreased, suggesting a general shift in response criterion. Taken together, the data suggest that a self-inhibition mechanism on the level of motor response codes contributes to response-repetition effects in task switching, which is possibly independent of task-specific mechanisms of strengthening of associations.

The effect of interstimulus interval on sequential effects in absolute identification

In absolute identification experiments, the participant is asked to identify stimuli drawn from a small set of items which differ on a single physical dimension (e.g., 10 tones which vary in frequency). Responses in these tasks show a striking pattern of sequential dependencies: The current response assimilates towards the immediately preceding stimulus but contrasts with the stimuli further back in the sequence. This pattern has been variously interpreted as resulting from confusion of items in memory, shifts in response criteria, or the action of selective attention, and these interpretations have been incorporated into competing formal models of absolute identification performance. In two experiments, we demonstrate that lengthening the time between trials increases contrast to both the previous stimulus and the stimulus two trials back. This surprising pattern of results is difficult to reconcile with the idea that sequential dependencies result from memory confusion or from criterion shifts, but is consistent with an account that emphasizes selective attention.

A signal detection study of the Colavita visual dominance effect

When presented with auditory, visual, or bimodal audiovisual stimuli in a speeded detection/discrimination task, participants fail to respond to the auditory component of the bimodal targets significantly more often than they fail to respond to the visual component. Signal detection theory (SDT) was used to explore the contributions of perceptual (sensitivity shifts) and decisional (shifts in response criteria) factors to this effect, known as the Colavita visual dominance effect. Participants performed a version of the Colavita task that had been modified to allow for SDT analyses. The participants had to detect auditory and visual targets (presented unimodally or bimodally) at their individually determined 75% detection thresholds. The results showed a significant decrease in participants' sensitivity to auditory stimuli when presented concurrently with visual stimuli (in the absence of any significant change in their response criterion), suggesting that Colavita visual dominance does not simply reflect a decisional effect, but can be explained, at least in part, as a truly perceptual phenomenon. The decrease in sensitivity (to auditory stimuli) may be attributable to the exogenous capture of participants' attention by the visual component of the bimodal target, thus leaving fewer attentional resources for the processing of the auditory stimulus. The reduction in auditory sensitivity reported here may be considered an example of crossmodal masking.

Changing the criterion for memory conformity in free recall and recognition

People's responses during memory studies are affected by what other people say. This memory conformity effect has been shown in both free recall and recognition. Here we examine whether accurate, inaccurate, and suggested answers are affected similarly when the response criterion is varied. In the first study, participants saw four pictures of detailed scenes and then discussed the content of these scenes with another participant who saw the same scenes, but with a couple of details changed. Participants were either told to recall everything they could and not to worry about making mistakes (lenient), or only to recall items if they were sure that they were accurate (strict). The strict instructions reduced the amount of inaccurate information reported that the other person suggested, but also reduced the number of accurate details recalled. In the second study, participants were shown a large set of faces and then their memory recognition was tested with a confederate on these and fillers. Here also, the criterion manipulation shifted both accurate and inaccurate responses, and those suggested by the confederate. The results are largely consistent with a shift in response criterion affecting accurate, inaccurate, and suggested information. In addition we varied the level of secrecy in the participants’ responses. The effects of secrecy were complex and depended on the level of response criterion. Implications for interviewing eyewitnesses and line-ups are discussed.

Perceptual learning in contrast detection: presence and cost of shifts in response criteria

Contemporary theoretical accounts of perceptual learning typically assume that observers are either unbiased or stably biased across the course of learning. However, standard methods for estimating thresholds, as they are typically used, do not allow this assumption to be tested. We present an approach that allows for this test specific to perceptual learning for contrast detection. We show that reliable decreases in detection thresholds and increases in hit rates are not uniformly accompanied by reliable increases in sensitivity (d'), but are regularly accompanied by reliable liberal shifts in response criteria (c). In addition, we estimate the extent to which sensitivity could have increased in the absence of these liberal shifts. The results pose a challenge to the assumption that perceptual learning has limited or no impact on response criteria.

Perceptual and decisional contributions to audiovisual interactions in the perception of apparent motion: A signal detection study

Motion information available to different sensory modalities can interact at both perceptual and post-perceptual (i.e., decisional) stages of processing. However, to date, researchers have only been able to demonstrate the influence of one of these components at any given time, hence the relationship between them remains uncertain. We addressed the interplay between the perceptual and post-perceptual components of information processing by assessing their influence on performance within the same experimental paradigm. We used signal detection theory to discriminate changes in perceptual sensitivity (d′) from shifts in response criterion (c) in performance on a detection (Experiment 1) and a classification (Experiment 2) task regarding the direction of auditory apparent motion streams presented in noise. In the critical conditions, a visual motion distractor moving either leftward or rightward was presented together with the auditory motion. The results demonstrated a significant decrease in sensitivity to the direction of the auditory targets in the crossmodal conditions as compared to the unimodal baseline conditions that was independent of the relative direction of the visual distractor. In addition, we also observed significant shifts in response criterion, which were dependent on the relative direction of the distractor apparent motion. These results support the view that the perceptual and decisional components involved in audiovisual interactions in motion processing can coexist but are largely independent of one another.

Eyewitness decisions in simultaneous and sequential lineups: A dual-process signal detection theory analysis

Many eyewitness researchers have argued for the application of a sequential alternative to the traditional simultaneous lineup, given its role in decreasing false identifications of innocent suspects (sequential superiority effect). However, Ebbesen and Flowe (2002) have recently noted that sequential lineups may merely bring about a shift in response criterion, having no effect on discrimination accuracy. We explored this claim, using a method that allows signal detection theory measures to be collected from eyewitnesses. In three experiments, lineup type was factorially combined with conditions expected to influence response criterion and/or discrimination accuracy. Results were consistent with signal detection theory predictions, including that of a conservative criterion shift with the sequential presentation of lineups. In a fourth experiment, we explored the phenomenological basis for the criterion shift, using the remember-know-guess procedure. In accord with previous research, the criterion shift in sequential lineups was associated with a reduction in familiarity-based responding. It is proposed that the relative similarity between lineup members may create a context in which fluency-based processing is facilitated to a greater extent when lineup members are presented simultaneously.

Cross-modal interactions in auditory and visual discrimination

Three experiments examined auditory–visual interactions using two sensory discrimination paradigms. Experiments 1 and 2 used a one-interval confidence-rating procedure and found modest effects of concurrent visual stimulation on auditory pitch and loudness discrimination, but little effect of auditory stimulation on visual brightness discrimination. The cross-modal interactions could have either a sensory or decisional basis. Experiment 3 used a two-interval same-different procedure and found no effect of visual stimulation on auditory sensitivity in pitch discrimination, and very little effect of auditory stimulation on visual sensitivity in brightness discrimination. Although the ensemble of results could be explained by sensory facilitation and/or inhibition that varies with the behavioral task, the pattern of these and related findings suggests instead that the cross-modal interactions result primarily from relatively late decisional processes (e.g. shifts in response criterion or ‘bias’).

Context effects in visual length perception: role of ocular, retinal, and spatial location.

In three experiments, we examined the transfer of orientation-contingent context effects between the eyes and across portions of the retina with or without variation in external spatial location. Previous research had shown that vertical lines are judged long, relative to horizontal lines, when the stimulus set comprises relatively long horizontals and short verticals (Contextual Condition B), as compared with the reverse when the stimulus set comprises relatively short horizontals and long verticals (Contextual Condition A). Consequently, the contextual set of stimuli influences the magnitude of the horizontal-vertical illusion (HVI), decreasing its size under Contextual Condition A and increasing its size under Contextual Condition B. Experiment 1 showed that exposing one eye to different stimulus contexts modulated the size of the HVI at the exposed eye but had little or no effect at the other eye. Experiments 2 and 3 showed that the effect of the contextual sets generalized poorly across adjacent portions of the retina but transferred almost perfectly across different locations in external space when retinal location was constant. Thus, orientation-contingent context effects in visual length perception appear to be specific to the eye and to the region of the retina stimulated, suggesting that these effects reflect relatively early and local changes in sensitivity, rather than relatively late and general shifts in response criteria.

Brain activations associated with shifts in response criterion on a recognition test.

Sensitivity and bias can be manipulated independently on a recognition test. The goal of this fMRI study was to determine whether neural activations associated with manipulations of a decision criterion would be anatomically distinct from neural activations associated with manipulations of memory strength and episodic retrieval. The results indicated that activations associated with shifting criteria (a manipulation of bias) were located in bilateral regions of the lateral cerebellum, lateral parietal lobe, and the dorsolateral prefrontal cortex extending from the supplementary motor area. These regions were anatomically distinct from activations in the prefrontal cortex produced during memory-based retrieval processes (manipulations of sensitivity), which tended to be more medial and anterior. These later activations are consistent with previous studies of episodic retrieval. Determining patterns of neural activations associated with decision-making processes relative to memory processes has important implications for Cognitive Neuroscience, including the use of these patterns to compare memory models in different paradigms.

Imagining stereotypes away: The moderation of implicit stereotypes through mental imagery.

Research on implicit stereotypes has raised important questions about an individual's ability to moderate and control stereotypic responses. With few strategies shown to be effective in moderating implicit effects, the present research investigates a new strategy based on focused mental imagery. Across 5 experiments, participants who engaged in counterstereotypic mental imagery produced substantially weaker implicit stereotypes compared with participants who engaged in neutral, stereotypic, or no mental imagery. This reduction was demonstrated with a variety of measures, eliminating explanations based on response suppression or shifts in response criterion. Instead, the results suggest that implicit stereotypes are malleable, and that controlled processes, such as mental imagery, may influence the stereotyping process at its early as well as later stages.

False alarms and false memories.

M. B. Miller and G. L. Wolford (1999) make two contributions. First, they add conditions to the basic Roediger-McDermott (1995) procedure and find that critical items are recalled and recognized more often if they are presented in the list than if they are not presented. These results agree with our own, which are briefly reviewed. Second, they apply signal detection theory to the paradigm and conclude that false responding is caused by a shift of response criterion. They present no evidence that requires this interpretation, however, and we discuss several reasons why their account is implausible. For example, even when fully informed subjects are asked to use a very strict criterion in responding, the false recognition phenomenon persists at high levels. Further, some variables produce opposite effects on veridical and false recall and recognition; this pattern is difficult to accommodate solely by a shift in response criterion. Therefore, little evidence exists that a simple shift of response criterion can explain false recall and false recognition phenomena in the Roediger-McDermott paradigm.